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Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
MTR, TRA-603. SUB-BASEMENT FLOOR PLAN. INLET/OUTLET TUNNELS FOR COOLANT WATER (NORTH SIDE) AND AIR (SOUTH SIDE). RABBIT CANAL AND BULKHEADS. SUMPS AND DRAINS. BLAW-KNOX 3150-3-7, 3/1950. INL INDEX NO. 531-0603-00-098-100006, REV. 4. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID
Cooled-turbine aerodynamic performance prediction from reduced primary to coolant total-temperature-ratio results
NASA Technical Reports Server (NTRS)
Goldman, L. J.
The prediction of the cooled aerodynamic performance, for both stators and turbines, at actual primary to coolant inlet total temperature ratios from the results obtained at a reduced total temperature ratio is described. Theoretical and available experimental results were compared for convection film and transpiration cooled stator vanes and for a film cooled, single stage core turbine. For these tests the total temperature ratio varied from near 1.0 to about 2.7. The agreement between the theoretical and the experimental results was, in general, reasonable.
Ultra-lean combustion at high inlet temperatures
NASA Technical Reports Server (NTRS)
Anderson, D. N.
Combustion at inlet air temperatures of 1100 to 1250 K was studied for application to advanced automotive gas turbine engines. Combustion was initiated by the hot environment, and therefore no external ignition source was used. Combustion was stabilized without a flameholder. The tests were performed in a 12 cm diameter test section at a pressure of 2.5 x 10 to the 5th power Pa, with reference velocities of 32 to 60 m/sec and at maximum combustion temperatures of 1350 to 1850 K. Number 2 diesel fuel was injected by means of a multiple source fuel injector. Unburned hydrocarbons emissions were negligible for all test conditions. Nitrogen oxides emissions were less than 1.9 g NO2/kg fuel for combustion temperatures below 1680 K. Carbon monoxide emissions were less than 16 g CO/kg fuel for combustion temperatures greater than 1600 K, inlet air temperatures higher than 1150 K, and residence times greater than 4.3 microseconds.
Design modification for the modular helium reactor for higher temperature operation and reliability studies for nuclear hydrogen production processesĀ
Reza, S.M. Mohsin
Design options have been evaluated for the Modular Helium Reactor (MHR) for higher temperature operation. An alternative configuration for the MHR coolant inlet flow path is developed to reduce the peak vessel temperature (PVT). The coolant inlet...
Design modification for the modular helium reactor for higher temperature operation and reliability studies for nuclear hydrogen production processes
Reza, S.M. Mohsin
Design options have been evaluated for the Modular Helium Reactor (MHR) for higher temperature operation. An alternative configuration for the MHR coolant inlet flow path is developed to reduce the peak vessel temperature (PVT). The coolant inlet...
Effect of Coolant Temperature and Mass Flow on Film Cooling of Turbine Blades
NASA Technical Reports Server (NTRS)
Garg, Vijay K.; Gaugler, Raymond E.
A three-dimensional Navier Stokes code has been used to study the effect of coolant temperature, and coolant to mainstream mass flow ratio on the adiabatic effectiveness of a film-cooled turbine blade. The blade chosen is the VKI rotor with six rows of cooling holes including three rows on the shower head. The mainstream is akin to that under real engine conditions with stagnation temperature = 1900 K and stagnation pressure = 3 MPa. Generally, the adiabatic effectiveness is lower for a higher coolant temperature due to nonlinear effects via the compressibility of air. However, over the suction side of shower-head holes, the effectiveness is higher for a higher coolant temperature than that for a lower coolant temperature when the coolant to mainstream mass flow ratio is 5% or more. For a fixed coolant temperature, the effectiveness passes through a minima on the suction side of shower-head holes as the coolant to mainstream mass flow, ratio increases, while on the pressure side of shower-head holes, the effectiveness decreases with increase in coolant mass flow due to coolant jet lift-off. In all cases, the adiabatic effectiveness is highly three-dimensional.
Study of the effect of oil and coolant temperatures on diesel engine brake specific fuel consumption
D. A. Bolis; J. H. Johnson; R. Callen
Diesel engine fuel consumption is mainly a function of engine component design and power requirements. However, fuel consumption can also be affected by the environment in which the engine operates. Two controlling parameters of the engine's thermal environment, oil temperature and coolant temperature, are considered. The effects of oil and coolant temperatures on Brake Specific Fuel Consumption (BSFC) are established
Redistribution of an inlet temperature distortion in an axial flow turbine stage
T. L. Butler; O. P. Sharma; H. D. Joslyn; R. P. Dring
The results of an experimental program aimed at determining the extent of the redistribution of an inlet temperature distortion in an axial flow turbine stage are presented. The program was conducted in a large-scale, low speed, single stage turbine where air, seeded with CO2 was introduced at one circumferential location upstream of the inlet guide vane. The migration of the
Experimental Investigation of an Air-Cooled Turbine Operating in a Turbojet Engine at Turbine Inlet Temperatures up to 2500 F
NASA Technical Reports Server (NTRS)
Cochran, Reeves P.; Dengler, Robert P.
An experimental investigation was made of an air-cooled turbine at average turbine inlet temperatures up to 2500 F. A modified production-model 12-stage axial-flow-compressor turbojet engine operating in a static sea-level stand was used as the test vehicle. The modifications to the engine consisted of the substitution of special combustor and turbine assemblies and double-walled exhaust ducting for the standard parts of the engine. All of these special parts were air-cooled to withstand the high operating temperatures of the investigation. The air-cooled turbine stator and rotor blades were of the corrugated-insert type. Leading-edge tip caps were installed on the rotor blades to improve leading-edge cooling by diverting the discharge of coolant to regions of lower gas pressure toward the trailing edge of the blade tip. Caps varying in length from 0.15- to 0.55-chord length were used in an attempt to determine the optimum cap length for this blade. The engine was operated over a range of average turbine inlet temperatures from about 1600 to about 2500 F, and a range of average coolant-flow ratios of 0.012 to 0.065. Temperatures of the air-cooled turbine rotor blades were measured at all test conditions by the use of thermocouples and temperature-indicating paints. The results of the investigation indicated that this type of blade is feasible for operation in turbojet engines at the average turbine inlet temperatures and stress levels tested(maximums of 2500 F and 24,000 psi, respectively). An average one-third-span blade temperature of 1300 F could be maintained on 0.35-chord tip cap blades with an average coolant-flow ratio of about 0.022 when the average turbine inlet temperature was 2500 F and cooling-air temperature was about 260 F. All of the leading-edge tip cap lengths improved the cooling of the leading-edge region of the blades, particularly at low average coolant-flow ratios. At high gas temperatures, such parts as the turbine stator and the combustor liners are likely to be as critical as the turbine rotor blades.
Stevenson, D.L.; Seleno, F.M.
Apparatus for injecting coolant into the fuel-air mixture supplied to a turbocharged internal combustion engine in which coolant is stored in a reservoir that is connected to the outlet side of a turbocharger compressor and is pressurized during times that the turbocharger is generating positive pressures above a predetermined level. The pressure in the reservoir forces coolant to the inlet side of the turbocharger to cool fuel and injection is interrupted when the pressures are below that level and cooling of the fuel-air mixture is not required.
Effect of inlet temperature on the performance of a catalytic reactor
D. N. Anderson
A 12 cm diameter by 15 cm long catalytic reactor was tested with No. 2 diesel fuel in a combustion test rig at inlet temperatures of 700, 800, 900, and 1000 K. Other test conditions included pressures of 3 and 6 x 10 to the 5th power Pa, reference velocities of 10, 15, and 20 m\\/s, and adiabatic combustion temperatures
Load following capability of CANDLE reactor by adjusting coolant operation condition
Sekimoto, Hiroshi; Nakayama, Sinsuke [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology 2-12-1-N1-17, Ookayama, Meguro-ku 152-8550 (Japan)
The load following capability of CANDLE reactor is investigated in the condition that the control rods are unavailable. Both sodium cooled metallic fuel fast reactor (SFR) and {sup 208}Pb cooled metallic fuel fast reactor (LFR) are investigated for their performance in power rate changing by changing its coolant operation condition; either coolant flow rate or coolant inlet temperature. The change by coolant flow rate is difficult especially for SFR because the maximum temperature criteria on cladding material may be violated. The power rate can be changed for its full range easily by changing the coolant temperature at the core inlet. LFR can reduce the same amount of power rate by smaller change of temperature than SFR. However, the coolant output temperature is generally decreased for this method and the thermal efficiency becomes worse.
Load following capability of CANDLE reactor by adjusting coolant operation condition
NASA Astrophysics Data System (ADS)
Sekimoto, Hiroshi; Nakayama, Sinsuke
The load following capability of CANDLE reactor is investigated in the condition that the control rods are unavailable. Both sodium cooled metallic fuel fast reactor (SFR) and 208Pb cooled metallic fuel fast reactor (LFR) are investigated for their performance in power rate changing by changing its coolant operation condition; either coolant flow rate or coolant inlet temperature. The change by coolant flow rate is difficult especially for SFR because the maximum temperature criteria on cladding material may be violated. The power rate can be changed for its full range easily by changing the coolant temperature at the core inlet. LFR can reduce the same amount of power rate by smaller change of temperature than SFR. However, the coolant output temperature is generally decreased for this method and the thermal efficiency becomes worse.
Analysis of a water-coolant leak into a very high-temperature vitrification chamber.
Felicione, F. S.
A coolant-leakage incident occurred during non-radioactive operation of the Plasma Hearth Process waste-vitrification development system at Argonne National Laboratory when a stray electric arc ruptured az water-cooling jacket. Rapid evaporation of the coolant that entered the very high-temperature chamber pressurized the normally sub-atmospheric system above ambient pressure for over 13 minutes. Any positive pressurization, and particularly a lengthy one, is a safety concern since this can cause leakage of contaminants from the system. A model of the thermal phenomena that describe coolant/hot-material interactions was developed to better understand the characteristics of this type of incident. The model is described and results for a variety of hypothetical coolant-leak incidents are presented. It is shown that coolant leak rates above a certain threshold will cause coolant to accumulate in the chamber, and evaporation from this pool can maintain positive pressure in the system long after the leak has been stopped. Application of the model resulted in reasonably good agreement with the duration of the pressure measured during the incident. A closed-form analytic solution is shown to be applicable to the initial leak period in which the peak pressures are generated, and is presented and discussed.
Method of and apparatus for removing silicon from a high temperature sodium coolant
Yunker, W.H.; Christiansen, D.W.
This patent discloses a method of and system for removing silicon from a high temperature liquid sodium coolant system for a nuclear reactor. The sodium is cooled to a temperature below the silicon saturation temperature and retained at such reduced temperature while inducing high turbulence into the sodium flow for promoting precipitation of silicon compounds and ultimate separation of silicon compound particles from the liquid sodium.
The influence of temperature and inlet velocity on cyclone pressure drop: a CFD study
Jolius Gimbun; T. G. Chuah; A. FakhruÆl-Razi; Thomas S. Y. Choong
This work presents a computational fluid dynamics (CFD) calculation to predict and to evaluate the effects of temperature and inlet velocity on the pressure drop of gas cyclones. The numerical solutions were carried out using spreadsheet and commercial CFD code Fluent 6.1. This paper also reviews four empirical models for the prediction of cyclone pressure drop, namely [Air pollution control:
From chip to cooling tower data center modeling: Part I Influence of server inlet temperature and temperature rise across cabinet
Thomas J. Breen; Ed J. Walsh; Jeff Punch; A. J. Shah; C. E. Bash
To achieve reductions in the power consumption of the data center cooling infrastructure, the current strategy in data center design is to increase the inlet temperature to the rack, while the current strategy for energy-efficient system thermal design is to allow increased temperature rise across the rack. Either strategy, or a combination of both, intuitively provides enhancements in the coefficient
The effects of inlet temperature and pressure distortion on turbojet performance
NASA Technical Reports Server (NTRS)
Braithwaite, W. M.; Graber, E. J., Jr.; Mehalic, C. M.
The effects on stability of steady-state, 180 degree extent circumferential distortions of inlet total temperature and pressure were experimentally determined for a turbojet engine. Results for both individual and combined temperature and pressure distortions are presented showing the losses incurred in stall pressure ratio and are compared with results predicted using a simplified parallel compressor model. The loss due to combined distortions was dependent upon the relative orientation between the low pressure and high temperature regions. Reasonable agreement was achieved between the predicted and observed loss in stall pressure ratio when based on a constant corrected speed relationship.
Performance of a high-work, low-aspect-ratio turbine stator tested with a realistic inlet radial temperature gradient
NASA Technical Reports Server (NTRS)
Stabe, Roy G.; Schwab, John R.
A 0.767-scale model of a turbine stator designed for the core of a high-bypass-ratio aircraft engine was tested with uniform inlet conditions and with an inlet radial temperature profile simulating engine conditions. The principal measurements were radial and circumferential surveys of stator-exit total temperature, total pressure, and flow angle. The stator-exit flow field was also computed by using a three-dimensional Navier-Stokes solver. Other than temperature, there were no apparent differences in performance due to the inlet conditions. The computed results compared quite well with the experimental results.
Experimental research of temperature and velocity fields in high-temperature flow of liquid heavy metal coolant
Besnosov, A. V., E-mail: email@example.com; Savinov, S. Yu., E-mail: email@example.com; Novozhilova, O. O.; Antonenkov, M. A. [Nizhni Novgorod State Technical University (Russian Federation)
Presented are the results of experimental research of temperature and velocity fields for lead and lead-bismuth coolant flows in channels having circular and annular cross sections under varying oxygen content in the coolant and varying characteristics of insulating coatings. Tests are performed under the following operating conditions: (1) lead-bismuth eutectic-temperature T = 400-520 Degree-Sign C, thermodynamic oxygen activity a = 10{sup -5}-10{sup 0}, average flow velocity of the coolant w = 0.12-1.84 m/s, value of magnetic induction B = 0-0.85 T, Reynolds number Re = (0.24-3.5) Multiplication-Sign 10{sup 5}, Hartmann number Ha = 0-500, and Peclet number Pe = 320-4600; (2) lead coolant-T = 400-550 Degree-Sign C, a = 10{sup -5}-10{sup 0}, w = 0.1-1.5 m/s, Re = (2.36-2.99) Multiplication-Sign 10{sup 5}, and Pe = 500-7000.
The high-temperature sodium coolant technology in nuclear power installations for hydrogen power engineering
NASA Astrophysics Data System (ADS)
Kozlov, F. A.; Sorokin, A. P.; Alekseev, V. V.; Konovalov, M. A.
In the case of using high-temperature sodium-cooled nuclear power installations for obtaining hydrogen and for other innovative applications (gasification and fluidization of coal, deep petroleum refining, conversion of biomass into liquid fuel, in the chemical industry, metallurgy, food industry, etc.), the sources of hydrogen that enters from the reactor plant tertiary coolant circuit into its secondary coolant circuit have intensity two or three orders of magnitude higher than that of hydrogen sources at a nuclear power plant (NPP) equipped with a BN-600 reactor. Fundamentally new process solutions are proposed for such conditions. The main prerequisite for implementing them is that the hydrogen concentration in sodium coolant is a factor of 100-1000 higher than it is in modern NPPs taken in combination with removal of hydrogen from sodium by subjecting it to vacuum through membranes made of vanadium or niobium. Numerical investigations carried out using a diffusion model showed that, by varying such parameters as fuel rod cladding material, its thickness, and time of operation in developing the fuel rods for high-temperature nuclear power installations (HT NPIs) it is possible to exclude ingress of cesium into sodium through the sealed fuel rod cladding. However, if the fuel rod cladding loses its tightness, operation of the HT NPI with cesium in the sodium will be unavoidable. Under such conditions, measures must be taken for deeply purifying sodium from cesium in order to minimize the diffusion of cesium into the structural materials.
Inlet Reynolds number and temperature effects on the steady-state performance of a TFE731-2 turbofan engine
NASA Technical Reports Server (NTRS)
Bobula, G. A.; Lottig, R. A.
Effects of varying engine inlet Reynolds number index (0.75, 0.50, 0.25, and 0.12) and temperature (289 and 244 K) on a TFE731-2 turbofan engine were evaluated. Results were classified as either compression system effects or effects on overall performance. Standard performance maps are used to present compression system performance. Overall performance parameters are presented as a function of low rotor speed corrected to engine inlet temperature.
Effect of inlet temperature and pressure on emissions from a premixing gas turbine primary zone combustor
NASA Technical Reports Server (NTRS)
Roffe, G.
Experiments were conducted to determine the performance of a premixing prevaporizing gas turbine primary zone combustor design over a range of combustor inlet temperatures from 700 to 1000 K and a range of inlet pressures from 40 to 240 N/sq cm. The 1 meter long combustor could be operated at pressures up to and including 120 N/sq cm without autoignition in the premixing duct or flashback from the stabilized combustion zone. Autoignition occurred in the mixer tube at the 240 N/sq cm pressure level with an entrance temperature of 830 K and a mixer residence time of 4 msec. Measured NOx level, combustion inefficiency, and hydrocarbon emission index correlated well with adiabatic flame temperature. The NOx levels varied from approximately 0.2 to 2.0 g NO2/kg fuel at combustion inefficiencies from 4 to 0.04 percent, depending upon adiabatic flame temperature and pressure. Measured NOx levels were sensitive to pressure. Tests were made at equivalence ratios ranging from 0.35 to 0.65. The overall total pressure drop for the configuration varied slightly with reference velocity and equivalence ratio, but never exceeded 3 percent.
Temperature controller for a fluid cooled garment
NASA Technical Reports Server (NTRS)
Chambers, A. B.; Blackaby, J. R.; Billingham, J. (inventors)
An automatic controller for controlling the inlet temperature of the coolant to a fluid cooled garment without requiring skin sensors is described. Temperature is controlled by the wearer's evaporative water loss rate.
Assessment of Candidate Molten Salt Coolants for the Advanced High Temperature Reactor (AHTR)
Williams, D.F.
The Advanced High-Temperature Reactor (AHTR) is a novel reactor design that utilizes the graphite-matrix high-temperature fuel of helium-cooled reactors, but provides cooling with a high-temperature fluoride salt. For applications at temperatures greater than 900 C the AHTR is also referred to as a Liquid-Salt-Cooled Very High-Temperature Reactor (LS-VHTR). This report provides an assessment of candidate salts proposed as the primary coolant for the AHTR based upon a review of physical properties, nuclear properties, and chemical factors. The physical properties most relevant for coolant service were reviewed. Key chemical factors that influence material compatibility were also analyzed for the purpose of screening salt candidates. Some simple screening factors related to the nuclear properties of salts were also developed. The moderating ratio and neutron-absorption cross-section were compiled for each salt. The short-lived activation products, long-lived transmutation activity, and reactivity coefficients associated with various salt candidates were estimated using a computational model. Table A presents a summary of the properties of the candidate coolant salts. Certain factors in this table, such as melting point, vapor pressure, and nuclear properties, can be viewed as stand-alone parameters for screening candidates. Heat-transfer properties are considered as a group in Sect. 3 in order to evaluate the combined effects of various factors. In the course of this review, it became apparent that the state of the properties database was strong in some areas and weak in others. A qualitative map of the state of the database and predictive capabilities is given in Table B. It is apparent that the property of thermal conductivity has the greatest uncertainty and is the most difficult to measure. The database, with respect to heat capacity, can be improved with modern instruments and modest effort. In general, ''lighter'' (low-Z) salts tend to exhibit better heat transfer and nuclear performance metrics. Lighter salts also tend to have more favorable (larger) moderating ratios, and thus should have a more favorable coolant-voiding behavior in-core. Heavy (high-Z) salts tend to have lower heat capacities and thermal conductivities and more significant activation and transmutation products. However, all of the salts are relatively good heat-transfer agents. A detailed discussion of each property and the combination of properties that served as a heat-transfer metric is presented in the body of this report. In addition to neutronic metrics, such as moderating ratio and neutron absorption, the activation properties of the salts were investigated (Table C). Again, lighter salts tend to have more favorable activation properties compared to salts with high atomic-number constituents. A simple model for estimating the reactivity coefficients associated with a reduction of salt content in the core (voiding or thermal expansion) was also developed, and the primary parameters were investigated. It appears that reasonable design flexibility exists to select a safe combination of fuel-element design and salt coolant for most of the candidate salts. Materials compatibility is an overriding consideration for high-temperature reactors; therefore the question was posed whether any one of the candidate salts was inherently, or significantly, more corrosive than another. This is a very complex subject, and it was not possible to exclude any fluoride salts based on the corrosion database. The corrosion database clearly indicates superior container alloys, but the effect of salt identity is masked by many factors which are likely more important (impurities, redox condition) in the testing evidence than salt identity. Despite this uncertainty, some reasonable preferences can be recommended, and these are indicated in the conclusions. The reasoning to support these conclusions is established in the body of this report.
Effect of steady-state temperature distortion and combined distortion on inlet flow to a turbofan engine
NASA Technical Reports Server (NTRS)
Soeder, R. H.; Bobula, G. A.
Flow angle, static pressure, total temperature and total pressure were measured in the inlet duct upstream of a turbofan engine operating with temperature distortion or combined pressure-temperature distortion. Such measurements are useful in the evaluation of analytical models of inlet distortion. A rotating gaseous-hydrogen burner and a circumferential 180 degrees-extent screen configuration mounted on a rotatable assembly generated the distortions. Reynolds number index was maintained at 0.5 and engine corrected low-rotor speeds were held at 6000 and 8600 rpm. The measurements showed that at the entrance to the engine, flow angle was largest in the hub region. As flow approached the engine, yaw angle (circumferential variation) increased and pitch angle (radial variation) decreased. The magnitude of static-pressure distortion measured along the inlet-duct and extended bullet nose walls increased exponentially as flow approached the engine.
Effect of Fuel-Air Ratio, Inlet Temperature, and Exhaust Pressure on Detonation
NASA Technical Reports Server (NTRS)
Taylor, E S; Leary, W A; Diver, J R
An accurate determination of the end-gas condition was attempted by applying a refined method of analysis to experimental results. The results are compared with those obtained in Technical Report no. 655. The experimental technique employed afforded excellent control over the engine variables and unusual cyclic reproducibility. This, in conjunction with the new analysis, made possible the determination of the state of the end-gas at any instant to a fair degree of precision. Results showed that for any given maximum pressure the maximum permissible end-gas temperature increased as the fuel-air ratio was increased. The tendency to detonate was slightly reduced by an increase in residual gas content resulting from an increase in exhaust backpressure with inlet pressure constant.
Knock-limited performance of several internal coolants
NASA Technical Reports Server (NTRS)
Bellman, Donald R; Evvard, John C
The effect of internal cooling on the knock-limited performance of an-f-28 fuel was investigated in a CFR engine, and the following internal coolants were used: (1) water, (2), methyl alcohol-water mixture, (3) ammonia-methyl alcohol-water mixture, (4) monomethylamine-water mixture, (5) dimethylamine-water mixture, and (6) trimethylamine-water mixture. Tests were run at inlet-air temperatures of 150 degrees and 250 degrees F. to indicate the temperature sensitivity of the internal-coolant solutions.
Evaluation of High Temperature Tensile and Creep Properties of Light Water Reactor Coolant Piping Materials for Severe Accident Analyses
Yuhei HARADA; Yu MARUYAMA; Akio MAEDA; Eiichi CHINO; Hiroaki SHIBAZAKI; Tamotsu KUDO; Akihide HIDAKA; Kazuichiro HASHIMOTO; Jun SUGIMOTO
It has been pointed out that the reactor coolant system piping could fail prior to the meltthrough of the reactor pressure vessel in a high pressure sequence of pressurized water reactor severe accidents. In order to apply to the evaluation of the piping failure which influences the subsequent accident progression, models for the strength of piping materials at high temperatures
Analysis of metal temperature and coolant flow with a thermal-barrier coating on a full-coverage-film-cooled turbine vane
NASA Technical Reports Server (NTRS)
Meitner, P. L.
The potential benefits of combining full-coverage film cooling with a thermal-barrier coating were investigated analytically for sections on the suction and pressure sides a high-temperature, high-pressure turbine vane. Metal and ceramic coating temperatures were calculated as a function of coating thickness and coolant flow. With a thermal-barrier coating, the coolant flows required for the chosen sections were half those of an uncoated design, and the metal outer temperatures were simultaneously reduced by over 111 K (200 F). For comparison, transpiration cooling was also investigated. Full-coverage film cooling of a coated vane required more coolant flow than did transpiration cooling.
NASA Technical Reports Server (NTRS)
Kutschenreuter, Paul
At hypersonic flight Mach numbers, particularly above Mo = 10, the inlet compression process is no longer adiabatic, real gas chemistry takes on extra importance, and the combined effects of entropy layer and viscous effects lead to highly nonuniform flow profile characteristics at the combustor entrance. Under such conditions, traditional inlet efficiency parameters can be unnecessarily cumbersome and/or lacking in the ability to appropriately characterize the inlet flow and to provide insight into propulsion system performance. Recent experience suggests that the use of inlet entropy increases inlet efficiency in hypersonic applications.
Correlation of cylinder-head temperatures and coolant heat rejections of a multicylinder, liquid-cooled engine of 1710-cubic-inch displacement
NASA Technical Reports Server (NTRS)
Lundin, Bruce T; Povolny, John H; Chelko, Louis J
Data obtained from an extensive investigation of the cooling characteristics of four multicylinder, liquid-cooled engines have been analyzed and a correlation of both the cylinder-head temperatures and the coolant heat rejections with the primary engine and coolant variables was obtained. The method of correlation was previously developed by the NACA from an analysis of the cooling processes involved in a liquid-cooled-engine cylinder and is based on the theory of nonboiling, forced-convection heat transfer. The data correlated included engine power outputs from 275 to 1860 brake horsepower; coolant flows from 50 to 320 gallons per minute; coolants varying in composition from 100 percent water to 97 percent ethylene glycol and 3 percent water; and ranges of engine speed, manifold pressure, carburetor-air temperature, fuel-air ratio, exhaust-gas pressure, ignition timing, and coolant temperature. The effect on engine cooling of scale formation on the coolant passages of the engine and of boiling of the coolant under various operating conditions is also discussed.
Transient simulation of coolant peak temperature due to prolonged fan and/or water pump operation after the vehicle is keyed-off
NASA Astrophysics Data System (ADS)
Pang, Suh Chyn; Masjuki, Haji Hassan; Kalam, Md. Abul; Hazrat, Md. Ali
Automotive designers should design a robust engine cooling system which works well in both normal and severe driving conditions. When vehicles are keyed-off suddenly after some distance of hill-climbing driving, the coolant temperature tends to increase drastically. This is because heat soak in the engine could not be transferred away in a timely manner, as both the water pump and cooling fan stop working after the vehicle is keyed-off. In this research, we aimed to visualize the coolant temperature trend over time before and after the vehicles were keyed-off. In order to prevent coolant temperature from exceeding its boiling point and jeopardizing engine life, a numerical model was further tested with prolonged fan and/or water pump operation after keying-off. One dimensional thermal-fluid simulation was exploited to model the vehicle's cooling system. The behaviour of engine heat, air flow, and coolant flow over time were varied to observe the corresponding transient coolant temperatures. The robustness of this model was proven by validation with industry field test data. The numerical results provided sensible insights into the proposed solution. In short, prolonging fan operation for 500 s and prolonging both fan and water pump operation for 300 s could reduce coolant peak temperature efficiently. The physical implementation plan and benefits yielded from implementation of the electrical fan and electrical water pump are discussed.
Effect of inlet-air humidity, temperature, pressure, and reference Mach number on the formation of oxides of nitrogen in a gas turbine combustor
NASA Technical Reports Server (NTRS)
Marchionna, N. R.; Diehl, L. A.; Trout, A. M.
Tests were conducted to determine the effect of inlet air humidity on the formation of oxides of nitrogen (NOx) from a gas turbine combustor. Combustor inlet air temperature ranged from 506 K (450 F) to 838 K (1050 F). The tests were primarily run at a constant pressure of 6 atmospheres and reference Mach number of 0.065. The NOx emission index was found to decrease with increasing inlet air humidity at a constant exponential rate: NOx = NOx0e-19H (where H is the humidity and the subscript 0 denotes the value at zero humidity). the emission index increased exponentially with increasing normalized inlet air temperature to the 1.14 power. Additional tests made to determine the effect of pressure and reference Mach number on NOx showed that the NOx emission index varies directly with pressure to the 0.5 power and inversely with reference Mach number.
Solar receiver protection means and method for loss of coolant flow
Glasgow, L.E.
An apparatus and method are disclosed for preventing a solar receiver utilizing a flowing coolant liquid for removing heat energy therefrom from overheating after a loss of coolant flow. Solar energy is directed to the solar receiver by a plurality of reflectors which rotate so that they direct solar energy to the receiver as the earth rotates. The apparatus disclosed includes a first storage tank for containing a first predetermined volume of the coolant and a first predetermined volume of gas at a first predetermined pressure. The first storage tank includes an inlet and outlet through which the coolant can enter and exit. The apparatus also includes a second storage tank for containing a second predetermined volume of the coolant and a second predetermined volume of the gas at a second predetermined pressure, the second storage tank having an inlet through which the coolant can enter. The first and second storage tanks are in fluid communication with each other through the solar receiver. The first and second predetermined coolant volumes, the first and second gas volumes, and the first and second predetermined pressures are chosen so that a predetermined volume of the coolant liquid at a predetermined rate profile will flow from the first storage tank through the solar receiver and into the second storage tank. Thus, in the event of a power failure so that coolant flow ceases and the solar reflectors stop rotating, a flow rate maintained by the pressure differential between the first and second storage tanks will be sufficient to maintain the coolant in the receiver below a predetermined upper temperature until the solar reflectors become defocused with respect to the solar receiver due to the earth's rotation.
Solar receiver protection means and method for loss of coolant flow
Glasgow, Lyle E. (Westlake Village, CA)
An apparatus and method for preventing a solar receiver (12) utilizing a flowing coolant liquid for removing heat energy therefrom from overheating after a loss of coolant flow. Solar energy is directed to the solar receiver (12) by a plurality of reflectors (16) which rotate so that they direct solar energy to the receiver (12) as the earth rotates. The apparatus disclosed includes a first storage tank (30) for containing a first predetermined volume of the coolant and a first predetermined volume of gas at a first predetermined pressure. The first storage tank (30) includes an inlet and outlet through which the coolant can enter and exit. The apparatus also includes a second storage tank (34) for containing a second predetermined volume of the coolant and a second predetermined volume of the gas at a second predetermined pressure, the second storage tank (34) having an inlet through which the coolant can enter. The first and second storage tanks (30) and (34) are in fluid communication with each other through the solar receiver (12). The first and second predetermined coolant volumes, the first and second gas volumes, and the first and second predetermined pressures are chosen so that a predetermined volume of the coolant liquid at a predetermined rate profile will flow from the first storage tank (30) through the solar receiver (12) and into the second storage tank (34). Thus, in the event of a power failure so that coolant flow ceases and the solar reflectors (16) stop rotating, a flow rate maintained by the pressure differential between the first and second storage tanks (30) and (34) will be sufficient to maintain the coolant in the receiver (12) below a predetermined upper temperature until the solar reflectors (16) become defocused with respect to the solar receiver (12) due to the earth's rotation.
Computer program MCAP-TOSS calculates steady-state fluid dynamics of coolant in parallel channels and temperature distribution in surrounding heat-generating solid
NASA Technical Reports Server (NTRS)
Lee, A. Y.
Computer program calculates the steady state fluid distribution, temperature rise, and pressure drop of a coolant, the material temperature distribution of a heat generating solid, and the heat flux distributions at the fluid-solid interfaces. It performs the necessary iterations automatically within the computer, in one machine run.
Effects of intake swirl and coolant temperature on spray structure of a high pressure multi-hole injector in a direct-injection gasoline engine
NASA Astrophysics Data System (ADS)
Kim, S.; Nouri, J. M.; Yan, Y.; Arcoumanis, C.
The spray characteristics of a 6-hole injector were examined in a single cylinder optical direct injection spark ignition engine. The effects of injection timing, in-cylinder charge motion, fuel injection pressure and coolant temperature were investigated using the 2-dimensional Mie scattering technique. It was confirmed that the in-cylinder charge motion played a major role in the fuel spray distribution during the induction stroke while injection timing had to be carefully considered at high injection pressures during the compression stroke to prevent spray impingement on the piston. A new approach has been applied to the processing of Mie images to analyse the effect of coolant temperature on the spray liquid phase structure. These results quantified the fraction of the liquid phase that was vaporised as a result of the increase in coolant temperature.
Metal temperatures and coolant flow in a wire cloth transpiration cooled turbine vane
NASA Technical Reports Server (NTRS)
Gladden, H. J.
An experimental heat transfer investigation was conducted on an air-cooled turbine vane made from wire-wound cloth material and supported by a central strut. Vane temperature data obtained are compared with temperature data from two full-coverage film-cooled vanes made of different laminated construction. Measured porous-airfoil temperatures are compared with predicted temperatures.
Cooling Characteristics of the V-1650-7 Engine. 1; Coolant-Flow Distribution, Cylinder Temperatures, and Heat Rejections at Typical Operating Conditions
NASA Technical Reports Server (NTRS)
Povolny, John H.; Bogdan, Louis J.
An investigation was conducted to determine the coolant-flow distribu tion, the cylinder temperatures, and the heat rejections of the V-165 0-7 engine . The tests were run a t several power levels varying from minimum fuel consumption to war emergency power and at each power l evel the coolant flows corresponded to the extremes of those likely t o be encountered in typical airplane installations, A mixture of 30-p ercent ethylene glycol and 70-percent water was used as the coolant. The temperature of each cylinder was measured between the exhaust val ves, between the intake valves, in the center of the head, on the exh aust-valve guide, at the top of the barrel on the exhaust side, and o n each exhaust spark-plug gasket. For an increase in engine power fro m 628 to approximately 1700 brake horsepower the average temperature for the cylinder heads between the exhaust valves increased from 437 deg to 517 deg F, the engine coolant heat rejection increased from 12 ,600 to 22,700 Btu. per minute, the oil heat rejection increased from 1030 to 4600 Btu per minute, and the aftercooler-coolant heat reject ion increased from 450 to 3500 Btu -per minute.
Effect of fluctuation in inlet airflow temperature on CFD simulation of air-blast chilling process
Zehua Hu; Da-Wen Sun
Setting the boundary condition of airflow temperature is an important factor affecting the predicting accuracy during the simulation of air-blast chilling process. In this study, numerical simulations using computational fluid dynamics (CFDs) were conducted to predict a coupled heat and mass transfer during chilling of a cooked ham. Based on the experimental airflow temperature data, a mathematical formula expressing the
Spontaneous ignition in afterburner segment tests at an inlet temperature of 1240 K and a pressure of 1 atmosphere with ASTM jet-A fuel
NASA Technical Reports Server (NTRS)
Schultz, D. F.; Branstetter, J. R.
A brief testing program was undertaken to determine if spontaneous ignition and stable combustion could be obtained in a jet engine afterburning operating with an inlet temperature of 1240 K and a pressure of 1 atmosphere with ASTM Jet-A fuel. Spontaneous ignition with 100-percent combustion efficiency and stable burning was obtained using water-cooled fuel spraybars as flameholders.
Effect of Gas/Steam Turbine Inlet Temperatures on Combined Cycle Having Air Transpiration Cooled Gas Turbine
NASA Astrophysics Data System (ADS)
Kumar, S.; Singh, O.
Worldwide efforts are being made for further improving the gas/steam combined cycle performance by having better blade cooling technology in topping cycle and enhanced heat recovery in bottoming cycle. The scope of improvement is possible through turbines having higher turbine inlet temperatures (TITs) of both gas turbine and steam turbine. Literature review shows that a combined cycle with transpiration cooled gas turbine has not been analyzed with varying gas/steam TITs. In view of above the present study has been undertaken for thermodynamic study of gas/steam combined cycle with respect to variation in TIT in both topping and bottoming cycles, for air transpiration cooled gas turbine. The performance of combined cycle with dual pressure heat recovery steam generator has been evaluated for different cycle pressure ratios (CPRs) varying from 11 to 23 and the selection diagrams presented for TIT varying from 1,600 to 1,900 K. Both the cycle efficiency and specific work increase with TIT for each pressure ratio. For each TIT there exists an optimum pressure ratio for cycle efficiency and specific work. For the CPR of 23 the best cycle performance is seen at a TIT of 1,900 K for maximum steam temperature of 570 ░C, which gives the cycle efficiency of 60.9 % with net specific work of 909 kJ/kg.
Investigations were conducted to determine the effects of temperature on ; the energy absorption of the moderatorcoolant in the OMRE. Results of ; calculations performed to determine the energy absorbed by the organic ; moderatorcoolant at 500, 550, 600, and 700-F are given. (J.R.D.)
Hepatic radiofrequency ablation with internally cooled probes: effect of coolant temperature on lesion size
Dieter Haemmerich; Louay Chachati; Andrew S. Wright; David M. Mahvi; J. G. Webster
Radiofrequency (RF) ablation is a minimally invasive method for treatment of primary and metastatic liver tumors. One of the currently commercially available devices employs an internally cooled 17-gauge needle probe. Within the probe, cool water is circulated during ablation, which cools tissue close to the probe resulting in larger lesions. We evaluated the effect of different cooling water temperatures on
Multiple-Reheat Brayton Cycles for Nuclear Power Conversion with Molten Coolants
Peterson, Per F. [University of California (United States)
Gas-turbine power conversion systems can have lower capital costs than comparable steam-turbine systems due to their higher power density. The recent commercialization of magnetic bearing systems for large turbomachinery now makes direct recuperated Brayton cycles the preferred power conversion choice for gas-cooled reactors. This paper presents a multiple-reheat closed gas cycle optimized to use energy input from liquid-metal or molten-salt coolants with temperatures as low as 550 to 650 deg. C. By utilizing reheat, these molten coolant gas cycles (MCGCs) have the potential for substantially higher thermal efficiency than current gas-cooled reactors if used with comparable turbine inlet temperatures. The MCGC system also eliminates the need for steam generators, which removes the potential for chemical reactions between the molten coolant and steam, and greatly simplifies the control of tritium for fusion energy systems.
Analysis of in-core coolant temperatures of FFTF instrumented fuels tests at full power
Hoth, C.W
Two full size highly instrumented fuel assemblies were inserted into the core of the Fast Flux Test Facility in December of 1979. The major objectives of these instrumented tests are to provide verification of the FFTF core conditions and to characterize temperature patterns within FFTF driver fuel assemblies. A review is presented of the results obtained during the power ascents and during irradiation at a constant reactor power of 400 MWt. The results obtained from these instrumented tests verify the conservative nature of the design methods used to establish core conditions in FFTF. The success of these tests also demonstrates the ability to design, fabricate, install and irradiate complex, instrumented fuel tests in FFTF using commercially procured components.
Thermal stratification potential in rocket engine coolant channels
NASA Technical Reports Server (NTRS)
Kacynski, Kenneth J.
The potential for rocket engine coolant channel flow stratification was computationally studied. A conjugate, 3-D, conduction/advection analysis code (SINDA/FLUINT) was used. Core fluid temperatures were predicted to vary by over 360 K across the coolant channel, at the throat section, indicating that the conventional assumption of a fully mixed fluid may be extremely inaccurate. Because of the thermal stratification of the fluid, the walls exposed to the rocket engine exhaust gases will be hotter than an assumption of full mixing would imply. In this analysis, wall temperatures were 160 K hotter in the turbulent mixing case than in the full mixing case. The discrepancy between the full mixing and turbulent mixing analyses increased with increasing heat transfer. Both analysis methods predicted identical channel resistances at the coolant inlet, but in the stratified analysis the thermal resistance was negligible. The implications are significant. Neglect of thermal stratification could lead to underpredictions in nozzle wall temperatures. Even worse, testing at subscale conditions may be inadequate for modeling conditions that would exist in a full scale engine.
The effects of inlet temperature and turbulence characteristics on the flow development inside a gas turbine exhaust diffuser
NASA Astrophysics Data System (ADS)
Bomela, Christian Loangola
The overall industrial gas turbine efficiency is known to be influenced by the pressure recovery in the exhaust system. The design and, subsequently, the performance of an industrial gas turbine exhaust diffuser largely depend on its inflow conditions dictated by the turbine last stage exit flow state and the restraints of the diffuser internal geometry. Recent advances in Computational Fluid Dynamics (CFD) tools and the availability of computer hardware at an affordable cost made the virtual tool a very attractive one for the analysis of fluid flow through devices like a diffuser. In this backdrop, CFD analyses of a typical industrial gas turbine hybrid exhaust diffuser, consisting of an annular diffuser followed by a conical portion, have been carried out with the purpose of improving the performance of these thermal devices using an open-source CFD code "OpenFOAM". The first phase in the research involved the validation of the CFD approach using OpenFOAM by comparing CFD results against published benchmark experimental data. The numerical results closely captured the flow reversal and the separated boundary layer at the shroud wall where a steep velocity gradient has been observed. The standard k --epsilon turbulence model slightly over-predicted the mean velocity profile in the casing boundary layer while slightly under-predicted it in the reversed flow region. A reliable prediction of flow characteristics in this region is very important as the presence of the annular diffuser inclined wall has the most dominant effect on the downstream flow development. The core flow region and the presence of the hub wall have only a minor influence as reported by earlier experimental studies. Additional simulations were carried out in the second phase to test the veracity of other turbulence models; these include RNG k--epsilon, the SST k--o, and the Spalart-Allmaras turbulence models. It was found that a high resolution case with 47.5 million cells using the SST k--o turbulence model produced a mean flow velocity profile at the middle of the annular diffuser portion that had the best overall match with the experiment. The RNG k --epsilon, however, better predicted the diffuser performance along the exhaust diffuser length by means of the pressure recovery coefficient. These results were obtained using uniform inflow conditions and steady-state simulations. As such, the last phase of our investigations involved varying the inflow parameters like the turbulence intensity, the inlet flow temperature, and the flow angularity, which constitute important characteristics of the turbine blade wake, to investigate their impact on the diffuser design and performance. These isothermal CFD simulations revealed that by changing the flow temperature from 15 to 427░C, the pressure recovery coefficient significantly increased. However, it has been shown that the increase of temperature had no effects on the size of the reversed flow region and the thickness of the separated casing boundary layer, although the flow appears to be more turbulent. Furthermore, it has been established that an optimum turbulence intensity of about 4% produced comparable diffuser performance as the experiment. We also found that a velocity angle of about 2.5░ at the last turbine stage will ensure a better exhaust diffuser performance.
M. D. Barber; W. G. Kipp
This patent describes a hydrometer unit for connection in an automobile coolant flow line comprising: a tubular fitting adapted to be connected to the coolant flow line; a coolant receiving chamber means connected to the tubular fitting for receiving coolant from the tubular fitting; and indicating float elements contained within the coolant receiving chamber means and adapted to rise therein
Barber, M.D.; Kipp, W.G.
This patent describes a hydrometer unit for connection in an automobile coolant flow line comprising: a tubular fitting adapted to be connected to the coolant flow line; a coolant receiving chamber means connected to the tubular fitting for receiving coolant from the tubular fitting; and indicating float elements contained within the coolant receiving chamber means and adapted to rise therein individually as a function of the specific gravity of the coolant. The coolant receiving chamber means includes a closure cap which when connected to the tubular fitting forms a coolant receiving chamber, retaining means for retaining the indicating float elements within the coolant receiving chamber, a viewing window member of a substantially clear material through which the float elements can be visually observed within the coolant receiving chamber means, and air venturi means located within the coolant receiving chamber means for automatically removing air which may collect within the coolant chamber means.
Influence of HTR core inlet and outlet temperatures on hydrogen generation efficiency using the sulfur-iodine water-splitting cycle
Buckingham, Robert; Brown, Lloyd; Russ, Ben [Gen Atom Co, San Diego, CA 92121 (United States); Lovera, Patrick; Carles, Philippe; Borgard, Jean-Marc; Yvon, Pascal [CEA, DEN, F-91191 Gif Sur Yvette, (France)
The performance of hydrogen production via thermochemical cycles is typically evaluated using thermal efficiency. In this study, the sulfur-iodine cycle with heat supplied by a high-temperature reactor (HTR) is analyzed. Two cases are examined: one flow sheet designed by General Atomics in the United States, the other by Commissariat a l'energie atomique et aux energies alternatives in France. In each case, HTR helium inlet and outlet temperatures are specified. Differences in these temperature specifications lead to process variations between the limy sheets and in how the hydrogen processes interface with the nuclear heat source. Two principal conclusions result from the analysis. First, the thermal efficiency tends to plateau above a certain outlet helium temperature. This is a characteristic effect of the method of Ozturk et al. for sulfuric acid decomposition. Second, it is clear that it is impractical to discuss efficiencies for the hydrogen process that are independent of defined operating parameters of the HTR. (authors)
William C. Seabergh
Much focus is placed on beach erosion on the open coast. However, coastal processes often occur on sandy shorelines interior to inlets that can lead to severe erosion. These shorelines lie adjacent to coastal inlets and extend around the inlet from the ocean to bay. In particular, an examination of coastal inlets with jetties or terminal groins that are connected
Optimizations of packed sorbent and inlet temperature for large volume-direct aqueous injection-gas chromatography to determine high boiling volatile organic compounds in water.
Yu, Bofan; Song, Yonghui; Han, Lu; Yu, Huibin; Liu, Yang; Liu, Hongliang
For the expanded application area, fast trace analysis of certain high boiling point (i.e., 150-250 ░C) volatile organic compounds (HVOCs) in water, a large volume-direct aqueous injection-gas chromatography (LV-DAI-GC) method was optimized for the following parameters: packed sorbent for sample on-line pretreatment, inlet temperature and detectors configuration. Using the composite packed sorbent self-prepared with lithium chloride and a type of diatomite, the method enabled safe injection of an approximately 50-100 ?L sample at an inlet temperature of 150 ░C in the splitless mode and separated HVOCs from water matrix in 2 min. Coupled with a flame ionization detector (FID), an electron capture detector (ECD) and a flame photometric detector (FPD), the method could simultaneously quantify 27 HVOCs that belong to seven subclasses (i.e., halogenated aliphatic hydrocarbons, chlorobenzenes, nitrobenzenes, anilines, phenols, polycyclic aromatic hydrocarbons and organic sulfides) in 26 min. Injecting a 50 ?L sample without any enrichment step, such as cryotrap focusing, the limits of quantification (LOQs) for the 27 HVOCs was 0.01-3 ?g/L. Replicate analyses of the 27 HVOCs spiked source and river water samples exhibited good precision (relative standard deviations ? 11.3%) and accuracy (relative errors ? 17.6%). The optimized LV-DAI-GC was robust and applicable for fast determination and automated continuous monitoring of HVOCs in surface water. PMID:24997514
Preliminary Study on Utilization of Carbon Dioxide as a Coolant of High Temperature Engineering Test Reactor with MOX and Minor Actinides Fuel
Fauzia, A. F.; Waris, A.; Novitrian [Bosscha Laboratory, Department of Physics, Nuclear Physics and Biophysics Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, INDONESIA Jl. Ganesa 10 Bandung 40132 (Indonesia)
High temperature engineering test reactor (HTTR) is an uranium oxide (UO2) fuel, graphite moderator and helium gas-cooled reactor with 30 MW in thermal output and outlet coolant temperature of 950 deg. C. Instead of using helium gas, we have utilized carbon dioxide as a coolant in the present study. Beside that, uranium and plutonium oxide (mixed oxide, MOX) and minor actinides have been employed as a new fuel type of HTTR. Utilization of plutonium and minor actinide is one of the support system to non-proliferation issue in the nuclear development. The enrichment for uranium oxide has been varied of 6-20% with plutonium and minor actinides concentration of 10%. In this study, burnup period is 1100 days. The reactor cell calculation was performed by using SRAC 2002 code, with nuclear data library was derived from JENDL3.2. Reactor core calculation was done by using CITATION module. The result shows that HTTR can achieve its criticality condition with 14% of {sup 235}U enrichment.
The effect of operating temperature on open, multimegawatt space power systems
NASA Astrophysics Data System (ADS)
Edenburn, M. W.
Reactor powered and combustion powered multimegawatt, burst mode, space power systems were studied to evaluate the effect of turbine inlet temperature will have on their performance and mass. Both systems will provide power to space based antiballistic missile weapons that require hydrogen for cooling, and both use this hydrogen coolant as a working fluid or as a fuel for power generation. The quantity of hydrogen needed for weapon cooling increases as the weapon's cooling load increases and as weapon coolant outlet temperature decreases. Also, the hydrogen needed by the turbines in both power systems increases as turbine inlet temperature decreases. When weapon cooling loads are above 40 to 50 percent of weapon power and weapon coolant outlet temperature is below 300 to 400 K, the weapon needs more hydrogen than the turbine in either the reactor or combustion powered systems using turbine inlet temperatures consistent with current material technology. There is very little system mass reduction to be gained by operating a burst mode power system at a turbine inlet temperature above present material temperature limits unless the weapon's cooling load is below 40 to 50 percent or coolant outlet temperature is above 300 to 400 K.
A liquid cooled garment temperature controller based on sweat rate
NASA Technical Reports Server (NTRS)
Chambers, A. B.; Blackaby, J. R.
An automatic controller for liquid cooled space suits is reported that utilizes human sweat rate as the primary input signal. The controller is so designed that the coolant inlet temperature is inversely proportional to the subject's latent heat loss as evidenced by evaporative water loss.
Development of a high-sensitivity quantitative analytical method for determining polycarbamate by gas chromatography-mass spectrometry incorporating temperature-programmable inlet on-column injection.
Kawamoto, Tatsuhiko; Yano, Miho; Makihata, Nobuko
A highly sensitive analytical method was developed using GC/MS with temperature-programmable inlet on-column injection (TPI on-column GC/MS) for determining methyl dimethyldithiocarbamate (DMDC-methyl) and dimethyl ethylenebisdithiocarbamate (EBDC-dimethyl), which are methyl derivatives of alkali decomposed polycarbamate. This method makes it possible to quantify 0.3 microg/l of polycarbamate in tap water, which is a 1/100 of the residual target value of 30 microg/l in Japan. Moreover, it now becomes possible to distinguish polycarbamate from other dithiocarbamate pesticides (DTCs) that have similar structures, including ziram and thiram, which only incorporate a DMDC side chain, or manzeb, maneb and zineb, which only incorporate an EBDC side chain, by simultaneously analyzing for DMDC-methyl and EBDC-dimethyl. PMID:15941051
Exploratory Investigation of Transpiration Cooling of a 40 deg Double Wedge using Nitrogen and Helium as Coolants at Stagnation Temperatures from 1,295 deg F to 2,910 deg F
NASA Technical Reports Server (NTRS)
Rashis, Bernard
An investigation of transpiration cooling has been conducted in the preflight jet of the Langley Pilotless Aircraft Research Station at Wallops Island, Va. The model consisted of a double wedge of 40 deg included angle having a porous stainless-steel specimen inserted flush with the top surface of the wedge. The tests were conducted at a free-stream Mach number of 2.0 for stagnation temperatures ranging from 1,295 F to 2,910 F. Nitrogen and helium were used as coolants and tests were conducted for values ranging from approximately 0.03 to 0.30 percent of the local weight flow rate. The data for both the nitrogen and helium coolants indicated greater cooling effectiveness than that predicted by theory and were in good agreement with the results for an 8 deg cone tested at a stagnation temperature of 600 F. The results indicate that the helium coolant, for the same amount of heat-transfer reduction, requires only about one-fourth to one-fifth the coolant flow weight as the nitrogen coolant.
Atmospheric effects on inlets for supersonic cruise aircraft
NASA Technical Reports Server (NTRS)
Cole, G. L.
Mixed-compression inlet dynamic behavior in the vicinity of unstart, was simulated and analyzed to investigate time response of an inlet's normal shock to independent disturbances in ambient temperature and pressure and relative velocity (longitudinal gust), with and without inlet controls active. The results indicate that atmospheric disturbances may be more important than internal disturbances in setting inlet controls requirements because they are usually not anticipated and because normal shock response to rapid atmospheric disturbances is not attenuated by the inlet, as it is for engine induced disturbances. However, before inlet control requirements can be fully assessed, more statistics on extreme atmospheric disturbances are needed.
Preliminary studies of coolant by-pass flows in a prismatic very high temperature reactor using computational fluid dynamics
Hiroyuki Sato; Richard Johnson; Richard Schultz
Three dimensional computational fluid dynamic (CFD) calculations of a typical prismatic very high temperature gas-cooled reactor (VHTR) were conducted to investigate the influence of gap geometry on flow and temperature distributions in the reactor core using commercial CFD code FLUENT. Parametric calculations changing the gap width in a whole core length model of fuel and reflector columns were performed. The simulations show the effects of core by-pass flows in the heated core region by comparing results for several gap widths including zero gap width. The calculation results underline the importance of considering inter-column gap width for the evaluation of maximum fuel temperatures and temperature gradients in fuel blocks. In addition, it is shown that temperatures of core outlet flow from gaps and channels are strongly affected by the gap width of by-pass flow in the reactor core.
Nanofluids: Future Industrial Coolants
NASA Astrophysics Data System (ADS)
Arora, Sakshi; Srivastava, Sunita
Nanofluids have emerged as a major area of research due to significant increase found in their thermal conductivity compared to the base fluids like Water, Ethylene Glycol, Toluene, etc. The enhanced transport properties of nanofluids and heat transfer efficiency have given them an edge over micro to macro sized particle suspensions. These fluids find great applications in thermal management as industrial coolants and various biomedical applications including cancer therapy. Major mechanism appears to be layering of liquid molecules at the solid-particle surface to form an interfacial nanolayer. This paper describes the dependence of effective thermal conductivity of nanofluids on nanoparticle concentration and transport properties of interfacial layer. We have studied the role of interfacial layer and nanoparticle Al2O3 concentration to the effective thermal conductivity of Al2O3/Water based nanofluid. Effect of temperature and pressure has also been investigated. Estimated values are found to match excellently with the available experimental data.
Experimental investigation of coolant-flow characteristics of a sintered porous turbine blade
NASA Technical Reports Server (NTRS)
Bartoo, Edward R; Schafer, Louis J , Jr; Richards, Hadley T
Local cooling-air flow rates through the walls of a sintered porous-metal turbine blade were measured at room temperature for a range of pressure drops. In order to check the validity of the correlation procedure, this procedure was used to correlate air-flow rates thorough two porous disks at temperatures up to 600 degrees F.245:00:Experimental investigation of coolant Data indicate the method permits room-temperature flow data to be used for heat-transfer work at elevated temperatures with reasonable accurach. Cooling-air flow distribution around the periphery of the test blade is presented for two internal cooling air pressures with the blade in a 1000 degrees Fahrenheit gas stream at a cascade-inlet Mach number of 0.45.
The induction of water to the inlet air as a means of internal cooling in aircraft-engine cylinders
NASA Technical Reports Server (NTRS)
Rothrock, Addison M; Krsek, Alois, Jr; Jones, Anthony W
Report presents the results of investigations conducted on a full-scale air-cooled aircraft-engine cylinder of 202-cubic inch displacement to determine the effects of internal cooling by water induction on the maximum permissible power and output of an internal-combustion engine. For a range of fuel-air and water-fuel ratios, the engine inlet pressure was increased until knock was detected aurally, the power was then decreased 7 percent holding the ratios constant. The data indicated that water was a very effective internal coolant, permitting large increases in engine power as limited by either knock or by cylinder temperatures.
Columbia University
Jamaica Bay Rockaway Inlet Dead Horse Bay Marina Raptor Point Mill Basin Inlet Pond Sports Concession Flatbush Avenue Hangar Row Historic District Ryan Visitor Center North Forty Natural Area M odel Environmental Study Center (New York City Board of Education) Park Nursery Armed Forces Reserve Center US Park
Machine coolant waste reduction by optimizing coolant life. Project summary
Pallansch, J.
The project was designed to study the following: A specific water-soluble coolant (Blasocut 2000 Universal) in use with a variety of machines, tools, and materials; Coolant maintenance practices associated with three types of machines; Health effects of use and handling of recycled coolant; Handling practices for chips and waste coolant; Chip/coolant separation; and Oil/water separation.
Surface cooling of scramjet engine inlets using heat pipe, transpiration, and film cooling
Modlin, J.M.; Colwell, G.T. (U.S. Army, Strategic Defense Command, Huntsville, AL (United States) Georgia Institute of Technology, Atlanta (United States))
This article reports the results of applying a finite-difference-based computational technique to the problem of predicting the transient thermal behavior of a scramjet engine inlet exposed to a typical hypersonic flight aerodynamic surface heating environment, including type IV shock interference heating. The leading-edge cooling model utilized incorporates liquid metal heat pipe cooling with surface transpiration and film cooling. Results include transient structural temperature distributions, aerodynamic heat inputs, and surface coolant distributions. It seems that these cooling techniques may be used to hold maximum skin temperatures to near acceptable values during the severe aerodynamic and type IV shock interference heating effects expected on the leading edge of a hypersonic aerospace vehicle scramjet engine. 15 refs.
Flow boiling with enhancement devices for cold plate coolant channel design
NASA Astrophysics Data System (ADS)
Boyd, Ronald D., Sr.; Smith, Alvin
The use of flow boiling for thermal energy transport is intended to provide an alternative for accommodating higher heat fluxes in commercial space systems. The objectives are to: (1) examine the variations in both the mean and local (axial and circumferential) heat transfer coefficients for a circular coolant channel with either smooth walls, spiral fins, or both spiral fins and a twisted tape; (2) examine the effects of channel diameter and subcooling; and (3) develop an improved reduction analysis and/or suggest possible heat transfer correlation of the present data. Freon-11 is the working fluid. Two-dimensional (circumferential and axial) wall temperature distributions were measured for coolant channels with the above noted internal geometries. The flow regimes which are being studied are: (1) single phase; (2) subcooled flow boiling; and (3) stratified flow boiling. The inside diameter of all test sections is near 1.0 cm. Cicumferentially averaged heat transfer coefficients at several axial locations were obtained for selected coolant channels for a mass velocity of 210 kg/sq m s, an exit pressure of 0.19 MPa (absolute), and an inlet subcooling of 20.8 C. Overall (averaged over the entire channel) heat transfer coefficients were compared for the above channel geometries. This comparison showed that the channel with large pitch spiral fins had higher heat transfer coefficients at all power levels.
Flow boiling with enhancement devices for cold plate coolant channel design
NASA Technical Reports Server (NTRS)
Boyd, Ronald D., Sr.; Smith, Alvin
The use of flow boiling for thermal energy transport is intended to provide an alternative for accommodating higher heat fluxes in commercial space systems. The objectives are to: (1) examine the variations in both the mean and local (axial and circumferential) heat transfer coefficients for a circular coolant channel with either smooth walls, spiral fins, or both spiral fins and a twisted tape; (2) examine the effects of channel diameter and subcooling; and (3) develop an improved reduction analysis and/or suggest possible heat transfer correlation of the present data. Freon-11 is the working fluid. Two-dimensional (circumferential and axial) wall temperature distributions were measured for coolant channels with the above noted internal geometries. The flow regimes which are being studied are: (1) single phase; (2) subcooled flow boiling; and (3) stratified flow boiling. The inside diameter of all test sections is near 1.0 cm. Cicumferentially averaged heat transfer coefficients at several axial locations were obtained for selected coolant channels for a mass velocity of 210 kg/sq m s, an exit pressure of 0.19 MPa (absolute), and an inlet subcooling of 20.8 C. Overall (averaged over the entire channel) heat transfer coefficients were compared for the above channel geometries. This comparison showed that the channel with large pitch spiral fins had higher heat transfer coefficients at all power levels.
Machine shops use coolants to improve the life and function of machine tools. hese coolants become contaminated with oils with use, and this contamination can lead to growth of anaerobic bacteria and shortened coolant life. his project investigated methods to extend coolant life ...
Radiant energy receiver having improved coolant flow control means
Hinterberger, H.
An improved coolant flow control for use in radiant energy receivers of the type having parallel flow paths is disclosed. A coolant performs as a temperature dependent valve means, increasing flow in the warmer flow paths of the receiver, and impeding flow in the cooler paths of the receiver. The coolant has a negative temperature coefficient of viscosity which is high enough such that only an insignificant flow through the receiver is experienced at the minimum operating temperature of the receiver, and such that a maximum flow is experienced at the maximum operating temperature of the receiver. The valving is accomplished by changes in viscosity of the coolant in response to the coolant being heated and cooled. No remotely operated valves, comparators or the like are needed.
A Heated Tube Facility for Rocket Coolant Channel Research
NASA Technical Reports Server (NTRS)
Green, James M.; Pease, Gary M.; Meyer, Michael L.
The capabilities of a heated tube facility used for testing rocket engine coolant channels at the NASA Lewis Research Center are presented. The facility uses high current, low voltage power supplies to resistively heat a test section to outer wall temperatures as high as 730 C (1350 F). Liquid or gaseous nitrogen, gaseous helium, or combustible liquids can be used as the test section coolant. The test section is enclosed in a vacuum chamber to minimize heat loss to the surrounding system. Test section geometry, size, and material; coolant properties; and heating levels can be varied to generate heat transfer and coolant performance data bases.
Decontaminating reactor coolant systems
R. Whitaker; C. Wood
Chemical agents and processes that reduce radioactivity levels where people must work make repairs in the coolant circuits of nuclear power reactors faster and less costly. The low-oxidation-state metal ions (LOMI) chemical process quickly dissolves tough corrosion films that hold radioactive isotopes. Radiation fields on pipe surfaces can be cut by a factor of 20 before repair crews go to
Automatic coolant flow control device for a nuclear reactor assembly
Hutter, Ernest (Wilmette, IL)
A device which controls coolant flow through a nuclear reactor assembly comprises a baffle means at the exit end of said assembly having a plurality of orifices, and a bimetallic member in operative relation to the baffle means such that at increased temperatures said bimetallic member deforms to unblock some of said orifices and allow increased coolant flow therethrough.
Automatic coolant flow control device for a nuclear reactor assembly
Hutter, E.
A device which controls coolant flow through a nuclear reactor assembly comprises a baffle means at the exit end of said assembly having a plurality of orifices, and a bimetallic member in operative relation to the baffle means such that at increased temperatures said bimetallic member deforms to unblock some of said orifices and allow increased coolant flow therethrough.
Fuel cell system with coolant flow reversal
Kothmann, Richard E. (Pittsburgh, PA)
Method and apparatus for cooling electrochemical fuel cell system components. Periodic reversal of the direction of flow of cooling fluid through a fuel cell stack provides greater uniformity and cell operational temperatures. Flow direction through a recirculating coolant fluid circuit is reversed through a two position valve, without requiring modulation of the pumping component.
Subcooled freon-11 flow boiling in top-heated finned coolant channels with and without a twisted tape
NASA Astrophysics Data System (ADS)
Smith, Alvin; Boyd, Ronald D., Sr.
An experimental study was conducted in top-heated finned horizontal tubes to study the effect of enhancement devices on flow boiling heat transfer in coolant channels. The objectives are to examine the variations in both the mean and local (axial and circumferential) heat transfer coefficients for circular coolant channels with spiral finned walls and/or spiral fins with a twisted tape, and improve the data reduction technique of a previous investigator. The working fluid is freon-11 with an inlet temperature of 22.2 C (approximately 21 C subcooling). The coolant channel's exit pressure and mass velocity are 0.19 M Pa (absolute) and 0.21 Mg/sq. ms, respectively. Two tube configurations were examined; i.e., tubes had either 6.52 (small pitch) or 4.0 (large pitch) fins/cm of the circumferential length (26 and 16 fins, respectively). The large pitch fins were also examined with a twisted tape insert. The inside nominal diameter of the copper channels at the root of the fins was 1.0 cm. The results show that by adding enhancement devices, boiling occurs almost simultaneously at all axial locations. The case of spiral fins with large pitch resulted in larger mean (circumferentially averaged) heat transfer coefficients, h sub m, at all axial locations. Finally, when twisted tape is added to the tube with large-pitched fins, the power required for the onset of boiling is reduced at all axial and circumferential locations.
Subcooled freon-11 flow boiling in top-heated finned coolant channels with and without a twisted tape
NASA Technical Reports Server (NTRS)
Smith, Alvin; Boyd, Ronald D., Sr.
An experimental study was conducted in top-heated finned horizontal tubes to study the effect of enhancement devices on flow boiling heat transfer in coolant channels. The objectives are to examine the variations in both the mean and local (axial and circumferential) heat transfer coefficients for circular coolant channels with spiral finned walls and/or spiral fins with a twisted tape, and improve the data reduction technique of a previous investigator. The working fluid is freon-11 with an inlet temperature of 22.2 C (approximately 21 C subcooling). The coolant channel's exit pressure and mass velocity are 0.19 M Pa (absolute) and 0.21 Mg/sq. ms, respectively. Two tube configurations were examined; i.e., tubes had either 6.52 (small pitch) or 4.0 (large pitch) fins/cm of the circumferential length (26 and 16 fins, respectively). The large pitch fins were also examined with a twisted tape insert. The inside nominal diameter of the copper channels at the root of the fins was 1.0 cm. The results show that by adding enhancement devices, boiling occurs almost simultaneously at all axial locations. The case of spiral fins with large pitch resulted in larger mean (circumferentially averaged) heat transfer coefficients, h sub m, at all axial locations. Finally, when twisted tape is added to the tube with large-pitched fins, the power required for the onset of boiling is reduced at all axial and circumferential locations.
Computation of Space Shuttle high-pressure cryogenic turbopump ball bearing two-phase coolant flow
NASA Technical Reports Server (NTRS)
Chen, Yen-Sen
A homogeneous two-phase fluid flow model, implemented in a three-dimensional Navier-Stokes solver using computational fluid dynamics methodology is described. The application of the model to the analysis of the pump-end bearing coolant flow of the high-pressure oxygen turbopump of the Space Shuttle main engine is studied. Results indicate large boiling zones and hot spots near the ball/race contact points. The extent of the phase change of the liquid oxygen coolant flow due to the frictional and viscous heat fluxes near the contact areas has been investigated for the given inlet conditions of the coolant.
NASA Astrophysics Data System (ADS)
Scott, James R.; Abbott, John M.
The internal fluid mechanics research program in inlets, ducts, and nozzles is a balanced effort between the development and application of computational tools and the conduct of experimental research. The computational effort involves the development and validation of advanced computational fluid dynamics (CFD) codes through comparison with data, the modification of existing codes to extend their range and accuracy, and the application of codes to practical problems to demonstrate their value in design. The experimental research involves both simplified and realistic complex geometries and is used for developing flow physics understanding, for validating advanced numerical analysis codes, and for developing physical models of flow phenomena. The inlet, duct, and nozzle research program is described according to three major classifications of flow phenomena: highly three-dimensional flow fields; shock and high-speed-mixing flow fields; and shear flow control. Specific examples of current and future elements of the research program are described for each of these phenomena. In particular, the highly three-dimensional flow field phenomenon is highlighted by describing the experimental and computational research program in transition ducts having a round-to-rectangular area variation. In the case of shock and high-speed-mixing flow fields, both experimental and computational results are presented for the mixing of a high-speed stream injected into a second high-speed stream. For shear flow control, research in the use of aerodynamic excitation to enhance the jet mixing process is described. In addition, results that stem from using small tabs protruding into a nozzle exit flow stream to enhance mixing are also presented. A three-dimensional, unsteady viscous code development effort that will provide a well-documented, user-friendly flow solver for computing inlet, duct, and nozzle flow fields in the future is described.
Development of Figure of Merits (FOMs) for Intermediate Coolant Characterization and Selection
Eung Soo Kim; Piyush Sabharwall; Nolan Anderson
This paper focuses on characterization of several coolant performances in the IHTL. There are lots of choices available for the IHTL coolants; gases, liquid metals, molten salts, and etc. Traditionally, the selection of coolants is highly dependent on engineer's experience and decisions. In this decision, the following parameters are generally considered: melting point, vapor pressure, density, thermal conductivity, heat capacity, viscosity, and coolant chemistry. The followings are general thermal-hydraulic requirements for the coolant in the IHTL: (1) High heat transfer performance - The IHTL coolant should exhibit high heat transfer performance to achieve high efficiency and economics; (2) Low pumping power - The IHTL coolant requires low pumping power to improve economics through less stringent pump requirements; (3) Low amount of coolant volume - The IHTL coolant requires less coolant volume for better economics; (4) Low amount of structural materials - The IHTL coolant requires less structural material volume for better economics; (5) Low heat loss - The IHTL requires less heat loss for high efficiency; and (6) Low temperature drop - The IHTL should allow less temperature drop for high efficiency. Typically, heat transfer coolants are selected based on various fluid properties such as melting point, vapor pressure, density, thermal conductivity, heat capacity, viscosity, and coolant chemistry. However, the selection process & results are highly dependent on the engineer's personal experience and skills. In the coolant selection, if a certain coolant shows superior properties with respect to the others, the decision will be very straightforward. However, generally, each coolant material exhibits good characteristics for some properties but poor for the others. Therefore, it will be very useful to have some figures of merits (FOMs), which can represent and quantify various coolant thermal performances in the system of interest. The study summarized in this paper focuses on developing general FOMs for the IHTL coolant selection and shows some estimation results.
Combustion Gas Turbine Power Enhancement by Refrigeration of Inlet AirĀ
Meher-Homji, C. B.; Mani, G.
in the ambient temperature. On hot days, a machine may experience considerable difficulty in meeting its power demand. One concept that has not received much attention is the cooling down of compressor inlet air. This paper will examine the theoretical...
CFD analyses of coolant channel flowfields
NASA Technical Reports Server (NTRS)
Yagley, Jennifer A.; Feng, Jinzhang; Merkle, Charles L.
The flowfield characteristics in rocket engine coolant channels are analyzed by means of a numerical model. The channels are characterized by large length to diameter ratios, high Reynolds numbers, and asymmetrical heating. At representative flow conditions, the channel length is approximately twice the hydraulic entrance length so that fully developed conditions would be reached for a constant property fluid. For the supercritical hydrogen that is used as the coolant, the strong property variations create significant secondary flows in the cross-plane which have a major influence on the flow and the resulting heat transfer. Comparison of constant and variable property solutions show substantial differences. In addition, the property variations prevent fully developed flow. The density variation accelerates the fluid in the channels increasing the pressure drop without an accompanying increase in heat flux. Analyses of the inlet configuration suggest that side entry from a manifold can affect the development of the velocity profile because of vortices generated as the flow enters the channel. Current work is focused on studying the effects of channel bifurcation on the flow field and the heat transfer characteristics.
Numerical Simulation For Supersonic Inlets
NASA Technical Reports Server (NTRS)
Varner, M. O.; Martindale, W. R.; Phares, W. J.; Kneile, K. R.; Adams, J. C., Jr.
Flows calculated for realistic engine-inlet conditions. Computer code LAPIN, large-perturbation inlet, developed to analyze large-perturbation, transient-flow fields in supersonic inlets. Robust, quick-running code capable of solving unsteady quasi-one-dimensional, inviscid-flow problems in mixed subsonic and supersonic regimes for inlets. Approach based upon quasi-one-dimensional, inviscid, unsteady formulation including engineering models of unstart/restart, bleed, bypass, and geometrical effects. Numerical solution of governing time-dependent equations of motion accomplished through shock-capturing, finite-difference algorithm. Program written in FORTRAN IV.
Finegan, John Raymond; Kreke, Francis Joseph; Casamassa, John Joseph
A flywheel for a pump, and in particular a flywheel having a number of high density segments for use in a nuclear reactor coolant pump. The flywheel includes an inner member and an outer member. A number of high density segments are provided between the inner and outer members. The high density segments may be formed from a tungsten based alloy. A preselected gap is provided between each of the number of high density segments. The gap accommodates thermal expansion of each of the number of segments and resists the hoop stress effect/keystoning of the segments.
Unsteady characteristics of inlet vortices
NASA Astrophysics Data System (ADS)
Wang, Z.; Gursul, I.
An experimental study of the unsteady characteristics of inlet vortices has been conducted using a high-frame rate digital particle image velocimetry system. The results revealed the formation of a pair of counter-rotating inlet vortices for the no-wind configuration and one single inlet vortex when there was crosswind. In all measurement planes, from near the ground to the inlet, evidence of vortex meandering with quasi-periodicity was found. The vortex meander is dominant in the direction of the crosswind, and its amplitude increases with crosswind velocity. The proper orthogonal decomposition analysis of the instantaneous velocity field suggested that the most energetic mode was a helical displacement wave, corresponding to the first helical mode. Similarities with the meandering of the trailing vortices from wings were noted. The present results also suggest that the unsteady characteristics of the focus of separation formed on the ground might be responsible for the unsteady nature of the inlet vortex.
The influence of humidification and temperature differences between inlet gases on water transport through the membrane of a proton exchange membrane fuel cell
NASA Astrophysics Data System (ADS)
Huang, Kuan-Jen; Hwang, Sheng-Jye; Lai, Wei-Hsiang
This paper discusses the effects of humidification and temperature differences of the anode and cathode on water transport in a proton exchange membrane fuel cell. Heaters are used to cause a difference in gas temperature between two electrodes before the gases enter the fuel cell. The results show that when the temperature of the cathode is higher than that of the anode, the electro-osmotic drag is suppressed. In contrast, when the temperature of the anode is higher than that of cathode, it is enhanced. These effects are more significant when the temperature difference between the anode and cathode is greater. The same trends are seen with back diffusion. Three cases are tested, and the results show that the suppression due to the temperature difference occurs even when the relative humidity is low at the hotter side. The water transport tendencies of electro-osmotic drag and back diffusion in different situations can be expressed as dominant percentages calculated by the water masses collected at the anode and cathode. The suppression effect due to the temperature difference is relatively insignificant with regard to back diffusion compared to electro-osmosis, so water tends to accumulate on the anode rather than the cathode side.
Investigation of Aerodynamic and Icing Characteristics of a Flush Alternate Inlet Induction System Air Scoop
NASA Technical Reports Server (NTRS)
Lewis, James P.
An investigation has been made in the NACA Lewis icing research tunnel to determine the aerodynamic and icing characteristics of a full-scale induction-system air-scoop assembly incorporating a flush alternate inlet. The flush inlet was located immediately downstream of the offset ram inlet and included a 180 deg reversal and a 90 deg elbow in the ducting between inlet and carburetor top deck. The model also had a preheat-air inlet. The investigation was made over a range of mass-air- flow ratios of 0 to 0.8, angles of attack of 0 and 4 deg airspeeds of 150 to 270 miles per hour, air temperatures of 0 and 25 F various liquid-water contents, and droplet sizes. The ram inlet gave good pressure recovery in both clear air and icing but rapid blockage of the top-deck screen occurred during icing. The flush alternate inlet had poor pressure recovery in both clear air and icing. The greatest decreases in the alternate-inlet pressure recovery were obtained at icing conditions of low air temperature and high liquid-water content. No serious screen icing was observed with the alternate inlet. Pressure and temperature distributions on the carburetor top deck were determined using the preheat-air supply with the preheat- and alternate-inlet doors in various positions. No screen icing occurred when the preheat-air system was operated in combination with alternate-inlet air flow.
Summary of investigations of engine response to distorted inlet conditions
NASA Technical Reports Server (NTRS)
Biesiadny, Thomas J.; Braithwaite, Willis M.; Soeder, Ronald H.; Abdelwahab, Mahmood
A survey is presented of experimental and analytical experience of the NASA Lewis Research Center in engine response to inlet temperature and pressure distortions. Results of experimental investigations and analytical modeling are reviewed together with a description of the hardware and the techniques employed. Distortion devices successfully simulated inlet distortion, and knowledge was gained on compression system response to different types of distortion. A list of NASA research references is included.
Summary of investigations of engine response to distorted inlet conditions
NASA Technical Reports Server (NTRS)
Biesiadny, T. J.; Braithwaite, W. M.; Soeder, R. H.; Abdelwahab, M.
A survey is presented of experimental and analytical experience of the NASA Lewis Research Center in engine response to inlet temperature and pressure distortions. This includes a description of the hardware and techniques employed, and a summary of the highlights of experimental investigations and analytical modeling. Distortion devices successfully simulated inlet distortion, and knowledge was gained about compression system response to different types of distortion. A list of NASA research references is included.
Coolant pressure distribution in wire-wrapped rod bundles
Wei, J.P.
To analyze thermal-hydraulic behavior in a wire-wrapped fuel or blanket assembly, it is necessary to evaluate the coolant flow field in the rod bundle. Evaluation of the coolant flow phenomenon in the wire-wrapped assembly becomes even more important when the bundle has a low pitch-to-diameter ratio or a wire-wrap configuration different from the current reference straight-start design or the assembly is located in a high radial power gradient region in a reactor. Subchannel analysis method (FULMIX-II) was developed to specifically treat the complex coolant transfer process within a wire-wrapped assembly and to determine the coolant temperature field accordingly.
Estimation of temperature-induced reactor coolant system and steam generator tube creep rupture probability under high-pressure severe accident conditions
Youngsuk Bang; Gunhyo Jung; Byungchul Lee; Kwang-Il Ahn
A severe accident has inherently significant uncertainties due to the complex phenomena and wide range of conditions. Because of its high temperature and pressure, performing experimental validation and practical application are extremely difficult. With these difficulties, there has been few experimental researches performed and there is no plant-specific experimental data. Instead, computer codes have been developed to simulate the accident
Experimental investigation of cavitation in pump inlet
NASA Astrophysics Data System (ADS)
Sikora, Roman; Bure?ek, Adam; Hru×Ēk, LumĒr; VaÜina, Martin
The article deals with experimental research of cavitation development in inlet tube of hydraulic pump. The pressures in inlet and outlet tube of the pump and flow rate were measured. Mineral oil was used as working fluid. The cavitation was visually evaluated in transparent inlet tube. The inlet tube underpressure was achieved by throttle valve. The relationship between the generation of bubbles and the inlet pressure is evaluated.
On-site profiling and speciation of polycyclic aromatic hydrocarbons at manufactured gas plant sites by a high temperature transfer line, membrane inlet probe coupled to a photoionization detector and gas chromatography/mass spectrometer
Thomas Considine; Albert Robbat Jr. [Tufts University, Medford, MA (United States). Chemistry Department, Center for Field Analytical Studies and Technology
A new high temperature transfer line, membrane inlet probe (HTTL-MIP) coupled to a photoionization detector (PID) and gas chromatograph/mass spectrometer (GC/MS) was used to rapidly profile and speciate polycyclic aromatic hydrocarbons (PAH) in the subsurface. PID signals were in agreement with GC/MS results. Correlation coefficients of 0.92 and 0.99 were obtained for discrete and composite samples collected from the same exact location. Continuous probe advancement with PID detection found coal tar, a dense nonaqueous phase liquid, in soil channels and saturated media. When samples were collected conventionally, split, solvent extracted, and analyzed in the field and confirmation laboratory, GC/MS measurement precision and accuracy were indistinguishable; despite the fact the field laboratory produced data five times faster than the laboratory using standard EPA methods. No false positive/negatives were found. Based on these findings, increased confidence in site conceptual models should be obtained, since PID response indicated total PAH presence/absence in 'real-time', while GC/MS provided information as to which PAH was present and at what concentration. Incorporation of this tool into a dynamic workplan will provide more data at less cost enabling environmental scientists, engineers, and regulators to better understand coal tar migration and its impact on human health and the environment. 24 refs., 3 figs., 4 tabs.
Design and Analysis Tools for Supersonic Inlets
NASA Technical Reports Server (NTRS)
Slater, John W.; Folk, Thomas C.
Computational tools are being developed for the design and analysis of supersonic inlets. The objective is to update existing tools and provide design and low-order aerodynamic analysis capability for advanced inlet concepts. The Inlet Tools effort includes aspects of creating an electronic database of inlet design information, a document describing inlet design and analysis methods, a geometry model for describing the shape of inlets, and computer tools that implement the geometry model and methods. The geometry model has a set of basic inlet shapes that include pitot, two-dimensional, axisymmetric, and stream-traced inlet shapes. The inlet model divides the inlet flow field into parts that facilitate the design and analysis methods. The inlet geometry model constructs the inlet surfaces through the generation and transformation of planar entities based on key inlet design factors. Future efforts will focus on developing the inlet geometry model, the inlet design and analysis methods, a Fortran 95 code to implement the model and methods. Other computational platforms, such as Java, will also be explored.
Method for removing cesium from a nuclear reactor coolant
Colburn, R.P.
A method of and system for removing cesium from a liquid metal reactor coolant including a carbon packing trap in the primary coolant system for absorbing a major portion of the radioactive cesium from the coolant flowing therethrough at a reduced temperature. A regeneration subloop system having a secondary carbon packing trap is selectively connected to the primary system for isolating the main trap therefrom and connecting it to the regeneration system. Increasing the temperature of the sodium flowing through the primary trap diffuses a portion of the cesium inventory thereof further into the carbon matrix while simultaneously redispersing a portion into the regeneration system for absorption at a reduced temperature by the secondary trap.
Reduction of Film Coolant in High Pressure Turbines
in the direction of increased turbine inlet temperatures to improve efficiency and power output. As a result the allowable metal temperatures of the alloys used for the turbine airfoils and endwalls are exceeded the heat transfer and convect hot core flow gases onto component surfaces. In this thesis four film cooling
1996 Coolant Flow Management Workshop
NASA Technical Reports Server (NTRS)
Hippensteele, Steven A. (Editor)
The following compilation of documents includes a list of the 66 attendees, a copy of the viewgraphs presented, and a summary of the discussions held after each session at the 1996 Coolant Flow Management Workshop held at the Ohio Aerospace Institute, adjacent to the NASA Lewis Research Center, Cleveland, Ohio on December 12-13, 1996. The workshop was organized by H. Joseph Gladden and Steven A. Hippensteele of NASA Lewis Research Center. Participants in this workshop included Coolant Flow Management team members from NASA Lewis, their support service contractors, the turbine engine companies, and the universities. The participants were involved with research projects, contracts and grants relating to: (1) details of turbine internal passages, (2) computational film cooling capabilities, and (3) the effects of heat transfer on both sides. The purpose of the workshop was to assemble the team members, along with others who work in gas turbine cooling research, to discuss needed research and recommend approaches that can be incorporated into the Center's Coolant Flow Management program. The workshop was divided into three sessions: (1) Internal Coolant Passage Presentations, (2) Film Cooling Presentations, and (3) Coolant Flow Integration and Optimization. Following each session there was a group discussion period.
Treatment of mixed waste coolant
Kidd, S.; Bowers, J.S. [Lawrence Livermore National Lab., CA (United States). Hazardous Waste Management Div.
The primary processes used at Lawrence Livermore National Laboratory (LLNL) for treatment of radioactively contaminated machine coolants are industrial waste treatment and in situ carbon adsorption. These two processes simplify approaches to meeting the sanitary sewer discharge limits and subsequent Land Disposal Restriction criteria for hazardous and mixed wastes (40 CFR 268). Several relatively simple technologies are used in industrial water treatment. These technologies are considered Best Demonstrated Available Technologies, or BDAT, by the Environmental Protection Agency. The machine coolants are primarily aqueous and contain water soluble oil consisting of ethanol amine emulsifiers derived from fatty acids, both synthetic and natural. This emulsion carries away metal turnings from a part being machined on a lathe or other machining tool. When the coolant becomes spent, it contains chlorosolvents carried over from other cutting operations as well as a fair amount of tramp oil from machine bearings. This results in a multiphasic aqueous waste that requires treatment of metal and organic contaminants. During treatment, any dissolved metals are oxidized with hydrogen peroxide. Once oxidized, these metals are flocculated with ferric sulfate and precipitated with sodium hydroxide, and then the precipitate is filtered through diatomaceous earth. The emulsion is broken up by acidifying the coolant. Solvents and oils are adsorbed using powdered carbon. This carbon is easily separated from the remaining coolant by vacuum filtration.
Evaluation of engine coolants under flow boiling conditions
McAssey, E.V. Jr.; Stinson, C. [Villanova Univ., PA (United States). Dept. of Mechanical Engineering; Gollin, M. [ARCO Chemical Co., Newtown Square, PA (United States)
An experimental program has been conducted to evaluate the heat transfer performance of two engine coolant mixtures, propylene-glycol/water and ethylene-glycol/water. In each mixture, the concentration was 50-50 by volume. Performance in this situation is defined as the ability to maintain a lower surface temperature for a given flux. The heat transfer regimes considered covered the range from single phase forced convection through saturated flow boiling. Results show that both coolants perform satisfactorily. However, in single phase convection, ethylene-glycol/water is slightly more effective. Conversely, for sub-cooled nucleate boiling and saturated boiling, propylene-glycol/water results in slightly lower metal temperatures.
Inlet Flow Valve Engine Analyses
NASA Technical Reports Server (NTRS)
Champagne, G. A.
Pratt&Whitney, under Task Order 13 of the NASA Large Engine Technology (LET) Contract, conducted a study to determine the operating characteristics, performance and weights of Inlet Flow Valve (IFV) propulsion concepts for a Mach 2.4 High Speed Civil Transport (HSCT).
TiAl Scramjet Inlet Flap Subelement Designed and Fabricated
NASA Technical Reports Server (NTRS)
Draper, Susan L.
Next-generation launch vehicles are being designed with turbine-based combined cycle (TBCC) propulsion systems having very aggressive thrust/weight targets and long lives. Achievement of these goals requires advanced materials in a wide spectrum of components. TiAl has been identified as a potential backstructure material for maintainable composite panel heat exchangers (HEX) in the inlet, combustor, and nozzle section of a TBCC propulsion system. Weight reduction is the primary objective of this technology. Design tradeoff studies have assessed that a TiAl structure, utilizing a high-strength, hightemperature TiAl alloy called Gamma MET PX,1 reduce weight by 41 to 48 percent in comparison to the baseline Inconel 718 configuration for the TBCC propulsion system inlet, combustor, and nozzle. A collaborative effort between the NASA Glenn Research Center, Pratt & Whitney, Engineering Evaluation & Design, PLANSEE AG (Austria), and the Austrian Space Agency was undertaken to design, manufacture, and validate a Gamma-MET PX TiAl structure for scramjet applications. The TiAl inlet flap was designed with segmented flaps to improve manufacturability, to better control thermal distortion and thermal stresses, and to allow for maintainable HEX segments. The design philosophy was to avoid excessively complicated shapes, to minimize the number of stress concentrations, to keep the part sizes reasonable to match processing capabilities, and to avoid risky processes such as welding. The conceptual design used a standard HEX approach with a double-pass coolant concept for centrally located manifolds. The flowpath side was actively cooled, and an insulation package was placed on the external side to save weight. The inlet flap was analyzed structurally, and local high-stress regions were addressed with local reinforcements.
Long life coolant pump technology
NASA Technical Reports Server (NTRS)
Design concepts were investigated to improve space system coolant pump technology to be suitable for mission durations of two years and greater. These design concepts included an improved bearing system for the pump rotating elements, consisting of pressurized conical bearings. This design was satisfactorily endurance tested as was a new prototype pump built using various other improved design concepts. Based upon an overall assessment of the results of the program it is concluded that reliable coolant pumps can be designed for three year space missions.
System and method for determining coolant level and flow velocity in a nuclear reactor
Brisson, Bruce William; Morris, William Guy; Zheng, Danian; Monk, David James; Fang, Biao; Surman, Cheryl Margaret; Anderson, David Deloyd
A boiling water reactor includes a reactor pressure vessel having a feedwater inlet for the introduction of recycled steam condensate and/or makeup coolant into the vessel, and a steam outlet for the discharge of produced steam for appropriate work. A fuel core is located within a lower area of the pressure vessel. The fuel core is surrounded by a core shroud spaced inward from the wall of the pressure vessel to provide an annular downcomer forming a coolant flow path between the vessel wall and the core shroud. A probe system that includes a combination of conductivity/resistivity probes and/or one or more time-domain reflectometer (TDR) probes is at least partially located within the downcomer. The probe system measures the coolant level and flow velocity within the downcomer.
Heat transfer to two-phase air/water mixtures flowing in small tubes with inlet disequilibrium
NASA Technical Reports Server (NTRS)
Janssen, J. M.; Florschuetz, L. W.; Fiszdon, J. P.
The cooling of gas turbine components was the subject of considerable research. The problem is difficult because the available coolant, compressor bleed air, is itself quite hot and has relatively poor thermophysical properties for a coolant. Injecting liquid water to evaporatively cool the air prior to its contact with the hot components was proposed and studied, particularly as a method of cooling for contingency power applications. Injection of a small quantity of cold liquid water into a relatively hot coolant air stream such that evaporation of the liquid is still in process when the coolant contacts the hot component was studied. No approach was found whereby heat transfer characteristics could be confidently predicted for such a case based solely on prior studies. It was not clear whether disequilibrium between phases at the inlet to the hot component section would improve cooling relative to that obtained where equilibrium was established prior to contact with the hot surface.
Thermal analysis of engine inlet anti-icing systems
NASA Technical Reports Server (NTRS)
Keith, Theo G., Jr.; De Witt, Kenneth J.; Nathman, James K.; Dietrich, Donald A.; Al-Khalil, Kamel M.
A hot air anti-icing system of a gas turbine engine inlet is analyzed numerically. A three-dimensional potential flow code, which accounts for compressibility effects, is used to determine the flowfield in and around the inlet. A particle trajectory code is developed using a local linearization technique. The trajectory code is used to calculate local water impingement rates. Energy balances are performed on both the surface runback water and the metallic skin to determine their temperature distributions. A variety of test cases are considered in order to validate the various numerical components of the process as well as to demonstrate the procedure.
Optimal control of a supersonic inlet to minimize frequency of inlet unstart
NASA Technical Reports Server (NTRS)
Lehtinen, B.; Zeller, J. R.; Geyser, L. C.
A preliminary investigation into the use of modern control theory for the design of controls for a supersonic inlet is described. In particular, the task of controlling a mixed-compression supersonic inlet is formulated as a linear optimal stochastic control and estimation problem. An inlet can exhibit an undesirable instability due to excessive inlet normal shock motion. For the optimal control formulation of the inlet problem, a non quadratic performance index, which is equal to the expected frequency of inlet unstarts, is used. This physically meaningful performance index is minimized for a range of inlet disturbance and measurement noise covariances.
Generic Hypersonic Inlet Module Analysis
NASA Technical Reports Server (NTRS)
Cockrell, Chares E., Jr.; Huebner, Lawrence D.
A computational study associated with an internal inlet drag analysis was performed for a generic hypersonic inlet module. The purpose of this study was to determine the feasibility of computing the internal drag force for a generic scramjet engine module using computational methods. The computational study consisted of obtaining two-dimensional (2D) and three-dimensional (3D) computational fluid dynamics (CFD) solutions using the Euler and parabolized Navier-Stokes (PNS) equations. The solution accuracy was assessed by comparisons with experimental pitot pressure data. The CFD analysis indicates that the 3D PNS solutions show the best agreement with experimental pitot pressure data. The internal inlet drag analysis consisted of obtaining drag force predictions based on experimental data and 3D CFD solutions. A comparative assessment of each of the drag prediction methods is made and the sensitivity of CFD drag values to computational procedures is documented. The analysis indicates that the CFD drag predictions are highly sensitive to the computational procedure used.
Low speed performance of a supersonic axisymmetric mixed compression inlet with auxiliary inlets
NASA Technical Reports Server (NTRS)
Wasserbauer, J. F.; Cubbison, R. W.; Trefny, C. J.
The aerodynamic performance of a representative supersonic cruise inlet was investigated using a fan simulator coupled to the inlet to provide characteristic noise signatures and to pump the inlet flow. Data were obtained at Mach numbers from 0 to 0.2 for the inlet equipped with an auxiliary inlet system that provided 20 to 40 percent of the fan flow. Results show that inlet performance improved when the inlet bleed systems were sealed; when the freestream Mach number was increased; and when the auxiliary inlets were opened. The inlet flow could not be choked by either centerbody translation or by increasing the fan speed when the 40 percent auxiliary inlet was incorporated. Previously announced in STAR as N83-27992
Reactor coolant pump shaft seal stability during station blackout
D. B. Rhodes; R. C. Hill; R. G. Wensel
Results are presented from an investigation into the behavior of Reactor Coolant Pump shaft seals during a potential station blackout (loss of all ac power) at a nuclear power plant. The investigation assumes loss of cooling to the seals and focuses on the effect of high temperature on polymer seals located in the shaft seal assemblies, and the identification of
Reactor coolant pump shaft seal behavior during station blackout
C. A. Kittmer; R. G. Wensel; D. B. Rhodes; R. Metcalfe; B. M. Cotnam; H. Gentili; W. J. Mings
A testing program designed to provide fundamental information pertaining to the behavior of reactor coolant pump (RCP) shaft seals during a postulated nuclear power plant station blackout has been completed. One seal assembly, utilizing both hydrodynamic and hydrostatic types of seals, was modeled and tested. Extrusion tests were conducted to determine if seal materials could withstand predicted temperatures and pressures.
Scramjet including integrated inlet and combustor
Kutschenreuter, P.H. Jr.; Blanton, J.C.
This patent describes a scramjet engine. It comprises: a first surface including an aft facing step; a cowl including: a leading edge and a trailing edge; an upper surface and a lower surface extending between the leading edge and the trailing edge; the cowl upper surface being spaced from and generally parallel to the first surface to define an integrated inlet-combustor therebetween having an inlet for receiving and channeling into the inlet-combustor supersonic inlet airflow; means for injecting fuel into the inlet-combustor at the step for mixing with the supersonic inlet airflow for generating supersonic combustion gases; and further including a spaced pari of sidewalls extending between the first surface to the cowl upper surface and wherein the integrated inlet-combustor is generally rectangular and defined by the sidewall pair, the first surface and the cowl upper surface.
Low-speed performance of an axisymmetric, mixed-compression, supersonic inlet with auxiliary inlets
NASA Technical Reports Server (NTRS)
Trefny, C. J.; Wasserbauer, J. W.
A test program was conducted to determine the aerodynamic performance and acoustic characteristics associated with the low-speed operation of a supersonic, axisymmetric, mixed-compression inlet with auxiliary inlets. Blow-in-auxiliary doors were installed on the NASA Ames P inlet. One door per quadrant was located on the cowl in the subsonic diffuser selection of the inlet. Auxiliary inlets with areas of 20 and 40 percent of the inlet capture area were tested statically and at free-stream Mach numbers of 0.1 and 0.2. The effects of boundary layer bleed inflow were investigated. A JT8D fan simulator driven by compressed air was used to pump inlet flow and to provide a characteristic noise signature. Baseline data were obtained at static free-stream conditions with the sharp P-inlet cowl lip replaced by a blunt lip. Auxiliary inlets increased overall total pressure recovery of the order of 10 percent.
Increased power input on aluminum heat-transfer surfaces: The effect on the corrosion protection provided by selected engine coolants
Van de Ven, P. [Texaco Inc., Beacon, NY (United States). Fuels and Lubricants Research Dept.; Miller, D.L. [Huntsman Corp., Austin, TX (United States)
Modern automotive engines require an efficient heat-dissipation at the heat-transfer surfaces in the engines. The coolant has to cope with increased engine power and consequently higher engine temperatures, while engine coolant volumes are decreasing. Heat-transfer has to be assured without compromising the other requirements for the engine coolant such as corrosion protection. A selection of ethylene glycol based engine coolants, representative of current coolant technologies, were tested in a dynamic heat-transfer test. They include a silicate based american coolant, a nitrite-containing and nitrite-free european formulation and a carboxylate based coolant. A propylene glycol based version of the carboxylate based coolant was also included in the test. The input-power into the hot coupon was varied from 38 W/cm{sup 2} to 115 W/cm{sup 2}. The effect on the corrosion protection was evaluated by weight loss measurements. Heat-transfer characteristics could be correlated to mid-section coupon temperatures. The results indicate that only the carboxylate based coolants provide corrosion protection over the whole heat-input range tested. The results also indicate that the performance by these coolants is only slightly affected by heat-input/metal temperature and that they do not impede the heat-transfer from metal to liquid.
Effect of inlet-air humidity on the formation of oxides of nitrogen in a gas-turbine combustor
NASA Technical Reports Server (NTRS)
Marchionna, N. R.
Tests were conducted to determine the effect of inlet-air humidity on the formation of oxides of nitrogen from a gas-turbine combustor. Combustor inlet-air temperature ranged from 450 F to 1050 F. The tests were run at a constant pressure of 6 atmospheres and reference Mach number of 0.065. The NO sub x emission index was found to decrease with increasing inlet-air humidity at a constant exponential rate of 19 percent per mass percent water vapor in the air. This decrease of NO sub x emission index with increasing humidity was found to be independent of inlet-air temperature.
Planar Inlet Design and Analysis Process (PINDAP)
NASA Technical Reports Server (NTRS)
Slater, John W.; Gruber, Christopher R.
The Planar Inlet Design and Analysis Process (PINDAP) is a collection of software tools that allow the efficient aerodynamic design and analysis of planar (two-dimensional and axisymmetric) inlets. The aerodynamic analysis is performed using the Wind-US computational fluid dynamics (CFD) program. A major element in PINDAP is a Fortran 90 code named PINDAP that can establish the parametric design of the inlet and efficiently model the geometry and generate the grid for CFD analysis with design changes to those parameters. The use of PINDAP is demonstrated for subsonic, supersonic, and hypersonic inlets.
Radial inlet guide vanes for a combustor
Zuo, Baifang; Simons, Derrick; York, William; Ziminsky, Willy S
A combustor may include an interior flow path therethrough, a number of fuel nozzles in communication with the interior flow path, and an inlet guide vane system positioned about the interior flow path to create a swirled flow therein. The inlet guide vane system may include a number of windows positioned circumferentially around the fuel nozzles. The inlet guide vane system may also include a number of inlet guide vanes positioned circumferentially around the fuel nozzles and adjacent to the windows to create a swirled flow within the interior flow path.
Axisymmetric inlet minimum weight design method
NASA Technical Reports Server (NTRS)
Nadell, Shari-Beth
An analytical method for determining the minimum weight design of an axisymmetric supersonic inlet has been developed. The goal of this method development project was to improve the ability to predict the weight of high-speed inlets in conceptual and preliminary design. The initial model was developed using information that was available from inlet conceptual design tools (e.g., the inlet internal and external geometries and pressure distributions). Stiffened shell construction was assumed. Mass properties were computed by analyzing a parametric cubic curve representation of the inlet geometry. Design loads and stresses were developed at analysis stations along the length of the inlet. The equivalent minimum structural thicknesses for both shell and frame structures required to support the maximum loads produced by various load conditions were then determined. Preliminary results indicated that inlet hammershock pressures produced the critical design load condition for a significant portion of the inlet. By improving the accuracy of inlet weight predictions, the method will improve the fidelity of propulsion and vehicle design studies and increase the accuracy of weight versus cost studies.
An evaluation of thermal energy storage options for precooling gas turbine inlet air
Z. I. Antoniak; D. R. Brown; M. K. Drost
Several approaches have been used to reduce the temperature of gas turbine inlet air. One of the most successful uses off-peak electric power to drive vapor-compression-cycle ice makers. The ice is stored until the next time high ambient temperature is encountered, when the ice is used in a heat exchanger to cool the gas turbine inlet air. An alternative concept
Low flight speed acoustic results for a supersonic inlet with auxiliary inlet doors
NASA Technical Reports Server (NTRS)
Woodward, R. P.; Glaser, F. W.; Lucas, J. G.
A model supersonic inlet with auxiliary inlet doors and bounday layer bleeds was acoustically tested in simulated low speed flight up to Mach 0.2 in the NASA Lewis 9x15 Anechoic Wind Tunnel and statically in the NASA Lewis Anechoic Chamber. A JT8D refan model was used as the noise source. Data were also taken for a CTOL inlet and for an annular inlet with simulated centerbody support struts. Inlet operation with open auxiliary doors increased the blade passage tone by about 10 dB relative to the closed door configuration although noise radiation was primarily through the main inlet rather than the doors. Numerous strong spikes in the noise spectra were associated with the bleed system, and were strongly affected by the centerbody location. The supersonic inlet appeared to suppress multiple pure tone (MPT) generation at the fan source. Inlet length and the presence of support struts were shown not to cause this MPT suppression.
Engine coolant compatibility with the nonmetals found in automotive cooling systems
Greaney, J.P.; Smith, R.A. [ARCO Chemical Co., Newtown Square, PA (United States)
High temperature, short term immersion testing was used to determine the impact of propylene and ethylene glycol base coolants on the physical properties of a variety of elastomeric and thermoplastic materials found in automotive cooling systems. The materials tested are typically used in cooling system hoses, radiator end tanks, and water pump seals. Traditional phosphate or borate-buffered silicated coolants as well as extended-life organic acid formulations were included. A modified ASTM protocol was used to carry out the testing both in the laboratory and at an independent testing facility. Post-test fluid chemistry including an analysis of any solids which may have formed is also reported. Coolant impact on elastomer integrity as well as elastomer-induced changes in fluid chemistry were found to be independent of the coolant`s glycol base.
Wave and Wind Effects on Inlet Circulation
NASA Astrophysics Data System (ADS)
Raubenheimer, B.; Wargula, A.; Orescanin, M. M.; Hopkins, J.; Elgar, S.
Observations and numerical simulations of the water circulation and morphological change in two separate, well-mixed inlets will be compared with each other. Tides, winds, waves, and currents were measured from May 1 to 28, 2012 in and near New River Inlet, NC. Offshore significant wave heights were 0 to 3 m, and wind speeds ranged from 0 to 16 m/s. The long, narrow inlet is about 1000 m wide where it opens onto the ebb shoal, narrows to 100 m wide about 1000 m inland, and connects to the Intracoastal Waterway (which connects to additional ocean inlets about 12 and 36 km north and south, respectively) about 3000 m inland. Tides in the inlet are progressive and inlet flows are in phase with water depths. Measurements also were collected during the summers of 2011-2014, including during Hurricanes Irene and Sandy (offshore significant wave heights > 5 m and winds > 15 m/s), in Katama Bay, MA, which connects to Vineyard Sound via Edgartown Channel and to the Atlantic Ocean via Katama Inlet. During this period, Katama Inlet migrated east about 1000 m, narrowed from 400 to 100 m wide, changed depth from 7 to 2 m, and lengthened from 200 to 1000 m. Tidal flows in Katama Inlet are forced by sea level gradients resulting from the 3-hr phase lag between tides in Vineyard Sound and the Atlantic Ocean. Analyses of the momentum balances suggest that waves drive flows into the mouths of the inlets during storms. The timing of the storms relative to ebb and flood, and wind effects, may affect the discharge and sediment transport through the inlet. Winds and waves also drive alongshore flows on the ebb shoals. Lateral flows at bends in New River Inlet, which may be important to the along-inlet transfer of momentum and to mixing, are affected by winds. The importance of connections to additional inlets in multi-inlet systems will be discussed. Funded by ONR, ASD(R&E), NSF, Sea Grant, and NDSEG.
Actuated Attic Inlets: A Progress Report
Technology Transfer Automated Retrieval System (TEKTRAN)
Attic inlets are being widely employed by poultry growers to alleviate high fuel costs during the brooding period. Pre-heated inlet air can reduce fuel usage and estimates for fuel savings were derived from field reports. Fuel usage was estimated for both large and small bird flocks for one yearÆ...
Corrosion of structural materials by lead-based reactor coolants.
Abraham, D. P.; Leibowitz, L.; Maroni, V. A.; McDeavitt, S. M.; Raraz, A. G.
Advanced nuclear reactor design has, in recent years, focused increasingly on the use of heavy-liquid-metal coolants, such as lead and lead-bismuth eutectic. Similarly, programs on accelerator-based transmutation systems have also considered the use of such coolants. Russian experience with heavy-metal coolants for nuclear reactors has lent credence to the validity of this approach. Of significant concern is the compatibility of structural materials with these coolants. We have used a thermal convection-based test method to allow exposure of candidate materials to molten lead and lead-bismuth flowing under a temperature gradient. The gradient was deemed essential in evaluating the behavior of the test materials in that should preferential dissolution of components of the test material occur we would expect dissolution in the hotter regions and deposition in the colder regions, thus promoting material transport. Results from the interactions of a Si-rich mild steel alloy, AISI S5, and a ferritic-martensitic stainless steel, HT-9, with the molten lead-bismuth are presented.
Hydrodynamics and equilibrium of a multiple-inlet system
A. Pacheco; ė. Ferreira; J. J. Williams; E. Garel; A. Vila-Concejo; J. A. Dias
Although it is generally acknowledged that most multiple inlets are unstable and cannot coexist, there is evidence to suggest that such inlets can indeed be stable over decadal time scales. Multiple-inlet systems servicing a single embayment, in contrast to single-inlet systems, confer particular hydrodynamic characteristics such as the potential existence of residual discharges and currents between the inlets. This paper
Computational modeling and validation for hypersonic inlets
NASA Technical Reports Server (NTRS)
Povinelli, Louis A.
Hypersonic inlet research activity at NASA is reviewed. The basis is the experimental tests performed with three inlets: the NASA Lewis Research Center Mach 5, the McDonnell Douglas Mach 12, and the NASA Langley Mach 18. Both three-dimensional parabolized Navier-Stokes and Navier-Stokes codes were used to compute the flow within the three inlets. Modeling assumptions in the codes involve the turbulence model, the nature of the boundary layer, shock wave boundary layer interaction, and the flow spilled to the outside of the inlet. Use of the codes in conjunction with the experimental data are helping to develop a clearer understanding of the inlet flow physics and to focus on the modeling improvements required in order to arrive at validated codes.
Cleaning of uranium vs machine coolant formulations
Cristy, S.S.; Byrd, V.R.; Simandl, R.F.
This study compares methods for cleaning uranium chips and the residues left on chips from alternate machine coolants based on propylene glycol-water mixtures with either borax, ammonium tetraborate, or triethanolamine tetraborate added as a nuclear poison. Residues left on uranium surfaces machined with perchloroethylene-mineral oil coolant and on surfaces machined with the borax-containing alternate coolant were also compared. In comparing machined surfaces, greater chlorine contamination was found on the surface of the perchloroethylene-mineral oil machined surfaces, but slightly greater oxidation was found on the surfaces machined with the alternate borax-containing coolant. Overall, the differences were small and a change to the alternate coolant does not appear to constitute a significant threat to the integrity of machined uranium parts.
Turbine Inlet Analysis of Injected Water Droplet Behavior
NASA Astrophysics Data System (ADS)
Hargrave, Kevin
Gas turbines have become widely used in the generation of power for cities. They are used all over the world and must operate under a wide variety of ambient conditions. Every turbine has a temperature at which it operates at peak capacity. In order to attain this temperature in the hotter months various cooling methods are used such as refrigeration inlet cooling systems, evaporative methods, and thermal energy storage systems. One of the more widely used is the evaporative systems because it is one of the safest and easiest to utilize method. However, the behavior of water droplets within the inlet to the turbine has not been extensively studied or documented. It is important to understand how the droplets behave within the inlet so that water droplets above a critical diameter will not enter the compressor and cause damage to the compressor blades. In order to do this a FLUENT simulation was constructed in order to determine the behavior of the water droplets and if any droplets remain at the exit of the inlet, along with their size. In order to do this several engineering drawings were obtained from SRP and studies in order to obtain the correct dimensions. Then the simulation was set up using data obtained from SRP and Parker-Hannifin, the maker of the spray nozzles. Then several sets of simulations were run in order to see how the water droplets behaved under various conditions. These results were then analyzed and quantified so that they could be easily understood. The results showed that the possible damage to the compressor increased with increasing temperature at a constant relative humidity. This is due in part to the fact that in order to keep a constant relative humidity at varying temperatures the mass fraction of water vapor in the air must be changed. As temperature increases the water vapor mass fraction must increase in order to maintain a constant relative humidity. This in turn makes it slightly increases the evaporation time of the water droplets. This will then lead to more droplets exiting the inlet and at larger diameters.
Wind- and Tide-Driven Cross-Inlet Circulation at New River Inlet, NC
NASA Astrophysics Data System (ADS)
Wargula, A.; Raubenheimer, B.; Elgar, S.
The importance of cross-channel wind forcing to inlet circulation is examined using observations of winds, waves, water levels, and currents collected in and near New River Inlet, NC during May 2012. Although the direct effect of local wind forcing may be neglected in the subtidal along-inlet momentum balance, which is dominated by the pressure gradient, wave radiation stress gradient, and bottom friction, cross-inlet winds may have a significant effect on along-inlet dynamics by driving cross-inlet flows (approximately 0.1 to 0.3 m/s), which can mix lateral and vertical gradients in momentum and water properties. New River Inlet is 1000 m wide at the mouth and tapers to 100 m wide about 1000 m away from the mouth after two sharp 90░ bends. Five colocated pressure gages and current profilers were deployed from the shallow (2-3 m water depth) ebb shoal outside the mouth through the deep (5-10 m depth) inlet channel to 200 m beyond the first 90░ bend. The inlet is well mixed, and along-inlet tidal currents ranged from +/- 1.5 m/s, offshore significant wave heights from 0.5 to 2.5 m, and wind speeds from 0 to 16 m/s. Time series of currents and winds were lowpass-filtered to examine subtidal wind effects. At the first 90░ bend, both surface and bottom cross-inlet flows were correlated (r2 = 0.6) with cross-inlet wind velocity. On the shallow ebb shoal, the cross-inlet flows also were correlated with cross-inlet wind velocity (r2 = 0.6). Cross-inlet flows exhibited a two-layer response to the wind inside the inlet and a depth-uniform response outside the mouth. The observations will be used to examine the momentum balance governing temporal and spatial variations in cross-inlet wind effects on inlet circulation. Funding provided by the Office of Naval Research, the Assistant Secretary of Defense for Research and Engineering, and a National Defense Science and Engineering Graduate Fellowship.
Transient behavior of supersonic flow through inlets
NASA Technical Reports Server (NTRS)
Pordal, H. S.; Khosla, P. K.; Rubin, S. G.
A solution technique to compute inlet flow behavior is presented. The phenomena of inlet unstart and restart are investigated using a flux-split procedure applied to the Euler and Reduced Navier Stokes (RNS) equations. A time consistent direct sparse matrix solver in conjunction with a domain decomposition strategy is applied to compute the transient flow behavior both internal and external to the inlet. Time varying shocks and time varying recirculation regions are efficiently analyzed. The code is quite general and is suitable for the computation of flow for a wide variety of geometries and over a wide range of Mach and Reynolds numbers.
Nonmarine upper cretaceous rocks, Cook Inlet, Alaska
Magoon, L.B. (Geological Survey, Menlo Park, CA); Griesbach, F.B.; Egbert, R.M.
A section of Upper Cretaceous (Maestrichtian) nonmarine sandstone, conglomerate, and siltstone with associated coal is exposed near Saddle mountain on the northwest flank of Cook Inlet basin, the only known surface exposure of nonmarine Upper Cretaceous rocks in the Cook Inlet area. The section, at least 83.3 m thick, unconformably overlies the Upper Jurassic Naknek Formation and is unconformably overlain by the lower Tertiary West Foreland Formation. These upper Cretaceous rocks correlate lithologically with the second or deeper interval of nonmarine Upper Cretaceous rocks penetrated in the lower Cook Inlet COST 1 well.
Effect of inlet and outlet flow conditions on natural gas parameters in supersonic separation process.
Yang, Yan; Wen, Chuang; Wang, Shuli; Feng, Yuqing
A supersonic separator has been introduced to remove water vapour from natural gas. The mechanisms of the upstream and downstream influences are not well understood for various flow conditions from the wellhead and the back pipelines. We used a computational model to investigate the effect of the inlet and outlet flow conditions on the supersonic separation process. We found that the shock wave was sensitive to the inlet or back pressure compared to the inlet temperature. The shock position shifted forward with a higher inlet or back pressure. It indicated that an increasing inlet pressure declined the pressure recovery capacity. Furthermore, the shock wave moved out of the diffuser when the ratio of the back pressure to the inlet one was greater than 0.75, in which the state of the low pressure and temperature was destroyed, resulting in the re-evaporation of the condensed liquids. Natural gas would be the subsonic flows in the whole supersonic separator, if the mass flow rate was less than the design value, and it could not reach the low pressure and temperature for the condensation and separation of the water vapor. These results suggested a guidance mechanism for natural gas supersonic separation in various flow conditions. PMID:25338207
Uranium Isotope Systematic in Saanich Inlet
NASA Astrophysics Data System (ADS)
Amini, M.; Holmden, C.; Francois, R.
As a redox-sensitive element Uranium has become the focus of stable isotope studies. Based on the nuclear field shift effect [1], U isotope fractionation was predicted as a function of U(IV)-U(VI) exchange reactions with the insoluble reduced U(IV) species being heavier than the soluble oxidized U(VI) species. Recently, variations in 238U/235U were reported in low temperature aqueous and sedimentary environments [2,3] indicating that U deposited in well-oxygenated environments is characterized by light isotopic composition, whereas suboxic and anoxic deposits tend towards a heavy isotopic signature. U isotope fractionation has been hence proposed as a promising new paleo-redox proxy. In order to test the efficacy of U isotope fractionation to record oxidation states in marine systems, we are investigating sediment samples deposited over a range of redox conditions in the seasonally anoxic Saanich Inlet, on the east coast of Vancouver Island. We have also made ?238U measurements for water samples from above and below the redoxcline. The measurements were carried out by MC-ICPMS using 233U/236U-double spike technique. The data are reported as ?238U relative to NBL 112a with a 238U/235U ratio of 137.88 (2sd). External precision is better than 0.10 permil (2sd). Eleven analyses of seawater performed over the course of this work yielded ?238U of -0.41▒0.07 permil (2sd). No clear difference in ?238U values has been found, thus far, in water samples collected at 10m (O2~380?M) and 200m (O2~1?M) depths from a single location in the middle of the inlet. The mean of two measurements of the deepwater sample yielded -0.43▒0.01 permil (2sd). Two measurements of the shallow water sample yielded a mean value of -0.38▒0.03 permil (2sd). The ?238U values for HF-HNO3 digestions of the organic rich sediments, one taken in the middle of the basin (3.11% organic carbon) below seasonally anoxic bottom waters (-0.22▒0.01 permil, n=2), and the other taken from the sill (1.29% organic carbon) below well-oxygenated bottom waters (-0.22 permil, n=1) are identical. The ?238U value matches previously reported values for suboxic sediments from the Peru margin [3], but is lighter than organic rich sediments from the Black Sea [3], where the bottom waters are strongly euxinic. The consistency in ?238U vaues between previously investigated suboxic sediment samples [3] and our two sediment samples indicates that the magnitude of the U isotopic fractionation is identical between seawater and sediments deposited under a range of bottom water oxygen conditions from oxygenated to anoxic. However, differences between the U isotope compositions in Saanich Inlet and those from the Black Sea remain to be explained, if U isotope fractionation is be used as a quantitative proxy for paleoredox in ancient oceans. [1] Schauble (2007) GCA 71, 2170- 2189. [2] Stirling et al. (2007) EPSL 264, 208-225. [3] Weyer et al. (2007) GCA 72, 345-399.
Sample inlet tube for ion source
Prior, David [Hermiston, OR; Price, John [Richland, WA; Bruce, Jim [Oceanside, CA
An improved inlet tube is positioned within an aperture through the device to allow the passage of ions from the ion source, through the improved inlet tube, and into the interior of the device. The inlet tube is designed with a larger end and a smaller end wherein the larger end has a larger interior diameter than the interior diameter of the smaller end. The inlet tube is positioned within the aperture such that the larger end is pointed towards the ion source, to receive ions therefrom, and the smaller end is directed towards the interior of the device, to deliver the ions thereto. Preferably, the ion source utilized in the operation of the present invention is a standard electrospray ionization source. Similarly, the present invention finds particular utility in conjunction with analytical devices such as mass spectrometers.
The Peel Inlet-Harvey Estuary Study.
ERIC Educational Resources Information Center
Walker, Warren; Black, Ronald
Describes how the department of physics of the Western Australian Institute of Technology (WAIT) has been involved in the Peel Inlet-Harvey Estuary study. An appendix which presents the departmental approach to curriculum matters is also included. (HM)
Noise suppression with high Mach number inlets
NASA Technical Reports Server (NTRS)
Lumsdaine, E.; Cherng, J. G.; Tag, I.
Experimental results were obtained for two types of high Mach number inlets, one with a translating centerbody and a fixed geometry inlet (collapsing cowl) with no centerbody. The aerodynamic and acoustic performance of these inlets was examined. The effects of area ratio, length/diameter ratio, and lip geometry were among several parameters investigated. The translating centerbody type inlet was found to be superior to the collapsing cowl both acoustically and aerodynamically, particularly for area ratios greater than 1.5. Comparison of length/diameter ratio and area ratio effects on performance near choked flow showed the latter to be more significant. Also, greater high frequency noise attenuation was achieved by increasing Mach number from low to high subsonic values.
Effect of inlet disturbances on fan inlet noise during a static test
NASA Technical Reports Server (NTRS)
Bekofske, K. L.; Sheer, R. E., Jr.; Wang, J. C. F.
Measurements of fan rotor inlet noise taken during static test situations are at variance with aircraft engine flight data. In particular, static tests generally yield a significantly higher tone at blade passage frequency than that measured during flight. To explain this discrepancy, the extent of the influence of inlet ground vortices and large-scale inlet turbulence on the forward-radiated fan noise measured at a static test facility was investigated. While such inlet disturbances were generated intentionally in an anechoic test chamber, far-field acoustic measurements and inlet flow-field hot-film mappings of a fan rotor were obtained. Experimental results indicate that the acoustic effect of such disturbances appears to be less severe for supersonic than for subsonic tip speeds. Further, a reverse flow that occurs on the exterior cowl in static test facilities appears to be an additional prime candidate for creating inlet disturbances and causing variance between flight and static acoustic data.
Circulation exchange patterns in Sinclair Inlet, Washington
Noble, Marlene A.; Rosenberger, Kurt J.; Paulson, Anthony J.; Gartner, Anne L.
In 1994, the U.S. Geological Survey (USGS), in cooperation with the U.S. Navy, deployed three sets of moorings in Sinclair Inlet, which is a relatively small embayment on the western side of Puget Sound (fig. 1). This inlet is home to the Puget Sound Naval Shipyard. One purpose of the measurement program was to determine the transport pathways and fate of contaminants known to be present in Sinclair Inlet. Extensive descriptions of the program and the resultant information about contaminant pathways have been reported in Gartner and others (1998). This report primarily focused on the bottom boundary layer and the potential for resuspension and transport of sediments on the seabed in Sinclair Inlet as a result of tides and waves. Recently (2013), interest in transport pathways for suspended and dissolved materials in Sinclair Inlet has been rekindled. In particular, the USGS scientists in Washington and California have been asked to reexamine the datasets collected in the earlier study to refine not only our understanding of transport pathways through the inlet, but to determine how those transport pathways are affected by subtidal currents, local wind stress, and fresh water inputs. Because the prior study focused on the bottom boundary layer and not the water column, a reanalysis of the datasets could increase our understanding of the dynamic forces that drive transport within and through the inlet. However, the early datasets are limited in scope and a comprehensive understanding of these transport processes may require more extensive datasets or the development of a detailed numerical model of transport processes for the inlet, or both.
A computational study of icing effects on the performance of an S-duct inlet
NASA Astrophysics Data System (ADS)
Jin, Wonjin
The performance of a diffusing S-duct inlet (M2129) is computationally studied for the effects of inlet icing. Different ice accretion shapes, predicted by numerical analysis in the literature reviewed, are simulated on the inlet lip. Two commercial codes, FLUENT and STAR-CCM+ are used for the steady- and unsteady-state computations. The shear-stress transport (SST) kappa-o turbulence model and large eddy simulation (LES) turbulence model are applied in the computations. The glaze ice shape, which is characterized by intrusive horns, degrades inlet performance, while the effect of the streamlined rime ice shape is negligible. At the free-stream Mach number of Minfinity =0.23, the glaze ice causes a 3.2 percent decrease in the total pressure recovery and a 26 percent reduction in the inlet mass flow rate. This result comes from the massive flow separation and flow blockage from the glaze ice horns. The total pressure recovery is further decreased by 22.8 percent, as the free-stream Mach number increases to Minfinity=0.85, due to the increased internal blockage and formation of internal shocks in the S-duct inlet. Also, the glaze iced inlet induces 6.6 percent increase in the engine thrust loss and the specific fuel consumption at Minfinity=0.25. The level of the ice-induced flow blockage by the ice accretion is also important for the inlet performance. The symmetrical glaze ice that covers the entire inlet lip portion causes a nearly 11.8 percent decrease in the total pressure recovery at Minfinity=0.475, whereas the top- or bottom-asymmetrical glaze ice that accretes on a portion of the inlet lip leads to just a 2.5 percent decrease. Also, the dynamic inlet distortion level, which is represented by the total pressure fluctuation at the engine face, is almost doubled with the symmetrical glaze ice when compared to the asymmetrical glaze ice. Therefore, the dynamic inlet distortion is proportional to the total pressure recovery that corresponds to the steady-state inlet distortion. Furthermore, the application of local angles of attack and local sideslip angles for the iced S-duct inlet contributes to the further degradation of the inlet performance, regardless of the ice shapes. However, the angles that provide the most distortion for each ice shape all differ due to the combined effects of the angle of attack or sideslip angle, icing location, and downward duct curvature. In addition, both the steady-state inlet distortion and dynamic inlet distortion become most severe at the highest angles tested: symmetrical (alpha=+20░), top-asymmetrical (alpha=-20░), bottom-asymmetrical (alpha=+20░), and side-asymmetrical glaze (beta=-20░). Finally, a strongly coupled temperature-total pressure distortion is created at the engine face under the icing condition. This coupling, as measured by the total pressure distortion parameter, increases the engine face distortion by 6.97 percent in the glaze iced inlet at Minfinity=0.85 when the inlet wall is heated to 350 K.
Code of Federal Regulations, 2012 CFR
...liquid-cooled engines, you may use water with or without rust inhibitors. (c) For coolants allowed in paragraphs (a) and (b) of this section, you may use rust inhibitors and additives required for lubricity, up to the levels that...
Code of Federal Regulations, 2013 CFR
...liquid-cooled engines, you may use water with or without rust inhibitors. (c) For coolants allowed in paragraphs (a) and (b) of this section, you may use rust inhibitors and additives required for lubricity, up to the levels that...
Code of Federal Regulations, 2014 CFR
...liquid-cooled engines, you may use water with or without rust inhibitors. (c) For coolants allowed in paragraphs (a) and (b) of this section, you may use rust inhibitors and additives required for lubricity, up to the levels that...
Code of Federal Regulations, 2010 CFR
...liquid-cooled engines, you may use water with or without rust inhibitors. (c) For coolants allowed in paragraphs (a) and (b) of this section, you may use rust inhibitors and additives required for lubricity, up to the levels that...
Code of Federal Regulations, 2011 CFR
...liquid-cooled engines, you may use water with or without rust inhibitors. (c) For coolants allowed in paragraphs (a) and (b) of this section, you may use rust inhibitors and additives required for lubricity, up to the levels that...
Coolant passage heat transfer with rotation
NASA Technical Reports Server (NTRS)
Hajek, T. J.; Higgins, A. W.
The objective is to develop a heat transfer and pressure drop data base, computational fluid dynamic techniques, and correlations for multi-pass rotating coolant passages with and without flow turbulators. The experimental effort is focused on the simulation of configurations and conditions expected in the blades of advanced aircraft high pressure turbines. With the use of this data base, the effects of Coriolis and buoyancy forces on the coolant side flow can be included in the design of turbine blades.
Investigation of normal shock inlets for highly maneuverable aircraft
NASA Technical Reports Server (NTRS)
Martin, A. W.
Concepts are investigated for obtaining both low cowl drag and good inlet performance at high angles of attack. The effect of a canard on inlet performance for a kidney shaped inlet in each of two vertical locations is discussed along with a sharp lip two dimensional inlet on a canardless forebody.
Two-dimensional symmetrical inlets with external compression
NASA Technical Reports Server (NTRS)
Ruden, P
The purpose of inlets like, for instance, those of air-cooled radiators and scoops is to take a certain air quantity out of the free stream and to partly convert the free-stream velocity into pressure. In the extreme case this pressure conversion may occur either entirely in the interior of the inlet (inlet with internal compression) or entirely in the free stream ahead of the inlet (inlet with external compression). In this report a theory for two-dimensional inlets with external compression is developed and illustrated by numerical examples. Intermediary forms between inlets with internal and external compression which can be derived from the latter are briefly discussed.
Status of Physics and Safety Analyses for the Liquid-Salt-Cooled Very High-Temperature Reactor (LS-VHTR)
Ingersoll, DT
A study has been completed to develop a new baseline core design for the liquid-salt-cooled very high-temperature reactor (LS-VHTR) that is better optimized for liquid coolant and that satisfies the top-level operational and safety targets, including strong passive safety performance, acceptable fuel cycle parameters, and favorable core reactivity response to coolant voiding. Three organizations participated in the study: Oak Ridge National Laboratory (ORNL), Idaho National Laboratory (INL), and Argonne National Laboratory (ANL). Although the intent was to generate a new reference LS-VHTR core design, the emphasis was on performing parametric studies of the many variables that constitute a design. The results of the parametric studies not only provide the basis for choosing the optimum balance of design options, they also provide a valuable understanding of the fundamental behavior of the core, which will be the basis of future design trade-off studies. A new 2400-MW(t) baseline design was established that consists of a cylindrical, nonannular core cooled by liquid {sup 7}Li{sub 2}BeF{sub 4} (Flibe) salt. The inlet and outlet coolant temperatures were decreased by 50 C, and the coolant channel diameter was increased to help lower the maximum fuel and vessel temperatures. An 18-month fuel cycle length with 156 GWD/t burnup was achieved with a two-batch shuffling scheme, while maintaining a core power density of 10 MW/m{sup 3} using graphite-coated uranium oxicarbide particle fuel enriched to 15% {sup 235}U and assuming a 25 vol-% packing of the coated particles in the fuel compacts. The revised design appears to have excellent steady-state and transient performance. The previous concern regarding the core's response to coolant voiding has been resolved for the case of Flibe coolant by increasing the coolant channel diameter and the fuel loading. Also, the LSVHTR has a strong decay heat removal performance and appears capable of surviving a loss of forced circulation (LOFC) even with failure to scram. Significant natural convection of the coolant salt occurs, resulting in fuel temperatures below steady-state values and nearly uniform temperature distributions during the transient.
Low flight speed acoustic results for a supersonic inlet with auxiliary inlet doors
NASA Technical Reports Server (NTRS)
Woodward, R. P.; Glaser, F. W.; Lucas, J. G.
A model supersonic inlet with auxiliary inlet doors and boundary layer bleeds was acoustically tested in simulated low speed flight up to Mach 0.2 in the NASA Lewis 9 x 15 Anechoic Wind Tunnel and statically in the NASA Lewis Anechoic Chamber. A JT8D refan model was used as the noise source. Data were also taken for a CTOL inlet and for an annular inlet with simulated centerbody support struts. Inlet operation with open auxiliary doors increased the blade passage tone by about 10 dB relative to the closed door configuration although noise radiation was primarily through the main inlet rather than the doors. Numerous strong spikes in the noise spectra were associated with the bleed system, and were strongly affected by the centerbody location. The supersonic inlet appeared to suppress multiple pure tone (MPT) generation at the fan source. Inlet length and the presence of support struts were shown not to cause this MPT suppression. Previously announced in STAR as N83-27794
Analysis of Buzz in a Supersonic Inlet
NASA Technical Reports Server (NTRS)
Chima, Rodrick V.
A dual-stream, low-boom supersonic inlet designed for use on a small, Mach 1.6 aircraft was tested experimentally in the 8- by 6-Foot Supersonic Wind Tunnel (SWT) at the NASA Glenn Research Center (GRC). The tests showed that the inlet had good recovery and stable operation over large mass flow range. The inlet went into buzz at mass flows well below that needed for engine operation, and the experiments generated a wealth of data during buzz. High frequency response pressure measurements and high-speed schlieren videos were recorded for many buzz events. The objective of the present work was to use computational fluid dynamics (CFD) to predict some of the experimental data taken during buzz, compare those predictions to the experimental data, and to use both datasets to explain the physics of the buzz cycle. The calculations were done with the Wind-US CFD code using a second-order time-accurate differencing scheme and the SST turbulence model. Computed Mach number contours were compared with schlieren images, and ensemble-averaged unsteady pressures were compared to data. The results showed that the buzz cycle consisted partly of spike buzz, an unsteady oscillation of the main shock at the spike tip while the inlet pressure dropped, and partly of choked flow while the inlet repressurized. Most of the results could be explained by theory proposed by Dailey in 1954, but did not support commonly used acoustic resonance explanations.
Characteristic parameters of superconductor-coolant interaction including high Tc current density limits
NASA Technical Reports Server (NTRS)
Frederking, T. H. K.
In the area of basic mechanisms of helium heat transfer and related influence on super-conducting magnet stability, thermal boundary conditions are important constraints. Characteristic lengths are considered along with other parameters of the superconducting composite-coolant system. Based on helium temperature range developments, limiting critical current densities are assessed at low fields for high transition temperature superconductors.
Thermal hydraulic characteristics during ingress of coolant and loss of vacuum events in fusion reactors
K. Takase; T. Kunugi; Y. Seki; H. Akimoto
The thermal hydraulic characteristics in the vacuum vessel (VV) of a fusion reactor under an ingress of coolant event (ICE) and a loss of vacuum event (LOVA) were investigated quantitatively using preliminary experimental apparatuses. In the ICE experiments, pressure rise characteristics in the VV were clarified for experimental parameters of the wall temperature and water temperature and for cases with
Interactive calculation procedures for mixed compression inlets
NASA Technical Reports Server (NTRS)
Reshotko, Eli
The proper design of engine nacelle installations for supersonic aircraft depends on a sophisticated understanding of the interactions between the boundary layers and the bounding external flows. The successful operation of mixed external-internal compression inlets depends significantly on the ability to closely control the operation of the internal compression portion of the inlet. This portion of the inlet is one where compression is achieved by multiple reflection of oblique shock waves and weak compression waves in a converging internal flow passage. However weak these shocks and waves may seem gas-dynamically, they are of sufficient strength to separate a laminar boundary layer and generally even strong enough for separation or incipient separation of the turbulent boundary layers. An understanding was developed of the viscous-inviscid interactions and of the shock wave boundary layer interactions and reflections.
Miniature piezo electric vacuum inlet valve
Keville, R.F.; Dietrich, D.D.
A miniature piezo electric vacuum inlet valve having a fast pulse rate and is battery operated with variable flow capability is disclosed. The low power (<1.6 watts), high pulse rate (<2 milliseconds), variable flow inlet valve is utilized for mass spectroscopic applications or other applications where pulsed or continuous flow conditions are needed. The inlet valve also has a very minimal dead volume of less than 0.01 std/cc. The valve can utilize, for example, a 12 Vdc input/750 Vdc, 3 mA output power supply compared to conventional piezo electric valves which require preloading of the crystal drive mechanism and 120 Vac, thus the valve of the present invention is smaller by a factor of three. 6 figs.
An experimental study of heat transfer in the rectangular coolant passages of a gas turbine rotor bladeĀ
Uddin, Mohammed Jalal
Modern gas turbines have high inlet temperatures to harness maximum power output, which causes different components to experience severe thermal stresses and fatigue. To achieve turbine blade durability goals, the blades are cooled with air...
Mach 5 inlet CFD and experimental results
NASA Technical Reports Server (NTRS)
Weir, Lois J.; Reddy, D. R.; Rupp, George D.
An experimental research program was conducted in the NASA Lewis Research Center 10 x 10 ft supersonic wind tunnel. The 2-D inlet model was designed to study the Mach 3.0 to 5.0 speed range for an over-under turbojet plus ramjet propulsion system. The model was extensively instrumented to provide both analytical code validation data as well as inlet performance information. Support studies for the program include flow field predictions with both 3-D parabolized Navier-Stokes (PNS) and 3-D full Navier-Stokes (FNS) analytical codes. Analytical predictions and experimental results are compared.
Reassessment of platforms in Cook Inlet, Alaska
Visser, R.C. [Belmar Engineering, Redondo Beach, CA (United States)
This paper presents the results of an audit of condition surveys and reassessment studies of several aging high-consequence platforms located in Cook Inlet, Alaska. The purpose of the study was to demonstrate that these platforms continue to be structurally safe and have a low risk potential for environmental damage. The effort included, (1) the preparation of a Cook Inlet platform database, (2) the selection of five platforms for more detailed review, (3) audits of condition surveys, and, (4) audits of structural assessments. All of the selected platforms were found fit-for-purpose.
Icing Characteristics and Anti-Icing Heat Requirements for Hollow and Ternally Modified Gas-Heated Inlet Guide Vanes
NASA Technical Reports Server (NTRS)
Gray, Vernon H.; Bowden, Dean T.
A two-dimensional inlet-guide-vane cascade was investigated to determine the effects of ice formations on the pressure losses across the guide vanes and to evaluate the heated gas flow and temperature required to prevent Icing at various conditions. A gas flow of approximately 0.4 percent of the inlet-air flow was necessary for anti-icing a hollow guide-vane stage at an inlet-gas temperature of 500 F under the following icing conditions: air velocity, 280 miles per hour; water content, 0.9 gram per cubic meter; and Inlet-air static temperature, 00 F. Also presented are the anti-icing gas flows required with modifications of the hollow Internal gas passage, which show heatinput savings greater than 50 percent.
Lead Coolant Test Facility Development Workshop
Paul A. Demkowicz
A workshop was held at the Idaho National Laboratory on May 25, 2005, to discuss the development of a next generation lead or lead-alloy coolant test facility. Attendees included representatives from the Generation IV lead-cooled fast reactor (LFR) program, Advanced Fuel Cycle Initiative, and several universities. Several participants gave presentations on coolant technology, existing experimental facilities for lead and lead-alloy research, the current LFR design concept, and a design by Argonne National Laboratory for an integral heavy liquid metal test facility. Discussions were focused on the critical research and development requirements for deployment of an LFR demonstration test reactor, the experimental scope of the proposed coolant test facility, a review of the Argonne National Laboratory test facility design, and a brief assessment of the necessary path forward and schedule for the initial stages of this development project. This report provides a summary of the presentations and roundtable discussions.
An implicit method for the calculation of inlet flow fields
NASA Technical Reports Server (NTRS)
Biringen, S.; Mcmillan, O. J.
Inlet flow fields are calculated by an implicit, time marching procedure to solve the thin layer Navier-Stokes equations formulated in body fitted coordinates. Because the method can be used for a flow field with both subsonic and supersonic regions, it is applicable to subcritical as well as supercritical inlet operation. Results are presented and discussed for an inlet of current design practice. Results include inviscid calculations performed for supercritical inlet operation with uniform and nonuniform inflow boundary conditions as well as for subcritical inlet operation with uniform inflow boundary conditions. Results for viscous calculations performed for supercritical inlet operation with uniform inflow boundary conditions are also discussed.
Cloud-Droplet Ingestion in Engine Inlets with Inlet Velocity Ratios of 1.0 and 0.7
NASA Technical Reports Server (NTRS)
Brun, Rinaldo J
The paths of cloud droplets into two engine inlets have been calculated for a wide range of meteorological and flight conditions. The amount of water in droplet form ingested by the inlets and the amount and distribution of water impinging on the inlet walls are obtained from these droplet-trajectory calculations. In both types of inlet, a prolate ellipsoid of revolution represents either part or all of the forebody at the center of an annular inlet to an engine. The configurations can also represent a fuselage of an airplane with side ram-scoop inlets. The studies were made at an angle of attack of 0 degree. The principal difference between the two inlets studied is that the inlet-air velocity of one is 0.7 that of the other. The studies of the two velocity ratios lead to some important general concepts of water ingestion in inlets.
On-Line Coolant Chemistry Analysis
LM Bachman
Impurities in the gas coolant of the space nuclear power plant (SNPP) can provide valuable indications of problems in the reactor and an overall view of system health. By monitoring the types and amounts of these impurities, much can be implied regarding the status of the reactor plant. However, a preliminary understanding of the expected impurities is important before evaluating prospective detection and monitoring systems. Currently, a spectroscopy system is judged to hold the greatest promise for monitoring the impurities of interest in the coolant because it minimizes the number of entry and exit points to the plant and provides the ability to detect impurities down to the 1 ppm level.
A Parametric Study of a Large Break in Reactor Inlet Header of CANDU6 Reactors Using RELAP5 Code
Prisecaru, Ilie; Dupleac, Daniel; Ghitescu, Petre [Power Plant Engineering Faculty, Politehnica Univ., 313 Splaiul Independentei, Bucharest (Romania); Biro, Lucian [National Commission for Nuclear Activities Control, 14 Libertatii Blvd., Bucharest (Romania)
A large break loss of coolant accident in a CANDU can lead to degraded fuel cooling in a large number of fuel channels due to the apparition of a prolonged flow stagnation period in the downstream core pass. The paper presents a parametric study of a reactor inlet header break. The parametric survey includes: the size of the break, the choked flow model employed, the emergency core cooling (ECC) performance and the core nodalization. The study is performed with RELAP5/SCDAP mod 3.4 and the results are compared with the safety analysis results. (authors)
Gas chromatography-full scan mass spectrometry determination of traces of chemical warfare agents and their impurities in air samples by inlet based thermal desorption of sorbent tubes.
Terzic, Oliver; Swahn, Irvine; Cretu, Gheorghita; Palit, Meehir; Mallard, Gary
A sensitive gas chromatography-mass spectrometry (GC-MS) based analytical method was developed for detection of the chemical warfare agents (CWA) and related compounds in air/vapor samples. The method uses a Tenax TA packed GC liner as an air/vapor sampling tube and Programmable Temperature-Vaporization (PTV) GC inlet as the thermal desorber. This approach eliminates secondary focusing step and allows transfer of desorbed analytes as sharp bands directly to the head of GC column. Use of a Peltier element for rapid cooling eliminates need for an external coolant. Minimal logistic and hardware needs make the method relatively inexpensive and especially suitable for a mobile laboratory. The limits of detection (LODs) of 0.8-2.9ng on tube for selected nerve and blister agents were achieved in the full scan MS mode. Simple derivatization method applied for detection of Lewisites 1 and 2 did not affect simultaneous analysis of other agents. The method was extensively evaluated with authentic CWA during the field trainings of the inspectors from the Organization for the Prohibition of Chemical Weapons (OPCW). The environmental area and personal samples were collected for a semi-quantitative determination of averaged airborne CWA concentration levels. PMID:22251886
Properties and stability of a Texas barrier beach inlet
Mason, Curtis
of this report. TABLE OF CONTENTS INTRODUCTION. Inlet Formation Inlet Stability LITERATURE REVIEW HISTORICAL BACKGROUND ~Pa e 1 5 8 12 15 HYDRAULIC PROPERTIES Tidal Data Seiche Activity Velocity Data Discharge Characteristics Bottom Shear Stress...
46 CFR 45.155 - Inlets and discharge piping: Valves.
Code of Federal Regulations, 2012 CFR
... false Inlets and discharge piping: Valves. 45.155 Section 45.155 Shipping...155 Inlets and discharge piping: Valves. (a) Except as provided in paragraphs...haveŚ (1) An automatic nonreturn valve with a positive means for closing;...
46 CFR 45.155 - Inlets and discharge piping: Valves.
Code of Federal Regulations, 2014 CFR
... false Inlets and discharge piping: Valves. 45.155 Section 45.155 Shipping...155 Inlets and discharge piping: Valves. (a) Except as provided in paragraphs...haveŚ (1) An automatic nonreturn valve with a positive means for closing;...
46 CFR 45.155 - Inlets and discharge piping: Valves.
Code of Federal Regulations, 2010 CFR
... false Inlets and discharge piping: Valves. 45.155 Section 45.155 Shipping...155 Inlets and discharge piping: Valves. (a) Except as provided in paragraphs...haveŚ (1) An automatic nonreturn valve with a positive means for closing;...
46 CFR 45.155 - Inlets and discharge piping: Valves.
Code of Federal Regulations, 2013 CFR
... false Inlets and discharge piping: Valves. 45.155 Section 45.155 Shipping...155 Inlets and discharge piping: Valves. (a) Except as provided in paragraphs...haveŚ (1) An automatic nonreturn valve with a positive means for closing;...
46 CFR 45.155 - Inlets and discharge piping: Valves.
Code of Federal Regulations, 2011 CFR
... false Inlets and discharge piping: Valves. 45.155 Section 45.155 Shipping...155 Inlets and discharge piping: Valves. (a) Except as provided in paragraphs...haveŚ (1) An automatic nonreturn valve with a positive means for closing;...
East rear, north part. Original power inlet is visible to ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
East rear, north part. Original power inlet is visible to the right of the current power inlet - Wellton-Mohawk Irrigation System, Pumping Plant No. 2, Bounded by Interstate 8 to south, Wellton, Yuma County, AZ
Reactor-coolant-pump-seal improvement
An investigation of PWR reactor coolant pump seal performance at seven operating nuclear power plants equipped with Combustion Engineering designed Nuclear Steam Supply Systems was performed between May and November of 1981. Also, a video tape training film was produced which includes RCP seal maintenance operations at the San Onofre Unit 2. Average RCP seal operating lifetime was 13 months,
NGNP Reactor Coolant Chemistry Control Study
Brian Castle
The main focus of this paper is to identify the most desirable ranges of impurity levels in the primary coolant to optimize component life in the primary circuit of the Next Generation Nuclear Plant (NGNP), which will either be a prismatic block or pebble bed reactor.
6. View southwest, culvert inlet with canal bank completely removed. ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
6. View southwest, culvert inlet with canal bank completely removed. Left to right: back of headwall; tops of high inlet barrels; vertical transition wall between high inlet barrels and low, interior, inlet barrels; tops of low interior barrels; vertical heartening planks and low cutoff wall along former edge of canal bank; dewatered canal bed. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ
Low speed performance of a supersonic axisymmetric mixed compression inlet with auxiliary inlets. [Lewis 9x15-ft anechoic wind tunnel tests
NASA Technical Reports Server (NTRS)
Wasserbauer, J. F.; Cubbison, R. W.; Trefny, C. J.
The aerodynamic performance of a representative supersonic cruise inlet was investigated using a fan simulator coupled to the inlet to provide characteristic noise signatures and to pump the inlet flow. Data were obtained at Mach numbers from 0 to 0.2 for the inlet equipped with an auxiliary inlet system that provided 20 to 40 percent of the fan flow. Results show that inlet performance improved when the inlet bleed systems were sealed; when the freestream Mach number was increased; and when the auxiliary inlets were opened. The inlet flow could not be choked by either centerbody translation or by increasing the fan speed when the 40 percent auxiliary inlet was incorporated.
The effect of fuel thermal conductivity on the behavior of LWR cores during loss-of-coolant accidents
NASA Astrophysics Data System (ADS)
Terrani, Kurt A.; Wang, Dean; Ott, Larry J.; Montgomery, Robert O.
The effect of variation in thermal conductivity of light water reactor fuel elements on core response during loss-of-coolant accident scenarios is examined. Initially, a simplified numerical analysis is utilized to determine the time scales associated with dissipation of stored energy from the fuel into the coolant once the fission reaction is stopped. The analysis is then followed by full reactor system thermal-hydraulics analysis of a typical boiling and pressurized water reactor subjected to a large break loss-of-coolant accident scenario using the TRACE code. Accordingly, sensitivity analyses to examine the effect of an increase in fuel thermal conductivity, up to 500%, on fuel temperature evolution during these transients are performed. Given the major differences in thermal-hydraulics design aspects of boiling and pressurized water reactors, different fuel and temperature responses during the simulated loss-of-coolant transients are observed.
ERDC/CHLTR-05-8 Coastal Inlets Research Program
US Army Corps of Engineers
, and shoreline erosion are all concerns at coastal inlets and are related to the transformation of wavesERDC/CHLTR-05-8 Coastal Inlets Research Program Laboratory Study of Hydrodynamics Near AbsorbingHydraulicsLaboratory Approved for public release; distribution is unlimited. #12;Coastal Inlets Research Program ERDC/CHL TR-05
Coastal Inlets Research Program ERDC/CHLTR-06-1
US Army Corps of Engineers
Coastal Inlets Research Program ERDC/CHLTR-06-1 Evaluation of Downdrift Shore Erosion, MattituckHydraulicsLaboratory Approved for public release; distribution is unlimited. #12;Coastal Inlets Research Program ERDC/CHL TR-06-1 April 2006 Evaluation of Downdrift Shore Erosion, Mattituck Inlet, New York: Section 111 Study Brian K
TACT 1: A computer program for the transient thermal analysis of a cooled turbine blade or vane equipped with a coolant insert. 2. Programmers manual
R. E. Gaugler
A computer program to calculate transient and steady state temperatures, pressures, and coolant flows in a cooled axial flow turbine blade or vane with an impingement insert is described. Coolant-side heat transfer coefficients are calculated internally in the program, with the user specifying either impingement or convection heat transfer at each internal flow station. Spent impingement air flows in a
TACT1, a computer program for the transient thermal analysis of a cooled turbine blade or vane equipped with a coolant insert. 1. Users manual
R. E. Gaugler
A computer program to calculate transient and steady state temperatures, pressures, and coolant flows in a cooled, axial flow turbine blade or vane with an impingement insert is described. Coolant side heat transfer coefficients are calculated internally in the program, with the user specifying either impingement or convection heat transfer at each internal flow station. Spent impingement air flows in
Coupled dynamic analysis of flow in the inlet section of a wave rotor constant volume combustor
Keith Cameron Smith
A wave rotor constant volume combustor (WRCVC) was designed and built as a collaborative work of Rolls Royce LibertyWorks, Indiana University-Purdue University at Indianapolis (IUPUI), and Purdue University, and ran experimental tests at Purdue's Zucrow Laboratories in 2009. ^ Instrumentation of the WRCVC rig inlet flow included temperature and pressure transducers upstream of the venturi and at the fuel delivery
A comparative assessment of alternative combustion turbine inlet air cooling system
Brown, D.R.; Katipamula, S.; Konynenbelt, J.H.
Interest in combustion turbine inlet air cooling (CTAC) has increased during the last few years as electric utilities face increasing demand for peak power. Inlet air cooling increases the generating capacity and decreases the heat rate of a combustion turbine during hot weather when the demand for electricity is generally the greatest. Several CTAC systems have been installed, but the general applicability of the concept and the preference for specific concepts is still being debated. Concurrently, Rocky Research of Boulder City, Nevada has been funded by the U.S. Department of Energy to conduct research on complex compound (ammoniated salt) chiller systems for low-temperature refrigeration applications.
Application of noncircular primary-air inlet geometries in the inshot burners of residential gas furnaces
Kolluri, P.; Kamal, A.; Gollahalli, S.R. [Univ. of Oklahoma, Norman, OK (United States). School of Aerospace and Mechanical Engineering
Experiments with an inshot burner used in residential natural gas furnaces are presented. The concentrations of NO{sub x}, NO, and CO in the combustion products of partially aerated natural gas flames were measured in a laboratory combustion chamber. When the conventional circular venturi inlet of the inshot burner was replaced by elliptic venturi inlets, an increase of up to 30% in the primary-air entrainment and a decrease of up to 20% in the NO{sub x} emission index were observed. Temperature field measurements in the flames were in conformity with the emission index measurements.
Inlet Turbulence and Length Scale Measurements in a Large Scale Transonic Turbine Cascade
NASA Technical Reports Server (NTRS)
Thurman, Douglas; Flegel, Ashlie; Giel, Paul
Constant temperature hotwire anemometry data were acquired to determine the inlet turbulence conditions of a transonic turbine blade linear cascade. Flow conditions and angles were investigated that corresponded to the take-off and cruise conditions of the Variable Speed Power Turbine (VSPT) project and to an Energy Efficient Engine (EEE) scaled rotor blade tip section. Mean and turbulent flowfield measurements including intensity, length scale, turbulence decay, and power spectra were determined for high and low turbulence intensity flows at various Reynolds numbers and spanwise locations. The experimental data will be useful for establishing the inlet boundary conditions needed to validate turbulence models in CFD codes.
Reactor coolant system depressurization in PWRs with U-tube steam generators
K. S. Quick; D. L. Knudson
Molten core materials could be ejected into the containment building by a high-pressure reactor coolant system (RCS) following reactor vessel failure during certain severe accidents. A rapid rise in containment temperature and pressure, or direct containment heating (DCH), could result from that high-pressure melt ejection (HPME). In an extreme case, the pressurization associated with DCH could lead to containment failure.
Effect of Microstructure on Failure Behavior of Light Water Reactor Coolant Piping under Severe Accident Conditions
Yuhei HARADA; Yu MARUYAMA; Akio MAEDA; Hiroaki SHIBAZAKI; Tamotsu KUDO; Akihide HIDAKA; Kazuichiro HASHIMOTO; Jun SUGIMOTO
In a severe accident of light water reactors, the reactor coolant system (RCS) piping might be subjected to thermal loads caused by the decay heat of the deposited fission products and the heat transfer from the hot gases, with an internal pressure in some accident sequences. Tests on the RCS piping failure were performed along with high temperature tensile and
Experiments and analysis, by the method of characteristics, on loss of coolant accidents
S. Banerjee; R. B. Jeffries; H. Goulding; T. Jaganathan
An outline of a technique for analysis of LOCAs by the method of ; characteristics and some comparisons with experiments are presented. Prediction ; of coolant density in the heated section, pressures, temperatures, and flow rates ; as functions of time following a pipe rupture are discussed. (GE) The Spanish ; Atomic Forum dedicated the 1972 lectures to the problem
Flow in the coolant passages of an internal combustion engine cylinder head
C. H. Liu; C. Vafidis; J. H. Whitelaw; R. Margary
Detailed measurements of the coolant flow field have been made in the water passages of the cylinder head of an internal combustion engine. They were obtained by casting a transparent acrylic model of the cylinder head and using a mixture of hydrocarbon fluids at a predetermined temperature and concentration which ensured that the refractive index of the fluid was identical
Modeling of liquid hydrogen flows and heat transfer in leading edge coolant systems
NASA Astrophysics Data System (ADS)
Carlisle, Robert G.; Wood, Houston G., III
The results of a numerical model analogous to the flow of liquid hydrogen coolant within the leading edge of the NASP engine structure is presented. The model involves the marching of the finite difference representation of the two dimensional reduced Navier-Stokes equations down a coolant passage. The model includes consideration of the effects of the variable thermophysical properties of hydrogen, axial conduction within the leading edge material, and the coupling of the energy and momentum equations in the flow. It predicts that the maximum temperature experienced in the simplified system described would be excessive under the worst-case heat transfer loads.
Influence of leading edge bluntness on hypersonic flow in a generic internal-compression inlet
NASA Astrophysics Data System (ADS)
Borovoy, V.; Egorov, I.; Mosharov, V.; Radchenko, V.; Skuratov, A.; Struminskaya, I.
Flow and heat transfer inside a generic inlet are investigated experimentally. The cross section of the inlet is rectangular. The inlet is installed on a flat plat at a significant distance from the leading edge. The experiments are performed in TsAGI wind tunnel UT-1M working in the Ludwieg tube mode at Mach number M? = 5 and Reynolds numbers (based on the plate length L = 320 mm) Re?L = 23 Ę 106 and 13 Ę 106. Steady flow duration is 40 ms. Optical panoramic methods are used for investigation of flow outside and inside the inlet as well. For this purpose, the cowl and one of two compressing wedges are made of a transparent material. Heat flux distribution is measured by thin luminescent Temperature Sensitive Paint (TSP). Surface flow and shear stress visualization is performed by viscous oil containing luminophor particles. The investigation shows that at high contraction ratio of the inlet, an increase of plate or cowl bluntness to some critical value leads to sudden change of the flow structure.
Testing and evaluation of small cavitating venturis with water at low inlet subcooling
NASA Astrophysics Data System (ADS)
Liou, S. G.; Chen, I. Y.; Sheu, J. S.
Cavitating venturi (CV) has been widely used as a flow control device in many different industries. In 1990, cavitating venturi was selected as the baseline flow control device in the Space Station Freedom's (SSF's) two-phase active thermal control system (ATCS). However, the design and the operation of the CVs used in SSF's ATCS is quite different in many ways from that typically used in the industry, such as low mass flow rate, small size, low pressure difference between inlet and outlet, and low inlet subcooling. During the prototypic ATCS' testing at NASA/Johnson Space Center, a phenomenon called overflow associated with throat superheat was observed. Although data was obtained and analyzed, no useful correlation for the superheat at rechoking was acquired. The objective of this study is to conduct a performance test on small CVs under low inlet subcooling. Water is used as the working fluid. Data acquisition and analysis are carried out under normal choked flow, over flow and recovery conditions. The effects of CV's size, fluid temperature, flow condition and inlet subcooling on CV performance are evaluated. Analysis of the test results showed that the superheat necessary for the onset of nucleation in pool boiling can be applied for the estimation of superheat required at rechoking for the CVs. With this postulated superheat and the predetermined CV loss coefficient, a equation as a function of inlet subcooling is recommended for predicting the pressure ratio at the recovery for the choked flow control in a mechanically pumped system.
7. View north at back (canal side) of culvert inlet, ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
7. View north at back (canal side) of culvert inlet, with canal bank completely removed. Background to foreground: back of inlet headwall with tops of high inlet barrels exposed; vertical transition wall between high inlet barrels and low, interior, inlet barrels; tops of low interior barrels; vertical heartening planks and low cutoff wall at site of former canal edge of canal bank; dewatered canal bed and plank sheathing on top of culvert barrels beneath canal bed. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ
A new approach for the design of hypersonic scramjet inlets
NASA Astrophysics Data System (ADS)
Raj, N. Om Prakash; Venkatasubbaiah, K.
A new methodology has been developed for the design of hypersonic scramjet inlets using gas dynamic relations. The approach aims to find the optimal inlet geometry which has maximum total pressure recovery at a prescribed design free stream Mach number. The design criteria for inlet is chosen as shock-on-lip condition which ensures maximum capture area and minimum intake length. Designed inlet geometries are simulated using computational fluid dynamics analysis. The effects of 1D, 2D inviscid and viscous effects on performance of scramjet inlet are reported here. A correction factor in inviscid design is reported for viscous effects to obtain shock-on-lip condition. A parametric study is carried out for the effect of Mach number at the beginning of isolator for the design of scramjet inlets. Present results show that 2D and viscous effects are significant on performance of scramjet inlet. Present simulation results are matching very well with the experimental results available from the literature.
Preliminary analysis of loss-of-coolant accident in Fukushima nuclear accident
Su'ud, Zaki; Anshari, Rio [Nuclear and Biophysics Research Group, Dept. of Physics, Bandung Institute of Technology, Jl.Ganesha 10, Bandung, 40132 (Indonesia)
Loss-of-Coolant Accident (LOCA) in Boiling Water Reactor (BWR) especially on Fukushima Nuclear Accident will be discussed in this paper. The Tohoku earthquake triggered the shutdown of nuclear power reactors at Fukushima Nuclear Power station. Though shutdown process has been completely performed, cooling process, at much smaller level than in normal operation, is needed to remove decay heat from the reactor core until the reactor reach cold-shutdown condition. If LOCA happen at this condition, it will cause the increase of reactor fuel and other core temperatures and can lead to reactor core meltdown and exposure of radioactive material to the environment such as in the Fukushima Dai Ichi nuclear accident case. In this study numerical simulation has been performed to calculate pressure composition, water level and temperature distribution on reactor during this accident. There are two coolant regulating system that operational on reactor unit 1 at this accident, Isolation Condensers (IC) system and Safety Relief Valves (SRV) system. Average mass flow of steam to the IC system in this event is 10 kg/s and could keep reactor core from uncovered about 3,2 hours and fully uncovered in 4,7 hours later. There are two coolant regulating system at operational on reactor unit 2, Reactor Core Isolation Condenser (RCIC) System and Safety Relief Valves (SRV). Average mass flow of coolant that correspond this event is 20 kg/s and could keep reactor core from uncovered about 73 hours and fully uncovered in 75 hours later. There are three coolant regulating system at operational on reactor unit 3, Reactor Core Isolation Condenser (RCIC) system, High Pressure Coolant Injection (HPCI) system and Safety Relief Valves (SRV). Average mass flow of water that correspond this event is 15 kg/s and could keep reactor core from uncovered about 37 hours and fully uncovered in 40 hours later.
Preliminary analysis of loss-of-coolant accident in Fukushima nuclear accident
NASA Astrophysics Data System (ADS)
Su'ud, Zaki; Anshari, Rio
Loss-of-Coolant Accident (LOCA) in Boiling Water Reactor (BWR) especially on Fukushima Nuclear Accident will be discussed in this paper. The Tohoku earthquake triggered the shutdown of nuclear power reactors at Fukushima Nuclear Power station. Though shutdown process has been completely performed, cooling process, at much smaller level than in normal operation, is needed to remove decay heat from the reactor core until the reactor reach cold-shutdown condition. If LOCA happen at this condition, it will cause the increase of reactor fuel and other core temperatures and can lead to reactor core meltdown and exposure of radioactive material to the environment such as in the Fukushima Dai Ichi nuclear accident case. In this study numerical simulation has been performed to calculate pressure composition, water level and temperature distribution on reactor during this accident. There are two coolant regulating system that operational on reactor unit 1 at this accident, Isolation Condensers (IC) system and Safety Relief Valves (SRV) system. Average mass flow of steam to the IC system in this event is 10 kg/s and could keep reactor core from uncovered about 3,2 hours and fully uncovered in 4,7 hours later. There are two coolant regulating system at operational on reactor unit 2, Reactor Core Isolation Condenser (RCIC) System and Safety Relief Valves (SRV). Average mass flow of coolant that correspond this event is 20 kg/s and could keep reactor core from uncovered about 73 hours and fully uncovered in 75 hours later. There are three coolant regulating system at operational on reactor unit 3, Reactor Core Isolation Condenser (RCIC) system, High Pressure Coolant Injection (HPCI) system and Safety Relief Valves (SRV). Average mass flow of water that correspond this event is 15 kg/s and could keep reactor core from uncovered about 37 hours and fully uncovered in 40 hours later.
Use of Internal Coolant as a Means of Permitting Increase in Engine Take-Off Power
NASA Technical Reports Server (NTRS)
Rothrock, Addison M
Engine tests, together with estimates made at Langley Memorial Aeronautical Laboratory, indicate that a 25-percent increase in take-off power can be obtained with present-day aircraft engines without increasing either the knock limit of the fuel or the external cooling requirements of the engine. This increase in power with present fuels and present external cooling is made possible through the use of an internal coolant inducted through the inlet manifold. Estimates on aircraft indicate that this 25-percent increase in power will permit an approximate usable increase of 8.5 percent in the take-off load of existing military airplanes. This increase in load is equivalent to an increase in the weight of gasoline normally carried of between 30 and 65 percent.
Conceptual design loss-of-coolant accident analysis for the Advanced Neutron Source reactor
Chen, N.C.J.; Wendel, M.W.; Yoder, G.L. Jr. (Oak Ridge National Lab., TN (United States))
A RELAP5 system model for the Advanced Neutron Source Reactor has been developed for performing conceptual safety analysis report calculations. To better represent thermal-hydraulic behavior of the core, three specific changes in the RELAP5 computer code were implemented: a turbulent forced-convection heat transfer correlation, a critical heat flux (CHF) correlation, and an interfacial drag correlation. The model consists of the core region, the heat exchanger loop region, and the pressurizing/letdown system region. Results for three loss-of-coolant accident analyses are presented: (1) an instantaneous double-ended guillotine (DEG) core outlet break with a cavitating venturi installed downstream of the core, (b) a core pressure boundary tube outer wall rupture, and (c) a DEG core inlet break with a finite break-formation time. The results show that the core can survive without exceeding the flow excursion of CHF thermal limits at a 95% probability level if the proper mitigation options are provided.
Increased coolant flow for H reactor
The purpose of this letter is to outline the immediate and long-range plans for increasing the H Reactor coolant flow. The flow can be increased, immediately from the present base of about 84,000 gpm to about 88,000 gpm via the following changes: routine purges; use of non-bumpered fuel; increasing the flow through Fringe enrichment and Fringe Poison tubes by changing
Evaluation of engine coolant recycling processes: Part 2
Bradley, W.H. [General Motors, Warren, MI (United States). Service Technology Group
Engine coolant recycling continues to provide solutions to both economic and environmental challenges often faced with the disposal of used engine coolant. General Motors` Service Technology Group (STG), in a continuing effort to validate the general practice of recycling engine coolants, has conducted an in-depth study on the capabilities of recycled coolants. Various recycling processes ranging from complex forms of fractional distillation to simple filtration were evaluated in this study to best represent the current state of coolant recycling technology. This study incorporates both lab and (limited) fleet testing to determine the performance capabilities of the recycled coolants tested. While the results suggest the need for additional studies in this area, they reveal the true capabilities of all types of engine coolant recycling technologies.
Performance of a short annular dump diffuser using suction-stabilized vortices at inlet Mach numbers to 0.41
NASA Technical Reports Server (NTRS)
Smith, J. M.; Juhasz, A. J.
A short, annular dump diffuser was designed to use suction to establish stabilized vortices on both walls for improved flow expansion in the region of an abrupt area change. The diffuser was tested at near ambient inlet pressure and temperature. The overall diffuser area ratio was 4.0. The inlet height was 2.54 cm and the exit pitot-static rakes were located at a distance from the vortex fence equal to two or six times the inlet height. Performance data were taken at near ambient temperature and pressure for nominal inlet Mach numbers of 0.18 to 0.41 with suction rates of 0 to 18 percent of the total inlet airflow. The exit velocity profile could be shifted toward either wall by adjusting the inner- or outer-wall suction rate. Symmetrical exit velocity profiles were unstable, with a tendency to shift back to hub- or tip-weighted profile. Diffuser effectiveness was increased from about 47 percent without suction to over 85 percent at a total suction rate of about 14 percent. The diffuser total pressure losses at inlet Mach numbers of 0.18 and 0.41 decreased from 1.1 and 5.6 percent without suction to 0.48 and 5.2 percent at total suction rates of 14.4 and 5.6 percent, respectively.
Improving an Inlet for Underwater Volatile Analyses
NASA Astrophysics Data System (ADS)
Chua, E.; Michel, A.; Wankel, S. D.; Kapit, J.
Although the deep ocean remains a challenging place to study, recent progress in technologies such as advanced in situ chemical sensors is beginning to broaden the scope of ocean exploration by enabling more comprehensive measurements at higher spatial and temporal resolutions. Such sensors are designed to be compatible with remotely and human operated vehicles and thus shed light on the geochemical composition of, and processes occurring in, seafloor environments. Among these sensors is a recently-developed in situ laser-based analyzer which utilizes Off-Axis Integrated Cavity Output Spectroscopy (ICOS). This instrument is capable of measuring stable carbon isotope ratios of methane (?13CCH4), making it a powerful tool for assessing biogeochemical activity in the deep sea. With the aim of improving the sensitivity of this membrane inlet-based chemical sensor, a Membrane Inlet Dissolved Gas Extractor (MIDGE) was developed. Recent work on the MIDGE focused on improving design elements with the aim of enhancing gas transport through the membrane and reducing water vapour in the gas stream. This was accomplished by implementing a newly-designed membrane flow-through inlet geometry, testing a variety of membrane materials, and incorporating an acidification module to evolve dissolved inorganic carbon (DIC) to gaseous CO2. We will report on results from a September 2014 research cruise, in which the MIDGE ICOS is to be deployed as part of an interdisciplinary mission conducting the first-ever in situ chemical and stable isotopic exploration of two seafloor sites in the Caribbean: the Barbados Mud Volcanoes and Kick 'em Jenny (KEJ). The goals of this project are to 1) use in situ measurements of methane and DIC carbon isotopes to enable biogeochemical exploration and mapping of methane seeps, and 2) measure the composition of bubble streams emanating from the crater of KEJ.
Secondary flow and heat transfer control in gas turbine inlet nozzle guide vanes
NASA Astrophysics Data System (ADS)
Burd, Steven Wayne
Endwall heat transfer is a very serious problem in the inlet nozzle guide vane region of gas turbine engines. To resolve heat transfer concerns and provide the desired thermal protection, modern cooling flows for the vane endwalls tend to be excessive leading to lossy and inefficient designs. Coolant introduction is further complicated by the flow patterns along vane endwall surfaces. They are three-dimensional and dominated by strong, complex secondary flows. To achieve performance goals for next-generation engines, more aerodynamically efficient and advanced cooling concepts, including combustor bleed cooling, must be investigated. To this end, the overall performance characteristics of several combustor bleed flow designs are assessed in this experimental study. In particular, their contributions toward secondary flow control and component cooling are documented. Testing is performed in a large-scale, guide vane simulator comprised of three airfoils encased between one contoured and one flat endwall. Core flow is supplied to this simulator at an inlet chord Reynolds number of 350,000 and turbulence intensity of 9.5%. Combustor bleed cooling flow is injected through the contoured endwall via inclined slots. The slots vary in cross-sectional area, have equivalent slot widths, and are positioned with their leeward edges 10% of the axial chord ahead of the airfoil leading edges. Measurements with hot-wire anemometry characterize the inlet and exit flow fields of the cascade. Total and static pressure measurements document aerodynamic performance. Thermocouple measurements detail thermal fields and permit evaluation of surface adiabatic effectiveness. To elucidate the effects of bleed injection, data are compared to an experiment taken without bleed. The influence of bleed mass flow rate and slot geometry on the aerodynamic losses and thermal protection arc given. This study suggests that such combustor bleed flow cooling offers significant thermal protection without imposing aerodynamic penalties. Such performance is contrary to the performance of present vane cooling schemes. The results of this investigation support designs which incorporate combustor coolant injection upstream of the airfoil leading edges. To complement, a short exploratory study regarding the effects of surface roughness was also performed. Results indicate modified cooling performance and significantly higher aerodynamic losses with rough surfaces.
Exciton-Polariton Gas as a Nonequilibrium Coolant
NASA Astrophysics Data System (ADS)
Klembt, Sebastian; Durupt, Emilien; Datta, Sanjoy; Klein, Thorsten; Baas, Augustin; Lķger, Yoan; Kruse, Carsten; Hommel, Detlef; Minguzzi, Anna; Richard, Maxime
Using angle-resolved Raman spectroscopy, we show that a resonantly excited ground-state exciton-polariton fluid behaves like a nonequilibrium coolant for its host solid-state semiconductor microcavity. With this optical technique, we obtain a detailed measurement of the thermal fluxes generated by the pumped polaritons. We thus find a maximum cooling power for a cryostat temperature of 50 K and below where optical cooling is usually suppressed, and we identify the participation of an ultrafast cooling mechanism. We also show that the nonequilibrium character of polaritons constitutes an unexpected resource: each scattering event can remove more heat from the solid than would be normally allowed using a thermal fluid with normal internal equilibration.
Exciton-polariton gas as a nonequilibrium coolant.
Klembt, Sebastian; Durupt, Emilien; Datta, Sanjoy; Klein, Thorsten; Baas, Augustin; Lķger, Yoan; Kruse, Carsten; Hommel, Detlef; Minguzzi, Anna; Richard, Maxime
Using angle-resolved Raman spectroscopy, we show that a resonantly excited ground-state exciton-polariton fluid behaves like a nonequilibrium coolant for its host solid-state semiconductor microcavity. With this optical technique, we obtain a detailed measurement of the thermal fluxes generated by the pumped polaritons. We thus find a maximum cooling power for a cryostat temperature of 50ĀK and below where optical cooling is usually suppressed, and we identify the participation of an ultrafast cooling mechanism. We also show that the nonequilibrium character of polaritons constitutes an unexpected resource: each scattering event can remove more heat from the solid than would be normally allowed using a thermal fluid with normal internal equilibration. PMID:26001012
Computational study of coolant flow of liquid hydrogen through an externally heated duct
NASA Astrophysics Data System (ADS)
Carlisle, Robert G.; Wood, Houston G., III
The computational modeling of the two-dimensional flow of liquid hydrogen coolant within the leading edge of the National Aero-Space Plane (NASP) engine structure is described. The model includes consideration of the effects of the variable thermophysical properties of hydrogen, axial conduction within the leading-edge material, and the coupling of the energy and momentum equations in the flow. The reduced Navier-Stokes equations are solved by parabolic marching of the discretized finite difference equations down the coolant passage. The importance of the consideration of the above factors was demonstrated as the calculated temperatures agreed with those predicted by earlier empirical methods for moderate heat transfers, but differed for the heat transfer magnitudes of interest. The form of the expression of the solid/fluid interface condition was found to be an important factor in determining the accuracy and speed of convergence of the algorithm. The ability of the hydrogen coolant system to cool the incident heat load was found to be marginal: moderately increased incident heat loads would exceed the capabilities of the modeled system. Parametric studies were done to show the relative importance of the temperature, pressure, and velocity of the coolant fluid on the cooling capabilities of the system.
Computational study of coolant flow of liquid hydrogen through an externally heated duct
Carlisle, R.G.; Wood, H.G. III (Virginia Univ., Charlottesville (United States))
The computational modeling of the two-dimensional flow of liquid hydrogen coolant within the leading edge of the National Aero-Space Plane (NASP) engine structure is described. The model includes consideration of the effects of the variable thermophysical properties of hydrogen, axial conduction within the leading-edge material, and the coupling of the energy and momentum equations in the flow. The reduced Navier-Stokes equations are solved by parabolic marching of the discretized finite difference equations down the coolant passage. The importance of the consideration of the above factors was demonstrated as the calculated temperatures agreed with those predicted by earlier empirical methods for moderate heat transfers, but differed for the heat transfer magnitudes of interest. The form of the expression of the solid/fluid interface condition was found to be an important factor in determining the accuracy and speed of convergence of the algorithm. The ability of the hydrogen coolant system to cool the incident heat load was found to be marginal: moderately increased incident heat loads would exceed the capabilities of the modeled system. Parametric studies were done to show the relative importance of the temperature, pressure, and velocity of the coolant fluid on the cooling capabilities of the system. 20 refs.
Effect of replacing surface inlets with blind or gravel inlets on sediment and phosphorus subsurface drainage losses.
Feyereisen, Gary W; Francesconi, Wendy; Smith, Douglas R; Papiernik, Sharon K; Krueger, Erik S; Wente, Christopher D
Open surface inlets that connect to subsurface tile drainage systems provide a direct pathway for movement of sediment, nutrients, and agrochemicals to surface waters. This study was conducted to determine the reduction in drainage effluent total suspended sediment (TSS) and phosphorus (P) concentrations and loads when open surface inlets were replaced with blind (in gravel capped with 30 cm of soil) or gravel (in very coarse sand/fine gravel) inlets. In Indiana, a pair of closed depressions in adjacent fields was fitted with open inlet tile risers and blind inlets in 2005 and monitored for flow and water chemistry. Paired comparisons on a storm event basis during the growing season for years 2006 to 2013 showed that TSS loads were 40.4 and 14.4 kg ha event for tile risers and blind inlets, respectively. Total P (TP) and soluble reactive P (SRP) loads were 66 and 50% less for the blind inlets, respectively. In Minnesota, TSS and SRP concentrations were monitored for 3 yr before and after modification of 24 open inlets to gravel inlets in an unreplicated large-field on-farm study. Median TSS concentrations were 97 and 8.3 mg L and median SRP concentrations were 0.099 and 0.064 mg L for the open inlet and gravel inlet periods, respectively. Median TSS and SRP concentrations were elevated for snowmelt vs. non-snowmelt seasons for open and gravel inlets. Both replacement designs reduced suspended sediment and P concentrations and loads. The Indiana study suggests blind inlets will be effective beyond a 10-yr service life. PMID:26023978
Flow instabilities in the core and the coolant circuit of advances low-boiling light water reacto: classification of causes and development of simulator for the future analysisĀ
Rezvyi, Aleksey
of the operating power plant's machines and equipment. Changes of heating surface temperatures, displacement borders of the flow patterns, and critical heat flux entail changes of the coolant flow parameters, finally causing changes of the initial primary system...
Effect of Blowing on Boundary Layer of Scarf Inlet
NASA Technical Reports Server (NTRS)
Gerhold, Carl H.; Clark, Lorenzo R.
When aircraft operate in stationary or low speed conditions, airflow into the engine accelerates around the inlet lip and pockets of turbulence that cause noise and vibration can be ingested. This problem has been encountered with engines equipped with the scarf inlet, both in full scale and in model tests, where the noise produced during the static test makes it difficult to assess the noise reduction performance of the scarf inlet. NASA Langley researchers have implemented boundary layer control in an attempt to reduce the influence of the flow nonuniformity in a 12-in. diameter model of a high bypass fan engine mounted in an anechoic chamber. Static pressures and boundary layer profiles were measured in the inlet and far field acoustic measurements were made to assess the effectiveness of the blowing treatment. The blowing system was found to lack the authority to overcome the inlet distortions. Methods to improve the implementation of boundary layer control to reduce inlet distortion are discussed.
Fan inlet disturbances and their effect on static acoustic data
NASA Technical Reports Server (NTRS)
Bekofske, K. L.; Sheer, R. E.; Wang, J. C. F.
There is evidence that measurements of fan-rotor inlet noise taken during static test situations are at variance with aircraft engine flight data. In particular, static tests generally yield a significantly higher tone at blade passing frequency than that measured during flight. An experimental program was carried out to investigate this discrepancy. Inlet ground vortices and large-scale inlet turbulence were generated intentionally in an anechoic test chamber. Far-field acoustic measurements and inlet flow field hot film mappings of a fan rotor were then carried out to study the influence of such inlet disturbances at a static test facility. Experimental results indicate that the acoustic effect of such disturbances appears to be less severe for supersonic than for subsonic tip speeds. Further, a reverse flow that occurs on the exterior cowl in static test facilities appears to be an additional prime candidate for creating inlet disturbances and causing variance between flight and static acoustic data.
Control of reactor coolant flow path during reactor decay heat removal
Hunsbedt, Anstein N. (Los Gatos, CA)
An improved reactor vessel auxiliary cooling system for a sodium cooled nuclear reactor is disclosed. The sodium cooled nuclear reactor is of the type having a reactor vessel liner separating the reactor hot pool on the upstream side of an intermediate heat exchanger and the reactor cold pool on the downstream side of the intermediate heat exchanger. The improvement includes a flow path across the reactor vessel liner flow gap which dissipates core heat across the reactor vessel and containment vessel responsive to a casualty including the loss of normal heat removal paths and associated shutdown of the main coolant liquid sodium pumps. In normal operation, the reactor vessel cold pool is inlet to the suction side of coolant liquid sodium pumps, these pumps being of the electromagnetic variety. The pumps discharge through the core into the reactor hot pool and then through an intermediate heat exchanger where the heat generated in the reactor core is discharged. Upon outlet from the heat exchanger, the sodium is returned to the reactor cold pool. The improvement includes placing a jet pump across the reactor vessel liner flow gap, pumping a small flow of liquid sodium from the lower pressure cold pool into the hot pool. The jet pump has a small high pressure driving stream diverted from the high pressure side of the reactor pumps. During normal operation, the jet pumps supplement the normal reactor pressure differential from the lower pressure cold pool to the hot pool. Upon the occurrence of a casualty involving loss of coolant pump pressure, and immediate cooling circuit is established by the back flow of sodium through the jet pumps from the reactor vessel hot pool to the reactor vessel cold pool. The cooling circuit includes flow into the reactor vessel liner flow gap immediate the reactor vessel wall and containment vessel where optimum and immediate discharge of residual reactor heat occurs.
8. View southwest at the northeastern end of culvert inlet, ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
8. View southwest at the northeastern end of culvert inlet, with canal bank completely removed. Left to right: back of curved wingwall; tops of high inlet barrels; vertical transition wall between high inlet barrels and low interior barrels; tops of low, interior barrels; vertical heartening planks at former canal edge of canal bank. - Delaware & Raritan Canal, Ten Mile Run Culvert, 1.5 miles South of Blackwells Road, East Millstone, Somerset County, NJ
Analysis of coolant flow and heat transfer in the SSME HPOTP Number 4 bearing assembly
NASA Technical Reports Server (NTRS)
Owens, S. F.; Costes, N. C.
The PHOENICS code has been applied to simulate the flow of liquid oxygen through the number 4 ball bearing assembly of the Space Shuttle Main Engine High-Pressure Oxidizer Turbopump. The Body-Fitted Coordinate system capability of PHOENICS was utilized to create a geometrically accurate model. Effects accounted for by the model include the rotation rate of the calculation domain, viscous heating in the liquid oxygen and two-phase effects due to LOX boiling. A separation program was used to account for conduction within a ball bearing element which was coupled with the PHOENICS flow and heat transfer analysis. Solutions have been obtained for the velocity and temperature fields within the LOX coolant and the temperature within the ball element. The predicted ball temperatures indicate that the coolant is boiling in the region near the ball surface.
Hypersonic Combustor Model Inlet CFD Simulations and Experimental Comparisons
NASA Technical Reports Server (NTRS)
Venkatapathy, E.; TokarcikPolsky, S.; Deiwert, G. S.; Edwards, Thomas A. (Technical Monitor)
Numerous two-and three-dimensional computational simulations were performed for the inlet associated with the combustor model for the hypersonic propulsion experiment in the NASA Ames 16-Inch Shock Tunnel. The inlet was designed to produce a combustor-inlet flow that is nearly two-dimensional and of sufficient mass flow rate for large scale combustor testing. The three-dimensional simulations demonstrated that the inlet design met all the design objectives and that the inlet produced a very nearly two-dimensional combustor inflow profile. Numerous two-dimensional simulations were performed with various levels of approximations such as in the choice of chemical and physical models, as well as numerical approximations. Parametric studies were conducted to better understand and to characterize the inlet flow. Results from the two-and three-dimensional simulations were used to predict the mass flux entering the combustor and a mass flux correlation as a function of facility stagnation pressure was developed. Surface heat flux and pressure measurements were compared with the computed results and good agreement was found. The computational simulations helped determine the inlet low characteristics in the high enthalpy environment, the important parameters that affect the combustor-inlet flow, and the sensitivity of the inlet flow to various modeling assumptions.
Tidal inlet variability in Mississippi River delta plain
Levin, D.; Nummedal, D.; Penland, S.
Stratigraphic sequences of deltaic and shallow marine origin commonly contain sand bodies transgressively overlying lower delta-plain and delta-front deposits. Although generally ascribed to barriers formed during the destructive phase of the delta cycle, most of this sand is probably of tidal-inlet origin because of the high preservation potential for sediment deposited below the base of the retreating shoreface in deep migratory tidal channels and their associated tidal deltas. To facilitate the identification of such units, this paper reviews the temporal evolution of the inlet sand bodies found along the rapidly transgressive shoreline of the abandoned Holocene Mississippi River deltas. This study also reveals that tide dominance of a coastline is not simply a function of tide range and wave height; it depends largely on the tidal prism, an inlet parameter which, in Louisiana, changes rapidly over time. Three distinct stages can be identified in the evolutionary sequence for Louisiana tidal inlets: (1) wave-dominated inlets with flood-tidal deltas, (2) tide-dominated inlets with large ebb deltas, and (3) wide, transitional inlets with sand bodies confined to the throat section. As the inlets migrate during the transgression, they will leave behind on the continental shelf, tidal sand bodies with a landward succession of facies changing from those characteristic of wave dominance, into tide dominance, and back again to transitional or wave-dominated inlets.
Inlet-Compressor Analysis Using Coupled CFD Codes
NASA Technical Reports Server (NTRS)
Cole, Gary; Suresh, Ambady; Townsend, Scott
Propulsion performance and operability are key factors in the development of a successful aircraft. For high-speed supersonic aircraft, mixed-compression inlets offer high performance but are susceptible to an instability referred to as unstart. An unstart occurs when a disturbance originating in the atmosphere or the engine causes the shock system to be expelled from the inlet. This event can have adverse effects on control of the aircraft, which is unacceptable for a passenger plane such as the high speed civil transport (HSCT). The ability to predict the transient response of such inlets to flow perturbations is, therefore, important to the proper design of the inlet and the control measures used to prevent unstart. Computational fluid dynamics (CFD) is having an increasing role in the analysis of individual propulsion components. isolated inlet studies are relatively easy to perform, but a major uncertainty is the boundary condition used at the inlet exit to represent the engine - the so-called compressor face boundary condition. A one-dimensional (I-D) Euler inlet simulation (ref. 1) showed that the predicted inlet unstart tolerance to free-stream pressure perturbations can vary by as much as a factor of about six, depending on the boundary condition used. Obviously, a thorough understanding of dynamic interactions between inlets and compressors/fans is required to provide the proper boundary condition.
Porous coolant tube holder for fuel cell stack
Guthrie, Robin J. (East Hartford, CT)
A coolant tube holder for a stack of fuel cells is a gas porous sheet of fibrous material adapted to be sandwiched between a cell electrode and a nonporous, gas impervious flat plate which separates adjacent cells. The porous holder has channels in one surface with coolant tubes disposed therein for carrying coolant through the stack. The gas impervious plate is preferably bonded to the opposite surface of the holder, and the channel depth is the full thickness of the holder.
Analysis of Loss-of-Coolant Accidents in the NBSR
Baek J. S.; Cheng L.; Diamond, D.
This report documents calculations of the fuel cladding temperature during loss-of-coolant accidents in the NBSR. The probability of a pipe failure is small and procedures exist to minimize the loss of water and assure emergency cooling water flows into the reactor core during such an event. Analysis in the past has shown that the emergency cooling water would provide adequate cooling if the water filled the flow channels within the fuel elements. The present analysis is to determine if there is adequate cooling if the water drains from the flow channels. Based on photographs of how the emergency water flows into the fuel elements from the distribution pan, it can be assumed that this water does not distribute uniformly across the flow channels but rather results in a liquid film flowing downward on the inside of one of the side plates in each fuel element and only wets the edges of the fuel plates. An analysis of guillotine breaks shows the cladding temperature remains below the blister temperature in fuel plates in the upper section of the fuel element. In the lower section, the fuel plates are also cooled by water outside the element that is present due to the hold-up pan and temperatures are lower than in the upper section. For small breaks, the simulation results show that the fuel elements are always cooled on the outside even in the upper section and the cladding temperature cannot be higher than the blister temperature. The above results are predicated on assumptions that are examined in the study to see their influence on fuel temperature.
Inlet-Compressor Analysis using Coupled CFD Codes
NASA Technical Reports Server (NTRS)
Cole, Gary; Suresh, Ambady; Townsend, Scott
Propulsion performance and operability are key factors in the development of a successful aircraft. For high-speed supersonic aircraft, mixed-compression inlets offer high performance but are susceptible to an instability referred to as unstart. An unstart occurs when a disturbance originating in the atmosphere or the engine causes the shock system to be expelled from the inlet. This event can have adverse effects on control of the aircraft, which is unacceptable for a passenger plane such as the high speed civil transport (HSCT). The ability to predict the transient response of such inlets to flow perturbations is, therefore, important to the proper design of the inlet and the control measures used to prevent unstart. Computational fluid dynamics (CFD) is having an increasing role in the analysis of individual propulsion components. Isolated inlet studies are relatively easy to perform, but a major uncertainty is the boundary condition used at the inlet exit to represent the engine - the so-called compressor face boundary condition. A one-dimensional (1-D) Euler inlet simulation showed that the predicted inlet unstart tolerance to free-stream pressure perturbations can vary by as much as a factor of about six, depending on the boundary condition used. Obviously a thorough understanding of dynamic interactions between inlets and compressors/fans is required to provide the proper boundary condition. To aid in this understanding and to help evaluate possible boundary conditions, an inlet-engine experiment was conducted at the University of Cincinnati. The interaction of acoustic pulses, generated in the inlet, with the engine were investigated. Because of the availability of experimental data for validation, it was decided to simulate the experiment using CFD. The philosophy here is that the inlet-engine system is best simulated by coupling (existing) specialized CFD component-codes. The objectives of this work were to aid in a better understanding of inlet-compressor interaction physics and the formulation of a more realistic compressor-face boundary condition for time-accurate CFD simulations of inlets. Previous simulations have used 1-D Euler engine simulations in conjunction with 1-D Euler and axisymmetric Euler inlet simulations. This effort is a first step toward CFD simulation of an entire engine by coupling multidimensional component codes.
Three-dimensional turbulent-mixing-length modeling for discrete-hole coolant injection into a crossflow
NASA Technical Reports Server (NTRS)
Wang, C. R.; Papell, S. S.
Three dimensional mixing length models of a flow field immediately downstream of coolant injection through a discrete circular hole at a 30 deg angle into a crossflow were derived from the measurements of turbulence intensity. To verify their effectiveness, the models were used to estimate the anisotropic turbulent effects in a simplified theoretical and numerical analysis to compute the velocity and temperature fields. With small coolant injection mass flow rate and constant surface temperature, numerical results of the local crossflow streamwise velocity component and surface heat transfer rate are consistent with the velocity measurement and the surface film cooling effectiveness distributions reported in previous studies.
Method for replacing PCB containing coolants in electrical induction apparatus with substantially PCB-free dielectric coolants
Atwood, G.
A method for replacing a coolant containing PCB in an electrical induction apparatus having a tank containing the coolant, an electrical winding and porous solid cellulosic electrical insulation immersed in the PCB-containing coolant with a substantially PCB-free high boiling dielectric permanent coolant to convert the electrical apparatus into one in which the rate of elution of PCB into the coolant is below the maximum allowable rate of elution into the coolant of an electrical apparatus rated as non-PCB, the solid porous electrical insulation being impregnated with the PCB-containing coolant, is described comprising the steps of: (a) draining the PCB-containing coolant from the tank to remove a major portion of the PCB-containing coolant contained by it; (b) filling the tank with an interim dielectric cooling liquid that is miscible with the PCB, is sufficiently low in viscosity to circulate within the tank and penetrate the interstices of the porous solid electrical insulation, and is capable of being readily separated from the PCB; (c) electrically operating the electrical induction apparatus and continuing the electrical operation for a period sufficient to elute PCB contained in the PCB-containing coolant impregnated in the porous solid insulation therefrom into the interim dielectric cooling liquid; (d) thereafter draining the interim dielectric cooling liquid containing the eluted PCB from the tank; (e) repeating the cycle of steps (b), (c) and (d) when the rate of elution of PCB into the interim dielectric cooling liquid exceeds 0.55 ppm of PCB per day based on the weight of the permanent dielectric coolant; and (f) filling the tank with a substantially PCB-free permanent coolant selected from the group consisting of high boiling, high viscosity, silicone oils, synthetic ester fluids, poly-alpha-olefin oils and hydrocarbon oils so as to reclasify the electrical apparatus to non-PCB status.
Assessment of Thermal and Hydrodynamic Fragmentation in Molten Fuel Coolant Interaction With Simulant System
Narayanan, K.S.; Das, S.K.; Jasmin Sudha, A.; Rao, E.H.V.M.; Lydia, G.; Murthy, S.S.; Kumareshan, M.; Harvey, J.; Kasinathan, N.; Rajan, M. [Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India)
In the Safety analysis of Fast Breeder Reactor, assessment of Molten Fuel Coolant Interaction (MFCI) assumes importance for two aspects, namely the characterization of the debris and severity of pressure pulses generation. An attempt has been made to investigate the debris generation characteristics with molten Woods Metal (Alloy of Bi 50% Pb 25% Sn 12.5% and Cd 12.5% and melting point of 346 K) - Water simulant system. Liquid Woods metal and liquid Uranium dioxide physical properties (Density, Surface tension and Kinematic viscosity) are similar. Experimental studies were conducted for various melt temperatures covering non - boiling, convective boiling and film boiling regimes of water, to assess the debris generation resulting from both hydrodynamic and thermal interaction. Woods metal was heated to the desired temperature and poured through a hot funnel having a nozzle of 8 mm release diameter into a water column of height up to 140 cm. Experiments were repeated for different coolant temperature and melt inventory up to 5 kg. The melt entry velocity was determined from video recordings. The debris is analyzed on the basis of interface temperature, Rayleigh-Taylor and Kelvin - Helmholtz instabilities. It is observed that Kelvin-Helmholtz instability is the dominant fragmentation phenomena. Contribution due to coolant boiling resulted in more debris generation in the size less than 4 mm. (authors)
Parametric study on maximum transportable distance and cost for thermal energy transportation using various coolants
Su-Jong Yoon; Piyush Sabharwall
The operation temperature of advanced nuclear reactors is generally higher than commercial light water reactors and thermal energy from advanced nuclear reactor can be used for various purposes such as district heating, desalination, hydrogen production and other process heat applications, etc. The process heat industry/facilities will be located outside the nuclear island due to safety measures. This thermal energy from the reactor has to be transported a fair distance. In this study, analytical analysis was conducted to identify the maximum distance that thermal energy could be transported using various coolants such as molten-salts, helium and water by varying the pipe diameter and mass flow rate. The cost required to transport each coolant was also analyzed. The coolants analyzed are molten salts (such as: KClMgCl2, LiF-NaF-KF (FLiNaK) and KF-ZrF4), helium and water. Fluoride salts are superior because of better heat transport characteristics but chloride salts are most economical for higher temperature transportation purposes. For lower temperature water is a possible alternative when compared with He, because low pressure He requires higher pumping power which makes the process very inefficient and economically not viable for both low and high temperature application.
Desensitization of over tip leakage in an axial turbine rotor by tip surface coolant injection
NASA Astrophysics Data System (ADS)
Rao, Nikhil Molahally
Mechanical energy extraction in axial flow turbine rotors occurs through a change in angular momentum of the working fluid. The gap between the turbine rotor and the stationary casing is referred to as the tip gap. High pressure turbine blades are typically un-shrouded and pressure driven flow through the tip gap is termed as over tip leakage. Over tip leakage reduces efficiency of the turbine stage and also causes thermal distress to blade tip surfaces. The gap height typically increases over the operational life of a turbine, leading to increased efficiency drop. The thermal load on the tip surface also increases with increasing gap height and is exacerbated by the radial transport of high temperature fluid found in the core of the combustor exit flow. Thus over tip leakage not only decreases stage efficiency, but also constrains it by limiting the maximum cycle temperature. Reducing the sensitivity of turbine performance to the effects of the tip gap is termed Tip Desensitization. An experimental investigation of tip desensitization through coolant injection from a tip surface trench was conducted in a large scale, low speed, rotating research turbine facility. Five out of twenty nine rotor blades, referred to as cooled blades, are provided with coolant injection at four locations, at 61%, 71%, 81%, and 91% blade tip axial chord length. At each of the first three locations the coolant jets are directed towards the blade pressure-side, while coolant is exhausted radially at the last location. The sensitivity of total pressure defect, due to over tip leakage, to tip gap height is reduced by both coolant injection and roughening of the casing surface. The total pressure defect due to the large gap height of 1.40% blade height is reduced to levels comparable to the defect due to a gap height of 0.72% blade height. The strong total pressure gradient that characterizes the leakage vortex due to the gap height of 1.40% blade height is considerably diminished by both coolant injection and roughening of the casing surface. Coolant injection from 81% chord location is most effective in reducing both the total pressure defect and the total pressure gradient. Casing surface roughness significantly shifts the leakage vortex towards blade suction surface reducing its interaction with the upper passage vortex. The benefit of casing surface roughness is greater at larger gap heights. (Abstract shortened by UMI.)
Transport of microbial biomass through the North Inlet ecosystem
Thomas H. Chrzanowski; L. Harold Stevenson; John D. Spurrier
Tidal fluctuations and transports of total microbial biomass (measured as adenosine triphosphate [ATP]) were investigated at three marsh creeks comprising the major transfer points between the North Inlet marsh and the adjoining aquatic ecosystems. Two creeks, Town Creek and North Jones Creek, form the inlet mouth and are the only marsh-ocean exchange points. The third creek, South Jones Creek, connects
Perforations in jet engine supersonic inlet increase shock stability
NASA Technical Reports Server (NTRS)
Keppler, C. R.
Modification of a conventional jet engine internal compression supersonic inlet results in increased shock stability and thus, engine instantaneous response to changes in inlet air properties. This technique provides a large amount of bleed near the maximum pressure recovery at the expense of minor bleed flow during critical operation.
A new system for preventing icing of gas turbine inlets
G. R. Gillingham
A new system for preventing condensate and precipitate icing of gas turbine inlet systems has been developed. This system uses a combination heat exchanger\\/moisture separator called an Anti-Ice Moisture Separator (AIMS) to provide icing protection without the need to heat the inlet air to 0 C or above. Turbine exhaust gas heats the AIMS surfaces and thereby prevents ice from
Validation of WIND for a Series of Inlet Flows
NASA Technical Reports Server (NTRS)
Slater, John W.; Abbott, John M.; Cavicchi, Richard H.
Validation assessments compare WIND CFD simulations to experimental data for a series of inlet flows ranging in Mach number from low subsonic to hypersonic. The validation procedures follow the guidelines of the AIAA. The WIND code performs well in matching the available experimental data. The assessments demonstrate the use of WIND and provide confidence in its use for the analysis of aircraft inlets.
A comprehensive field study was conducted comparing the performance of PM(sub 10) inlets under a variety of field conditions. Inlets for low flow, medium flow, and high flow samplers were evaluated at four sampling locations providing a range of concentrations and particle sizes....
Experimental Investigation of Actuators for Flow Control in Inlet Ducts
John Vaccaro; Yossef Elimelech; Michael Amitay
Attractive to aircraft designers are compact inlets, which implement curved flow paths to the compressor face. These curved flow paths could be employed for multiple reasons. One of which is to connect the air intake to the engine embedded in the aircraft body. A compromise must be made between the compactness of the inlet and its aerodynamic performance. The aerodynamic
NISTIR 6458 Characterization of the Inlet Combustion Air in
Magee, Joseph W.
NISTIR 6458 Characterization of the Inlet Combustion Air in NIST's Reference Spray Combustion January 2000 #12;ii Contents page Introduction 1 Reference Spray Combustion Facility 3 Numerical;1 Characterization of the Inlet Combustion Air in NIST's Reference Spray Combustion Facility: Effect of Vane Angle
The performance of a centrifugal compressor with high inlet prewhirl
A. Whitfield; A. H. Abdullah
The performance requirements of centrifugal compressors usually include a broad operating range between surge and choke. This becomes increasingly difficult to achieve as increased pressure ratio is demanded. In order to suppress the tendency to surge and extend the operating range at low flow rates, inlet swirl is often considered through the application of inlet guide vanes. To generate high
Computational Study of the Aerodynamic Performance of Subsonic Scarf Inlets
John M. Abbott
A computational study has been conducted to assess the aerodynamic performance of subsonic scarf inlets. The computations were performed using the WIND 3D Navier-Stokes CFD code. The objective of the study was to investigate the aerodynamic performance of scarf inlets wherein the circumferential extent, ?, over which the transition from the extended lower lip to the non-extended lip was the
Isolated testing of highly maneuverable inlet con cepts
NASA Technical Reports Server (NTRS)
Norby, W. P.; Haeffele, B. A.; Burley, R. R.
Ten percent scale models of a Mach 2.2 two dimensional inlet and a Mach 2.0 axisymmetric inlet were tested in the NASA Lewis Research Center 8'x6' Supersonic Wind Tunnel as part of a cooperative effort with the McDonnell Aircraft Company. The objective of this effort was to test methods designed to increase the maneuvering performance of fighter aircraft inlets. Maneuvering improvement concepts were tested up to 40-deg angle of attack for Mach numbers of 0.6 and 0.9, and up to 25 deg for Mach numbers 1.2 and 1.4. Maneuvering improvement concepts included a rotating cowl lip, auxiliary inlets aft of the inlet throat, and a retracting centerbody for the axisymmetric inlet. Test results show that the rotating cowl design was effective in improving subsonic maneuvering performance for both inlets. Auxiliary inlets did not produce significant performance increases for either model. The retracted centerbody resulted in some performance benefits at high angles of attack. None of the maneuvering improvement concepts were effective at Mach 1.2 and 1.4.
Ocean City Inlet, Maryland: a catalyst for coastal change
Knowles, S.C.; May, S.K.
Ocean City Inlet is located along the microtidal Atlantic Ocean coastline of Maryland. The inlet was opened by a hurricane in 1933 and stabilized with a double jetty system in 1934. Dramatic shoreline recession has occurred downdrift of the inlet with accretion to the north. Analysis of these trends has led past researchers to conclude that inlet stabilization is the principal cause. Analysis of shoreline position change maps for the period 1849-1980 reveals that this area had been receding significantly prior to inlet stabilization. For the period 1849-1933, a 16km long recessional embayment was centered about 16km south of the present inlet. Maximum mean shoreline recession rates approached 4m/yr near the center of the embayment. During the period from 1933-1980, maximum mean recession rates south of the inlet approached 8m/yr. The measured recession rates of northern Assateague Island represent island migration, not erosion. The cartographic area has shown little change during the 130+ years of shoreline mapping. The coastal geomorphic changes observed at Ocean City represent response to long term coastal processes, perhaps re-adjustment due to the rise in Holocene sea-level. Ocean City Inlet may be a catalyst for the observed changes, exaggerating a pre-existing process-response system.
Blade row dynamic digital compressor program. Volume 1: J85 clean inlet flow and parallel compressor models
NASA Technical Reports Server (NTRS)
Tesch, W. A.; Steenken, W. G.
The results are presented of a one-dimensional dynamic digital blade row compressor model study of a J85-13 engine operating with uniform and with circumferentially distorted inlet flow. Details of the geometry and the derived blade row characteristics used to simulate the clean inlet performance are given. A stability criterion based upon the self developing unsteady internal flows near surge provided an accurate determination of the clean inlet surge line. The basic model was modified to include an arbitrary extent multi-sector parallel compressor configuration for investigating 180 deg 1/rev total pressure, total temperature, and combined total pressure and total temperature distortions. The combined distortions included opposed, coincident, and 90 deg overlapped patterns. The predicted losses in surge pressure ratio matched the measured data trends at all speeds and gave accurate predictions at high corrected speeds where the slope of the speed lines approached the vertical.
Assessment of tidal inlet evolution and stability using sediment budget computations and hydraulic parameter analysis
A. Pacheco; A. Vila-Concejo; ė. Ferreira; J. A. Dias
Research into the response of coastlines to the opening and stabilisation of inlets has been limited by the availability of suitable data, the shortcomings of existing formulae when applied to different inlets, and the difficulties particular to multi-inlet situations. Our appraisal of methodologies for studying inlet dynamics leads us to formulate a new approach for investigating inlet evolution and stability
Catalytically-Promoted Analyte Derivatization Inside a Gas Chromatographic Inlet
Fowler, William K.; Gamble, Kelly J.; Wright, Amber R.
Reported here is a preliminary assessment of the feasibility of catalyzing on-line derivatization reactions inside the inlet (i.e., the injection port) of a gas chromatograph (GC) with solid heterogeneous catalysts. The experiments described here entail the installation of candidate catalysts inside the GC inlet liner and the subsequent injection of analyte/reagent mixtures onto the catalyst beds. Two catalysts are identified, each of which clearly catalyzes one of the chosen model derivatization reactions in the inlet of a GC. This result supports our hypothesis that on-line derivatizations can, in principle, be reproducibly catalyzed inside the GC inlet by solid heterogeneous catalysts and that the presence of such catalysts in the inlet do not necessarily cause a serious loss of instrument performance or chromatographic efficiency. PMID:20822662
Minimum weight design of a generic axisymmetric inlet
NASA Technical Reports Server (NTRS)
Nadell, Shari-Beth
A new minimum weight design method for high-speed axisymmetric inlets was demonstrated on a generic inlet. The method uses Classical Beam Theory and shell buckling to determine the minimum required equivalent isotropic thickness for a stiffened shell based on prescribed structural design requirements and load conditions. The optimum spacing and equivalent isotropic thickness of ring frame supports are computed to prevent buckling. The method thus develops a preliminary structural design for the inlet and computes the structural weight. Finite element analyses were performed on the resulting inlet design to evaluate the analytical results. Comparisons between the analytical and finite element stresses and deflections identified areas needing improvement in the analytical method. The addition of the deflection due to shear and a torsional buckling failure mode to the new method brought its results in line with those from the finite element analyses. Final validation of the new method will be made using data from actual inlets.
Application of quadratic optimization to supersonic inlet control
NASA Technical Reports Server (NTRS)
Lehtinen, B.; Zeller, J. R.
The application of linear stochastic optimal control theory to the design of the control system for the air intake (inlet) of a supersonic air-breathing propulsion system is discussed. The controls must maintain a stable inlet shock position in the presence of random airflow disturbances and prevent inlet unstart. Two different linear time invariant control systems are developed. One is designed to minimize a nonquadratic index, the expected frequency of inlet unstart, and the other is designed to minimize the mean square value of inlet shock motion. The quadratic equivalence principle is used to obtain the best linear controller that minimizes the nonquadratic performance index. The two systems are compared on the basis of unstart prevention, control effort requirements, and sensitivity to parameter variations.
Inlet flow field investigation. Part 1: Transonic flow field survey
NASA Technical Reports Server (NTRS)
Yetter, J. A.; Salemann, V.; Sussman, M. B.
A wind tunnel investigation was conducted to determine the local inlet flow field characteristics of an advanced tactical supersonic cruise airplane. A data base for the development and validation of analytical codes directed at the analysis of inlet flow fields for advanced supersonic airplanes was established. Testing was conducted at the NASA-Langley 16-foot Transonic Tunnel at freestream Mach numbers of 0.6 to 1.20 and angles of attack from 0.0 to 10.0 degrees. Inlet flow field surveys were made at locations representative of wing (upper and lower surface) and forebody mounted inlet concepts. Results are presented in the form of local inlet flow field angle of attack, sideflow angle, and Mach number contours. Wing surface pressure distributions supplement the flow field data.
Technical findings related to Generic Issue 23: Reactor coolant pump seal failure
C. J. Ruger; W. J. Jr. Luckas
Reactor coolant pumps contain mechanical seals to limit the leakage of pressurized coolant from the reactor coolant system to the containment. These seals have the potential to leak, and a few have degraded and even failed resulting in a small break loss of coolant accident (LOCA). As a result, ''Reactor Coolant Pump Seal Failure,'' Generic Issue 23 was established. This
Experimental investigation of a Mach 6 fixed-geometry inlet featuring a swept external-internal compression flow field
NASA Technical Reports Server (NTRS)
Torrence, M. G.
An investigation of a fixed-geometry, swept external-internal compression inlet was conducted at a Mach number of 6.0 and a test-section Reynolds number of 1.55 x 10 to the 7th power per meter. The test conditions was constant for all runs with stagnation pressure and temperature at 20 atmospheres and 500 K, respectively. Tests were made at angles of attack of -5 deg, 0 deg, 3 deg, and 5 deg. Measurements consisted of pitot- and static-pressure surveys in inlet throat, wall static pressures, and surface temperatures. Boundary-layer bleed was provided on the centerbody and on the cowl internal surface. The inlet performance was consistently high over the range of the angle of attack tested, with an overall average total pressure recovery of 78 percent and corresponding adiabatic kinetic-energy efficiency of 99 percent. The inlet throat flow distribution was uniform and the Mach number and pressure level were of the correct magnitude for efficient combustor design. The utilization of a swept compression field to meet the starting requirements of a fixed-geometry inlet produced neither flow instability nor a tendency to unstart.
Metallurgical Investigation of Cracked Adaptor Welded to Cryogenic Dump Coolant Line of Engine Test Stand
Abhay K. Jha; K. Sreekumar; P. P. Sinha
In the upper stages of satellite launch vehicles, a cryogenic propulsion system is used because of its high specific impulse.\\u000a Such stages were tested for qualification using ground hot test facility. During one of the hot tests, the stainless steel\\u000a adaptor welded to the engine dump coolant line, and used for accommodating temperature sensors, broke away from the tube.\\u000a The
Power module assemblies with staggered coolant channels
Herron, Nicholas Hayden; Mann, Brooks S; Korich, Mark D
A manifold is provided for supporting a power module assembly with a plurality of power modules. The manifold includes a first manifold section. The first face of the first manifold section is configured to receive the first power module, and the second face of the first manifold section defines a first cavity with a first baseplate thermally coupled to the first power module. The first face of the second manifold section is configured to receive the second power module, and the second face of the second manifold section defines a second cavity with a second baseplate thermally coupled to the second power module. The second face of the first manifold section and the second face of the second manifold section are coupled together such that the first cavity and the second cavity form a coolant channel. The first cavity is at least partially staggered with respect to second cavity.
Journal of Coastal Research SI 59 98-110 West Palm Beach, Florida 2011 New Ebb-Tidal Delta at an Old Inlet, Shark River Inlet, New Jersey
US Army Corps of Engineers
at an Old Inlet, Shark River Inlet, New Jersey Tanya M. Beck and Nicholas C. Kraus ABSTRACT BECK, T.M. and KRAUS, N.C., 2011. New Ebb-Tidal Delta at an Old Inlet, Shark River Inlet, New Jersey. In: Roberts, T of Coastal Research, Special Issue, No. 59, pp. 98-110. West Palm Beach (Florida), ISSN 0749-0208. Shark
Coolant voiding analysis following SGTR for an HLMC reactor
M. T. Farmer; B. W. Spencer; J. J. Sienicki
Concepts are under development at Argonne National Laboratory for a small, modular, proliferation-resistant nuclear power steam supply system. Of primary interest here is the simplified system design, featuring steam generators that are directly immersed in the lead-bismuth eutectic (LBE) coolant of the primary system. To support the safety case for this design approach, model development and analysis of transient coolant
System for automated diagnosis of reactor-coolant pumps
H. C. Gabler; D. M. Stevens; D. J. Morris; S. W. Glass; G. A. Sommerfield; D. Harrison
The Reactor-Coolant Pump Monitoring and Diagnostic System will combine seal and rotating machinery analyses to provide continuous, comprehensive, and unattended watch over the four reactor coolant pumps at Davis-Besse. Initial demonstration of the system will provide machine protection, and investigate the opportunity for incipient failure detection. The longer range benefit will be a better understanding of the mechanisms behind seal
73. View of line of stainless steel coolant storage tanks ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
73. View of line of stainless steel coolant storage tanks for bi-sodium sulfate/water coolant solution at first floor of transmitter building no. 102. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK
The effect of inlet conditions on lean premixed gas turbine combustor performance
NASA Astrophysics Data System (ADS)
Vilayanur, Suresh Ravi
The combustion community is today faced with the goal to reduce NOx at high efficiencies. This requirement has directed attention to the manner by which air and fuel are treated prior to and at the combustor inlet. This dissertation is directed to establishing the role of combustor inlet conditions on combustor performance, and to deriving an understanding of the relationship between inlet conditions and combustion performance. To investigate the complex effect of inlet parameters on combustor performance, (1) a test facility was designed and constructed, (2) hardware was designed and fabricated, (3) a statistically based technique was designed and applied, and (4) detailed in-situ measurements were acquired. Atmospheric tests were performed at conditions representative of industrial combustors: 670 K inlet preheat and an equivalence ratio of 0.47, and make the study immediately relevant to the combustion community. The effects of premixing length, fuel distribution, swirl angle, swirl vane thickness and swirl solidity were investigated. The detailed in-situ measurements were performed to form the database necessary to study the responsible mechanisms. A host of conventional and advanced diagnostics were used for the investigation. In situ measurements included the mapping of the thermal and velocity fields of the combustor, obtaining species concentrations inside the combustor, and quantifying the fuel-air mixing entering the combustor. Acoustic behavior of the combustor was studied, including the application of high speed videography. The results reveal that the principal statistically significant effect on NOx production is the inlet fuel distribution, and the principal statistically significant effect on CO production is the swirl strength. Elevated levels of NOx emission result when the fuel is weighted to the centerline. Eddies shedding off the swirler hub ignite as discrete packets, and due to the elevated concentrations of fuel, reach higher temperatures than uniformly mixed packets. This shedding of eddies leads to an acoustic emission that can be identified in a select frequency range. The CO production is related to the swirl strength due to the proportion of products entrained into the recirculation zone. Neither lean blowout nor combustion efficiency are affected by the inlet condition variation within the range studied.
Liquid air as a coolant for thermal management of long-length HTS cable systems
NASA Astrophysics Data System (ADS)
Demko, Jonathan; Hassenzahl, William
Direct current (dc), high temperature superconducting (HTS) cable systems have been suggested as an effective method of transmitting very large amounts of electric power (up to 10 GW) over very long distances (thousands of kilometers). This is made possible mainly by the high-current-carrying capability of the HTS materials when operated below their critical temperatures and by their near zero resistance to constant current. Most HTS cable concepts rely on liquid nitrogen or gaseous helium as the coolant. As an alternative, liquid air offers certain benefits and is discussed here as a cable system coolant. Air has a lower freezing temperature than nitrogen, it can be produced locally, and a liquid air leak will not displace the oxygen in a closed compartment. The dc cable design concept proposed by the Electric Power Research Institute (EPRI) in which the coolant flows in a cryogenic enclosure that includes the cable and a separate return tube, and refrigeration stations positioned every 10 to 20 km is assumed for this analysis. Both go and return lines are contained in a single vacuum envelope. The thermal management of this superconducting cable concept with liquid air in long-distance HTS power cables is developed in this paper. The results are compared to the use of liquid nitrogen, gaseous helium and gaseous hydrogen.
Distribution of coolant flow rate in a steam generator in natural coolant circulation regimes
A. Ya. Blagoveshchenskii; V. L. Leont'eva; A. G. Mitryukhin
ConclusionsĀĀThe large hydraulic nonuniformity of steam generator pipes operating in parallel in the natural coolant circulation regime\\u000a results in a lower efficiency of the heat-transfer surface during emergency cooldown of the reactor plant, and it limits the\\u000a operational possibilities, specifically, for using this regime at partial power levels. It is obvious that circulation reversal\\u000a in the pipes of steam generators
Southern Salish Sea Habitat Map Series: Admiralty Inlet
Cochrane, Guy R.; Dethier, Megan N.; Hodson, Timothy O.; Kull, Kristine K.; Golden, Nadine E.; Ritchie, Andrew C.; Moegling, Crescent; Pacunski, Robert E.
Puget Sound is separated into four interconnected basins; Whidbey, Central (Main), Hood Canal, and South (Thomson, 1994). The Whidbey, Central, and Hood Canal basins are the three main branches of the Puget Sound estuary and are separated from the Strait of Juan de Fuca by a double sill at Admiralty Inlet. The Admiralty Inlet map area includes the Inlet and a portion of the Whidbey Basin (fig. 1). The shallower South Basin is separated by a sill at Tacoma Narrows and is highly branched with numerous finger inlets. Flow within Puget Sound is dominated by tidal currents of as much as 1 m/s at Admiralty Inlet, reducing to approximately 0.5 m/s in the Central Basin (Lavelle and others, 1988). The lack of silt and clay-sized sediments in the Admiralty Inlet map area is likely a result of the strong currents (see Ground-Truth Studies for the Admiralty Inlet Map Area, sheet 3). The subtidal component of flow reaches approximately 0.1 m/s and is driven by density gradients arising from the contrast in salty ocean water at the entrance and freshwater inputs from stream flow (Lavelle and others, 1988). The total freshwater input
The performance of a centrifugal compressor with high inlet prewhirl
Whitfield, A. [Univ. of Bath (United Kingdom). Dept. of Mechanical Engineering; Abdullah, A.H. [Univ. Technology Malaysia, Johore Baharu (Malaysia). Dept. of Mechanical Engineering
The performance requirements of centrifugal compressors usually include a broad operating range between surge and choke. This becomes increasingly difficult to achieve as increased pressure ratio is demanded. In order to suppress the tendency to surge and extend the operating range at low flow rates, inlet swirl is often considered through the application of inlet guide vanes. To generate high inlet swirl angles efficiently, an inlet volute has been applied as the swirl generator, and a variable geometry design developed in order to provide zero swirl. The variable geometry approach can be applied to increase the swirl progressively or to switch rapidly from zero swirl to maximum swirl. The variable geometry volute and the swirl conditions generated are described. The performance of a small centrifugal compressor is presented for a wide range of inlet swirl angles. In addition to the basic performance characteristics of the compressor, the onsets of flow reversals at impeller inlet are presented, together with the development of pressure pulsations, in the inlet and discharge ducts, through to full surge. The flow rate at which surge occurred was shown, by the shift of the peak pressure condition and by the measurement of the pressure pulsations, to be reduced by over 40%.
Flow Simulation of Supersonic Inlet with Bypass Annular Duct
NASA Technical Reports Server (NTRS)
Kim, HyoungJin; Kumano, Takayasu; Liou, Meng-Sing; Povinelli, Louis A.; Conners, Timothy R.
A relaxed isentropic compression supersonic inlet is a new concept that produces smaller cowl drag than a conventional inlet, but incurs lower total pressure recovery and increased flow distortion in the (radially) outer flowpath. A supersonic inlet comprising a bypass annulus to the relaxed isentropic compression inlet dumps out airflow of low quality through the bypass duct. A reliable computational fluid dynamics solution can provide considerable useful information to ascertain quantitatively relative merits of the concept, and further provide a basis for optimizing the design. For a fast and reliable performance evaluation of the inlet performance, an equivalent axisymmetric model whose area changes accounts for geometric and physical (blockage) effects resulting from the original complex three-dimensional configuration is proposed. In addition, full three-dimensional calculations are conducted for studying flow phenomena and verifying the validity of the equivalent model. The inlet-engine coupling is carried out by embedding numerical propulsion system simulation engine data into the flow solver for interactive boundary conditions at the engine fan face and exhaust plane. It was found that the blockage resulting from complex three-dimensional geometries in the bypass duct causes significant degradation of inlet performance by pushing the terminal normal shock upstream.
Unstart coupling mechanism analysis of multiple-modules hypersonic inlet.
Hu, Jichao; Chang, Juntao; Wang, Lei; Cao, Shibin; Bao, Wen
The combination of multiplemodules in parallel manner is an important way to achieve the much higher thrust of scramjet engine. For the multiple-modules scramjet engine, when inlet unstarted oscillatory flow appears in a single-module engine due to high backpressure, how to interact with each module by massflow spillage, and whether inlet unstart occurs in other modules are important issues. The unstarted flowfield and coupling characteristic for a three-module hypersonic inlet caused by center module II and side module III were, conducted respectively. The results indicate that the other two hypersonic inlets are forced into unstarted flow when unstarted phenomenon appears on a single-module hypersonic inlet due to high backpressure, and the reversed flow in the isolator dominates the formation, expansion, shrinkage, and disappearance of the vortexes, and thus, it is the major factor of unstart coupling of multiple-modules hypersonic inlet. The coupling effect among multiple modules makes hypersonic inlet be more likely unstarted. PMID:24348146
Starting Mechanisms for High Contraction Ratio Hypersonic Inlets
NASA Astrophysics Data System (ADS)
Grainger, A.; Tirtey, S. C.; Boyce, R. R.; Paris, S.; Paniagua, G.
A coupled numerical/experimental study of two, variable geometry mechanisms for starting high contraction ratio hypersonic inlets has been conducted within the framework of the SCRAMSPACE Scramjet- based Access-to-Space Systems project. The first of the two mechanisms investigated involves opening and closing two doors on the inner inlet wall, and is intended to be integrated into the planned SCRAMSPACE I scramjet flight experiment. The second method investigated involves sliding two oblique doors, located upstream of the inlet entrance, up over the body of the scramjet. Successful inlet starting at a flight Mach number of 8 at a low altitude and 0░ angle of attack was achieved when utilising the opening doors inlet starting mechanism. Additional simulations of the performance of this mechanism at various altitudes along the SCRAMSPACE descent trajectory have been performed, to investigate the effects of more viscous inlet flows at rarefied conditions. These results show that it is possible to ensure a started inlet flow for the entire trajectory when utilising variable geometry.
Modeling and small-break loss-of-coolant accident analysis of Comanche Peak Steam Electric Station using RELAP5/MOD2Ā
Salim, Parvez
of the steam generator and passes through 25 Relief Valve Nozzle Water Spray Connection from Reactor Coolant Inlet Line Water Spray Nozzle Steam Space Normal Water Level Electric Heater Bundle Level Sensing Nozzle (typical of 3) Surge Diffuser... Pressurized Water Reactor System 2 RELAP5 Separator Model 3 Schematic of a PWR Nuclear Steam Supply System 4 PWR Reactor Vessel 5 PWR Pressurizer 6 U-tube Steam Generator Schematic Page 15 22 23 25 26 7 Steady-State RELAP5 Model for Comanche Peak...
Aerodynamic design of a supersonic three-dimensional inlet
NASA Astrophysics Data System (ADS)
Goonko, Yu. P.; Alexandrov, E. A.
The results of designing and numerical gas-dynamic modeling a supersonic three-dimensional inlet of a new type are considered. A ramp of external compression of this inlet is the V-shaped body forming an initial plane oblique shock wave and a subsequent isentropic compression wave. The inlet incorporates an entrance section of internal compression, where also a plane oblique shock wave and a subsequent isentropic compression wave are formed by a cowl. The designed three-dimensional inlet has small inclination angles of compression surfaces, which ensures its low wave drag. According to the estimates of inlet efficiency in terms of the compression ratio and the total pressure recovery factor, it is close to the optimal two-dimensional shocked inlet of external compression considered by Oswatisch as well as Petrov and Ukhov. The flow in the inlet was computed with the use of the Euler and Navier Ś Stokes codes provided by the commercial package ōFLUENTö. The flow in the inlet throat in the design regime computed under the inviscid flow approximation is uniform. The most substantial effect of the flow viscosity in this regime manifests itself in the interaction of the shock wave from the cowl with the boundary layer on the V-shaped compression body in the inlet internal duct. According to computed data, the boundary layer separation does not occur in this case; however, due to viscosity effects, reflected shock waves are formed here which results in significant deviations of flow structure as compared to the computed inviscid flow.
Internal flow characteristics of a multistage compressor with inlet pressure distortion. [J85-13 turbojet engine studies
NASA Technical Reports Server (NTRS)
Debogdan, C. E.; Moss, J. E., Jr.; Braithwaite, W. M.
The measured distribution of compressor interstage pressures and temperatures resulting from a 180 deg inlet-total-pressure distortion for a J85-13 turbojet engine is reported. Extensive inner stage instrumentation combined with stepwise rotation of the inlet distortion gave data of high circumferential resolution. The steady-state pressures and temperatures along with the amplitude, extent, and location of the distorted areas are given. Data for 80, 90, and 100 percent of rotor design speed are compared with clean (undistorted) inlet flow conditions to show pressure and temperature behavior within the compressor. Both overall and stagewise compressor performances vary only slightly when clean and distorted inlet conditions are compared. Total and static pressure distortions increase in amplitude in the first few stages of the compressor and then attenuate fairly uniformly to zero at the discharge. Total-temperature distortion induced by the pressure distortion reached a maximum amplitude by the first two stages and decayed only a little through the rest of the compressor. Distortion amplitude tended to peak in line with the screen edges, and, except for total and static pressure in the tip zone, there was little swirl in the axial direction.
Feasibility study of inlet shock stability system of YF-12
NASA Technical Reports Server (NTRS)
Blausey, G. C.; Coleman, D. M.; Harp, D. S.
The feasibility of self actuating bleed valves as a shock stabilization system in the inlet of the YF-12 is considered for vortex valves, slide valves, and poppet valves. Analytical estimation of valve performance indicates that only the slide and poppet valves located in the inlet cowl can meet the desired steady state stabilizing flows, and of the two the poppet valve is substantially faster in response to dynamic disturbances. The poppet valve is, therefore, selected as the best shock stability system for the YF-12 inlet.
Estimation of additive forces and moments for supersonic inlets
NASA Technical Reports Server (NTRS)
Perkins, Stanley C., Jr.; Dillenius, Marnix F. E.
A technique for estimating the additive forces and moments associated with supersonic, external compression inlets as a function of mass flow ratio has been developed. The technique makes use of a low order supersonic paneling method for calculating minimum additive forces at maximum mass flow conditions. A linear relationship between the minimum additive forces and the maximum values for fully blocked flow is employed to obtain the additive forces at a specified mass flow ratio. The method is applicable to two-dimensional inlets at zero or nonzero angle of attack, and to axisymmetric inlets at zero angle of attack. Comparisons with limited available additive drag data indicate fair to good agreement.
Estimation of Inlet Lip Forces at Subsonic and Supersonic Speeds
NASA Technical Reports Server (NTRS)
Moeckel, W E
The effects of lip thickness on inlet performance are estimated as functions of mass flow for subsonic and supersonic flight speeds. At subsonic speeds, pressure-recovery losses and additive drag are shown to decrease linearly with increasing lip frontal area if the maximum suction force is attained. At supersonic speeds, inlet drag increases linearly with inlet lip frontal area at full mass flow. For reduced mass flow, some reduction in additive drag is possible with lips of moderate thickness, but the magnitude of this reduction becomes negligible as flight speed increases.
Salt water infiltration in two artificial sea inlets in the Belgian dune area
NASA Astrophysics Data System (ADS)
Vandenbohede, A.; Lebbe, L.; Gysens, Stefaan; Delecluyse, Kevin; DeWolf, Peter
SummaryIn the dune area of the Westhoek Nature Reserve, situated in the western Belgian coastal plain, two artificial tidal inlets were made aiming to enhance biodiversity. The infiltration of salt water in these tidal inlets was carefully monitored because a fresh water lens is present in the phreatic dune aquifer. This forms an important source of fresh water which is for instance exploited by a water company. The infiltration was monitored over a period of two years by means of electromagnetic borehole measurements (EM39) and by measurements of fresh water heads and temperature using a large number of observation wells. EM39 observations point to aquifer heterogeneity as a determining factor in the movement of the salt infiltration water. It is shown that part of the infiltration water moves further in the dunes instead of towards the sea. On the long term run, possibility exists that salt water enters the extraction's capture zone. This issue needs further monitoring and study. Fresh water head and temperature data illustrate that the main period of infiltration is confined to spring tide when large amounts of salt water enter the tidal inlets.
Tangential blowing for control of strong normal shock - Boundary layer interactions on inlet ramps
NASA Technical Reports Server (NTRS)
Schwendemann, M. F.; Sanders, B. W.
The use of tangential blowing from a row of holes in an aft facing step is found to provide good control of the ramp boundary layer, normal shock interaction on a fixed geometry inlet over a wide range of inlet mass flow ratios. Ramp Mach numbers of 1.36 and 1.96 are investigated. The blowing geometry is found to have a significant effect on system performance at the highest Mach number. The use of high-temperature air in the blowing system, however, has only a slight effect on performance. The required blowing rates are significantly high for the most severe test conditions. In addition, the required blowing coefficient is found to be proportional to the normal shock pressure rise.
Shuttle Centaur engine cooldown evaluation and effects of expanded inlets on start transient
NASA Technical Reports Server (NTRS)
As part of the integration of the RL10 engine into the Shuttle Centaur vehicle, a satisfactory method of conditioning the engine to operating temperatures had to be established. This procedure, known as cooldown, is different from the existing Atlas Centaur due to vehicle configuration and mission profile differenced. The program is described, and the results of a Shuttle Centaur cooldown program are reported. Mission peculiarities cause substantial variation in propellant inlet conditions between the substantiated Atlas Centaur and Shuttle Centaur with the Shuttle Centaur having much larger variation in conditions. A test program was conducted to demonstrate operation of the RL10 engine over the expanded inlet conditions. As a result of this program, the Shuttle Centaur requirements were proven satisfactory. Minor configuration changes incorporated as a result of this program provide substantial reduction in cooldown propellant consumption.
Fiber optics for aircraft engine/inlet control
NASA Technical Reports Server (NTRS)
Baumbick, R. J.
NASA programs that focus on the use of fiber optics for aircraft engine/inlet control are reviewed. Fiber optics for aircraft control is attractive because of its inherent immunity to EMI and RFI noise. Optical signals can be safely transmitted through areas that contain flammable or explosive materials. The use of optics also makes remote sensing feasible by eliminating the need for electrical wires to be connected between sensors and computers. Using low-level optical signals to control actuators is also feasible when power is generated at the actuator. Each application of fiber optics for aircraft control has different requirements for both the optical cables and the optical connectors. Sensors that measure position and speed by using slotted plates can use lossy cables and bundle connectors if data transfer is in the parallel mode. If position and speed signals are multiplexed, cable and connector requirements change. Other sensors that depend on changes in transmission through materials require dependable characteristics of both the optical cables and the optical connectors. A variety of sensor types are reviewed, including rotary position encoders, tachometers, temperature sensors, and blade tip clearance sensors for compressors and turbines. Research on a gallium arsenide photoswitch for optically switched actuators that operate at 250 C is also described.
The relationships between certain physical and chemical variables and the seasonal dynamics of phytoplankton assemblages of two inlets of a shallow hypertrophic lake with different nutrient inputs.
Celik, Kemal; Ongun, Tugba
The relationships between water discharge, temperature, total dissolved solids (TDS) conductivity, turbidity, nitrate, ammonium, phosphate and the seasonal dynamics of phytoplankton assemblages of two inlets of a shallow hypertrophic lake (Lake Manyas, Turkey) were studied between January 2003 and December 2004. The results showed that different levels of water discharge, turbidity, conductivity, TDS and nutrients could lead to the development of significantly different phytoplankton assemblages in inlets of shallow hypertrophic lakes. The multiple regression analysis identified water discharge, turbidity and water temperature as the driving factors behind the dynamics of phytoplankton biovolume in the studied inlets. The first two axes of Canonical Correspondence Analysis (CCA) explained 78% of the total variance in dominant phytoplankton species at Si?irci Inlet and 88% at Kocańay Inlet, respectively. The purpose of this study was to determine the relationships between water discharge, temperature, conductivity, turbidity, pH, TDS, nitrate, ammonium, phosphate and the seasonal dynamics of phytoplankton assemblages of two inlets of the shallow hypertrophic Lake Manyas, Turkey by means of multivariate statistical analysis. PMID:16897515
Unsteady Analysis of Inlet-Compressor Acoustic Interactions Using Coupled 3-D and 1-D CFD Codes
NASA Technical Reports Server (NTRS)
Suresh, A.; Cole, G. L.
It is well known that the dynamic response of a mixed compression supersonic inlet is very sensitive to the boundary condition imposed at the subsonic exit (engine face) of the inlet. In previous work, a 3-D computational fluid dynamics (CFD) inlet code (NPARC) was coupled at the engine face to a 3-D turbomachinery code (ADPAC) simulating an isolated rotor and the coupled simulation used to study the unsteady response of the inlet. The main problem with this approach is that the high fidelity turbomachinery simulation becomes prohibitively expensive as more stages are included in the simulation. In this paper, an alternative approach is explored, wherein the inlet code is coupled to a lesser fidelity 1-D transient compressor code (DYNTECC) which simulates the whole compressor. The specific application chosen for this evaluation is the collapsing bump experiment performed at the University of Cincinnati, wherein reflections of a large-amplitude acoustic pulse from a compressor were measured. The metrics for comparison are the pulse strength (time integral of the pulse amplitude) and wave form (shape). When the compressor is modeled by stage characteristics the computed strength is about ten percent greater than that for the experiment, but the wave shapes are in poor agreement. An alternate approach that uses a fixed rise in duct total pressure and temperature (so-called 'lossy' duct) to simulate a compressor gives good pulse shapes but the strength is about 30 percent low.
The impact of radiolytic yield on the calculated ECP in PWR primary coolant circuits
NASA Astrophysics Data System (ADS)
Urquidi-Macdonald, Mirna; Pitt, Jonathan; Macdonald, Digby D.
A code, PWR-ECP, comprising chemistry, radiolysis, and mixed potential models has been developed to calculate radiolytic species concentrations and the corrosion potential of structural components at closely spaced points around the primary coolant circuits of pressurized water reactors (PWRs). The pH( T) of the coolant is calculated at each point of the primary-loop using a chemistry model for the B(OH) 3 + LiOH system. Although the chemistry/radiolysis/mixed potential code has the ability to calculate the transient reactor response, only the reactor steady state condition (normal operation) is discussed in this paper. The radiolysis model is a modified version of the code previously developed by Macdonald and coworkers to model the radiochemistry and corrosion properties of boiling water reactor primary coolant circuits. In the present work, the PWR-ECP code is used to explore the sensitivity of the calculated electrochemical corrosion potential (ECP) to the set of radiolytic yield data adopted; in this case, one set had been developed from ambient temperature experiments and another set reported elevated temperatures data. The calculations show that the calculated ECP is sensitive to the adopted values for the radiolytic yields.
Flow boiling with enhancement devices for cold plate coolant channel design
NASA Technical Reports Server (NTRS)
Boyd, Ronald D.
Future space exploration and commercialization will require more efficient heat rejection systems. For the required heat transfer rates, such systems must use advanced heat transfer techniques. Forced two phase flow boiling heat transfer with enhancements falls in this category. However, moderate to high quality two phase systems tend to require higher pressure losses. This report is divided into two major parts: (1) Multidimensional wall temperature measurement and heat transfer enhancement for top heated horizontal channels with flow boiling; and (2) Improved analytical heat transfer data reduction for a single side heated coolant channel. Part 1 summarizes over forty experiments which involve both single phase convection and flow boiling in a horizontal channel heated externally from the top side. Part 2 contains parametric dimensionless curves with parameters such as the coolant channel radius ratio, the Biot number, and the circumferential coordinate.
Copper-based micro-channel cooler reliably operated using solutions of distilled-water and ethanol as a coolant
NASA Astrophysics Data System (ADS)
Chin, A. K.; Nelson, A.; Chin, R. H.; Bertaska, R.; Jacob, J. H.
Copper-based micro-channel coolers (Cu-MCC) are the lowest thermal-resistance heat-sinks for high-power laserdiode (LD) bars. Presently, the resistivity, pH and oxygen content of the de-ionized water coolant, must be actively controlled to minimize cooler failure by corrosion and electro-corrosion. Additionally, the water must be constantly exposed to ultraviolet radiation to limit the growth of micro-organisms that may clog the micro-channels. In this study, we report the reliable, care-free operation of LD-bars attached to Cu-MCCs, using a solution of distilledwater and ethanol as the coolant. This coolant meets the storage requirements of Mil-Std 810G, e.g. exposure to a storage temperature as low as -51░C and no growth of micro-organisms during passive storage.
Flow analysis and control in a subsonic inlet
Tournier, Serge (Serge E.)
S-duct inlets are commonly used on subsonic cruise missiles, as they offer a good compromise between compactness, low observability and aerodynamic performance. Though currently used S-ducts exhibit good performance in ...
28. Main water inlet and outlet pipes under central corridor ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
28. Main water inlet and outlet pipes under central corridor of filtration bed building. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT
Experimental and Numerical Investigation of Hypersonic Jaws Inlet
NASA Astrophysics Data System (ADS)
Dong, Hao; Wang, Cheng-Peng; Cheng, Ke-Ming
In order to obtain the flow field characteristics and the influence of boundary layer, numerical simulations and wind tunnel tests are conducted for two streamline traced Jaws inlets at Mach number 7. The inlets are designed based on a flow field with 8-7 planar shock wave (the ramp in pitch plane is inclined at 8░ to the free stream and in yaw plane is inclined at 7░ to the free stream, yielding planar shocks). In the study, the static pressure distributions were measured and analyzed along the plane-symmetric centerline of the inlet with and without the boundary layer correction, respectively. Results show that boundary layer correction can obviously weaken the viscous influence to the inlet, increasing the mass flow coefficient and improving total pressure recovery.
Three dimensional viscous analysis of a hypersonic inlet
NASA Technical Reports Server (NTRS)
Reddy, D. R.; Smith, G. E.; Liou, M.-F.; Benson, Thomas J.
The flow fields in supersonic/hypersonic inlets are currently being studied at NASA Lewis Research Center using 2- and 3-D full Navier-Stokes and Parabolized Navier-Stokes solvers. These tools have been used to analyze the flow through the McDonnell Douglas Option 2 inlet which has been tested at Calspan in support of the National Aerospace Plane Program. Comparisons between the computational and experimental results are presented. These comparisons lead to better overall understanding of the complex flows present in this class of inlets. The aspects of the flow field emphasized in this work are the 3-D effects, the transition from laminar to turbulent flow, and the strong nonuniformities generated within the inlet.
Three dimensional viscous analysis of a hypersonic inlet
NASA Technical Reports Server (NTRS)
Reddy, D. R.; Smith, G. E.; Liou, M.-F.; Benson, T. J.
The flow fields in supersonic/hypersonic inlets are currently being studied at NASA Lewis Research Center using 2- and 3-d full Navier-Stokes and parabolized Navier-Stokes solvers. These tools have been used to analyze the flow through the McDonnell Douglas Option 2 inlet which has been tested at Calspan in support of the National Aerospace Plane Program. Comparisons between the computational and experimental results are presented. These comparisons lead to better overall understanding of the complex flows present in this class of inlets. The aspects of the flow field emphasized in this work are the 3-D effects, the transition from laminar to turbulent flow, and the strong nonuniformities generated within the inlet.
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
2. OVERALL VIEW OF ISLAND LAKE, WITH INLET IN FOREGROUND, LOOKING SOUTH - High Mountain Dams in Upalco Unit, Island Lake Dam, Ashley National Forest, 4.8 miles North of Miners Gulch Campground, Mountain Home, Duchesne County, UT
46 CFR 153.354 - Venting system inlet.
Code of Federal Regulations, 2010 CFR
...Equipment Cargo Venting Systems ¦ 153.354 Venting system inlet. A venting system must terminate in the vapor space above the cargo when the tank is filled to a 2 percent ullage and the tankship has no heel or...
14 CFR 25.941 - Inlet, engine, and exhaust compatibility.
Code of Federal Regulations, 2011 CFR
...and engine inlet and exhaust configurations; (b) The dynamic effects of the operation of these (including consideration...the part of the pilot to avoid exceeding an operational or structural limitation of the airplane; and (c) In showing...
14 CFR 25.941 - Inlet, engine, and exhaust compatibility.
Code of Federal Regulations, 2013 CFR
...and engine inlet and exhaust configurations; (b) The dynamic effects of the operation of these (including consideration...the part of the pilot to avoid exceeding an operational or structural limitation of the airplane; and (c) In showing...
40 CFR 91.407 - Engine inlet and exhaust systems.
Code of Federal Regulations, 2012 CFR
...Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test Procedures ¦ 91.407 Engine inlet and exhaust systems. (a) The...
An experimental investigation into enhancing pulsejet performance through inlet redesignĀ
Wood, Randolph Handley, 1967-
operation, the engine was tested in a moving flow of air. The experimental data consisted of combustion chamber pressure measurements, inlet pressure measurements and thrust measurements. The diffuser configuration successfully achieved the research...
Flow control optimization in a jet engine serpentine inlet duct
Kumar, Abhinav
Computational investigations were carried out on an advanced serpentine jet engine inlet duct to understand the development and propagation of secondary flow structures. Computational analysis which went in tandem with experimental investigation...
Reactor coolant pump monitoring and diagnostic system
Singer, R.M.; Gross, K.C.; Walsh, M. (Argonne National Lab., IL (USA)); Humenik, K.E. (Maryland Univ., Baltimore, MD (USA))
In order to reliably and safely operate a nuclear power plant, it is necessary to continuously monitor the performance of numerous subsystems to confirm that the plant state is within its prescribed limits. An important function of a properly designed monitoring system is the detection of incipient faults in all subsystems (with the avoidance of false alarms) coupled with an information system that provides the operators with fault diagnosis, prognosis of fault progression and recommended (either automatic or prescriptive) corrective action. In this paper, such a system is described that has been applied to reactor coolant pumps. This system includes a sensitive pattern-recognition technique based upon the sequential probability ratio test (SPRT) that detects incipient faults from validated signals, an expert system embodying knowledge bases on pump and sensor performance, extensive hypertext files containing operating and emergency procedures as well as pump and sensor information and a graphical interface providing the operator with easily perceived information on the location and character of the fault as well as recommended corrective action. This system is in the prototype stage and is currently being validated utilizing data from a liquid-metal cooled fast reactor (EBR-II). 3 refs., 4 figs.
Corrosion problems with aqueous coolants, final report
Diegle, R B; Beavers, J A; Clifford, J E
The results of a one year program to characterize corrosion of solar collector alloys in aqueous heat-transfer media are summarized. The program involved a literature review and a laboratory investigation of corrosion in uninhibited solutions. It consisted of three separate tasks, as follows: review of the state-of-the-art of solar collector corrosion processes; study of corrosion in multimetallic systems; and determination of interaction between different waters and chemical antifreeze additives. Task 1 involved a comprehensive review of published literature concerning corrosion under solar collector operating conditions. The reivew also incorporated data from related technologies, specifically, from research performed on automotive cooling systems, cooling towers, and heat exchangers. Task 2 consisted of determining the corrosion behavior of candidate alloys of construction for solar collectors in different types of aqueous coolants containing various concentrations of corrosive ionic species. Task 3 involved measuring the degradation rates of glycol-based heat-transfer media, and also evaluating the effects of degradation on the corrosion behavior of metallic collector materials.
Longer life for glyco-based stationary engine coolants
Hohlfeld, R. [Dow Chemical Co., Houston, TX (United States)
Large, stationary diesel engines used to compress natural gas that is to be transported down pipelines generate a great deal of heat. Unless this heat is dissipated efficiently, it will eventually cause an expensive breakdown. Whether the coolant uses ethylene glycol or propylene glycol, the two major causes of glycol degradation are heat and oxidation. The paper discusses inhibitors that enhance coolant service life and presents a comprehensive list of do`s and don`ts for users to gain a 20-year coolant life.
A flux-split solution procedure for unsteady inlet flows
NASA Technical Reports Server (NTRS)
Pordal, H. S.; Khosla, P. K.; Rubin, S. G.
The unstart and restart of an axisymmetric inlet is investigated using a flux-split procedure applied to the Euler and Reduced Navier Stokes (RNS) equations. A time consistent direct sparse matrix solver is applied to compute the transient flow field both internal and external to the inlet. Time varying oblique and normal shocks are captured. The code is quite general and is applicable for subsonic, transonic and supersonic free streams. The current analysis is concerned with supersonic flight conditions.
A Comparison of Coolant Options for Brayton Power Conversion Heat Rejection Systems
NASA Technical Reports Server (NTRS)
Mason, Lee S.; Siamidis, John
This paper describes potential heat rejection design concepts for Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) and surface power applications. The Brayton Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Sodium potassium (NaK) and H2O are two coolant working fluids that have been investigated in the design of a pumped loop and heat pipe space HRS. In general NaK systems are high temperature (300 to 1000 K) low pressure systems, and H2O systems are low temperature (300 to 600 K) high pressure systems. NaK is an alkali metal with health and safety hazards that require special handling procedures. On the other hand, H2O is a common fluid, with no health hazards and no special handling procedures. This paper compares NaK and H20 for the HRS pumped loop coolant working fluid. A detailed Microsoft Excel (Microsoft Corporation, Redmond, WA) analytical model, HRS_Opt, was developed to evaluate the various HRS design parameters. It is capable of analyzing NaK or H2O coolant, parallel or series flow configurations, and numerous combinations of other key parameters (heat pipe spacing, diameter and radial flux, radiator facesheet thickness, fluid duct system pressure drop, system rejected power, etc.) of the HRS. This paper compares NaK against water for the HRS coolant working fluid with respect to the relative mass, performance, design and implementation issues between the two fluids.
A Comparison of Coolant Options for Brayton Power Conversion Heat Rejection Systems
Siamidis, John [Thermal Energy Conversion Branch, Analex Corporation, 21000 Brookpark Rd., Cleveland, OH, 44135 (United States); Mason, Lee [Thermal Energy Conversion Branch, NASA Glenn Research Center, 21000 Brookpark Rd., Cleveland, OH, 44135 (United States)
This paper describes potential heat rejection design concepts for Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) and surface power applications. The Brayton Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Sodium potassium (NaK) and H2O are two coolant working fluids that have been investigated in the design of a pumped loop and heat pipe space HRS. In general NaK systems are high temperature (300 to 1000 K) low pressure systems, and H2O systems are low temperature (300 to 600 K) high pressure systems. NaK is an alkali metal with health and safety hazards that require special handling procedures. On the other hand, H2O is a common fluid, with no health hazards and no special handling procedures. This paper compares NaK and H2O for the HRS pumped loop coolant working fluid. A detailed excel analytical model, HRS{sub O}pt, was developed to evaluate the various HRS design parameters. It is capable of analyzing NaK or H2O coolant, parallel or series flow configurations, and numerous combinations of other key parameters (heat pipe spacing, diameter and radial flux, radiator facesheet thickness, fluid duct system pressure drop, system rejected power, etc.) of the HRS. This paper compares NaK against water for the HRS coolant working fluid with respect to the relative mass, performance, design and implementation issues between the two fluids.
Large-Scale Low-Boom Inlet Test Overview
NASA Technical Reports Server (NTRS)
Hirt, Stefanie
This presentation provides a high level overview of the Large-Scale Low-Boom Inlet Test and was presented at the Fundamental Aeronautics 2011 Technical Conference. In October 2010 a low-boom supersonic inlet concept with flow control was tested in the 8'x6' supersonic wind tunnel at NASA Glenn Research Center (GRC). The primary objectives of the test were to evaluate the inlet stability and operability of a large-scale low-boom supersonic inlet concept by acquiring performance and flowfield validation data, as well as evaluate simple, passive, bleedless inlet boundary layer control options. During this effort two models were tested: a dual stream inlet intended to model potential flight hardware and a single stream design to study a zero-degree external cowl angle and to permit surface flow visualization of the vortex generator flow control on the internal centerbody surface. The tests were conducted by a team of researchers from NASA GRC, Gulfstream Aerospace Corporation, University of Illinois at Urbana-Champaign, and the University of Virginia
Inlet Flow Control and Prediction Technologies for Embedded Propulsion Systems
NASA Technical Reports Server (NTRS)
McMillan, Michelle L.; Mackie, Scott A.; Gissen, Abe; Vukasinovic, Bojan; Lakebrink, Matthew T.; Glezer, Ari; Mani, Mori; Mace, James L.
Fail-safe, hybrid, flow control (HFC) is a promising technology for meeting high-speed cruise efficiency, low-noise signature, and reduced fuel-burn goals for future, Hybrid-Wing-Body (HWB) aircraft with embedded engines. This report details the development of HFC technology that enables improved inlet performance in HWB vehicles with highly integrated inlets and embedded engines without adversely affecting vehicle performance. In addition, new test techniques for evaluating Boundary-Layer-Ingesting (BLI)-inlet flow-control technologies developed and demonstrated through this program are documented, including the ability to generate a BLI-like inlet-entrance flow in a direct-connect, wind-tunnel facility, as well as, the use of D-optimal, statistically designed experiments to optimize test efficiency and enable interpretation of results. Validated improvements in numerical analysis tools and methods accomplished through this program are also documented, including Reynolds-Averaged Navier-Stokes CFD simulations of steady-state flow physics for baseline, BLI-inlet diffuser flow, as well as, that created by flow-control devices. Finally, numerical methods were employed in a ground-breaking attempt to directly simulate dynamic distortion. The advances in inlet technologies and prediction tools will help to meet and exceed "N+2" project goals for future HWB aircraft.
Velocity profile of water vapor inside a cavity with two axial inlets and two outlets
NASA Astrophysics Data System (ADS)
Guadarrama-Cetina, Josķ; Ruiz ChavarrĒa, Gerardo
To study the dynamics of Breath Figure phenomenon, a control of both the rate of flow and temperature of water vapor is required. The experimental setup widely used is a non hermetically closed chamber with cylindrical geometry and axial inlets and outlets. In this work we present measurements in a cylindrical chamber with diameter 10 cm and 1.5 cm height, keeping a constant temperature (10 ░C). We are focused in the velocity field when a gradient of the temperatures is produced between the base plate and the vapor. With a flux of water vapor of 250 mil/min at room temperature (21 ░C), the Reynolds number measured in one inlet is 755. Otherwise, the temperatures of water vapor varies from 21 to 40 ░C. The velocity profile is obtained by hot wire anemometry. We identify the stagnations and the possibly instabilities regions for an empty plate and with a well defined shape obstacle as a fashion sample. Facultad de Ciencias, UNAM.
High-temperature turbine technology program hot-gas path development test. Part II. Testing
Horner, M.W.
This topical report of the US Department of Energy High-Temperature Turbine Technology (DOE-HTTT) Phase II program presents the results of testing full-scale water-cooled first-stage and second-stage turbine nozzles at design temperature and pressure to verify that the designs are adequate for operation in a full-scale turbine environment. Low-cycle fatigue life of the nozzles was demonstrated by subjecting cascade assemblies to several hundred simulated startup/shutdown turbine cycles. This testing was accomplished in the Hot-Gas Path Development Test Stand (HGPDTS), which is capable of evaluating full-scale combustion and turbine nozzle components. A three-throat cascade of the first-stage turbine nozzle was successfully tested at a nozzle inlet gas temperature of 2630/sup 0/F and a nozzle inlet pressure of 11.3 atmospheres. In addition to steady-state operation at the design firing temperature, the nozzle cascade was exposed to a simulated startup/shutdown turbine cycle by varying the firing temperature. A total of 42 h at the design point and 617 thermal cycles were accumulated during the test periods. First-stage nozzle test results show that measured metal and coolant temperatures correspond well to the predicted design values. This nozzle design has been shown to be fully satisfactory for the application (2600/sup 0/F), with growth capability to 3000/sup 0/F firing temperature. A post-test metallurgical examination of sectioned portions of the tested nozzles shows a totally bonded structure, confirming the test results and attesting to the successful performance of water-cooled composite nozzle hardware.
The US Environmental Protection Agency in cooperation with the State of New Jersey evaluated chemical filtration and distillation technologies designed to recycle automotive and heavy-duty engine coolants. These evaluations addressed the product quality, waste reduction and econo...
Transient two-phase performance of LOFT reactor coolant pumps
Chen, T.H.; Modro, S.M.
Performance characteristics of Loss-of-Fluid Test (LOFT) reactor coolant pumps under transient two-phase flow conditions were obtained based on the analysis of two large and small break loss-of-coolant experiments conducted at the LOFT facility. Emphasis is placed on the evaluation of the transient two-phase flow effects on the LOFT reactor coolant pump performance during the first quadrant operation. The measured pump characteristics are presented as functions of pump void fraction which was determined based on the measured density. The calculated pump characteristics such as pump head, torque (or hydraulic torque), and efficiency are also determined as functions of pump void fractions. The importance of accurate modeling of the reactor coolant pump performance under two-phase conditions is addressed. The analytical pump model, currently used in most reactor analysis codes to predict transient two-phase pump behavior, is assessed.
Investigation of cleaner technologies to minimize automotive coolant wastes
Randall, P.M.
The U.S. Environmental Protection Agency in cooperation with the State of New Jersey evaluated chemical filtration and distillation technologies designed to recycle automotive and heavy-duty engine coolants. These evaluations addressed the product quality, waste reduction, and economic issues. In addition, the authors examined the potential for substituting propylene glycol for ethylene glycol based engine coolant formulations. (Copyright (c) 1993 Butterworth-Heinemann Ltd.)
Optimized Coolant-Flow Diverter For Increased Bearing Life
NASA Technical Reports Server (NTRS)
Subbaraman, Maria R.; Butner, Myles F.
Coolant-flow diverter for rolling-element bearings in cryogenic turbopump designed to enhance cooling power of flow in contact with bearings and thereby reduce bearing wear. Delivers jets of coolant as close as possible to hot spots at points of contact between balls and race. Also imparts swirl that enhances beneficial pumping effect. Used with success in end ball bearing of high-pressure-oxidizer turbopump.
Reactor coolant seal testing under station blackout conditions
Failures of reactor coolant pump (RCP) seals that could result in a significant loss-of-coolant inventory are of current concern to the US Nuclear Regulatory Commission. Particular attention is being focused on seal behavior during station blackout conditions, when failure of on-site emergency diesel generators occurs simultaneously with loss of all off-site alternating current power. Under these conditions, both seal injection
Analysis of thrust augmentation of turbojet engines by water injection at compressor inlet including charts for calculating compression processes with water injection
NASA Technical Reports Server (NTRS)
Wilcox, E Clinton; Trout, Arthur M
A psychrometric chart having total pressure (sum of partial pressures of air and water vapor) as a variable, a Mollier diagram for air saturated with water vapor, and charts showing the thermodynamic properties of various air-water vapor and exhaust gas-water vapor mixtures are presented as aids in calculating the thrust augmentation of a turbojet engine resulting from the injection of water at the compressor inlet. Curves are presented that show the theoretical performance of the augmentation method for various amounts of water injected and the effects of varying flight Mach number, altitude, ambient-air temperature, ambient relative humidity, compressor pressure ratio, and inlet-diffuser efficiency. Numerical examples, illustrating the use of the psychrometric chart and the Mollier diagram in calculating both compressor-inlet and compressor-outlet conditions when water is injected at the compressor inlet, are presented.
Demonstrated survivability of a high temperature optical fiber cable on a 1500 pound thrust rocket chamber
NASA Technical Reports Server (NTRS)
Sovie, Amy L.
A demonstration of the ability of an existing optical fiber cable to survive the harsh environment of a rocket engine was performed at the NASA Lewis Research Center. The intent of this demonstration was to prove the feasibility of applying fiber optic technology to rocket engine instrumentation systems. Extreme thermal transient tests were achieved by wrapping a high temperature optical fiber, which was cablized for mechanical robustness, around the combustion chamber outside wall of a 1500 lb Hydrogen-Oxygen rocket engine. Additionally, the fiber was wrapped around coolant inlet pipes which were subject to near liquid hydrogen temperatures. Light from an LED was sent through the multimode fiber, and output power was monitored as a function of time while the engine was fired. The fiber showed no mechanical damage after 419 firings during which it was subject to transients from 30 K to 350 K, and total exposure time to near liquid hydrogen temperatures in excess of 990 seconds. These extreme temperatures did cause attenuation greater than 3 dB, but the signal was fully recovered at room temperature. This experiment demonstrates that commercially available optical fiber cables can survive the environment seen by a typical rocket engine instrumentation system, and disclose a temperature-dependent attenuation observed during exposure to near liquid hydrogen temperatures.
Corrugated and Composite Nozzle-Inlets for Thrust and Noise Benefits
NASA Technical Reports Server (NTRS)
Gilinsky, M.; Blankson, I. M.; Gromov, V. G.; Sakharov, V. I.
The following research results are based on development of an approach previously proposed and investigated in for optimum nozzle design to obtain maximum thrust. The design was denoted a Telescope nozzle. A Telescope nozzle contains one or several internal designs, which are inserted at certain locations into a divergent conical or planar main nozzle near its exit. Such a design provides additional thrust augmentation over 20% by comparison with the optimum single nozzle of equivalent lateral area, What is more, experimental acoustic tests have discovered an essential noise reduction due to application of Telescope nozzles. In this paper, some additional theoretical results are presented for Telescope nozzles and a similar approach is applied for aero-performance improvement of a supersonic inlet. Numerical simulations were conducted for supersonic flow into the divergent portion of a 2D or axisymmetric nozzle with several plane or conical designs as well as into a 2D or axisymmetric supersonic inlet with a forebody. The Kryko-Godunov marching numerical scheme for inviscid supersonic flows was used. Several cases were tested using the NASA CFL3d and IM/MSU Russian codes based on the full Navier-Stokes equations. Numerical simulations were conducted for non reacting flows (both codes) as well as for real high temperature gas flows with non-equilibrium chemical reactions (the latter code). In general, these simulations have confirmed essential benefits of Telescope design applications in propulsion system. Some preliminary numerical simulations of several typical inlet designs were conducted with the goal of inlet design optimization for maneuvering flight conditions.
Control of Inflow Distortion in a Scarf Inlet
NASA Technical Reports Server (NTRS)
Gerhold, Carl H.; Clark, Lorenzo R.; Biedron, Robert T.
The scarf inlet has the potential to reduce aircraft inlet noise radiation to the ground by reflecting it into the space above the engine. Without forward motion of the engine, the non-symmetry of the inlet causes inflow distortion which generates noise that is greater than the noise reduction of the scarf. However, acoustic evaluations of aircraft engines are often done on static test stands. A method to reduce inflow distortion by boundary layer suction is proposed and evaluated using a model of a high bypass ratio engine located in an anechoic chamber. The design goal of the flow control system is to make the inflow to the inlet circumferentially uniform and to eliminate reversed flow. This minimizes the inflow distortion and allows for acoustic evaluation of the scarf inlet on a static test stand. The inlet boundary layer suction effectiveness is evaluated both by aerodynamic and by acoustic measurements. Although the design goal is not met, the control system is found to have a beneficial effect on the engine operation, reducing blade stall and speed variation. This is quantified by two acoustic benefits, reduction both of the variability of tone noise and of the low frequency wideband noise due to the inflow distortion. It is felt that a compromise in the manufacture of the control hardware contributes to the inability of the control system to perform as expected from the analysis. The control system with sufficient authority is felt to have the potential to permit reliable acoustic testing in a static configuration of engines with non-symmetric inlets. Because the control system can improve operation of the engine, it may also have the potential to reduce noise and vibration and enhance engine longevity during low speed ground operations in the terminal area.
Nuclear-radiation-actuated valve. [Patent application; for increasing coolant flow to blanket
Christiansen, D.W.; Schively, D.P.
The present invention relates to a breeder reactor blanket fuel assembly coolant system valve which increases coolant flow to the blanket fuel assembly to minimize long-term temperature increases caused by fission of fissile fuel created from fertile fuel through operation of the breeder reactor. The valve has a valve first part (such as a valve rod with piston) and a valve second part (such as a valve tube surrounding the valve rod, with the valve tube having side slots surrounding the piston). Both valve parts have known nuclear radiation swelling characteristics. The valve's first part is positioned to receive nuclear radiation from the nuclear reactor's fuel region. The valve's second part is positioned so that its nuclear radiation induced swelling is different from that of the valve's first part. The valve's second part also is positioned so that the valve's first and second parts create a valve orifice which changes in size due to the different nuclear radiation caused swelling of the valve's first part compared to the valve's second part. The valve may be used in a nuclear reactor's core coolant system.
Assessment of fiber optic sensors for aging monitoring of industrial liquid coolants
NASA Astrophysics Data System (ADS)
Riziotis, Christos; El Sachat, Alexandros; Markos, Christos; Velanas, Pantelis; Meristoudi, Anastasia; Papadopoulos, Aggelos
Lately the demand for in situ and real time monitoring of industrial assets and processes has been dramatically increased. Although numerous sensing techniques have been proposed, only a small fraction can operate efficiently under harsh industrial environments. In this work the operational properties of a proposed photonic based chemical sensing scheme, capable to monitor the ageing process and the quality characteristics of coolants and lubricants in industrial heavy machinery for metal finishing processes is presented. The full spectroscopic characterization of different coolant liquids revealed that the ageing process is connected closely to the acidity/ pH value of coolants, despite the fact that the ageing process is quite complicated, affected by a number of environmental parameters such as the temperature, humidity and development of hazardous biological content as for example fungi. Efficient and low cost optical fiber sensors based on pH sensitive thin overlayers, are proposed and employed for the ageing monitoring. Active sol-gel based materials produced with various pH indicators like cresol red, bromophenol blue and chorophenol red in tetraethylorthosilicate (TEOS), were used for the production of those thin film sensitive layers deposited on polymer's and silica's large core and highly multimoded optical fibers. The optical characteristics, sensing performance and environmental robustness of those optical sensors are presented, extracting useful conclusions towards their use in industrial applications.
Influence of coolant pH on corrosion of 6061 aluminum under reactor heat transfer conditions
Pawel, S.J.; Felde, D.K.; Pawel, R.E.
To support the design of the Advanced Neutron Source (ANS), an experimental program was conducted wherein aluminum alloy specimens were exposed at high heat fluxes to high-velocity aqueous coolants in a corrosion test loop. The aluminum alloys selected for exposure were candidate fuel cladding materials, and the loop system was constructed to emulate the primary coolant system for the proposed ANS reactor. One major result of this program has been the generation of an experimental database defining oxide film growth on 6061 aluminum alloy cladding. Additionally, a data correlation was developed from the database to permit the prediction of film growth for any reasonable thermal-hydraulic excursion. This capability was utilized effectively during the conceptual design stages of the reactor. During the course of this research, it became clear that the kinetics of film growth on the aluminum alloy specimens were sensitively dependent on the chemistry of the aqueous coolant and that relatively small deviations from the intended pH 5 operational level resulted in unexpectedly large changes in the corrosion behavior. Examination of the kinetic influences and the details of the film morphology suggested that a mechanism involving mass transport from other parts of the test loop was involved. Such a mechanism would also be expected to be active in the operating reactor. This report emphasizes the results of experiments that best illustrate the influence of the nonthermal-hydraulic parameters on film growth and presents data to show that comparatively small variations in pH near 5.0 invoke a sensitive response. Simply, for operation in the temperature and heat flux range appropriate for the ANS studies, coolant pH levels from 4.5 to 4.9 produced significantly less film growth than those from pH 5.1 to 6. A mechanism for this behavior based on the concept of treating the entire loop as an active corrosion system is presented.
A study of fractionating inlet systems for the dichotomous air sampler
Ripps, Gerald Joseph
APPROACH Introduction Particle Generation Particle Sizing Static Testing Wind Tunnel Testing Filter Analysis RESULTS OF TESTS WITH DIFFERENT INLET DESIGNS 13 13 15 17 Introduction Inlet Design Cone Inlet Open Top Inlet Narrow Slit Inlet 17... with the dichotomous air sampler. The test devices were operated under simulated field conditions and used to collect monodisperse aerosol particles of known sizes. The results of this study will be available to environmental regulatory agencies to provide insight...
Characterization of a storm surge exposed arctic inlet: Shaktoolik, Alaska
NASA Astrophysics Data System (ADS)
Ohman, K. A.; Erikson, L. H.; Kinsman, N.
The Inupiaq community of Shaktoolik, in northwestern Alaska is constructed on a low-lying barrier spit located on Norton Sound. The inhabited portion of the spit is ~200m across and vulnerable to flooding from both the open water and lagoon sides during storm events. Previously modeled storm events estimate elevated sea surfaces reaching a maximum storm surge of 6.4m (21 feet) in the Norton Sound region. Historical storm events have been documented every few years in the region, usually occurring during the fall, but storm surge heights in Shaktoolik have never been recorded. An inlet is located at the northern terminus of the barrier spit, adjacent to the community, and provides access for fishing boats to and from the sheltered lagoon. This research focuses on the responses of Shaktoolik's inlet to storm surge and subsequent flooding of the spit. Fieldwork conducted in July 2011 focused on mapping the on land and nearshore coastal morphology of the barrier system. Prior to this, limited baseline data about the Shaktoolik coastal zone was available. The research goals for this project are to understand the morphodynamics of the inlet and surrounding coastal area and to analyze impacts on the inlet by storm surge events. This study is in support of a larger geohazard mapping project with the Alaska Department of Geological and Geophysical Surveys. Onshore, beach profiles and wrackline positions were surveyed, and grain size samples were collected north and south of the inlet. These data provide insight into the longshore sediment transport patterns, past flood levels, and the extent of possible flooding and inundation in the future. In the nearshore, bathymetric data, current velocity measurements, and suspended and bedload sediment samples were obtained seaward of the spit, in the inlet, and within the lagoon. Nearshore measurements characterize the inlet channel depths and composition, and locate areas of sediment deposition. In addition, three months of fall seasonal water levels were collected hourly on the lagoon side of the inlet in order to capture tide ranges and storm surge heights. Further analysis will include historical storm surge flooding estimates for Shaktoolik, water height ranges for storm events, and inlet current velocities and discharge rates.
Experimental study of different control methods for hypersonic air inlets
NASA Astrophysics Data System (ADS)
Falempin, F.; Goldfeld, M. A.; Semenova, Yu. V.; Starov, A. V.; Timofeev, K. Yu.
An experimental study of different control methods for hypersonic air inlets aimed at ensuring reliable starting of these apparatuses and improving their operating characteristics in the range of Mach numbers 2 to 8 is reported. Conditions for boundary-layer separation and possibilities for preventing this separation by using modified diffuser configurations and/or perforation bleedage are examined. An air-inlet model was tested for operation in an intermittent wind tunnel and in a blow-down wind tunnel respectively in the Mach-number ranges 2 to 6 and 5 to 8. Distributions of static and total air pressures on the walls of the model and in several cross sections were measured, together with air flow coefficients and total-pressure recovery coefficients. Perforation bleedage is shown to offer an efficient means to facilitate air-inlet starting. Perforation bleed has enabled a more than two-fold increase in the air flow coefficient on the model with sidewalls. A perforation-bleed panel installed closer to the air-inlet throat proved to be more efficient. The possibility of sudden starting of the air-inlet apparatus was checked in the intermittent wind tunnel; it was shown that, here, sudden starting could be realized. The data obtained in the intermittent wind tunnel proved to be consistent with data obtained in the blow-down wind tunnel with up to 150-ms blowdown time.
Development of the Planar Inlet Design and Analysis Process (PINDAP)
NASA Technical Reports Server (NTRS)
Gruber, Christopher R.
The aerodynamic development of an engine inlet requires a comprehensive program of both wind tunnel testing and Computational Fluid Dynamics (CFD) simulations. To save time and resources, much "testing" is done using CFD before any design ever enters a wind tunnel. The focus of my project this summer is on CFD analysis tool development. In particular, I am working to further develop the capabilities of the Planar Inlet Design and Analysis Process (PINDAP). "PINDAP" is a collection of computational tools that allow for efficient and accurate design and analysis of the aerodynamics about and through inlets that can make use of a planar (two-dimensional or axisymmetric) geometric and flow assumption. PINDAP utilizes the WIND CFD flow solver, which is capable of simulating the turbulent, compressible flow field. My project this summer is a continuation of work that I performed for two previous summers. Two years ago, I used basic features of the PINDAP to design a Mach 5 hypersonic scramjet engine inlet and to demonstrate the feasibility of the PINDAP. The following summer, I worked to develop its geometry and grid generation capabilities to include subsonic and supersonic inlets, complete bodies and cowls, conic leading and trailing edges, as well as airfoils. These additions allowed for much more design flexibility when using the program.
Experimental Investigation of Flow Control in a Compact Inlet Duct
NASA Astrophysics Data System (ADS)
Debronsky, Brian; Amitay, Michael
Attractive to aircraft designers are compact inlets, which implement curved flow paths from the air intake of the engine to the compressor face. A compromise must be made between the compactness of the inlet and its aerodynamic performance. The aerodynamic purpose of inlets is to decelerate the oncoming flow before reaching the engine while minimizing total pressure loss, unsteadiness and distortion. Low length-to-diameter ratio inlets have a high degree of curvature, which inevitably causes flow separation and secondary flows. To address this issue, active flow control was implemented on a compact (L/D = 1.6) inlet to improve its performance metrics. The experiments were conducted at a Mach number of 0.44, where the actuation from an array of skewed and pitched jets produced streamwise vortices opposite to the secondary flow structures. The actuation resulted in an improved pressure recovery at the aerodynamic interface plane (AIP), where both the strength of the secondary structures and the flow unsteadiness were significantly reduced. Northrop Grumman Corporation.
Modeling the Effects of Coolant Application in Friction Stir Processing on Material Microstructure Using 3D CFD Analysis
NASA Astrophysics Data System (ADS)
Aljoaba, Sharif; Dillon, Oscar; Khraisheh, Marwan; Jawahir, I. S.
The ability to generate nano-sized grains is one of the advantages of friction stir processing (FSP). However, the high temperatures generated during the stirring process within the processing zone stimulate the grains to grow after recrystallization. Therefore, maintaining the small grains becomes a critical issue when using FSP. In the present reports, coolants are applied to the fixture and/or processed material in order to reduce the temperature and hence, grain growth. Most of the reported data in the literature concerning cooling techniques are experimental. We have seen no reports that attempt to predict these quantities when using coolants while the material is undergoing FSP. Therefore, there is need to develop a model that predicts the resulting grain size when using coolants, which is an important step toward designing the material microstructure. In this study, two three-dimensional computational fluid dynamics (CFD) models are reported which simulate FSP with and without coolant application while using the STAR CCM+ CFD commercial software. In the model with the coolant application, the fixture (backing plate) is modeled while is not in the other model. User-defined subroutines were incorporated in the software and implemented to investigate the effects of changing process parameters on temperature, strain rate and material velocity fields in, and around, the processed nugget. In addition, a correlation between these parameters and the Zener-Holloman parameter used in material science was developed to predict the grain size distribution. Different stirring conditions were incorporated in this study to investigate their effects on material flow and microstructural modification. A comparison of the results obtained by using each of the models on the processed microstructure is also presented for the case of Mg AZ31B-O alloy. The predicted results are also compared with the available experimental data and generally show good agreement.
Development and Transient Analysis of a Helical-coil Steam Generator for High Temperature Reactors
Nathan V. Hoffer; Nolan A. Anderson; Piyush Sabharwall
A high temperature gas-cooled reactor (HTGR) is under development by the Next Generation Nuclear Plant (NGNP) Project at the Idaho National Laboratory (INL). Its design emphasizes electrical power production which may potentially be coupled with process heat for hydrogen production and other industrial applications. NGNP is considering a helical-coil steam generator for the primary heat transport loop heat exchanger based on its increased heat transfer and compactness when compared to other steam generators. The safety and reliability of the helical-coil steam generator is currently under evaluation as part of the development of NGNP. Transients, such as loss of coolant accidents (LOCA), are of interest in evaluating the safety of steam generators. In this study, a complete steam generator inlet pipe break (double ended pipe break) LOCA was simulated by an exponential loss of primary side pressure. For this analysis, a model of the helical-coil steam generator was developed using RELAP5-3D, an INL inhouse systems analysis code. The steam generator model behaved normally during the transient simulating the complete steam generator inlet pipe break LOCA. Further analysis is required to comprehensively evaluate the safety and reliability of the helical-coil steam generator design in the NGNP setting.
Seasonal variability of the suspended particulate matter concentration in Chupa Inlet of the White Sea
NASA Astrophysics Data System (ADS)
Mityaev, M. V.; Berger, V. Ya.
Studies of the dynamics of the concentration of the suspended particulate matter (SPM) and Corg in the seawater of Chupa Inlet were performed for the three-year period of 2010-2012. In general, the concentration of SPM increased from the spring through the summer, decreased through the autumn period, and declined dramatically in the winter. The ratio of the organic matter in the SPM decreased gradually from the surface water layer to the bottom and averaged 61%. The abiotic factors affecting the SPM concentration and suspended organic matter were studied; the water temperature and tide events were named as the liming ones.
Monitoring seabird populations in areas of oil and gas development on the Alaskan Continental Shelf: Oceanic, shelf and coastal seabird assemblages at the mouth of a tidally-mixed estuary (Cook Inlet, Alaska). Final report
Piatt, J.F.
Surveys were conducted in July, 1992 to study the distribution and abundance of seabirds in a 12,500 sq km area of lower Cook Inlet, Alaska. Seabirds at the sea surface, fish below the surface (estimated acoustically), and sea surface temperature and salinity were recorded on 415 ten-minute transects covering 1225 linear km. Sea temperature and salinity (CTD) profiles of the water column and zooplankton tows were obtained on stations crossing the entrance to Cook Inlet.
Effects of selected design variables on three ramp, external compression inlet performance. [boundary layer control bypasses, and mass flow rate
NASA Technical Reports Server (NTRS)
Kamman, J. H.; Hall, C. L.
Two inlet performance tests and one inlet/airframe drag test were conducted in 1969 at the NASA-Ames Research Center. The basic inlet system was two-dimensional, three ramp (overhead), external compression, with variable capture area. The data from these tests were analyzed to show the effects of selected design variables on the performance of this type of inlet system. The inlet design variables investigated include inlet bleed, bypass, operating mass flow ratio, inlet geometry, and variable capture area.
Operating method for gas turbine with variable inlet vanes
Morishita, Susumu; Miyake, Yoshiyaki; Uchida, Seishi.
A method is described of operating a gas turbine engine having a centrifugal compressor which is driven by a high-pressure turbine, and wherein the centrifugal compressor is the only compressor of the engine, comprising the steps of: positioning a variable inlet guide vane at an inlet air passage of the centrifugal compressor for adjusting the air flow rate through the engine; and changing the orientation of the guide vane while keeping the speed of rotation of the engine at a high level near its rated value to control the output of the engine by controlling the air flow rate through the engine.
Development of a three-dimensional supersonic inlet flow analysis
NASA Technical Reports Server (NTRS)
Buggeln, R. C.; Mcdonald, H.; Levy, R.; Kreskovsky, J. P.
A method for computing three dimensional flow in supersonic inlets is described. An approximate set of governing equations is given for viscous flows which have a primary flow direction. The governing equations are written in general orthogonal coordinates. These equations are modified in the subsonic region of the flow to prevent the phenomenon of branching. Results are presented for the two sample cases: a Mach number equals 2.5 flow in a square duct, and a Mach number equals 3.0 flow in a research jet engine inlet. In the latter case the computed results are compared with the experimental data. A users' manual is included.
Large perturbation flow field analysis and simulation for supersonic inlets
NASA Technical Reports Server (NTRS)
Varner, M. O.; Martindale, W. R.; Phares, W. J.; Kneile, K. R.; Adams, J. C., Jr.
An analysis technique for simulation of supersonic mixed compression inlets with large flow field perturbations is presented. The approach is based upon a quasi-one-dimensional inviscid unsteady formulation which includes engineering models of unstart/restart, bleed, bypass, and geometry effects. Numerical solution of the governing time dependent equations of motion is accomplished through a shock capturing finite difference algorithm, of which five separate approaches are evaluated. Comparison with experimental supersonic wind tunnel data is presented to verify the present approach for a wide range of transient inlet flow conditions.
Advanced two-stage compressor program design of inlet stage
NASA Technical Reports Server (NTRS)
Bryce, C. A.; Paine, C. J.; Mccutcheon, A. R. S.; Tu, R. K.; Perrone, G. L.
The aerodynamic design of an inlet stage for a two-stage, 10/1 pressure ratio, 2 lb/sec flow rate compressor is discussed. Initially a performance comparison was conducted for an axial, mixed flow and centrifugal second stage. A modified mixed flow configuration with tandem rotors and tandem stators was selected for the inlet stage. The term conical flow compressor was coined to describe a particular type of mixed flow compressor configuration which utilizes axial flow type blading and an increase in radius to increase the work input potential. Design details of the conical flow compressor are described.
Optimal exposure of thoracic inlet vascular structures: transmanubrial approach.
Smythe, W Roy; Reznik, Scott I
Exposure of the neurovascular structures of the thoracic inlet is limited by the bony thorax and clavicle. A cervicothoracic approach with resection of the medial one third of the clavicle or total claviculectomy provide excellent exposure but may render the patient with a significant cosmetic and functional defect. We describe a transmanubrial approach that preserves rigid fixation of the shoulder girdle and allows full access to the thoracic inlet. This technique is straightforward and may be easily modified to fit the particular needs of the patient, including access to the proximal brachiocephalic vessels, the hilum of the lung and the vertebral bodies of the lower cervical and upper thoracic spine. PMID:18342731
Turbidity-current channels in Queen Inlet, Glacier Bay, Alaska
Carlson, P.R.; Powell, R.D.; Rearic, D.M.
Queen Inlet is unique among Glacier Bay fjords because it alone has a branching channel system incised in the Holocene sediment fill of the fjord floor. Queen Inlet and other known channel-containing fjords are marine-outwash fjords; the tidewater glacial fjords do not have steep delta fronts on which slides are generated and may not have a sufficient reservoir of potentially unstable coarse sediment to generate channel-cutting turbidity currents. Presence or absence of channels, as revealed in the ancient rock record, may be one criterion for interpreting types of fjords. -Authors
Computer programs for calculating potential flow in propulsion system inlets
NASA Technical Reports Server (NTRS)
Stockman, N. O.; Button, S. L.
In the course of designing inlets, particularly for VTOL and STOL propulsion systems, a calculational procedure utilizing three computer programs evolved. The chief program is the Douglas axisymmetric potential flow program called EOD which calculates the incompressible potential flow about arbitrary axisymmetric bodies. The other two programs, original with Lewis, are called SCIRCL AND COMBYN. Program SCIRCL generates input for EOD from various specified analytic shapes for the inlet components. Program COMBYN takes basic solutions output by EOD and combines them into solutions of interest, and applies a compressibility correction.
Relevance of Infragravity Waves in a Wave Dominated Shallow Inlet
NASA Astrophysics Data System (ADS)
Olabarrieta, M.; Bertin, X.
Infragravity (IG) waves have received a growing attention over the last decade and they have been shown to partly control dune erosion, barrier breaching, development of seiches in harbors or the circulation on fringing reefs. Although the relevance IG waves in surf and swash zone dynamics is well recognized, their dynamics and effects on tidal inlets and estuaries have not been analyzed. This study investigates the importance of IG waves at Albufeira Lagoon Inlet, a shallow wave-dominated inlet located on the western Coast of Portugal. Water levels and currents were measured synchronously during a two-day field experiment carried out at Albufeira Lagoon Inlet in September 2010. Apart from the tidally induced gravity wave modulations and wave induced setup inside the lagoon, an important IG wave contribution was identified. Low frequency oscillations were noticeable in the free surface elevation records and produced fluctuations of up to 100% in current intensities. While IG waves in the ebb shoal were present during the whole tidal cycle, the absence of IG waves characterized the ebbing tide inside the lagoon. The energy in the IG frequency band gradually increased from low tide to high tide, and disappeared during the ebbing tide. The modeling system Xbeach was applied to hindcast the hydrodynamics during the field experiment period. The model captures the main physics related with the IG wave generation and propagation inside the inlet, and reproduced the IG blocking during the ebb as identified in the measurements. This behavior was explained by the combination of advection and wave blocking induced by opposing tidal currents. Both measurements and numerical results suggested the bound wave release as the dominant mechanism responsible for IG wave generation. The fact that IG waves only propagate at flood tide has strong implications on the sediment balance of the inlet and contribute to inlet infilling under energetic wave conditions. It is expected that IG waves contribute to the shoaling or closure of wave-dominated inlets during winter months, although this hypothesis will have to be verified at other sites.
Cladding embrittlement during postulated loss-of-coolant accidents.
Billone, M.; Yan, Y.; Burtseva, T.; Daum, R.; Nuclear Engineering Division
The effect of fuel burnup on the embrittlement of various cladding alloys was examined with laboratory tests conducted under conditions relevant to loss-of-coolant accidents (LOCAs). The cladding materials tested were Zircaloy-4, Zircaloy-2, ZIRLO, M5, and E110. Tests were performed with specimens sectioned from as-fabricated cladding, from prehydrided (surrogate for high-burnup) cladding, and from high-burnup fuel rods which had been irradiated in commercial reactors. The tests were designed to determine for each cladding material the ductile-to-brittle transition as a function of steam oxidation temperature, weight gain due to oxidation, hydrogen content, pre-transient cladding thickness, and pre-transient corrosion-layer thickness. For short, defueled cladding specimens oxidized at 1000-1200 C, ring compression tests were performed to determine post-quench ductility at {le} 135 C. The effect of breakaway oxidation on embrittlement was also examined for short specimens oxidized at 800-1000 C. Among other findings, embrittlement was found to be sensitive to fabrication processes--especially surface finish--but insensitive to alloy constituents for these dilute zirconium alloys used as cladding materials. It was also demonstrated that burnup effects on embrittlement are largely due to hydrogen that is absorbed in the cladding during normal operation. Some tests were also performed with longer, fueled-and-pressurized cladding segments subjected to LOCA-relevant heating and cooling rates. Recommendations are given for types of tests that would identify LOCA conditions under which embrittlement would occur.
Experimental investigation of water injection in subsonic diffuser of a conical inlet operation at free-stream Mach number of 2.5
NASA Technical Reports Server (NTRS)
Beke, Andrew
A spike-type nose inlet with sharp-lip cowl was investigated at a free-stream Mach number of 2.5 with water injection in its 16-inch diameter, 11-foot-long subsonic diffuser section. Inlet total temperature of exit with liquid-air ratios of about 0.04 with no apparent change in the critical pressure recovery. The observed temperature drops were less than the theoretically predicted values, and the amount of water evaporated was 35 to 50 percent less than that theoretically possible.
A comparison of predicted and measured inlet distortion flows in a subsonic axial inlet flow compressor rotor
NASA Technical Reports Server (NTRS)
Owen, Albert K.
Detailed flow measurements were taken inside an isolated axial compressor rotor operating subsonically near peak efficiency. These Laser Anemometer measurements were made with two inlet velocity profiles. One profile consisted of an unmodified baseline flow, and the second profile was distorted by placing axisymmetric screens on the hub and shroud well upstream of the rotor. A detailed comparison in the rotor relative reference frame between a Navier-Stokes solver and the measured experimental results showed good agreement between the predicted and measured flows. A primary flow is defined in the rotor and deviations and the computed predictions is made to assess the development of a passage vortex due to the distortion of the inlet flow. Computer predictions indicate that a distorted inlet profile has a minimal effect on the development of the flow in the rotor passage and the resulting passage vortex.
Sloshing of coolant in a seismically isolated reactor
Wu, Ting-shu; Gvildys, J.; Seidensticker, R.W.
During a seismic event, the liquid coolant inside the reactor vessel will have sloshing motion which is a low-frequency phenomenon. In a reactor system incorporated with seismic isolation, the isolation frequency usually is also very low. There is concern on the potential amplification of sloshing motion of the liquid coolant. This study investigates the effects of seismic isolation on the sloshing of liquid coolant inside the reactor vessel of a liquid metal cooled reactor. Based on a synthetic ground motion whose response spectra envelop those specified by the NRC Regulator Guide 1.60, it is found that the maximum sloshing wave height increases from 18 in. to almost 30 in. when the system is seismically isolated. Since higher sloshing wave may introduce severe impact forces and thermal shocks to the reactor closure and other components within the reactor vessel, adequate design considerations should be made either to suppress the wave height or to reduce the effects caused by high waves.
Mechanical characteristics of stability-bleed valves for a supersonic inlet. [for the YF-12 aircraft
NASA Technical Reports Server (NTRS)
Neiner, G. H.; Dustin, M. O.; Cole, G. L.
Mechanical characteristics of a set of direct-operated relief valves used in a throat-bypass stability-bleed system designed for the YF-12 aircraft inlet are described. A comparison of data taken before and after the windtunnel tests (at room temperature) showed that both the effective spring rate and the piston friction had decreased during the wind tunnel tests. In neither the effective spring rate nor the piston friction was the magnitude of change great enough to cause significant impairment of overall system effectiveness. No major valve mechanical problems were encountered in any of the tests. During high temperature bench tests, piston frictional drag increased. The friction returned to its initial room temperature value when the stability-bleed valve was disassembled and reassembled. The problem might be solved by using a different material for the piston sleeve bearing and the piston rings.
The Effect of the Inlet Mach Number and Inlet-boundary-layer Thickness on the Performance of a 23 Degree Conical-diffuser-tail-pipe Combination
NASA Technical Reports Server (NTRS)
Persh, Jerome
An investigation was conducted to determine the effect of the inlet Mach number and entrance-boundary-layer thickness on the performance of a 23 degree 21-inch conical-diffuser - tail-pipe combination with a 2:1 area ratio. The air flows used in this investigation covered an inlet Mach number range from 0.17 to 0.89 and corresponding Reynolds numbers of 1,700,000 to 7,070,000. Results are reported for two inlet-boundary-layer thicknesses. Over the entire range of flows, the mean value of the inlet displacement thickness is about 0.034 inch for the thinner inlet boundary layer and about 0.170 inch for the case of the thicker inlet boundary layer. The performance of the diffuser - tail-pipe combination is presented together with examples of longitudinal static-pressure distribution and the results of boundary-layer pressure surveys made at six points along the diffuser wall. The results indicated a progressive diminution of the static-pressure recovery and a steady increase in the total-pressure losses as the inlet Mach number was increased for both inlet-boundary-layer thicknesses. The ratio of actual static-pressure rise to that theoretically possible was much less and the total-pressure losses were greater for the case of the thicker inlet boundary layer throughout the speed range investigated. With the thinner inlet boundary layer, flow separation occurred at the diffuser exit at all inlet Mach numbers.Unseparated flow alternating with separated flow was observed near the inlet at the higher velocities. For the case of the thicker inlet boundary layer, the origin of the separated region occurred in the vicinity of the inlet-duct-diffuser junction section at all Mach numbers.
Choice of coolant in commercial tokamak power plants
Abdou, M.A.; Graumann, D.
The STARFIRE design study focused on solid tritium breeder blankets in order to minimize the stored chemical energy. The most suitable coolant candidates with solid tritium breeders are water and helium. This paper presents the results of a comparative study of the two coolants. The study shows clear advantages for the choice of pressurized water for the conditions of the STARFIRE tokamak power plant design. The study also identifies those areas where development is required in order to utilize the potential advantages of helium.
Hypersonic Magneto-Fluid-Dynamic Compression in Cylindrical Inlet
NASA Technical Reports Server (NTRS)
Shang, Joseph S.; Chang, Chau-Lyan
Hypersonic magneto-fluid-dynamic interaction has been successfully performed as a virtual leading-edge strake and a virtual cowl of a cylindrical inlet. In a side-by-side experimental and computational study, the magnitude of the induced compression was found to be depended on configuration and electrode placement. To better understand the interacting phenomenon the present investigation is focused on a direct current discharge at the leading edge of a cylindrical inlet for which validating experimental data is available. The present computational result is obtained by solving the magneto-fluid-dynamics equations at the low magnetic Reynolds number limit and using a nonequilibrium weakly ionized gas model based on the drift-diffusion theory. The numerical simulation provides a detailed description of the intriguing physics. After validation with experimental measurements, the computed results further quantify the effectiveness of a magnet-fluid-dynamic compression for a hypersonic cylindrical inlet. At a minuscule power input to a direct current surface discharge of 8.14 watts per square centimeter of electrode area produces an additional compression of 6.7 percent for a constant cross-section cylindrical inlet.
INDEX TO VOLUME 174AX INITIAL REPORTS Absecon Inlet Formation
INDEX TO VOLUME 174AX INITIAL REPORTS A Absecon Inlet Formation biostratigraphy, A:38 calcareous:1Ł65 background and objectives, A Suppl. 1:4Ł5 This index covers the Initial Reports of Volumes 174AX and 174AX by "A Suppl." followed by the chapter with a colon [A Suppl. (sum- mary):] or (A Suppl. 1:). The index
Several ambient air samplers that have been designated by the U. S. EPA as Federal Reference Methods (FRMs) for measuring particulate matter nominally less than 10 um (PM10) include the use of a particular inlet design that aspirates particulate matter from the atmosphere at 1...
Generation of Turbulent Inlet Conditions for Thermal Boundary Layer Simulations
Juan G. Araya
Realistic environments generally imply spatially evolving turbulent boundary layers, being the flat plate the typical example. In this case, periodic boundary conditions cannot be established in the streamwise direction as in fully developed flows in channels. For this reason, it is necessary to generate turbulent fluctuations at the inlet of the computational domain at every time step. Lund et al.
Separation control in a conical diffuser with an annular inlet
Kin Pong Lo; Christopher Elkins; John Eaton
Conical diffusers are commonly used in turbomachines to slow down the flow and recover pressure. In typical applications such as the diffuser behind a power turbine, the inlet to the diffuser is an annulus. A large central separation bubble forms if the central hub ends abruptly. A long streamlined tail cone can eliminate the separation, but it is often unfeasible
Preliminary Investigation of a New Type of Supersonic Inlet
NASA Technical Reports Server (NTRS)
Ferri, Antonio; Nucci, Louis M
A supersonic inlet with supersonic deceleration of the flow entirely outside of the inlet is considered. A particular arrangement with fixed geometry having a central body with a circular annular intake is analyzed, and it is shown theoretically that this arrangement gives high pressure recovery for a large range of Mach number and mass flow and therefore is practical for use on supersonic airplanes and missiles. For some Mach numbers the drag coefficient for this type of inlet is larger than the drag coefficient for the type of inlet with supersonic compression entirely inside, but the pressure recovery is larger for all flight conditions. The differences in drag can be eliminated for the design Mach number. Experimental results confirm the results of the theoretical analysis and show that pressure recoveries of 95 percent for Mach numbers of 1.33 and 1.52, 92 percent for a Mach number of 1.72, and 86 percent for a Mach number of 2.10 are possible, with the configurations considered. If the mass flow decreases, the total drag coefficient increases gradually and the pressure recovery does not change appreciably. The results of this work were first presented in a classified document issued in 1946.
Micro-Ramps for External Compression Low-Boom Inlets
NASA Technical Reports Server (NTRS)
Rybalko, Michael; Loth, Eric; Chima, Rodrick V.; Hirt, Stefanie M.; DeBonis, James R.
The application of vortex generators for flow control in an external compression, axisymmetric, low-boom concept inlet was investigated using RANS simulations with three-dimensional (3-D), structured, chimera (overset) grids and the WIND-US code. The low-boom inlet design is based on previous scale model 1- by 1-ft wind tunnel tests and features a zero-angle cowl and relaxed isentropic compression centerbody spike, resulting in defocused oblique shocks and a weak terminating normal shock. Validation of the methodology was first performed for micro-ramps in supersonic flow on a flat plate with and without oblique shocks. For the inlet configuration, simulations with several types of vortex generators were conducted for positions both upstream and downstream of the terminating normal shock. The performance parameters included incompressible axisymmetric shape factor, separation area, inlet pressure recovery, and massflow ratio. The design of experiments (DOE) methodology was used to select device size and location, analyze the resulting data, and determine the optimal choice of device geometry. The optimum upstream configuration was found to substantially reduce the post-shock separation area but did not significantly impact recovery at the aerodynamic interface plane (AIP). Downstream device placement allowed for fuller boundary layer velocity profiles and reduced distortion. This resulted in an improved pressure recovery and massflow ratio at the AIP compared to the baseline solid-wall configuration.
Investigation of Inlet Concepts for Maneuver Improvement at Transonic Speeds
NASA Technical Reports Server (NTRS)
Latham, E.; Gawienowski, J.; Meriwether, F.
A 15 percent scale lightweight fighter type inlet forebody was tested in the Ames 14 foot transonic wind tunnel at Mach numbers of 0.7, 0.9, and 1.04. The inlet was a two dimensional horizontal ramp system designed for a Mach number of 2.2. Four inlet devices designed to prevent or delay cowl-lip boundary layer separation or to improve the inlet internal flow characteristics at high angles of attack were investigated. The devices used to control cowl-lip separation consisted of cowl leading edge flaps, slotted flaps, and tangential blowing. To improve the internal flow characteristics, discrete jet nozzle flows were directed downstream and parallel to the duct surface in the subsonic diffuser to energize the wall boundary layer. The discrete jets used in the subsonic diffuser were also tested in combination with each of the cowl leading edge devices. Test measurements included engine-face total pressure recovery, steady state distortion, dynamic distortion, duct boundary layer profiles, and duct-surface static pressures.
Muir and Riggs Glaciers, Muir Inlet, Alaska - 1950
This, the first of two repeat photographs, documents significant changes that have occurred during the nine years between photographs A and B. Although Muir Glacier has retreated more than 3 kilometers and thinned more than 100 meters, exposing Muir Inlet, it remains connected with tributary Riggs G...
Cross contamination in dual inlet isotope ratio mass spectrometers
H. A. J. Meijer; R. E. M. Neubert; G. H. Visser
Since the early days of geochemical isotope ratio mass spectrometry there has always been the problem of cross contamination, i.e. the contamination of the sample gas with traces of reference gas (and vice versa) in a dual inlet system and the analyzer itself. This was attributable to valve leakages and could be corrected for. In modern leak-free machines this problem
D. Brett Martinson; Terry Thomas
Inlet filters are a common method for enhancing water quality in rainwater harvesting systems. They range from cheap cloth or gravel filters to complex and expensive multi-stage systems. Field experience has shown, however that filters often suffer from a lack of maintenance so self-cleaning is an advantage. Filters can clean themselves by dividing the water stream into two components; the
Simulation of Mist Transport for Gas Turbine Inlet Air Cooling
Ting Wang; Xianchang Li; Venu Pinninti
The output and efficiency of gas turbines are reduced significantly during the summer. Gas turbine inlet air-cooling is considered a simple and effective method to increase the power output as well as thermal efficiency. Among various cooling schemes, fog cooling (a direct evaporative cooling) has gained increasing popularity due to its simplicity and low installation cost. During fog cooling, water
HINCOF-1: a Code for Hail Ingestion in Engine Inlets
NASA Technical Reports Server (NTRS)
Gopalaswamy, N.; Murthy, S. N. B.
One of the major concerns during hail ingestion into an engine is the resulting amount and space- and time-wise distribution of hail at the engine face for a given geometry of inlet and set of atmospheric and flight conditions. The appearance of hail in the capture streamtube is invariably random in space and time, with respect to size and momentum. During the motion of a hailstone through an inlet, a hailstone undergoes several processes, namely impact with other hailstones and material surfaces of the inlet and spinner, rolling and rebound following impact; heat and mass transfer; phase change; and shattering, the latter three due to friction and impact. Taking all of these factors into account, a numerical code, designated HINCOF-I, has been developed for determining the motion hailstones from the atmosphere, through an inlet, and up to the engine face. The numerical procedure is based on the Monte-Carlo method. The report presents a description of the code, along with several illustrative cases. The code can be utilized to relate the spinner geometry - conical or, more effective, elliptical - to the possible diversion of hail at the engine face into the bypass stream. The code is also useful for assessing the influence of various hail characteristics on the ingestion and distribution of hailstones over the engine face.
Flow control optimization in a jet engine serpentine inlet ductĀ
Kumar, Abhinav
.....................................................................................................5 Figure 3: Effect of orientation on the interaction of synthetic jet with flow......................9 Figure 4: Flow visualization.............................................................................................10 Figure 5: Effect... zones............................................................19 Figure 8: Final mesh generated on the multi-block grid ..................................................20 Figure 9: Inlet face and symmetry face grid...
Membrane mass spectrometer inlet for quantitation of nitric oxide.
Lewis, R S; Deen, W M; Tannenbaum, S R; Wishnok, J S
Nitric oxide (NO) is an important physiological and biochemical messenger that may be involved in endogenous carcinogenesis and cell toxicity via formation of N-nitroso compounds or direct DNA damage by nitrosating agents arising from the reaction of NO with O2. To study the reaction of NO with O2 in model systems and the formation and disappearance of NO in more physiological systems such as cell cultures, we adapted and optimized a membrane mass spectrometer inlet specifically for such analyses. The inlet consisted of Silastic tubing inserted into a Swagelok 'tee', which was attached to the mass spectrometer via the tuning probe. Kinetics of NO disappearance can be followed under electron impact conditions until NO2 interferes via the formation of NO+ during fragmentation of NO2+. The aqueous NO concentration for minimum detection was determined to be 1.4 microM. The inlet response time to step changes in aqueous NO concentrations was 7.0 s, fast enough to permit real-time measurements of aqueous NO changes upon addition of O2. Finally, the depletion of aqueous NO was observed in the presence of O2. The relative steady state responses of inlets designed for gas or aqueous samples, and their relative response times, are explained by an analysis based on mass transfer theory. PMID:8431501
Coarse mode aerosol measurement using a Low Turbulence Inlet
NASA Astrophysics Data System (ADS)
Brooke, J.; Bart, M.; Trembath, J.; McQuaid, J. B.; Brooks, B. J.; Osborne, S.
The Sahara desert is a major natural source of global mineral dust emissions (Forster et al., 2007) through the mobilisation and lifting of dust particles into the atmosphere from dust storms. A significant fraction of this dust is in the aerosol coarse mode (Weinzierl et al., 2009). It is highlighted of the difficulty in making accurate and reliable measurements from an aircraft platform, particularly that of coarse mode aerosol (Wendisch et al., 2004). To achieve the measurement of a representative aerosol sample an aerosol inlet, on an aircraft, is required for the delivery of the sample to the instruments making the measurements. Inlet design can modify aerosol size distribution through either underestimating due to aerosol losses or overestimation due to enhancements. The Low Turbulence Inlet (LTI) was designed to improve inlet efficiency. This is achieved by reducing turbulence flow within the tip of the inlet, reducing impaction of particles to the walls of the inlet (Wilson et al., 2004). The LTI further maintains isokinetic sampling flow (free stream velocity, U0 and sampling velocity, U are equal to 1). Dust aerosol over the Sahara desert provides an excellent environment to test and quantify the capabilities of the LTI on the FAAM BAe 146, whilst enabling in-situ dust measurement. The LTI was operated during the Fennec field campaign in June 2011 with 11 flights during the campaign over Mauritania and Mali. We are using the LTI to provide critical information on the sampling characteristics of the inlet used by nearly all aerosol instruments inside the aircraft (AMS, Nephelometer, PSAP, and CCN). Inlet experiments were performed with identical Optical Particle Counters (OPC) connected to the rosemount and LTI with size distribution for each inlet measured and Rosemount enhancements determined. Rosemount inlet enhancements were determined to be 2 to 4 times for particles up to 2.5 Ąm. A key parameter in aerosol measurement is size distribution, in which the LTI is a critical method of sampling quantifiably coarse mode aerosol up to 12 Ąm into the FAAM BAe 146 aircraft. Size distributions for the Fennec field campaign will be presented. Size distributions from the LTI are found to compare well with that of the externally mounted aircraft probes. A Compact Cascade Impactor (CCI) was incorporated along the sample line and used to collect size segregated particle samples on polyurethane foam (PUF) substrates. X-Ray Diffraction (XRD) analysis is to be used to determine mineralogy of the dust samples. From known dust mineralogy it will be possible to infer the particles optical properties, specifically refractive index. This work was supported by the Natural Environment Research Council and the Met Office. Acknowledgements include Dr J. Wilson, University of Denver, Fennec, FAAM, DLR and Avalon. Forster et al., 2007; Intergovernmental Panel on Climate Change, Cambridge University Press. Weinzierl et al. 2006; Tellus B 61, 96-117. Wendisch et al. 2004; Bulletin of the American Meteorological Society 85, 89-91. Wilson et al. 2004; Aerosol Science and Technology 38, 790-802.
Effect of inlet and outlet shellside flow and heat transfer on the performance of HTGR straight tube heat exchangers
Since the mid-1970s, various high temperature gas-cooled reactor (HTGR) steam generator, auxiliary heat exchanger (AHE), recuperator, and intermediate heat exchanger (IHX) designs have been proposed that use straight tube configurations. Each of these designs requires 90-deg turns in the helium gas flow at the inlet and\\/or outlet of the tube bundle. To evaluate the effect of these turns on the
Comparison of the Aeroacoustics of Two Small-Scale Supersonic Inlets
NASA Technical Reports Server (NTRS)
Ng, Wing
An aerodynamic and acoustic investigation was performed on two small-scale supersonic inlets to determine which inlet would be more suitable for a High Speed Civil Transport (HSCT) aircraft during approach and takeoff flight conditions. The comparison was made between an axisymmetric supersonic P inlet and a bifurcated two-dimensional supersonic inlet. The 1/14 scale model supersonic inlets were used in conjunction with a 4.1 in (10.4 cm) turbofan engine simulator. A bellmouth was utilized on each inlet to eliminate lip separation commonly associated with airplane engine inlets that are tested under static conditions. Steady state measurements of the aerodynamic flowfield and acoustic farfield were made in order to evaluate the aeroacoustic performance of the inlets. The aerodynamic results show the total pressure recovery of the two inlets to be nearly identical, 99% at the approach condition and 98% at the takeoff condition. At the approach fan speed (60% design speed), there was no appreciable difference in the acoustic performance of either inlet over the entire 0 deg to 110 deg farfield measurement sector. The inlet flow field results at the takeoff fan speed (88% design speed), show the average inlet throat Mach number for the P inlet (Mach 0.52) to be approximately 2 times that of the 2D inlet (Mach 0.26). The difference in the throat Mach number is a result of the smaller throughflow area of the P inlet. This reduced area resulted in a 'soft choking' of the P inlet which lowered the tone and overall sound pressure levels of the simulator in the forward sector by an average of 9 dB and 3 dB, respectively, when compared to the 2D inlet.
Analysis data on samples from the TMI-2 reactor-coolant system and reactor-coolant bleed tank
Nitschke, R.L.
Two liquid samples from the Three Mile Island Unit 2 (TMI-2) Reactor Coolant System (RCS) and three liquid samples from the three Reactor Coolant Bleed Tanks (RCBT) were taken during the time period March 29, 1979 to August 14, 1980. The samples were analyzed for radionuclide concentrations by two independent laboratories, Exxon Nuclear Idaho Co., Inc. (ENICO) and EG and G Idaho, Inc. at the Idaho National Engineering Laboratory (INEL). The RCS sample taken on March 29, 1979 was also analyzed by Science Applications, Inc. (SAI). This report presents the methods used and the results of these analyes. 14 tables.
Compression-ignition Engine Performance at Altitudes and at Various Air Pressures and Temperatures
NASA Technical Reports Server (NTRS)
Moore, Charles S; Collins, John H
Engine test results are presented for simulated altitude conditions. A displaced-piston combustion chamber on a 5- by 7-inch single cylinder compression-ignition engine operating at 2,000 r.p.m. was used. Inlet air temperature equivalent to standard altitudes up to 14,000 feet were obtained. Comparison between performance at altitude of the unsupercharged compression-ignition engine compared favorably with the carburetor engine. Analysis of the results for which the inlet air temperature, inlet air pressure, and inlet and exhaust pressure were varied indicates that engine performance cannot be reliably corrected on the basis of inlet air density or weight of air charge. Engine power increases with inlet air pressure and decreases with inlet air temperatures very nearly as straight line relations over a wide range of air-fuel ratios. Correction factors are given.
Antimony tartrate corrosion inhibitive composition for coolant systems
Payerle, N.E.
An automobile coolant concentrate is described comprising (a) a liquid polyhydric alcohol chosen from the group consisting of ethylene glycol, propylene glycol, diethylene glycol and mixtures thereof, and (b) corrosion inhibitors in a corrosion inhibitory amount with respect to corrosion of lead-containing solders, the corrosion inhibitors comprising (i) an alkali metal antimony tartrate, and (ii) an azole compound.
Reactor coolant pump shaft seal behavior during blackout conditions
The United States Nuclear Regulatory Commission has classified the problem of reactor coolant pump seal failures as an unresolved safety issue. This decision was made in large part due to experimental results obtained from a research program developed to study shaft seal performance during station blackout and reported in this paper. Testing and analysis indicated a potential for pump seal
37. Upper level, chromate tanks (formerly provided coolant to missile ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
37. Upper level, chromate tanks (formerly provided coolant to missile guidance section, retractor cables for lock pin in front of ladder at left - Ellsworth Air Force Base, Delta Flight, Launch Facility, On County Road T512, south of Exit 116 off I-90, Interior, Jackson County, SD
This evaluation addresses the product quality, waste reduction and economic issues involved in recycling automotive and heavy-duty engine coolants. he specific recycling units evaluated are a fleet-size unit and a portable unit, both based on the technology of chemical filtration...
The U.S. Environmental Protection Agency in cooperation with the State of New Jersey evaluated chemical filtration and distillation technologies designed to recycle automotive and heavy-duty engine coolants. hese evaluations addressed the product quality, waste reduction, and eco...
Robotic inspection of PWR coolant pump casing welds
W. R. Pratt; J. W. Alford; J. B. Davis
As of January 1, 1995, the Swedish Nuclear Inspectorate began requiring more thorough inspections of cast stainless-steel components in nuclear power plants, including pressurized water reactor (PWR) reactor coolant pump (RCP) casings. The examination requirements are established by fracture mechanics analyses of component weldments and demonstrated test system detection capabilities. This may include full volumetric inspection or some portion thereof.
Advanced Mechanical Seals For Primary Coolant Pumps In PWR Service
David Zagres
Primary pumps are one of the most severe applications of mechanical end face shaft seals. Flowserve has leveraged its unique position as a major Original Equipment Manufacturer (OEM) for primary coolant pumps, backed by the in-house technology of one of the world's foremost suppliers of sealing equipment, to provide advanced mechanical seals for these stringent requirements. However, it has been
April 7, 1998 Studies of Coolant Compatibility with Beryllium
Cinabro, David
and to have thermal and flow properties similar to water. Attractive properties already known include that PF to have coolant and flow properties not much different from those of water and a radiation length longer physical properties between water and PF200. Property H 2 O PF200 Radiation Length (cm) 36:1 52 [1
Nano liquid-metal fluid as ultimate coolant
Kun-Quan Ma; Jing Liu
We proposed for the first time the concept of the nano liquid-metal fluid, aiming to establish an engineering route to make the highest conductive coolant. Using several widely accepted theoretical models for characterizing the nano fluid, the thermal conductivity enhancement of the liquid-metal fluid due to addition of more conductive nano particles was predicted. Further, the effects of particle size,
This evaluation addresses the product quality, waste reduction, and economic issues involved in recycling automotive and heavy-duty engine coolants for a facility such as the New Jersey Department of Transportation garage in Ewing, New Jersey. he specific recycling evaluated is b...
Effect of coolant chemistry on PWR radiation transport processes
Large, N.R.; Woodwark, D.R. (UKAEA Harwell Lab. (UK))
The effect of various PWR-type coolant chemistry regimes on the behavior of corrosion products has been studied in the DIDO Water Loop at Harwell. In this volume a compilation of operational and experimental data is presented. 63 figs., 50 tabs.
Effect of coolant chemistry on PWR radiation transport processes
Large, N.R.; Woodwark, D.R. (UKAEA Harwell Lab. (UK))
The effect of various PWR-type coolant chemistry regimes on the behavior of corrosion products has been studied in the DIDO Water Loop at Harwell. In this volume the loop is described and details of operational and experimental procedures are given. 3 refs., 20 figs., 6 tabs.
Integral coolant channels supply made by melt-out method
NASA Technical Reports Server (NTRS)
Escher, W. J. D.
Melt-out method of constructing strong, pressure-tight fluid coolant channels for chambers is accomplished by cementing pins to the surface and by depositing a melt-out material on the surface followed by two layers of epoxy-resin impregnated glass fibers. The structure is heated to melt out the low-melting alloy.
Bennett, W D; Goodman, R L; Heaberlin, S W; Hesson, G M; Nealley, C; Kirg, L L; Marshall, R K; McNair, G W; Meitzler, W D; Neally, G W; Parchen, L J; Pilger, J P; Rausch, W N; Russcher, G E; Schreiber, R E; Wildung, N J
Pressurized water reactor loss-of-coolant accident (LOCA) phenomena are being simulated with a series of experiments in the U-2 loop of the National Research Universal Reactor at Chalk River, Ontario, Canada. The first of these experiments includes up to 45 parametric thermal-hydraulic tests to establish the relationship among the reflood delay time of emergency coolant, the reflooding rate, and the resultant fuel rod cladding peak temperature. Subsequent experiments establish the fuel rod failure characteristics at selected peak cladding temperatures. Fuel rod cladding pressurization simulates high burnup fission gas pressure levels of modern PWRs. This document contains both an experiment overview of the LOCA simulation program and a review of the safety analyses performed by Pacific Northwest Laboratory (PNL) to define the expected operating conditions as well as to evaluate the worst case operating conditions. The primary intent of this document is to supply safety information required by the Chalk River Nuclear Laboratories (CRNL), to establish readiness to proceed from one test phase to the next and to establish the overall safety of the experiment. A hazards review summarizes safety issues, normal operation and three worst case accidents that have been addressed during the development of the experiment plan.
Dynamic characterization and active control of unstarts in a near-isentropic supersonic inlet
Ahsun, Umair, 1972-
A near-isentropic supersonic inlet, at Mach 2.2, has been designed to give enhanced recovery and thus increased range for a supersonic transport aircraft. In such a design a mixed compression inlet design is typically used. ...
40 CFR 53.63 - Test procedure: Wind tunnel inlet aspiration test.
Code of Federal Regulations, 2010 CFR
...2010-07-01 false Test procedure: Wind tunnel inlet aspiration test. 53... ¦ 53.63 Test procedure: Wind tunnel inlet aspiration test. (a...at elevated wind speeds. This wind tunnel test uses a single-sized,...
33 CFR 110.182 - Atlantic Ocean off Fort George Inlet, near Mayport, Fla.
Code of Federal Regulations, 2013 CFR
...Waters 1 2013-07-01 2013-07-01 false Atlantic Ocean off Fort George Inlet, near Mayport, Fla. 110...ANCHORAGE REGULATIONS Anchorage Grounds ¦ 110.182 Atlantic Ocean off Fort George Inlet, near Mayport, Fla....
33 CFR 110.182 - Atlantic Ocean off Fort George Inlet, near Mayport, Fla.
Code of Federal Regulations, 2012 CFR
...Waters 1 2012-07-01 2012-07-01 false Atlantic Ocean off Fort George Inlet, near Mayport, Fla. 110...ANCHORAGE REGULATIONS Anchorage Grounds ¦ 110.182 Atlantic Ocean off Fort George Inlet, near Mayport, Fla....
33 CFR 110.182 - Atlantic Ocean off Fort George Inlet, near Mayport, Fla.
Code of Federal Regulations, 2011 CFR
...Waters 1 2011-07-01 2011-07-01 false Atlantic Ocean off Fort George Inlet, near Mayport, Fla. 110...ANCHORAGE REGULATIONS Anchorage Grounds ¦ 110.182 Atlantic Ocean off Fort George Inlet, near Mayport, Fla....
33 CFR 110.182 - Atlantic Ocean off Fort George Inlet, near Mayport, Fla.
Code of Federal Regulations, 2014 CFR
...Waters 1 2014-07-01 2014-07-01 false Atlantic Ocean off Fort George Inlet, near Mayport, Fla. 110...ANCHORAGE REGULATIONS Anchorage Grounds ¦ 110.182 Atlantic Ocean off Fort George Inlet, near Mayport, Fla....
A Computational Study of Icing Effects on the Performance of an S-Duct Inlet
Jin, Wonjin
ice when compared to the asymmetrical glaze ice. Therefore, the dynamic inlet distortion is proportional to the total pressure recovery that corresponds to the steady-state inlet distortion. Furthermore, the application of local angles of attack...
50 CFR 226.220 - Critical habitat for the Cook Inlet beluga whale (Delphinapterus leucas).
Code of Federal Regulations, 2014 CFR
...2014-10-01 2014-10-01 false Critical habitat for the Cook Inlet beluga whale (Delphinapterus...COMMERCE MARINE MAMMALS DESIGNATED CRITICAL HABITAT ¦ 226.220 Critical habitat for the Cook Inlet beluga whale...
NASA Technical Reports Server (NTRS)
Berenson, P. J.; Robertson, W. G.
The problems in human comfort in heat stress are emphasized, with less emphasis placed upon cold exposure problems. Physiological parameters related to human thermal interactions are discussed, as well as data concerning thermal protective clothing. The energy balance equation, heat transfer equation, thermal comfort, heat stress, and cold stress are also considered. A two node model of human temperature regulation in FORTRAN is appended.
Numerical simulation of supersonic inlets using a three-dimensional viscous flow analysis
NASA Technical Reports Server (NTRS)
Anderson, B. H.; Towne, C. E.
A three dimensional fully viscous computer analysis was evaluated to determine its usefulness in the design of supersonic inlets. This procedure takes advantage of physical approximations to limit the high computer time and storage associated with complete Navier-Stokes solutions. Computed results are presented for a Mach 3.0 supersonic inlet with bleed and a Mach 7.4 hypersonic inlet. Good agreement was obtained between theory and data for both inlets. Results of a mesh sensitivity study are also shown.
A Cylindrical Thermal Precipitator with a Particle Size-selective Inlet
Bin Wang; Shu Tao; Da-Ren Chen
We designed a thermal precipitator in a cylindrical configuration with a size-selective inlet and investigated its performance in experiments using DMA-classified particles of sodium chloride (NaCl) and polystyrene latex (PSL). Our investigation was performed in two parts: (1) using the size selective inlet to determine the best inlet-to-wall distance for optimal impaction of 1Ā?m particles; (2) using a simple inlet
Flow in a simple swirl chamber with and without controlled inlet forcing
R. Thambu; B. T. Babinchak; P. M. Ligrani; C. R. Hedlund; H.-K. Moon; B. Glezer
Results are presented from a swirl chamber with and without controlled inlet forcing. The controlled inlet forcing is induced\\u000a using arrays of vortex generators placed along one wall of the swirl chamber inlet duct. Flow visualization results are given,\\u000a along with surveys of circumferential mean velocity, static pressure, and total pressure, at Reynolds numbers (based on inlet\\u000a duct characteristics) as
10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems.
Code of Federal Regulations, 2011 CFR
...Acceptance criteria for reactor coolant system venting...Section 50.46a Energy NUCLEAR REGULATORY COMMISSION...Acceptance criteria for reactor coolant system venting systems. Each nuclear power reactor must be provided...
10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems.
Code of Federal Regulations, 2014 CFR
...Acceptance criteria for reactor coolant system venting...Section 50.46a Energy NUCLEAR REGULATORY COMMISSION...Acceptance criteria for reactor coolant system venting systems. Each nuclear power reactor must be provided...
10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems.
Code of Federal Regulations, 2013 CFR
...Acceptance criteria for reactor coolant system venting...Section 50.46a Energy NUCLEAR REGULATORY COMMISSION...Acceptance criteria for reactor coolant system venting systems. Each nuclear power reactor must be provided...
10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems.
Code of Federal Regulations, 2010 CFR
...Acceptance criteria for reactor coolant system venting...Section 50.46a Energy NUCLEAR REGULATORY COMMISSION...Acceptance criteria for reactor coolant system venting systems. Each nuclear power reactor must be provided...
10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems.
Code of Federal Regulations, 2012 CFR
...Acceptance criteria for reactor coolant system venting...Section 50.46a Energy NUCLEAR REGULATORY COMMISSION...Acceptance criteria for reactor coolant system venting systems. Each nuclear power reactor must be provided...
Modular Porous Plate Sublimator /MPPS/ requires only water supply for coolant
NASA Technical Reports Server (NTRS)
Rathbun, R. J.
Modular porous plate sublimators, provided for each location where heat must be dissipated, conserve the battery power of a space vehicle by eliminating the coolant pump. The sublimator requires only a water supply for coolant.
33 CFR 165.T05-0145 - Safety Zone, Barnegat Inlet; Barnegat Light, NJ.
Code of Federal Regulations, 2014 CFR
...Barnegat Inlet; Barnegat Light, NJ. 165.T05-0145...Barnegat Inlet; Barnegat Light, NJ. (a) Location...of Barnegat Inlet, Barnegat Light, NJ in an area bounded on the Northwest of the...do so in accordance with the directions provided by the Captain...
Assessment of Inlet Cooling to Enhance Output of a Fleet of Gas TurbinesĀ
Wang, T.; Braquet, L.
An analysis was made to assess the potential enhancement of a fleet of 14 small gas turbines' power output by employing an inlet air cooling scheme at a gas process plant. Various gas turbine (GT) inlet air cooling schemes were reviewed. The inlet...
33 CFR 80.703 - Little River Inlet, SC to Cape Romain, SC.
Code of Federal Regulations, 2014 CFR
...2014-07-01 2014-07-01 false Little River Inlet, SC to Cape Romain, SC...LINES Seventh District ¦ 80.703 Little River Inlet, SC to Cape Romain, SC...easternmost extremity of Waties Island across Little River Inlet. (b) From...
33 CFR 80.703 - Little River Inlet, SC to Cape Romain, SC.
Code of Federal Regulations, 2012 CFR
...2012-07-01 2012-07-01 false Little River Inlet, SC to Cape Romain, SC...LINES Seventh District ¦ 80.703 Little River Inlet, SC to Cape Romain, SC...easternmost extremity of Waties Island across Little River Inlet. (b) From...
33 CFR 80.703 - Little River Inlet, SC to Cape Romain, SC.
Code of Federal Regulations, 2011 CFR
...2011-07-01 2011-07-01 false Little River Inlet, SC to Cape Romain, SC...LINES Seventh District ¦ 80.703 Little River Inlet, SC to Cape Romain, SC...easternmost extremity of Waties Island across Little River Inlet. (b) From...
33 CFR 80.703 - Little River Inlet, SC to Cape Romain, SC.
Code of Federal Regulations, 2010 CFR
...2010-07-01 2010-07-01 false Little River Inlet, SC to Cape Romain, SC...LINES Seventh District ¦ 80.703 Little River Inlet, SC to Cape Romain, SC...easternmost extremity of Waties Island across Little River Inlet. (b) From...
33 CFR 80.703 - Little River Inlet, SC to Cape Romain, SC.
Code of Federal Regulations, 2013 CFR
...2013-07-01 2013-07-01 false Little River Inlet, SC to Cape Romain, SC...LINES Seventh District ¦ 80.703 Little River Inlet, SC to Cape Romain, SC...easternmost extremity of Waties Island across Little River Inlet. (b) From...
Validation of Inlet and Exhaust Boundary Conditions for a Cartesian Method
Shishir A. Pandya; Scott M. Murman; Michael J. Aftosmis
Inlets and exhaust nozzles are often omitted in aerodynamic simulations of aircraft due to the complexities involved in the modeling of engine details and flow physics. However, the omission is often improper since inlet or plume flows may have a substantial e ect on vehicle aerodynamics. A method for modeling the e ect of inlets and exhaust plumes using boundary
Design and Numerical Investigation of Advanced Radial Inlet for a Centrifugal Compressor Stage
Yunbae Kim; Jay Koch
The performance of a centrifugal compressor stage can be seriously affected by inlet flow distortions due to an unsatisfactory inlet configuration and the resulting flow structure. In this study, two radial inlets were designed for a centrifugal compressor stage and investigated numerically using a commercially available 3D viscous Navier-Stokes code. The intent of the design was to minimize the total
Inverse design of centrifugal compressor vaned diffusers in inlet shear flows
A three-dimensional inverse design method in which the blade (or vane) geometry is designed for specified distributions of circulation and blade thickness is applied to the design of centrifugal compressor vaned diffusers. Two generic diffusers are designed, one with uniform inlet flow (equivalent to a conventional design) and the other with a sheared inlet flow. The inlet shear flow effects
Assessment of Inlet Cooling to Enhance Output of a Fleet of Gas Turbines
Wang, T.; Braquet, L.
An analysis was made to assess the potential enhancement of a fleet of 14 small gas turbines' power output by employing an inlet air cooling scheme at a gas process plant. Various gas turbine (GT) inlet air cooling schemes were reviewed. The inlet...
FORTRAN program to generate engine inlet flow contour maps and distortion parameters
NASA Technical Reports Server (NTRS)
Dicus, J. H.
A computer program is presented and described that generates jet engine inlet flow contour maps and inlet flow distortion parameters. The program input consists of an array of measurements describing the flow conditions at the engine inlet. User-defined distortion parameters may be calculated.
US Army Corps of Engineers
458 EBB-TIDAL DELTA DEVELOPMENT WHERE BEFORE THERE WAS NONE, SHARK RIVER INLET, NEW JERSEY TANYA email@example.com. Abstract: The navigation channel at Shark River Inlet, NJ, is the responsibility of the U.S. Army Corps of Engineers, New York District. Until about the year 2000, the ocean entrance to Shark River Inlet required
30 CFR 77.303 - Hot gas inlet chamber dropout doors.
Code of Federal Regulations, 2011 CFR
...2011-07-01 2011-07-01 false Hot gas inlet chamber dropout doors. 77...COAL MINES Thermal Dryers ¦ 77.303 Hot gas inlet chamber dropout doors. Thermal dryer systems which employ a hot gas inlet chamber shall be equipped...
30 CFR 77.303 - Hot gas inlet chamber dropout doors.
Code of Federal Regulations, 2010 CFR
...2010-07-01 2010-07-01 false Hot gas inlet chamber dropout doors. 77...COAL MINES Thermal Dryers ¦ 77.303 Hot gas inlet chamber dropout doors. Thermal dryer systems which employ a hot gas inlet chamber shall be equipped...
30 CFR 77.303 - Hot gas inlet chamber dropout doors.
Code of Federal Regulations, 2014 CFR
...2014-07-01 2014-07-01 false Hot gas inlet chamber dropout doors. 77...COAL MINES Thermal Dryers ¦ 77.303 Hot gas inlet chamber dropout doors. Thermal dryer systems which employ a hot gas inlet chamber shall be equipped...
30 CFR 77.303 - Hot gas inlet chamber dropout doors.
Code of Federal Regulations, 2013 CFR
...2013-07-01 2013-07-01 false Hot gas inlet chamber dropout doors. 77...COAL MINES Thermal Dryers ¦ 77.303 Hot gas inlet chamber dropout doors. Thermal dryer systems which employ a hot gas inlet chamber shall be equipped...
30 CFR 77.303 - Hot gas inlet chamber dropout doors.
Code of Federal Regulations, 2012 CFR
...2012-07-01 2012-07-01 false Hot gas inlet chamber dropout doors. 77...COAL MINES Thermal Dryers ¦ 77.303 Hot gas inlet chamber dropout doors. Thermal dryer systems which employ a hot gas inlet chamber shall be equipped...
Influence of the inlet air in efficiency of photocatalytic devices for mineralization of VOCs in air-conditioning installations.
Jimenez-Relinque, E; Castellote, M
Nowadays, a large proportion of photocatalytic oxidation (PCO) devices are being implemented in heating, ventilation and air-conditioning systems. However, no systematic studies have been carried out regarding the influence of inlet air preconditioning. To analyse the impact of the inlet air-conditions into photocatalytic efficiency, a simulated air-conditioning duct with flowing gas through inside was designed. Isobutylene was chosen as the target VOCs. The concentration in the gas phase was monitored using a photoionization detector. The influence of flow rate, relative humidity and temperature on the VOC removal efficiency was analysed. Experimental results were presented in terms of gas-removal efficiency (?) and clean air delivery rate (CADR) and analysed on a kinetic basis. From them, the weight of each parameter in the global process has been determined, from bigger to smaller contribution, flow>temperature>relative humidity. Also, the relevance of the inlet air conditions has been illustrated in a model room in order to determinate the time necessary to obtain a threshold value accomplishing with enough air quality and the energy consumption of the device. Additionally, the photocatalytic decontamination has been assimilated to the "air exchange rate", a parameter commonly used in indoor air quality studies. The results show that preconditioning of air can improve the efficiency of photocatalytic devices and bring important energy savings. PMID:24584640
Visualizing Coolant Flow in Sodium Reactor Subassemblies
Uniformity of temperature controls peak power output. Interchannel cross-flow is the principal cross-assembly energy transport mechanism. The areas of fastest flow all occur at the exterior of the assembly. Further, the fast moving region winds around the assembly in a continuous swath. This Nek5000 simulation uses an unstructured mesh with over one billion grid points, resulting in five billion degrees of freedom per time slice. High speed patches of turbulence due to vertex shedding downstream of the wires persist for about a quarter of the wire-wrap periodic length. Credits: Science: Paul Fisher and Aleks Obabko, Argonne National Laboratory? Visualization: Hank Childs and Janet Jacobsen, Lawrence Berkeley National Laboratory?? This research used resources of the Argonne Leadership Computing Facility at Argonne National Laboratory, which is supported by the Office of Science of the U.S. Dept. of Energy under contract DE-AC02-06CH11357. This research was sponsored by the Department of Energy's Office of Nuclear Energy's NEAMS program.
Nose and inlet duct radomes for the firebolt aerial target
L. C. Hoots
Radomes of the Firebolt Aerial Target (AQM-81A) facilitate an uncommon set of operational conditions. The target vehicle is first carried captively. Stones may be dislodged from the runway and impact the Nose or Inlet Duct Radomes with considerable force. The drone has various flight profiles after launch, encompassing levels of MACH 1.2 at 35,000 feet to MACH 4 at 100,000
47. View of "dry air inlets" to waveguides entering scanner ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
47. View of "dry air inlets" to waveguides entering scanner building 105. Dried air is generated under pressure by Ingersoll-Rand dehumidified/dessicator and compressor system. View is at entrance from passageway that links into corner of scanner building. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK
Increasing the cavitational quality of spiral double-inlet pumps
V. P. Brazhnik; G. G. Teslenko
A comparison of the parameters of line pumps Sl~ 1250-140 and Sl~ 800-100 indicates that they can be combined. Therefore, we designed a combined line pump model 8~1250\\/800, which consists of a singlestage spiral pump with a centrifugal double-inlet wheel and with pre-engaged wheels. The pump housing has a horizontal connection and is sealed with a vapor-tight gasket. The lower
Engine air cleaner inlet tube for automotive engine
Bagger, J.E.; Barba, J.M.; Haese, R.D.; Park, A.
This patent describes an engine air cleaner inlet tube for bringing air from outside the engine compartment of an automotive vehicle to the engine, it comprises: an entry section comprising at least a generally hemispherical chamber for receiving air drawn from outside the engine compartment; a venturi section, having a circular configuration, coupled to and extending radially from the chamber; and an exit section coupled to the venturi section, with the exit section being adapted for connection with an air cleaner system.
Protection of Overhead Conductors at the Inlet to a Connector
Trofimov, S. V. [Electric Power Research Institute (VNIIE) (Russian Federation)
A method that enables determination of maximum amplitudes of standing vibration waves, off-horizontal angles of the conductors, moments of resistance, and cutting forces in any cross section of any type of conductor and connector with the help of 'SVT-connector' software is described. Comparative values of the mentioned parameters at the outlet of the conductor from rigid dress and at the inlet to the connector are presented.
The Roosevelt Inlet shipwreck: identification, analysis, and historical context
McVae, Bridget Christine
. First manufactured by Josiah Wedgewood in 1762, creamware was initially 16 manufactured as another alternative to Chinese porcelain. 2 This inexpensive earthenware quickly became popular both in England and in the colonies. In a stroke...,000 artifacts recovered from the Roosevelt Inlet shipwreck, not a single sherd was of pearlware. First produced in 1779 by Josiah Wedgewood, pearlware 1:1 19 became immensely popular in the former American colonies.7 The fact that there was absolutely...
Properties and stability of a Texas barrier beach inletĀ
Mason, Curtis
of 1929. Comparison of the 1930 snd 1935 shorelines presented in Figure 9, indicates that significant erosion of the gulf shoreline occurred in the intervening years, with about three hundred fifty yards of beach lost on either side of the inlet.... Although a hurricane did strike the coast in 1932, examination of additional charts revealed that continued erosion occurred only from the Brazos River to about PIGURE 9. ? BROWN CEDAR CUT SHORELINE CONTOURS, 1930 AND 1935 29 ten miles west of Brown...
Laboratory Analysis of Vortex Dynamics For Shallow Tidal Inlets
Whilden, Kerri Ann
OF FIGURES FIGURE Page 1 Shallow Water Wave Basin Including Idealized Inlet Con guration. : 8 2 Raw Image From One Camera. : : : : : : : : : : : : : : : : : : : : : 9 3 Inverted Image With Mean Image Subtracted. : : : : : : : : : : : : : 10 4 DaVis PIV Output... review, see Nicolau del Roure et al. [18]), the evolution of jet generated vortex dipoles has been experimentally studied by Wells and van Heijst [22] and Afanasyev [2] using potential ow theory. Both used a thin layer of denser uid to limit the 3D e...
Evaluation of core damage sequences initiated by loss of reactor coolant pump seal cooling
S. Mitra; R. Baradaran; R. Youngblood
This report is concerned with core damage accident sequences initiated by loss of component cooling water, leading to loss of reactor coolant pump seal cooling, subsequent primary coolant leakage, and failure to make up the coolant loss. Three plants are considered: Indian Point Unit 3, Midland Unit 2, and Calvert Cliffs Unit 1. It is shown that design differences in
Reactor Coolant Pump seal issues and their applicability to new reactor designs
C. J. Ruger; J. C. Higgins
Reactor Coolant Pumps (RCPs) of various types are used to circulate the primary coolant through the reactor in most reactor designs. RCPs generally contain mechanical seals to limit the leakage of pressurized reactor coolant along the pump drive shaft into the containment. The relatively large number of RCP seal and seal auxiliary system failures experienced at US operating plants during
Modular Dual Coolant Pb-17Li Blanket Design For ARIES-CS Compact Stellarator Power Plant
Raffray, A. Renķ
Modular Dual Coolant Pb-17Li Blanket Design For ARIES-CS Compact Stellarator Power Plant X.R. Wanga of the modular dual coolant blanket concept. The overall layout of the blanket module including the He coolant maintenance schemes include both a field-period-based maintenance approach and a modular maintenance approach
A model for coolant void reactivity evaluation in assemblies of CANDU cells
F. Talebi; G. Marleau; J. Koclas
Coolant void reactivity is a very important safety parameter in CANDU reactor analysis. Here we evaluate the coolant void reactivity in a 2ū2 heterogeneous assembly of CANDU cells using the code DRAGON. Since the current version of DRAGON can only treat the coolant void reactivity for a single CANDU cell, an approximate model for the geometry must be considered to
Study on Difficulties Peculiar to The Water Coolants for Manned Space Systems
Hiroyasu Mizuno; Ichiro Aoki; Yoshiyasu Hayakawa; Koki Oikawa; Kichiro Imagawa
Active Thermal Control System (ATCS) is used to collect and transfer a large amount of heat in the Japanese Experiment Module (JEM) Pressurized Module, which adopts a water-based coolant. To use this system, it is important to control and maintain coolant properties on orbit. This paper presents improvements of the water-based coolant to maintain its properties, detailed examples of anomalies
Experiment Operations Plan for a Loss-of-Coolant Accident Simulation in the National Research Universal Reactor Materials Tests 1 and 2
Russcher, G. E.; Wilson, C. L.; Marshall, R, K.; King, L. L.; Parchen, L. J.; Pilger, J. P.; Hesson, G. M.; Mohr, C. L.
A loss of Coolant Accident (LOCA) simulation program is evaluating the thermal-hydraulic and mechanical effects of LOCA conditions on pressurized water reactor test fuel bundles. This experiment operation plan for the second and third experiments of the program will provide peak fuel cladding temperatures of up to 1172K (1650{degree}F) and 1061K (1450{degree}) respectively. for a long enough time to cause test fuel cladding deformation and rupture in both. Reflood coolant delay times and the reflooding rates for the experiments were selected from thermal-hydraulic data measured in the National Research Universal (NRU) reactor facilities and test train assembly during the first experiment.
Methane oxidation in Saanich Inlet during summer stratification
NASA Technical Reports Server (NTRS)
Ward, B. B.; Kilpatrick, K. A.; Wopat, A. E.; Minnich, E. C.; Lidstrom, M. E.
Saanich Inlet, British Columbia, an fjord on the southeast coast of Vancouver Island, typically stratifies in summer, leading to the formation of an oxic-anoxic interface in the water column and accumulation of methane in the deep water. The results of methane concentration measurements in the water column of the inlet at various times throughout the summer months in 1983 are presented. Methane gradients and calculated diffusive fluxes across the oxic-anoxic interface increased as the summer progressed. Methane distribution and consumption in Saanich Inlet were studied in more detail during August 1986. At this time, a typical summer stratification with an oxic-anoxic interface around 140 m was present. At the interface, steep gradients in nutrient concentrations, bacterial abundance and methane concentration were observed. Methane oxidation was detected in the aerobic surface waters and in the anaerobic deep layer, but highest rates occurred in a narrow layer at the oxic-anoxic interface. Estimated methane oxidation rates were suffcient to consume 100 percent of the methane provided by diffusive flux from the anoxic layer. Methane oxidation is thus a mechanism whereby atmospheric flux from anoxic waters is minimized.
Prediction of sound radiation from different practical jet engine inlets
NASA Technical Reports Server (NTRS)
Meyer, W. L.; Zinn, B. T.
Computer codes which were based upon a special integral representation of the external solutions of the Helmholtz equation were upgraded so that they would yield accurate results for the acoustic radiation patterns in the field surrounding an axisymmetric body for nondimensional wave numbers, based on duct radius, of up to twenty. The accuracy of these computer programs was checked by the use of the point source method for the generation of exact solutions and then by comparison with the results of other experimental and theoretical studies. These computer codes were used in a parametric study of the dependence of the radiated sound field on input modal distribution, wave number, and inlet lip shape. The results of this study show that: (1) as the wave number (i.e., cut off ratio) is increased for a given input modal distribution that the acoustic radiation peak moves towards the inlet centerline and becomes more compact (i.e., narrows); (2) as the input mode number is increased for a given cut off ratio the acoustic radiation peak moves away from the inlet centerline and becomes more compact.
Inlet Flow Control and Prediction Technologies for Embedded Propulsion Systems
NASA Technical Reports Server (NTRS)
McMillan, Michelle L.; Gissen, Abe; Vukasinovic, Bojan; Lakebrink, Matthew T.; Glezer, Ari; Mani, Mori; Mace, James
Fail-safe inlet flow control may enable high-speed cruise efficiency, low noise signature, and reduced fuel-burn goals for hybrid wing-body aircraft. The objectives of this program are to develop flow control and prediction methodologies for boundary-layer ingesting (BLI) inlets used in these aircraft. This report covers the second of a three year program. The approach integrates experiments and numerical simulations. Both passive and active flow-control devices were tested in a small-scale wind tunnel. Hybrid actuation approaches, combining a passive microvane and active synthetic jet, were tested in various geometric arrangements. Detailed flow measurements were taken to provide insight into the flow physics. Results of the numerical simulations were correlated against experimental data. The sensitivity of results to grid resolution and turbulence models was examined. Aerodynamic benefits from microvanes and microramps were assessed when installed in an offset BLI inlet. Benefits were quantified in terms of recovery and distortion changes. Microvanes were more effective than microramps at improving recovery and distortion.
Prediction of sound radiated from different practical jet engine inlets
NASA Technical Reports Server (NTRS)
Zinn, B. T.; Meyer, W. L.
Existing computer codes for calculating the far field radiation patterns surrounding various practical jet engine inlet configurations under different excitation conditions were upgraded. The computer codes were refined and expanded so that they are now more efficient computationally by a factor of about three and they are now capable of producing accurate results up to nondimensional wave numbers of twenty. Computer programs were also developed to help generate accurate geometrical representations of the inlets to be investigated. This data is required as input for the computer programs which calculate the sound fields. This new geometry generating computer program considerably reduces the time required to generate the input data which was one of the most time consuming steps in the process. The results of sample runs using the NASA-Lewis QCSEE inlet are presented and comparison of run times and accuracy are made between the old and upgraded computer codes. The overall accuracy of the computations is determined by comparison of the results of the computations with simple source solutions.
Volcanic tsunamis and prehistoric cultural transitions in Cook Inlet, Alaska
Beget, J.; Gardner, C.; Davis, K.
The 1883 eruption of Augustine Volcano produced a tsunami when a debris avalanche traveled into the waters of Cook Inlet. Older debris avalanches and coeval paleotsunami deposits from sites around Cook Inlet record several older volcanic tsunamis. A debris avalanche into the sea on the west side of Augustine Island ca. 450??years ago produced a wave that affected areas 17??m above high tide on Augustine Island. A large volcanic tsunami was generated by a debris avalanche on the east side of Augustine Island ca. 1600??yr BP, and affected areas more than 7??m above high tide at distances of 80??km from the volcano on the Kenai Peninsula. A tsunami deposit dated to ca. 3600??yr BP is tentatively correlated with a southward directed collapse of the summit of Redoubt Volcano, although little is known about the magnitude of the tsunami. The 1600??yr BP tsunami from Augustine Volcano occurred about the same time as the collapse of the well-developed Kachemak culture in the southern Cook Inlet area, suggesting a link between volcanic tsunamis and prehistoric cultural changes in this region of Alaska. ?? 2008 Elsevier B.V.
Novel inlet-airframe integration methodology for hypersonic waverider vehicles
NASA Astrophysics Data System (ADS)
Ding, Feng; Liu, Jun; Shen, Chi-bing; Huang, Wei
With the aim of integrating a ramjet or scramjet with an airframe, a novel inlet-airframe integration methodology for the hypersonic waverider vehicle is proposed. For this newly proposed design concept and for the specified flight conditions, not only the forebody of the vehicle but also its engine cowl and wings can ride on the bow shock wave, causing the bow shock wave to remain attached to the leading edge for the entire length of the vehicle. Thus, this integrated vehicle can take full advantage of the waverider's high lift-to-drag ratio characteristics and the ideal pre-compression surface for the engine. In this work, a novel inlet-airframe integrated axisymmetric basic flow model that accounts for both external and internal flows is first designed using the method of characteristics and the streamline tracing technique. Subsequently, the design of the inlet-airframe integrated waverider vehicle is generated from the integrated axisymmetric basic flow model using the streamline tracing technique. Then, the design methodologies of both the integrated axisymmetric basic flow model and the integrated waverider vehicle are verified by a computational numerical method. Finally, the viscous effects and performance of both the integrated axisymmetric basic flow model and the integrated waverider vehicle are analysed under the design condition using the numerical computation. The obtained results show that the proposed approach is effective in designing the integrated hypersonic waverider vehicle.
Marine benthic habitat mapping of Muir Inlet, Glacier Bay National Park and Preserve, Alaska, with an evaluation of the Coastal and Marine Ecological Classification Standard III
Trusel, Luke D.; Cochrane, Guy R.; Etherington, Lisa L.; Powell, Ross D.; Mayer, Larry A.
Seafloor geology and potential benthic habitats were mapped in Muir Inlet, Glacier Bay National Park and Preserve, Alaska, using multibeam sonar, ground-truth information, and geological interpretations. Muir Inlet is a recently deglaciated fjord that is under the influence of glacial and paraglacial marine processes. High glacially derived sediment and meltwater fluxes, slope instabilities, and variable bathymetry result in a highly dynamic estuarine environment and benthic ecosystem. We characterize the fjord seafloor and potential benthic habitats using the Coastal and Marine Ecological Classification Standard (CMECS) recently developed by the National Oceanic and Atmospheric Administration (NOAA) and NatureServe. Substrates within Muir Inlet are dominated by mud, derived from the high glacial debris flux. Water-column characteristics are derived from a combination of conductivity temperature depth (CTD) measurements and circulation-model results. We also present modern glaciomarine sediment accumulation data from quantitative differential bathymetry. These data show Muir Inlet is divided into two contrasting environments: a dynamic upper fjord and a relatively static lower fjord. The accompanying maps represent the first publicly available high-resolution bathymetric surveys of Muir Inlet. The results of these analyses serve as a test of the CMECS and as a baseline for continued mapping and correlations among seafloor substrate, benthic habitats, and glaciomarine processes.
An Analysis of an Automatic Coolant Bypass in the International Space Station Node 2 Internal Active Thermal Control System
NASA Technical Reports Server (NTRS)
Clanton, Stephen E.; Holt, James M.; Turner, Larry D. (Technical Monitor)
A challenging part of International Space Station (ISS) thermal control design is the ability to incorporate design changes into an integrated system without negatively impacting performance. The challenge presents itself in that the typical ISS Internal Active Thermal Control System (IATCS) consists of an integrated hardware/software system that provides active coolant resources to a variety of users. Software algorithms control the IATCS to specific temperatures, flow rates, and pressure differentials in order to meet the user-defined requirements. What may seem to be small design changes imposed on the system may in fact result in system instability or the temporary inability to meet user requirements. The purpose of this paper is to provide a brief description of the solution process and analyses used to implement one such design change that required the incorporation of an automatic coolant bypass in the ISS Node 2 element.
Heat transfer performance of engine coolants under sub-cooled boiling conditions
Bhowmick, S.; Branchi, C.; McAssey, E.V. Jr. [Villanova Univ., PA (United States). Dept. of Mechanical Engineering; Gollin, M. [ARCO Chemical Co., Newtown Square, PA (United States)
An experimental program has been conducted to evaluate the heat transfer performance of two engine cooling fluid mixtures, propylene-glycol/water and ethylene-glycol/water. These tests were performed under conditions closely simulating normal engine operation. For both mixtures, results were obtained over a range of heat transfer regimes from single phase convection to saturated flow boiling. Tests showed that propylene-glycol/water and ethylene-glycol/water have very similar heat transfer performances. Performance is defined as the steady state wall temperature maintained for a given surface heat flux and test section inlet velocity. For the lowest velocity tested, the test section experienced saturated boiling over approximately one-half of its heated length. The experimental results were also compared to analytical predictions based upon the Chen correlation. At higher fluxes, the analytical methods under-predicted the test section wall temperature.
Experimental Measurement of Transonic Fan Wake Response to Uniform and Simulated Boundary Layer Ingesting Inlet Flows
NASA Technical Reports Server (NTRS)
O'Brien, Walter F.; Ferrar, Anthony M.; Arend, David
BWB Aircraft with embedded engines and BLI inlets offer attractive advantages in terms of reduced noise from engines and increased range and fuel economy. The BLI inlet produces inlet distortion patterns that can reduce fan performance and stall margin, and can produce undesirable forced responses. Knowledge of the dynamic response of fan flow when subjected to flow distortions of the type produced by BLI inlets is important for the design of distortion tolerant fans. This project is investigating fan response to flow distortion by measuring the response of the fan of a JT15D engine to a flow pattern following the results of the NASA Inlet A BLI wind tunnel tests.
Analysis of results from wind tunnel tests of inlets for an advanced turboprop nacelle installation
NASA Technical Reports Server (NTRS)
Hancock, J. P.; Lyman, V.; Pennock, A. P.
Inlets for tractor installations of advanced turboprop propulsion systems were tested in three phases, covering a period from November, 1982 to January, 1984. Nacelle inlet configuration types included single scoop, twin scoop, and annular arrangements. Tests were performed with and without boundary layer diverters and several different diverter heights were tested for the single scoop inlet. This same inlet was also tested at two different axial positions. Test Mach numbers ranged from Mach 0.20 to 0.80. Types of data taken were: (1) internal and external pressures, including inlet throat recoveries; (2) balance forces, including thrust-minus-drag; and (3) propellar blade stresses.
Dynamics of suspended matter concentration in Chupa Inlet (Karelian Coast, the White Sea) in summer and autumn
NASA Astrophysics Data System (ADS)
Mityaev, M. V.; Gerasimova, M. V.
Studies on the water and suspended matter concentration dynamics were performed for the summer and autumn periods in Kruglaya Bay, Chupa Inlet (Karelian Coast, the White Sea). The tidal cycle appeared as the major factor defining the water salinity, temperature, and suspended matter concentration. The water temperature and suspended matter concentration increased during low tide, and the opposite pattern was observed for water salinity; all the processes were true for both surface and bottom water layers. Therefore, we conclude that major bulk of the allochtonous suspended matter is carried into the sea by the ebb stream.
CFD-Based Design Optimization Tool Developed for Subsonic Inlet
NASA Technical Reports Server (NTRS)
The traditional approach to the design of engine inlets for commercial transport aircraft is a tedious process that ends with a less-than-optimum design. With the advent of high-speed computers and the availability of more accurate and reliable computational fluid dynamics (CFD) solvers, numerical optimization processes can effectively be used to design an aerodynamic inlet lip that enhances engine performance. The designers' experience at Boeing Corporation showed that for a peak Mach number on the inlet surface beyond some upper limit, the performance of the engine degrades excessively. Thus, our objective was to optimize efficiency (minimize the peak Mach number) at maximum cruise without compromising performance at other operating conditions. Using a CFD code NPARC, the NASA Lewis Research Center, in collaboration with Boeing, developed an integrated procedure at Lewis to find the optimum shape of a subsonic inlet lip and a numerical optimization code, ADS. We used a GRAPE-based three-dimensional grid generator to help automate the optimization procedure. The inlet lip shape at the crown and the keel was described as a superellipse, and the superellipse exponents and radii ratios were considered as design variables. Three operating conditions: cruise, takeoff, and rolling takeoff, were considered in this study. Three-dimensional Euler computations were carried out to obtain the flow field. At the initial design, the peak Mach numbers for maximum cruise, takeoff, and rolling takeoff conditions were 0.88, 1.772, and 1.61, respectively. The acceptable upper limits on the takeoff and rolling takeoff Mach numbers were 1.55 and 1.45. Since the initial design provided by Boeing was found to be optimum with respect to the maximum cruise condition, the sum of the peak Mach numbers at takeoff and rolling takeoff were minimized in the current study while the maximum cruise Mach number was constrained to be close to that at the existing design. With this objective, the optimum design satisfied the upper limits at takeoff and rolling takeoff while retaining the desirable cruise performance. Further studies are being conducted to include static and cross-wind operating conditions in the design optimization procedure. This work was carried out in collaboration with Dr. E.S. Reddy of NYMA, Inc.
The Total-Pressure Recovery and Drag Characteristics of Several Auxiliary Inlets at Transonic Speeds
NASA Technical Reports Server (NTRS)
Dennard, John S.
Several flush and scoop-type auxiliary inlets have been tested for a range of Mach numbers from 0.55 to 1.3 to determine their transonic total-pressure recovery and drag characteristics. The inlet dimensions were comparable with the thickness of the boundary layer in which they were tested. Results indicate that flush inlets should be inclined at very shallow angles with respect to the surface for optimum total-pressure recovery and drag characteristics. Deep, narrow inlets have lower drag than wide shallow ones at Mach numbers greater than 0.9 but at lower Mach numbers the wider inlets proved superior. Inlets with a shallow approach ramp, 7 deg, and diverging ramp walls which incorporated boundary-layer bypass had lower drag than any other inlet tested for Mach numbers up to 1.2 and had the highest pressure recovery of all of the flush inlets. The scoop inlets, which operated in a higher velocity flow than the flush inlets, had higher drag coefficients. Several of these auxiliary inlets projected multiple, periodic shock waves into the stream when they were operated at low mass-flow ratios.
Ultra high bypass Nacelle aerodynamics inlet flow-through high angle of attack distortion test
NASA Technical Reports Server (NTRS)
Larkin, Michael J.; Schweiger, Paul S.
A flow-through inlet test program was conducted to evaluate inlet test methods and determine the impact of the fan on inlet separation when operating at large angles of attack. A total of 16 model configurations of approximately 1/6 scale were tested. A comparison of these flow-through results with powered data indicates the presence of the fan increased separation operation 3 degrees to 4 degrees over the flow through inlet. Rods and screens located at the fan face station, that redistribute the flow, achieved simulation of the powered-fan results for separation angle of attack. Concepts to reduce inlet distortion and increase angle of attack capability were also evaluated. Vortex generators located on the inlet surface increased inlet angle of attack capability up to 2 degrees and reduced inlet distortion in the separated region. Finally, a method of simulating the fan/inlet aerodynamic interaction using blockage sizing method has been defined. With this method, a static blockage device used with a flow-through model will approximate the same inlet onset of separation angle of attack and distortion pattern that would be obtained with an inlet model containing a powered fan.
Development of an Inlet Pressure Sensor for Control in a Left Ventricular Assist Device
Fritz, Bryan; Cysyk, Joshua; Newswanger, Ray; Weiss, William; Rosenberg, Gerson
A Tesla type continuous flow left ventricular assist device (VAD) has been designed by Penn State and Advanced Bionics, Inc. (ABI). When a continuous flow device is employed, care must be taken to limit low pressures in the ventricle that can produce an obstruction to the inlet cannula or trigger arrhythmias. Design of an inexpensive, semi-conductor strain gage inlet pressure sensor to detect suction has been completed. The research and design analysis included finite element modeling of the sensing region. Sensitivity, step-response, temperature dependence and hysteresis tests have been performed on prototype units. All sensors were able to withstand the maximum expected strain of 82 ?in/in at 500 mmHg internal pressure. Average sensitivity was 0.52 ▒0.24 ?V/mmHg with 0.5 V excitation (n=5 units). Step response time for a 0 to 90 mmHg step change averaged 22 milliseconds. Hysteresis was measured by applying and holding 75mmHg internal pressure for 4 hours, followed by a zero pressure measurement, and ranged from -15 mmHg to 4.1 mmHg (n=3 units). Offset drift varied between 180 and -140 mmHg over a four week period. (n=2 units). Span temperature sensitivity ranged from 18 to -21 ?V/░C (n=5 units). Gain temperature sensitivity ranged from -7.4 to 4.9 ?V/░C (n=5 units). With the inherent drift, it is currently not possible to use the transducer to measure actual pressures, but it can easily be used to measure pressure changes throughout the cardiac cycle. This signal can then be used in the control system to avoid ventricular suction events. PMID:20335797
Glycol coolants improve heat transfer and corrosion control
Holfield, R. [Dow Chemical Co., Midland, MI (United States)
Various liquids from plain water to exotic fluids have been used as coolants in large stationary diesel engines that drive compressors on natural gas pipeline distribution systems. Although water is an efficient heat transfer medium, its drawbacks of freezing at {minus}32 F and boiling at 212 F seriously limit its usefulness. Special glycol-based heat transfer fluids are available and refined specifically for long-term needs of gas compressor engines. Appropriate corrosion inhibitors have been formulated for metallurgy and operating conditions encountered with these engines. Propylene glycol was developed as an alternative for use in environmentally sensitive areas. Glycol-based fluids must be specifically inhibited for industrial applications because uninhibited or improperly inhibited coolants can seriously damage reciprocating engines.
Health physics aspects of processing EBR-I coolant
Burke, L.L.; Thalgott, J.O.; Poston, J.W. Jr.
The sodium-potassium reactor coolant removed from the Experimental Breeder Reactor Number One after a partial reactor core meltdown had been stored at the Idaho National Engineering and Environmental Laboratory for 40 years. The State of Idaho considered this waste the most hazardous waste stored in the state and required its processing. The reactor coolant was processed in three phases. The first phase converted the alkali metal into a liquid sodium-potassium hydroxide. The second phase converted this caustic to a liquid sodium-potassium carbonate. The third phase solidified the sodium-potassium carbonate into a form acceptable for land disposal. Health physics aspects and dose received during each phase of the processing are discussed.
Optimization of fast breeder reactors employing innovative liquid metal coolants
Pilarski, Stevan [Electricite de France R and D, 1 Avenue du General de Gaulle, 92141 Clamart (France); CNAM, 292 rue Saint-Martin 75141 Paris Cedex 03 (France)
In this paper we propose a comparative assessment of fast breeder reactor core concepts employing Pb, Pb- Mg and Pb-{sup 7}Li as primary coolants and oxide and nitride fuels. Starting from a common reference core to make the comparison relevant, each coolant candidate is associated to an optimized design that takes into account its specific physical properties. For each core, we perform a neutronic analysis and an assessment of its safety potential. In comparison with the case of Pb, the use of Pb-Mg and Pb-{sup 7}Li increases the void reactivity effect. On the other hand, the breeding gain also increases, and the Doppler effect is enhanced, leading to a favorable behaviour concerning safety. (author)
Use of experimental separation limits in the theoretical design of V/STOL inlets
NASA Technical Reports Server (NTRS)
Boles, M. A.; Stockman, N. O.
Experimental data from several model inlets are used to generate two parameters which are related to the limit of operation for inlet flow separation. One parameter, called the diffusion ratio, is the ratio of the peak velocity on the inlet surface to the velocity at the diffuser exit and is related to the boundary-layer separation at low throat Mach numbers. The other parameter, the peak Mach number on the inlet surface, is related to the separation at high throat Mach numbers. These parameters are easily calculated from potential flow solutions and thus can be used as a design tool in screening proposed inlet geometries. An illustrative example of an application to an inlet design study for a tilt nacelle VTOL airplane is presented. The value of contraction ratio required to meet the operating requirements yet allow the inlet to remain free of separation as indicated by the two separation parameters is shown.
Reliable reactor coolant pump seal performance - the station's role
N. E. Pothier; R. Metcalfe
During the early days of the Canada deuterium uranium (CANDU) power reactor program, operators and designers learned that close attention to reactor coolant pump (RCP) seals was imperative for achieving high-capacity factors. This lesson was driven home by unpredictable and frequent seal failures in the following early CANDU plants. Those seal failures caused forced outages, maintenance\\/dose burdens, and heavy-water losses.
Evaluation of organic moderator/coolants for fusion breeder blankets
Romero, J.B.
Organic coolants have several attractive features for fusion breeder blanket design. Their apparent compatibility with lithium and their ideal physical and nuclear properties allows straight-forward, high performance designs. Radiolytic damage can be reduced to about the same order as comparable fission systems by using multiplier/stripper blanket designs. Tritium recovery from the organic should be straightforward, but additional data is needed to make a better assessment of the economics of the process.
92. View of transmitter building no. 102 first floor coolant ...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
92. View of transmitter building no. 102 first floor coolant process water tanks (sodium bisulfate solution), stainless steel, for electronic systems cooling in transmitter and MIP rooms. RCA Services Company 29 September, 1960, official photograph BMEWS Project by unknown photograph, Photographic Services, Riverton, NJ, BMEWS, clear as negative no. A-1226 - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK
Expert system for online surveillance of nuclear reactor coolant pumps
Gross, Kenny C. (Bolingbrook, IL); Singer, Ralph M. (Naperville, IL); Humenik, Keith E. (Columbia, MD)
An expert system for online surveillance of nuclear reactor coolant pumps. This system provides a means for early detection of pump or sensor degradation. Degradation is determined through the use of a statistical analysis technique, sequential probability ratio test, applied to information from several sensors which are responsive to differing physical parameters. The results of sequential testing of the data provide the operator with an early warning of possible sensor or pump failure.
Acceptance criteria for reactor coolant pumps and valves
Gupta, N.K.; Miller, R.F.; Sindelar, R.L.
Each of the six primary coolant loop systems of the Savannah River Site (SRS) production reactors contains one reactor coolant pump, one PUMP suction side motor operated valve, and other smaller valves. The pumps me double suction, double volute, and radially split type pumps. The valves are different size shutoff and control valves rated from ANSI B16.5 construction class 150 to class 300. The reactor coolant system components, also known as the process water system (PWS), are classified as nuclear Safety Class I components. These components were constructed in the 1950`s in accordance with the then prevailing industry practices. No uniform construction codes were used for design and analysis of these components. However, no pressure boundary failures or bolting failures have ever been recorded throughout their operating history. Over the years, the in-service inspection (ISI) was limited to visual inspection of the pressure boundaries, and surface and volumetric examination of the pressure retaining bolts. Efforts are now underway to implement ISI requirements similar to the ASME Section XI requirements for pumps and valves. This report discusses the new ISI requirements which also call for volumetric examination of the pump casing and valve body welds.
Calculation of compressible flow in and about three-dimensional inlets with and without auxiliary inlets by a higher-order panel method
NASA Technical Reports Server (NTRS)
Hess, J. L.; Friedman, D. M.
A three dimensional higher order panel method was specialized to the case of inlets with auxiliary inlets. The resulting program has a number of graphical input-output features to make it highly useful to the designer. The various aspects of the program are described instructions for its use are presented.
APT Blanket System Loss-of-Coolant Accident (LOCA) Based on Initial Conceptual Design - Case 1: External HR Break Near Inlet Header
Hamm, L.L.
The APT blanket system has about 57 MW of thermal energy deposited within the blanket region under normal operating conditions from the release of neutrons and the interaction of the High energy particles with the blanket materials. This corresponds to about 48 percent of total thermal energy deposited in the APT target/blanket system. The deposited thermal energy under normal operation conditions is an important input parameter used in the thermal-hydraulic design and accident analysis.
APT Blanket System Loss-of-Coolant Accident (LOCA) Based on Initial Conceptual Design - Case 4: External Pressurizer Surge Line Break Near Inlet Header
Hamm, L.L.
This report is one of a series of reports documenting accident scenario simulations for the Accelerator Production of Tritium (APT) blanket heat removal systems. The simulations were performed in support of the Preliminary Safety Analysis Report (PSAR) for the APT.
APT Blanket System Loss-of-Coolant Accident Based on Initial Conceptual Design - Case 5: External RHR Break Near Inlet Header
Hamm, L.L.
This report is one of a series of reports that document normal operation and accident simulations for the Accelerator Production of Tritium (APT) blanket heat removal system. These simulations were performed for the Preliminary Safety Analysis Report.
Asymmetrical Flow Simulation of Icing Effects in S-Duct Inlets at Angle of Attack
NASA Astrophysics Data System (ADS)
Jin, Wonjin; Taghavi, Ray R.; Farokhi, Saeed
The effect of flow angularity on an S-duct inlet with icing is computationally investigated. Flow angularity is simulated through angle-of-attack, and sideslip in addition to asymmetrical ice accretion on the inlet lip. A commercial CFD code, STAR-CCM+ is used for the steadystate computations with the shear-stress transport (SST)
A Numerical and Experimental Study of Coflow Laminar Diffusion Flames: Effects of Gravity and Inlet Velocity
NASA Technical Reports Server (NTRS)
Cao, S.; Bennett, B. A. V.; Ma, B.; Giassi, D.; Stocker, D. P.; Takahashi, F.; Long, M. B.; Smooke, M. D.
In this work, the influence of gravity, fuel dilution, and inlet velocity on the structure, stabilization, and sooting behavior of laminar coflow methane-air diffusion flames was investigated both computationally and experimentally. A series of flames measured in the Structure and Liftoff in Combustion Experiment (SLICE) was assessed numerically under microgravity and normal gravity conditions with the fuel stream CH4 mole fraction ranging from 0.4 to 1.0. Computationally, the MC-Smooth vorticity-velocity formulation of the governing equations was employed to describe the reactive gaseous mixture; the soot evolution process was considered as a classical aerosol dynamics problem and was represented by the sectional aerosol equations. Since each flame is axisymmetric, a two-dimensional computational domain was employed, where the grid on the axisymmetric domain was a nonuniform tensor product mesh. The governing equations and boundary conditions were discretized on the mesh by a nine-point finite difference stencil, with the convective terms approximated by a monotonic upwind scheme and all other derivatives approximated by centered differences. The resulting set of fully coupled, strongly nonlinear equations was solved simultaneously using a damped, modified Newton's method and a nested Bi-CGSTAB linear algebra solver. Experimentally, the flame shape, size, lift-off height, and soot temperature were determined by flame emission images recorded by a digital camera, and the soot volume fraction was quantified through an absolute light calibration using a thermocouple. For a broad spectrum of flames in microgravity and normal gravity, the computed and measured flame quantities (e.g., temperature profile, flame shape, lift-off height, and soot volume fraction) were first compared to assess the accuracy of the numerical model. After its validity was established, the influence of gravity, fuel dilution, and inlet velocity on the structure, stabilization, and sooting tendency of laminar coflow methane-air diffusion flames was explored further by examining quantities derived from the computational results.
Evaluation of Flush-Mounted, S-Duct Inlets with Large Amounts of Boundary Layer Ingestion
NASA Technical Reports Server (NTRS)
Berrier, Bobby L.; Morehouse, Melissa B.
A new high Reynolds number test capability for boundary layer ingesting inlets has been developed for the NASA Langley Research Center 0.3-Meter Transonic Cryogenic Tunnel. Using this new capability, an experimental investigation of four S-duct inlet configurations with large amounts of boundary layer ingestion (nominal boundary layer thickness of about 40% of inlet height) was conducted at realistic operating conditions (high subsonic Mach numbers and full-scale Reynolds numbers). The objectives of this investigation were to 1) provide a database for CFD tool validation on boundary layer ingesting inlets operating at realistic conditions and 2) provide a baseline inlet for future inlet flow-control studies. Tests were conducted at Mach numbers from 0.25 to 0.83, Reynolds numbers (based on duct exit diameter) from 5.1 million to a full-scale value of 13.9 million, and inlet mass-flow ratios from 0.39 to 1.58 depending on Mach number. Results of this investigation indicate that inlet pressure recovery generally decreased and inlet distortion generally increased with increasing Mach number. Except at low Mach numbers, increasing inlet mass-flow increased pressure recovery and increased distortion. Increasing the amount of boundary layer ingestion (by decreasing inlet throat height) or ingesting a boundary layer with a distorted (adverse) profile decreased pressure recovery and increased distortion. Finally, increasing Reynolds number had almost no effect on inlet distortion but increased inlet recovery by about one-half percent at a Mach number near cruise.
Evaluation of lifetime and analytical performance of gas chromatographic inlet septa for analysis of reactive semivolatile organic compounds.
Westland, Jessica; Organtini, Kari; Dorman, Frank L
A comparison of septum degradation data obtained from a variety of standard GC septa, including the Thermogreen LB-2, AG3 (Green), Thermolite, BTO and the Merlin Microseal were evaluated. This study was conducted to determine analytical system lifetime between inlet maintenance based on chromatographic performance of reactive compounds as a function of septum aging through repeated injections. It is widely accepted that gas chromatographic septa degrade relative to the operating temperature of the injector and also based on the physical interaction with the syringe needle. This interaction may cause shedding of particles which then accumulate in the injection port liner, or possibly on the GC column in rare cases. This will likely lead to reactive compound breakdown in the injection port of flash-vaporizing inlets and thus reduce the amount of time that an instrument may be operated between inlet maintenance. Evaluations of the septa were based on the performance of the organochlorine compounds, endrin and 4,4'-DDT. These two compounds act as general indicators for the overall inertness of the GC injector, and their performance may be used to extrapolate to the performance of many other compounds. The average lifetime in terms of the number of injections for the studied septa was determined to range from 151 injections to nearly 2000 injections, depending on the septum. These values were found to be repeatable within the same septa material, or within class. The injection lifetime was found to be statistically different between different septa, however, indicating that not all septa are equivalent in terms of their durability to repeated injections. Additionally, some septa were found to predominately cause degradation of endrin, while others were found to cause reactivity of 4,4'-DDT, indicating that a difference in septa material may cause differences in what types of compounds become reactive in the GC inlet. PMID:22503928
Development and Application of the Reactor Coolant On-Line Leakage Evaluation Model for Pressurized Water Reactors
Liang, Thomas K.S.; Hung, H.-J.; Chang, C.-J. [Institute of Nuclear Energy Research, Taiwan (China)
With the consideration of mass unbalance, coolant shrinking, and compressibility, a model for reactor coolant leakage evaluation has been developed to quantify on-line the system leakage rate with conventional system measurements, regardless of where the leak occurs. This model has been derived from the system of total continuity, and it divides the reactor coolant system (RCS) into two regions, namely, the saturated and subcooled regions. The pressurizer is considered as a saturated region, and the remaining part of the RCS is regarded as a subcooled region. Taking the on-line measurements of the RCS including the RCS pressure, temperature, pressurizer water level, and charging and letdown flow rates, this model can directly evaluate on-line the RCS leakage rate. It is noted that this model is applicable only if the RCS remains subcooled. To verify the applicability of this model, data generated by RELAP5/MOD3 simulation and experimental measurements from the Institute of Nuclear Energy Research, Taiwan, Integral System Test Facility were adopted to assess this model. With further on-line verification against the Maanshan training simulator, this model was finally delivered to the Maanshan nuclear power plant (a three-looped Westinghouse pressurized water reactor) to assist the operator training and on-line evaluation of the RCS leakage rate. The smallest amount of leak flow that can be detected by the ROCK model is 3 gal/min.
An investigation of engine influence on inlet performance. [conducted in the Ames 40- by 80-foot wind tunnel
NASA Technical Reports Server (NTRS)
Hodder, B. K.
The performance of a conventional engine/inlet installation, in which inlet and engine flow field interaction occurs, was compared to the performance of the same inlet remote coupled to the engine. The remote coupled inlet configuration decouples the influence of the engine on the inlet flow field and simulates current small scale inlet test techniques in which inlet airflow is provided by a vacuum source or coupled engine. The investigation was conducted in the NASA-Ames 40- by 80-foot wind tunnel using a General Electric TF-34 turbofan engine and a subsonic inlet having an average inlet contraction ratio of 1.26. Test results indicated that engine interaction allows the inlet to operate with lower distortion levels at and beyond the separation angle-of-attack experienced without engine interaction.
Oxidation of SiC cladding under Loss of Coolant Accident (LOCA) conditions in LWRs
Lee, Y.; Yue, C.; Arnold, R. P.; McKrell, T. J.; Kazimi, M. S. [Dept. of Nuclear Science and Engineering, Massachusetts Inst. of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307 (United States)
An experimental assessment of Silicon Carbide (SiC) cladding oxidation rate in steam under conditions representative of Loss of Coolant Accidents (LOCA) in light water reactors (LWRs) was conducted. SiC oxidation tests were performed with monolithic alpha phase tubular samples in a vertical quartz tube at a steam temperature of 1140 deg. C and steam velocity range of 1 to 10 m/sec, at atmospheric pressure. Linear weight loss of SiC samples due to boundary layer controlled reaction of silica scale (SiO{sub 2} volatilization) was experimentally observed. The weight loss rate increased with increasing steam flow rate. Over the range of test conditions, SiC oxidation rates were shown to be about 3 orders of magnitude lower than the oxidation rates of zircaloy 4. A SiC volatilization correlation for developing laminar flow in a vertical channel is formulated. (authors)
The addition of zinc to primary reactor coolant for enhanced PWSCC resistance
Esposito, J.N.; Economy, G.; Byers, W.A.; Esposito, J.B.; Pement, F.W.; Jacko, R.J.; Bergmann, C.A. [Westinghouse Electric Corp., Pittsburgh, PA (United States)
The effect of zinc borate additions on the primary water stress corrosion cracking (PWSCC) of specimens exposed to simulated pressurized water reactor (PWR) primary coolant was evaluated in the laboratory. Highly stressed reverse U-bend (RUB) specimens of Alloy 600MA, Alloy 600TT, and Alloy 690TT, were exposed under simulated PWR conditions of chemistry, temperature and pressure. Statistically significant reductions in the initiation and extent of observed cracking of the RUB`s were observed as a function of zinc additions versus controlled experiments in the absence of zinc additives. Coupons of other primary side materials of interest showed that both overall corrosion and metal release to solution were reduced in the presence of zinc. Additional qualification work, considering all aspects of system performance, is presently ongoing.
Prototypic Thermal-Hydraulic Experiment in NRU to Simulate Loss-of-Coolant Accidents
Mohr, C. L.; Hesson, G. M.; Russcher, G. E.; Marsh, R. K.; King, L. L.; Wildung, N. J.; Rausch, W. N.; Bennett, W. D.
Quick-look test results are reported for the initial test series of the Loss-of-Coolant Accident (LOCA) Simulation in the National Research Universal {NRU) test program, conducted by Pacific Northwest Laboratory (PNL) for the U.S. Nuclear Regulatory Commission (NRC). This test was devoted to evaluating the thermal-hydraulic characteristics of a full-length light water reactor (LWR) fuel bundle during the heatup, reflood, and quench phases of a LOCA. Experimental results from 28 tests cover reflood rates of 0.74 in./sec to 11 in./sec and delay times to initiate reflood of 3 sec to 66 sec. The results indicate that current analysis methods can predict peak temperatures within 10% and measured quench times for the bundle were significantly less than predicted. For reflood rates of 1 in./sec where long quench times were predicted (>2000 sec}, measured quench times of 200 sec were found.
Temporary core liquid level depression during a cold-leg small-break loss-of-coolant accident; The effect of break size and power level
Koizumi, Y.; Kumamaru, H.; Kukita, Y.; Taska, K. (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)); Mimura, Y. (ISL Co., Jonan, Mito-shi, Ibaraki-ken 310 (JP))
This paper reports on cold-leg small-break loss-of-coolant accident experiments that were conducted for break areas ranging from 0.5 to 10% of the scaled cold-leg flow area using the Large-Scale Test Facility (LSTF). The LSTF is a 1/48 volumetrically scaled simulator of a Westinghouse-type pressurized water reactor. For all the experiments, the core collapsed liquid level was temporarily depressed when liquid in the primary loop U-bend (crossover leg) was being cleared by steam. For scaled break areas {lt}2.5%, the minimum core liquid level was equal to the lowest elevation of the crossover leg. For break areas {gt}5%, the minimum core level was even lower because differential pressures created by the residual liquid holdup in the steam generator (SG) upflow side affected the core liquid level adversely. This influence of SG liquid holdup on the minimum core liquid level was larger for larger break sizes within the range of these experiments; thus, a more severe core level depression was seen for larger break sizes. Also, for the same break size, the core level depression was more severe when higher core power values were used for the simulation of the postscram core power decay. The RELAP5/MOD2 code reasonably observed in the experiments; however, several shortcomings were found in interfacial drag calculation for the SG U-tube inlet and the hot-leg outlet to the SG inlet plenum and core.
TACT1, a computer program for the transient thermal analysis of a cooled turbine blade or vane equipped with a coolant insert. 1. Users manual
NASA Technical Reports Server (NTRS)
Gaugler, R. E.
A computer program to calculate transient and steady state temperatures, pressures, and coolant flows in a cooled, axial flow turbine blade or vane with an impingement insert is described. Coolant side heat transfer coefficients are calculated internally in the program, with the user specifying either impingement or convection heat transfer at each internal flow station. Spent impingement air flows in a chordwise direction and is discharged through the trailing edge and through film cooling holes. The ability of the program to handle film cooling is limited by the internal flow model. Sample problems, with tables of input and output, are included in the report. Input to the program includes a description of the blade geometry, coolant supply conditions, outside thermal boundary conditions, and wheel speed. The blade wall can have two layers of different materials, such as a ceramic thermal barrier coating over a metallic substrate. Program output includes the temperature at each node, the coolant pressures and flow rates, and the inside heat-transfer coefficients.
Heat transfer characteristics for some coolant additives used for water cooled engines
Abou-Ziyan, H.Z.; Helali, A.H.B. [Helwan Univ., Cairo (Egypt)
Engine coolants contain certain additives to prevent engine overheating or coolant freezing in cold environments. Coolants, also, contain corrosion and rust inhibitors, among other additives. As most engines are using engine cooling solutions, it is of interest to evaluate the effect of engine coolants on the boiling heat transfer coefficient. This has its direct impact on radiator size and environment. This paper describes the apparatus and the measurement techniques. Also, it presents the obtained boiling heat transfer results at different parameters. Three types of engine coolants and their mixtures in distilled water are evaluated, under sub-cooled and saturated boiling conditions. A profound effect of the presence of additives in the coolant, on heat transfer, was clear since changes of heat transfer for different coolants were likely to occur. The results showed that up to 180% improvement of boiling heat transfer coefficient is experienced with some types of coolants. However, at certain concentrations other coolants provide deterioration or not enhancement in the boiling heat transfer characteristics. This investigation proved that there are limitations, which are to be taken into consideration, for the composition of engine coolants in different environments. In warm climates, ethylene glycol should be kept at the minimum concentration required for dissolving other components, whereas borax is beneficial to the enhancement of the heat transfer characteristics.
Axial inlet conversion to a centrifugal compressor with magnetic bearings
Novecosky, T. (NOVA Corp., Edmonton, Alberta (Canada))
NOVA's Alberta Gas Transmission Division transports natural gas via pipeline throughout the province of Alberta, Canada, exporting it to eastern Canada, US, and British Columbia. There is a continuing effort to operate the facilities and pipeline at the highest possible efficiency. One area being addressed to improve efficiency is compression of the gas. By improving compressor efficiency, fuel consumption and hence operating costs can be reduced. One method of improving compressor efficiency is by converting the compressor to an axial inlet configuration, a conversion that has been carried out more frequently in the past years. Concurrently, conventional hydrodynamic bearings have been replaced with magnetic bearings on many centrifugal compressors. This paper discusses the design and installation for converting a radial overhung unit to an axial inlet configuration, having both magnetic bearings and a thrust reducer. The thrust reducer is required to reduce axial compressor shaft loads, to a level that allows the practical installation of magnetic bearings within the space limitations of the compressor (Bear and Gibson, 1992).
Numerical simulation of supersonic and hypersonic inlet flow fields
NASA Technical Reports Server (NTRS)
Mcrae, D. Scott; Kontinos, Dean A.
This report summarizes the research performed by North Carolina State University and NASA Ames Research Center under Cooperative Agreement NCA2-719, 'Numerical Simulation of Supersonic and Hypersonic Inlet Flow Fields". Four distinct rotated upwind schemes were developed and investigated to determine accuracy and practicality. The scheme found to have the best combination of attributes, including reduction to grid alignment with no rotation, was the cell centered non-orthogonal (CCNO) scheme. In 2D, the CCNO scheme improved rotation when flux interpolation was extended to second order. In 3D, improvements were less dramatic in all cases, with second order flux interpolation showing the least improvement over grid aligned upwinding. The reduction in improvement is attributed to uncertainty in determining optimum rotation angle and difficulty in performing accurate and efficient interpolation of the angle in 3D. The CCNO rotational technique will prove very useful for increasing accuracy when second order interpolation is not appropriate and will materially improve inlet flow solutions.
Internal Designs Application for Inlet and Nozzle Aeroperformance Improvement
NASA Technical Reports Server (NTRS)
Gilinsky, M.; Blankson, I. M.
The following research results are based on development of an approach previously proposed by the authors for optimum nozzle design to obtain maximum thrust. The design was denoted a Telescope nozzle. A Telescope nozzle contains one or several internal designs of certain location, which are inserted at certain locations into a divergent conical or planar main nozzle near its exit. Such a design provides additional thrust augmentation over 20% by comparison with the optimum single nozzle of equivalent lateral area. What is more, recent experimental acoustic tests have discovered an essential noise reduction due to Telescope nozzles application. In this paper, some additional theoretical results are presented for Telescope nozzles and a similar approach is applied for aeroperformance improvement of a supersonic inlet. In addition, a classic gas dynamics problem of a similar supersonic flow into a plate has been analyzed. In some particular cases, new exact analytical solutions are obtained for a flow into a wedge with an oblique shock wave. Numerical simulations were conducted for supersonic flow into a divergent portion of a 2D or axisymmetric nozzle with several plane or conuical designs as well as into a 2D or axisymmetric supersonic inlet with a forebody. The 1st order Kryko-Godunov marching numerical scheme for inviscid supersonic flows was used. Several cases were tested using the NASA CFL3d code based on full Navier-Stokes equations. Numerical simulation results have confirmed essential benefits of Telescope design applications in propulsion systems.
Internal Designs Application for Inlet and Nozzle Aeroperformance Improvement
NASA Technical Reports Server (NTRS)
Gilinsky, M.; Blankson, I. M.
The following research results are based on development of an approach previously proposed by the authors for optimum nozzle design to obtain maximum thrust. The design was denoted a Telescope nozzle. A Telescope nozzle contains one or several internal designs of certain location, which are inserted at certain locations into a divergent conical or planar main nozzle near its exit. Such a design provides additional thrust augmentation over 20% by comparison with the optimum single nozzle of equivalent lateral area. What is more, recent experimental acoustic tests have discovered an essential noise reduction due to Telescope nozzles application. In this paper, some additional theoretical results are presented for Telescope nozzles and a similar approach is applied for aeroperformance improvement of a supersonic inlet. In addition, a classic gas dynamics problem of a similar supersonic flow into a plate has been analyzed. In some particular cases, new exact analytical solutions are obtained for a flow into a wedge with an oblique shock wave. Numerical simulations were conducted for supersonic flow into a divergent portion of a 2D or axisymmetric nozzle with several plane or conical designs as well as into a 2D or axisymmetric supersonic inlet with a forebody. The 1st order Kryko-Godunov march- ing numerical scheme for inviscid supersonic flows was used. Several cases were tested using the NASA CFL3d code based on full Navier-Stokes equations. Numerical simulation results have confirmed essential benefits of Telescope design applications in propulsion systems.
Internal Designs Application for Inlet and Nozzle Aeroperformance Improvement
NASA Technical Reports Server (NTRS)
Gilinsky, M.; Blankson, I. M.
The following research results are based on development of an approach previously proposed by the authors for optimum nozzle design to obtain maximum thrust. The design was denoted a Telescope nozzle. A Telescope nozzle contains one or several internal designs of certain location, which are inserted at certain locations into a divergent conical or planar main nozzle near its exit. Such a design provides additional thrust augmentation over 20% by comparison with the optimum single nozzle of equivalent lateral area. What is more, recent experimental acoustic tests have discovered an essential noise reduction due to Telescope nozzles application. In this paper, some additional theoretical results are presented for Telescope nozzles and a similar approach is applied for aeroperformance improvement of a supersonic inlet. In addition, a classic gas dynamics problem of a similar supersonic flow into a plate has been analyzed. In some particular cases, new exact analytical solutions are obtained for a flow into a wedge with an oblique shock wave. Numerical simulations were conducted for supersonic flow into a divergent portion of a 2D or axisymmetric nozzle with several plane or conical designs as well as into a 2D or axisymmetric supersonic inlet with a forebody. The 1st order Kryko-Godunov marching numerical scheme for inviscid supersonic flows was used. Several cases were tested using the NASA CFL3d code based on full Navier-Stokes equations. Numerical simulation results have confirmed essential benefits of Telescope design applications in propulsion systems.
On the inlet vortex system. [preventing jet engine damage caused by debris pick-up
NASA Technical Reports Server (NTRS)
Bissinger, N. C.; Braun, G. W.
The flow field of a jet engine with an inlet vortex, which can pick up heavy debris from the ground and damage the engine, was simulated in a small water tunnel by means of the hydrogen bubble technique. It was found that the known engine inlet vortex is accompained by a vortex system, consisting of two inlet vortices (the ground based and the trailing one), secondary vortices, and ground vortices. Simulation of the ground effect by an inlet image proved that the inlet vortex feeds on free stream vorticity and can exist without the presence of a ground boundary layer. The structural form of the inlet vortex system was explained by a simple potential flow model, which showed the number, location, and the importance of the stagnation points. A retractable horizontal screen or an up-tilt of the engine is suggested as countermeasure against debris ingestion.
Aerodynamic and acoustic behavior of a YF-12 inlet at static conditions
NASA Technical Reports Server (NTRS)
Bangert, L. H.; Feltz, E. P.; Godby, L. A.; Miller, L. D.
An aeroacoustic test program to determine the cause of YF-12 inlet noise suppression was performed with a YF-12 aircraft at ground static conditions. Data obtained over a wide range of engine speeds and inlet configurations are reported. Acoustic measurements were made in the far field and aerodynamic and acoustic measurements were made inside the inlet. The J-58 test engine was removed from the aircraft and tested separately with a bellmouth inlet. The far field noise level was significantly lower for the YF-12 inlet than for the bellmouth inlet at engine speeds above 5500 rpm. There was no evidence that noise suppression was caused by flow choking. Multiple pure tones were reduced and the spectral peak near the blade passing frequency disappeared in the region of the spike support struts at engine speeds between 6000 and 6600 rpm.
Low-speed test of translating lip axisymmetric inlets for subsonic transports
NASA Technical Reports Server (NTRS)
Henne, P. A.
Translating lip, axisymmetric inlets have been tested at freestream Mach numbers between 0.0 and 0.30 and at angles of attack between 0 and 90 degrees. Three isolated inlet models were tested. One model represented the inlet geometry at cruise, that is, with no lip translation. The other two models had forward translating lips with different contours. The low forward speed inlet angle-of-attack capability with the translating lip was increased more than twenty degrees over the basic untranslated lip configuration at the higher inlet airflows. The static inlet performance with the translating lip was also greatly improved. The design translation distance, defined by potential flow analysis, was near optimum.
An Interactive, Design and Educational Tool for Supersonic External-Compression Inlets
NASA Technical Reports Server (NTRS)
Benson, Thomas J.
A workstation-based interactive design tool called VU-INLET was developed for the inviscid flow in rectangular, supersonic, external-compression inlets. VU-INLET solves for the flow conditions from free stream, through the supersonic compression ramps, across the terminal normal shock region and the subsonic diffuser to the engine face. It calculates the shock locations, the capture streamtube, and the additive drag of the inlet. The inlet geometry can be modified using a graphical user interface and the new flow conditions recalculated interactively. Free stream conditions and engine airflow can also be interactively varied and off-design performance evaluated. Flow results from VU-INLET can be saved to a file for a permanent record, and a series of help screens make the simulator easy to learn and use. This paper will detail the underlying assumptions of the models and the numerical methods used in the simulator.
Effects of inlet\\/outlet configurations on the electrostatic capture of airborne nanoparticles and viruses
Jaesung Jang; Demir Akin; Rashid Bashir
Motivated by capture and detection of airborne biological agents in real time with a cantilever biosensor without introducing the agents into liquids, we present the effects of inlet\\/outlet configurations of a homemade particle collector on the electrostatic capture of airborne 100 nm diameter nanoparticles under swirling gas flows. This particle collector has three different inlet\\/outlet configurations: forward inlet\\/outlet (FO), backward
Influence of Inlet Configurations on the Refrigerant Distribution of a Dual Cold-Plate System
Kai-Shing Yang; Kun-Huang Yu; Ing-Youn Chen; Chi-Chuan Wang
This study examines the refrigerant distribution of a dual cold-plate system subject to the influence of heating load and inlet configurations. Three inlet configurations, namely, uniformly divided, side-entrance, and inlet inclination, are examined. For an unequal heating load for both uniformly divided and side-entrance configurations, it is found that the distribution of mass flow rate subject to the influence of
Aspiration and sampling efficiencies of the TSP and louvered particulate matter inlets.
Kenny, Lee; Beaumont, Geoff; Gudmundsson, Anders; Thorpe, Andrew; Koch, Wolfgang
An experimental system was developed for the rapid measurement of the aspiration/transfer efficiency of aerosol samplers in a wind tunnel. We attempted to measure the aspiration and particle transfer characteristics of two inlets commonly used for sampling airborne Particulate Matter (PM): the 'Total Suspended Particulate' or TSP inlet, and the louvered 'dichotomous sampler inlet' typically used in sampling PM10 or PM2.5. We were able to determine the fraction of the external aerosol that enters the inlet and is transferred through it, and hence is available for collection by a filter, or further size fractionation into PM10 or PM2.5. This 'sampling efficiency' was analysed as a function of dimensionless aerodynamic parameters in order to understand the factors governing inlet performance. We found that for the louvered inlet the sampling efficiency increases as the external wind increases. Under all conditions expected in practical use the louvered inlet aspirates sufficient PM to allow either PM10 or PM2.5 to be selected downstream. The TSP inlet's sampling efficiency decreases with increasing external wind, and the TSP inlet is likely to under-sample the coarse end of the PM10 fraction at moderate and high external winds. As this inlet is generally not used with a downstream size fractionator, changes in sampling efficiency directly affect the measured aerosol concentration. We also investigated whether it is possible to dimensionally scale the PM inlets to operate at either higher or lower flow rates, while preserving the same sampling characteristics as the current full-scale, 16.67 L min(-1) versions. In the case of the louvered inlet, our results indicate that scaling to lower flow rates is possible; scaling to higher flow rates was not tested. For the TSP sampler, the sampling efficiency changes if the sampler is scaled to operate at smaller or larger flow rates, leading to unreliable performance. PMID:15877170
Velocity distributions on two-dimensional wing-duct inlets by conformal mapping
NASA Technical Reports Server (NTRS)
Perl, W; Moses, H E
The conformal-mapping method of the Cartesian mapping function is applied to the determination of the velocity distribution on arbitrary two-dimensional duct-inlet shapes such as are used in wing installations. An idealized form of the actual wing-duct inlet is analyzed. The effects of leading edge stagger, inlet-velocity ratio, and section lift coefficients on the velocity distribution are included in the analysis. Numerical examples are given and, in part, compared with experimental data.
A study of fractionating inlet systems for the dichotomous air samplerĀ
Ripps, Gerald Joseph
December 1979 Major Subject: Civil Engineering A STUDY OF FRACTIONING INLET SYSTEMS FOR THE DICHOTOMOUS AIR SAMPLER A Thesis by GERALD JOSEPH RIFFS Approved as to style and content (Cha rman 'f Committee) (Member) (Member) (Head of Department... TESTS VITA 48 56 LIST QF TABLES Table Comparison of cone angles P acute 22 Effect of cone inlet spacing Effectiveness of various inlets 23 24 Sampling effectiveness for various system jet sizes 32 LIST OF FIGURES ~iciure Pacae Aerosol...
How, bedform migration rates and sedinent transport in a tidal inlet
Work reported here forms part of the EU MAST3 INDIA 1 project (Inlet Dynamics Initiative: Algarve), studying the dynamics of a small, highly dynamic tidal inlet in the Ria Formosa, Algarve, Portugal, O'Connor et al., 1999, Figure l. Using the multi-sensor PIP (POL Instrument Package) deployed at various positions in the Barra Nova inlet from a small jack-up barge, Figure
Biases in ion transmission through an electrospray ionization-mass spectrometry capillary inlet
Jason S. Page; Ioan Marginean; Erin Shammel Baker; Ryan T. Kelly; Keqi Tang; Richard D. Smith
A heated capillary inlet for an electrospray ionization mass spectrometry (ESI-MS) interface was compared with shorter versions\\u000a of the inlet to determine the effects on transmission and ionization efficiencies for low-flow (nano) electrosprays. Five\\u000a different inlet lengths were studied, ranging from 6.4 to 1.3 cm. As expected, the electrospray current transmission efficiency\\u000a increased with decreasing capillary length due to reduced
Incidence angle bounds for lip flow separation of three 13.97-centimeter-diameter inlets
NASA Technical Reports Server (NTRS)
Luidens, R. W.; Abbott, J. M.
Low speed wind tunnel tests were conducted to establish a procedure for determining inlet-lip flow separation and to make preliminary examination of the incidence angle bounds for lip flow separation on inlets intended for the nacelles of STOL (short takeoff and landing) aircraft. Three inlets were tested. Two of the inlets had short centerbodies with lower lip area contraction ratios of 1.30 and 1.44. The third inlet had a cylindrical centerbody extended forward into the inlet throat with a lower lip area contraction ratio of 1.44. The inlets were sized to fit a 13.97 centimeter-diameter fan. For inlet throat Mach numbers less than about 0.43, the lip flow separation angle was increased by either increasing the ratio of throat velocity to freestream velocity (Vt/Vo) or by increasing the lower lip area contraction ratio. For throat Mach numbers greater than a certain value (ranging from 0.43 to 0.52), increasing throat Mach number in some cases resulted in a decrease in the lip flow separation angle. Extending a cylindrical centerbody into the inlet throat increased the flow separation angle for nearly all values of Vt/Vo.
Shock Position Control for Mode Transition in a Turbine Based Combined Cycle Engine Inlet Model
NASA Technical Reports Server (NTRS)
Csank, Jeffrey T.; Stueber, Thomas J.
A dual flow-path inlet for a turbine based combined cycle (TBCC) propulsion system is to be tested in order to evaluate methodologies for performing a controlled inlet mode transition. Prior to experimental testing, simulation models are used to test, debug, and validate potential control algorithms which are designed to maintain shock position during inlet disturbances. One simulation package being used for testing is the High Mach Transient Engine Cycle Code simulation, known as HiTECC. This paper discusses the development of a mode transition schedule for the HiTECC simulation that is analogous to the development of inlet performance maps. Inlet performance maps, derived through experimental means, describe the performance and operability of the inlet as the splitter closes, switching power production from the turbine engine to the Dual Mode Scram Jet. With knowledge of the operability and performance tradeoffs, a closed loop system can be designed to optimize the performance of the inlet. This paper demonstrates the design of the closed loop control system and benefit with the implementation of a Proportional-Integral controller, an H-Infinity based controller, and a disturbance observer based controller; all of which avoid inlet unstart during a mode transition with a simulated disturbance that would lead to inlet unstart without closed loop control.
Analysis of a Channeled Centerbody Supersonic Inlet for F-15B Flight Research
NASA Technical Reports Server (NTRS)
Ratnayake, Nalin A.
The Propulsion Flight Test Fixture at the NASA Dryden Flight Research Center is a unique test platform available for use on the NASA F-15B airplane, tail number 836, as a modular host for a variety of aerodynamics and propulsion research. The first experiment that is to be flown on the test fixture is the Channeled Centerbody Inlet Experiment. The objectives of this project at Dryden are twofold: 1) flight evaluation of an innovative new approach to variable geometry for high-speed inlets, and 2) flight validation of channeled inlet performance prediction by complex computational fluid dynamics codes. The inlet itself is a fixed-geometry version of a mixed-compression, variable-geometry, supersonic in- let developed by TechLand Research, Inc. (North Olmsted, Ohio) to improve the efficiency of supersonic flight at off-nominal conditions. The concept utilizes variable channels in the centerbody section to vary the mass flow of the inlet, enabling efficient operation at a range of flight conditions. This study is particularly concerned with the starting characteristics of the inlet. Computational fluid dynamics studies were shown to align well with analytical predictions, showing the inlet to remain unstarted as designed at the primary test point of Mach 1.5 at an equivalent pressure altitude of 29,500 ft local conditions. Mass-flow-related concerns such as the inlet start problem, as well as inlet efficiency in terms of total pressure loss, are assessed using the flight test geometry.
A capillary gas chromatographic inlet for the analysis of trace concentrations of compounds.
Sonchik, S M; Walker, J Q
An important consideration in glass capillary column gas chromatography is the choice of the best sample inlet system for either splitting or splitless injection. This paper describes a simple direct glass-lined inlet, and describes its advantages over conventional split and splitless injection systems for trace component analysis. Several analyses are described which illustrate the superiority of the new direct inlet for these applications. The design of the new direct inlet system is such that column efficiency is not impaired and is equivalent to that of split injections. PMID:19847989
Tolerance of Mach 2.50 axisymmetric mixed-compression inlets to upstream flow variations
NASA Technical Reports Server (NTRS)
Choby, D. A.
An investigation of the tolerances of two Mach 2.50 axisymmetric mixed-compression inlets to upstream flow variations was conducted. Tolerances of each inlet to angle of attack as a function of decreasing free-stream Mach number were obtained. A local region of overcompression was formed on the leeward side of the inlet at maximum angle of attack before unstart. This region of overcompression corresponded to local subsonic flow conditions ahead of the geometric throat. A uniform Mach number gradient of 0.10 at the cowl lip plane did not affect the inlet's pressure recovery, mass flow ratio, or diffuser exit total-pressure distortion.
Investigation of Methods for the Structural Weight Analysis of a Mach 2.4 Axisymmetric Inlet
NASA Technical Reports Server (NTRS)
Nadell, Shari-Beth
Structural design and analysis tools appropriate for estimating the structural weight of an axisymmetric inlet designed for Mach 2.4 cruise were evaluated. Little information regarding the inlet mechanical design is available in the preliminary design phase, so it is necessary to first develop a reasonable structural design before estimating the inlet weight. The Internally Pressurized Structure Synthesis and Optimization (IPSSO) program, employing an analytical approach, was chosen for evaluation due to its combined design and analysis capabilities. The inlet design produced by IPSSO was then analyzed using the NASTRAN finite element program. The finite element analysis was performed to help identify the limitations of the analytically based code as well as to evaluate NASTRAN for this application. Comparison between the IPSSO inlet weight and that of a similar inlet developed by the Boeing Commercial Airplane Group was also made. Program evaluation concluded that the combined use of IPSSO to create an initial design and NASTRAN to perform a numerical analysis would provide the capability to evaluate a limited number of inlet design The development of a new tool for the minimum weight design and analysis of inlet structures would be required for greater flexibility in evaluating inlet conceptual designs.
Fundamental Aeronautics Program: Supersonics Project. Channeled Center-Body Inlet Experiment Overview
NASA Technical Reports Server (NTRS)
SaintJohn, Clint; Ratnayake, Nalin; Frederick, Mike
The presentation describes supersonic flight testing accomplished on a novel mixed compression axisymmetric inlet utilizing channels for off design flow matching rather than a translating centerbody concept.
Cavitation performance and flow characteristic in a centrifugal pump with inlet guide vanes
NASA Astrophysics Data System (ADS)
Tan, L.; Zha, L.; Cao, S. L.; Wang, Y. C.; Gui, S. B.
The influence of prewhirl regulation by inlet guide vanes (IGVs) on cavitation performance and flow characteristic in a centrifugal pump is investigated. At the impeller inlet, the streamlines are regulated by the IGVs, and the axial velocity distribution is also influenced by the IGVs. Due to the total pressure loss on the IGVs, the cavitation performance of the centrifugal pump degrades. The cavitation area in impeller with IGVs is larger than one without IGVs. The specify values of total pressure loss between the suction pipe inlet and impeller inlet for three cavitation conditions show that the IGVs will generate additional pressure loss, which is related to the IGVs angles and cavitation conditions.
Observations of Seafloor Roughness in a Tidally Modulated Inlet
NASA Astrophysics Data System (ADS)
Lippmann, T. C.; Hunt, J.
The vertical structure of shallow water flows are influenced by the presence of a bottom boundary layer, which spans the water column for long period waves or mean flows. The nature of the boundary is determined in part by the roughness elements that make up the seafloor, and includes sometimes complex undulations associated with regular and irregular shaped bedforms whose scales range several orders of magnitude from orbital wave ripples (10-1 m) to mega-ripples (100 m) and even larger features (101-103) such as sand waves, bars, and dunes. Modeling efforts often parameterize the effects of roughness elements on flow fields, depending on the complexity of the boundary layer formulations. The problem is exacerbated by the transient nature of bedforms and their large spatial extent and variability. This is particularly important in high flow areas with large sediment transport, such as tidally dominated sandy inlets like New River Inlet, NC. Quantification of small scale seafloor variability over large spatial areas requires the use of mobile platforms that can measure with fine scale (order cm) accuracy in wide swaths. The problem is difficult in shallow water where waves and currents are large, and water clarity is often limited. In this work, we present results from bathymetric surveys obtained with the Coastal Bathymetry Survey System, a personal watercraft equipped with a Imagenex multibeam acoustic echosounder and Applanix POS-MV 320 GPS-aided inertial measurement unit. This system is able to measure shallow water seafloor bathymetry and backscatter intensity with very fine scale (10-1 m) resolution and over relatively large scales (103 m) in the presence of high waves and currents. Wavenumber spectra show that the noise floor of the resolved multibeam bathymetry is on the order of 2.5 - 5 cm in amplitude, depending on water depths ranging 2 - 6 m, and about 30 cm in wavelength. Seafloor roughness elements are estimated from wavenumber spectra across the inlet from bathymetric maps of the seafloor obtained with 10-25 cm horizontal resolution. Implications of the effects of the bottom variability on the vertical structure of the currents will be discussed. This work was supported by ONR and NOAA.
A versatile cryo-focussing flow switching gas chromatography inlet for trace analysis of intractable compounds.
Apps, Peter; Mmualefe, Lesego
A wide variety of samples that can be analysed by gas chromatography do not lend themselves to the usual preparation of solvent extracts for split-splitless injections, and are best handled by purge and trap or equilibrium headspace sampling. A cryo-focussing, flow switching gas chromatography inlet system that handles different types of sample without the need for hardware changes has been prototyped. It provides excellent repeatability and linearity with liquid injections, purge and trap, and equilibrium headspace samples, in both split and splitless modes. The performance of the system was tested with sub-nanogram quantities of challenging analytes such as free carboxylic acids, alcohols, diols, phenols and aldehydes, and volatiles purged from contaminated soil, mammal faeces, a pesticide formulation, and a spice. Repeatability RSDs for peak areas were consistently below 11% and repeatabilities of retention times below 0.05%, independently of sample type (liquid or gas phase) and nature or quantity of compound. Regression coefficients of peak areas vs. quantity were typically ? 0.999 over two orders of magnitude ranges extending down to below 0.01 ng, also independently of sample and analyte. Limits of quantitation were robustly below 0.1-0.2 ng. Peak shapes and resolution are the same with use of the cryo-trap and flow switch as they are with conventional injections. Performance is robust to flow rate and, for most compounds, to trapping and desorption temperature. The cryo-trapping flow switching inlet's performance parameters match those of other sample introduction systems, and are achieved with sub-nanogram quantities of intractable analytes. PMID:22920301
Use of microPCM fluids as enhanced liquid coolants in automotive EV and HEV vehicles. Final report
Mulligan, James C.; Gould, Richard D.
Proof-of-concept experiments using a specific microPCM fluid that potentially can have an impact on the thermal management of automotive EV and HEV systems have been conducted. Samples of nominally 20-micron diameter microencapsulated octacosane and glycol/water coolant were prepared for testing. The melting/freezing characteristics of the fluid, as well as the viscosity, were determined. A bench scale pumped-loop thermal system was used to determine heat transfer coefficients and wall temperatures in the source heat exchanged. Comparisons were made which illustrate the enhancements of thermal performance, reductions of pumping power, and increases of heat transfer which occur with the microPCM fluid.
Preventing fuel failure for a beyond design basis accident in a fluoride salt cooled high temperature reactor
Minck, Matthew J. (Matthew Joseph)
The fluoride salt-cooled high-temperature reactor (FHR) combines high-temperature coated-particle fuel with a high-temperature salt coolant for a reactor with unique market and safety characteristics. This combination can ...
Development of mobile, on-site engine coolant recycling utilizing reverse-osmosis technology
Kughn, W. [Toxguard Fluid Technologies, Irvine, CA (United States). CEO; Eaton, E.R. [Penray Companies, Inc., Elk Grove Village, IL (United States)
This paper presents the history of the development of self-contained, mobile, high-volume, engine coolant recycling by reverse osmosis (R/O). It explains the motivations, created by government regulatory agencies, to minimize the liability of waste generators who produce waste engine coolant by providing an engine coolant recycling service at the customer`s location. Recycling the used engine coolant at the point of origin minimizes the generators` exposure to documentation requirements, liability, and financial burdens by greatly reducing the volume of used coolant that must be hauled from the generator`s property. It describes the inherent difficulties of recycling such a highly contaminated, inconsistent input stream, such as used engine coolant, by reverse osmosis. The paper reports how the difficulties were addressed, and documents the state of the art in mobile R/O technology. Reverse osmosis provides a purified intermediate fluid that is reinhibited for use in automotive cooling systems. The paper offers a review of experiences in various automotive applications, including light-duty, medium-duty and heavy-duty vehicles operating on many types of fuel. The authors conclude that mobile embodiments of R/O coolant recycling technology provide finished coolants that perform equivalently to new coolants as demonstrated by their ability to protect vehicles from freezing, corrosion damage, and other cooling system related problems.
F-18 HARV dirty probes on inlet rake
NASA Technical Reports Server (NTRS)
Pressure transducers are housed in tubes on the inlet rake of NASA's F-18 High Alpha Research Vehicle (HARV) to test pressure distortion patterns at different angles of attack. Located at the engine face, these probes provide information on how to adjust the engine to accomodate the distortions. The highly modified F-18 airplane flew 383 flights at NASA's Dryden Flight Research Center, over a nine year period and demonstrated concepts that greatly increase fighter maneuverability. Among concepts proven in the aircraft is the use of paddles to direct jet engine exhaust in cases of extreme altitudes where conventional control surfaces lose effectiveness. Another concept, developed by NASA Langley Research Center, is a deployable wing-like surface installed on the nose of the aircraft for increased right and left (yaw) control on nose-high flight angles.
Comparative study of turbulence models in predicting hypersonic inlet flows
NASA Technical Reports Server (NTRS)
Kapoor, Kamlesh; Anderson, Bernhard H.; Shaw, Robert J.
A numerical study was conducted to analyze the performance of different turbulence models when applied to the hypersonic NASA P8 inlet. Computational results from the PARC2D code, which solves the full two-dimensional Reynolds-averaged Navier-Stokes equation, were compared with experimental data. The zero-equation models considered for the study were the Baldwin-Lomax model, the Thomas model, and a combination of the Baldwin-Lomax and Thomas models; the two-equation models considered were the Chien model, the Speziale model (both low Reynolds number), and the Launder and Spalding model (high Reynolds number). The Thomas model performed best among the zero-equation models, and predicted good pressure distributions. The Chien and Speziale models compared very well with the experimental data, and performed better than the Thomas model near the walls.
Predicted upwash angles at engine inlets for STOL aircraft
NASA Technical Reports Server (NTRS)
Albers, J. A.
Upwash angles were predicted for a STOL lifting system by using a two-dimensional potential flow analysis. Upwash angles are presented for distances ahead of the wing leading edge of 50, 75, and 100 percent of wing chord. The upwash angle was determined to be insensitive to the vertical location of the engine inlet. For a wide range of takeoff and landing conditions, the upwash angle was found to be a function of the total two-dimensional lift coefficient. Upwash angles, along with typical flow fields, are presented for a range of total two-dimensional lift coefficients from 2 to 12. Three-dimensional effects were considered in estimating upwash angles for an unswept-wing externally blown flap aircraft. For this STOL configuration, effective upwash angles during takeoff, approach, and waveoff conditions were found to be 22 deg, 26 deg, and 36 deg, respectively.
Mass independent kinetic energy reducing inlet system for vacuum environment
Reilly, Peter T.A.
A particle inlet system comprises a first chamber having a limiting orifice for an incoming gas stream and a micrometer controlled expansion slit. Lateral components of the momentum of the particles are substantially cancelled due to symmetry of the configuration once the laminar flow converges at the expansion slit. The particles and flow into a second chamber, which is maintained at a lower pressure than the first chamber, and then moves into a third chamber including multipole guides for electromagnetically confining the particle. The vertical momentum of the particles descending through the center of the third chamber is minimized as an upward stream of gases reduces the downward momentum of the particles. The translational kinetic energy of the particles is near-zero irrespective of the mass of the particles at an exit opening of the third chamber, which may be advantageously employed to provide enhanced mass resolution in mass spectrometry.
Mass independent kinetic energy reducing inlet system for vacuum environment
Reilly, Peter T. A. [Knoxville, TN
A particle inlet system comprises a first chamber having a limiting orifice for an incoming gas stream and a micrometer controlled expansion slit. Lateral components of the momentum of the particles are substantially cancelled due to symmetry of the configuration once the laminar flow converges at the expansion slit. The particles and flow into a second chamber, which is maintained at a lower pressure than the first chamber, and then moves into a third chamber including multipole guides for electromagnetically confining the particle. The vertical momentum of the particles descending through the center of the third chamber is minimized as an upward stream of gases reduces the downward momentum of the particles. The translational kinetic energy of the particles is near-zero irrespective of the mass of the particles at an exit opening of the third chamber, which may be advantageously employed to provide enhanced mass resolution in mass spectrometry.
Mass independent kinetic energy reducing inlet system for vacuum environment
Reilly, Peter T.A.
A particle inlet system comprises a first chamber having a limiting orifice for an incoming gas stream and a micrometer controlled expansion slit. Lateral components of the momentum of the particles are substantially cancelled due to symmetry of the configuration once the laminar flow converges at the expansion slit. The particles and flow into a second chamber, which is maintained at a lower pressure than the first chamber, and then moves into a third chamber including multipole guides for electromagnetically confining the particle. The vertical momentum of the particles descending through the center of the third chamber is minimized as an upward stream of gases reduces the downward momentum of the particles. The translational kinetic energy of the particles is near-zero irrespective of the mass of the particles at an exit opening of the third chamber, which may be advantageously employed to provide enhanced mass resolution in mass spectrometry.
A Case Study Of Applying Infrared Thermography To Identify A Coolant Leak In A Municipal Ice Skating Rink
NASA Astrophysics Data System (ADS)
Wallace, Jay R.
This paper deals with the application of infrared imaging radiometry as a diagnostic inspection tool for locating a concealed leak in the refrigeration system supplying glycol coolant to the arena floor of an ice skating rink in a municipal coliseum facility. Scanning approximately 10 miles of black iron tubing embedded in the arena floor resulted in locating a leak within the supply/return side of the system. A secondary disclosure was a restriction to normal coolant flow in some delivery loops caused by sludge build-up. Specific inspection procedures were established to enhance temperature differentials suitable for good thermal imaging. One procedure utilized the temperature and pressure of the city water supply; a second the availability of 130F hot water from the facility's boiler system; and a third the building's own internal ambient temperature. Destructive testing and other data collection equipment confirmed the thermographic findings revealing a section of corrosion damaged pipe. Repair and flushing of the system was quickly completed with a minimum of construction costs and inconvenience. No financial losses were incurred due to the interruption of scheduled revenue events. Probable cause for the shutdown condition was attributed to a flawed installation decision made 15 years earlier during the initial construction stage.
Effects of inlet distortion on the development of secondary flows in a subsonic axial inlet compressor rotor. Ph.D. Thesis - Toledo Univ., OH
NASA Technical Reports Server (NTRS)
Owen, Albert K.
Detailed flow measurements were taken inside an isolated axial compressor rotor operating subsonically near peak efficiency. Laser anemometer measurements were made with two inlet velocity profiles. One profile consisted of an unmodified baseline flow, and the second profile was distorted by placing axisymmetric screens on the hub and shroud well upstream of the rotor. A primary flow is defined in the rotor and deviations from this primary flow for each inlet flow condition identified. A comparison between the two flow deviations is made to assess the development of a passage vortex due to the distortion of the inlet flow. A comparison of experimental results with computational predictions from a Navier-Stokes solver showed good agreement between predicted and measured flow. Measured results indicate that a distorted inlet profile has minimal effect on the development of the flow in the rotor passage and the resulting passage vortex.
Application technology progress report: Evaluation of PM10 commercial inlets and development of an inlet for new Rocky Flats Plant surveillance air sampler, January 1986December 1986
G. Langer; C. A. Deitesfeld
Work during 1986 was concerned with developing a new PM-10 inlet for use at Rocky Flats Plant (RFP), Golden, Colorado. The commercial units that we evaluated did not allow for recovery of the >10-..mu..m dust fraction as may be required by EPA and DOE for nuclear installations. One of them, the Wedding PM-10 Inlet, did not meet the PM-10 cut-point
High-Subsonic Performance Characteristics and Boundary-Layer Investigations of a 12 10-Inch-Inlet-Diameter Conical Diffuser
NASA Technical Reports Server (NTRS)
Little, B. H., Jr.; Wilbur, Stafford W.
Performance and boundary-layer data were taken in a 12 degree 10-inch inlet-diameter conical diffuser of 2:1 exit- to inlet-area ratio. These data were taken for two inlet-boundary-layer conditions. The first condition was that of a thinner inlet boundary later (boundary-layer displacement thickness, delta* approximately equal to 0.034) produced by an inlet section approximately 1 inlet diameter in length between the entrance bell and the diffuser. The second condition was a thicker inlet boundary layer (delta* approximately equal to 0.120) produced by an additional inlet section length of approximately 6 diameters. Longitudinal static-pressure distributions were measured fro wall static orifices. Transverse total- and static-pressure surveys were made at the inlet and exit stations. Boundary-layer velocity distributions were measured at seven stations between the inlet and exit. These data were obtained for a Reynolds number (based on inlet diameter) range of 1 x 10(exp 6) to 3.9 x 10(exp 6). The corresponding Mach number range was from M = 0.2 to choking. At the maximum-power-available condition supersonic flow was obtained as far as 4.5 inches downstream from the diffuser inlet with a maximum Mach number of M approximately equal to 1.5. The total-pressure loss through the diffuser in percentage of inlet dynamic pressure was approximately 2.5 percent for the thinner inlet boundary later and 5.5 percent for the thicker inlet boundary later over the lower subsonic range. These valued increased with increasing flow rate- the values for the thicker inlet boundary later more than those for the thinner inlet boundary layer. The diffuser effectiveness, expressed as the ratio of the actual static-pressure rise to the ideal static-pressure rise, was about 85 percent for the thinner inlet boundary layer and about 67 percent for the thicker inlet boundary later in the lower subsonic range. These values decrease with increasing flow rate. Separated flow was observed for both inlet-boundary-layer conditions in the region of adverse pressure gradient just downstream of the transition curvature from inlet section to diffuser. The flow for the thinner-inlet-boundary-layer condition did not fully re-establish itself along the diffuser walls. The thicker inlet-boundary-layer flow, while not completely re-establishing the normal flow pattern downstream of the separated region, did re-establish more successfully than the thinner inlet boundary layer.
The NASA Ames Hypersonic Combustor-Model Inlet CFD Simulations and Experimental Comparisons
NASA Technical Reports Server (NTRS)
Venkatapathy, E.; Tokarcik-Polsky, S.; Deiwert, G. S.; Edwards, Thomas A. (Technical Monitor)
Computations have been performed on a three-dimensional inlet associated with the NASA Ames combustor model for the hypersonic propulsion experiment in the 16-inch shock tunnel. The 3-dimensional inlet was designed to have the combustor inlet flow nearly two-dimensional and of sufficient mass flow necessary for combustion. The 16-inch shock tunnel experiment is a short duration test with test time of the order of milliseconds. The flow through the inlet is in chemical non-equilibrium. Two test entries have been completed and limited experimental results for the inlet region of the combustor-model are available. A number of CFD simulations, with various levels of simplifications such as 2-D simulations, 3-D simulations with and without chemical reactions, simulations with and without turbulent conditions, etc., have been performed. These simulations have helped determine the model inlet flow characteristics and the important factors that affect the combustor inlet flow and the sensitivity of the flow field to these simplifications. In the proposed paper, CFD modeling of the hypersonic inlet, results from the simulations and comparison with available experimental results will be presented.
Distribution of Clay Minerals in Lower Cook Inlet and Kodiak Shelf Sediment, Alaska
Distribution of Clay Minerals in Lower Cook Inlet and Kodiak Shelf Sediment, Alaska James R. llein-five surface samples from lower Cook Inlet and forty-three from Kodiak shelf, Alaska, were analyzed for clay percentages of clay minerals. This is because modern ocean currents vigorously rework surficial sediment
Axisymmetric Calculations of a Low-Boom Inlet in a Supersonic Wind Tunnel
NASA Technical Reports Server (NTRS)
Chima, Rodrick V.; Hirt, Stefanie M.; Reger, Robert
This paper describes axisymmetric CFD predictions made of a supersonic low-boom inlet with a facility diffuser, cold pipe, and mass flow plug within wind tunnel walls, and compares the CFD calculations with the experimental data. The inlet was designed for use on a small supersonic aircraft that would cruise at Mach 1.6, with a Mach number over the wing of 1.7. The inlet was tested in the 8-ft by 6-ft Supersonic Wind Tunnel at NASA Glenn Research Center in the fall of 2010 to demonstrate the performance and stability of a practical flight design that included a novel bypass duct. The inlet design is discussed here briefly. Prior to the test, CFD calculations were made to predict the performance of the inlet and its associated wind tunnel hardware, and to estimate flow areas needed to throttle the inlet. The calculations were done with the Wind-US CFD code and are described in detail. After the test, comparisons were made between computed and measured shock patterns, total pressure recoveries, and centerline pressures. The results showed that the dual-stream inlet had excellent performance, with capture ratios near one, a peak core total pressure recovery of 96 percent, and a large stable operating range. Predicted core recovery agreed well with the experiment but predicted bypass recovery and maximum capture ratio were high. Calculations of offdesign performance of the inlet along a flight profile agreed well with measurements and previous calculations.