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  2. Thank you both of you. With all the inputs, I was able to calculate the force required. I changed the dispensing mechanism from rack and pinion to Power screw and all works fine now. Thanks a ton for your time and help.
  3. Yesterday
  4. They work just like the 1980s cartoon series "Battle of the Planets"....G-Force!
  5. Last week
  6. I shan't give you the answer, as that is doing the job for you, but I will pont you in the right direction...(besides, there is sufficient ambiguity in your description to make this rather awkward without lots of clarification) If you ignore compressability, model this as a "Constant Volume", you know the diameters of the pipes, and you also know how much total area the outlets are...the back-calculation is very simple from there! Good luck
  7. Hi All, I have 3 pipes of 10" inches ID - 10 meter long (with 1" inch perforated holes at 0.2 m equi spaced)coneected to 30" main pipe ID. I wanted to calculate the amount of air (CFM)required to get 2m/s velocity outlet from each pipe. Any help would be highly appreciated. Thanks so much in Advance.
  8. Earlier
  9. I have a question on fluid mechanics. I want to write a question to fluid mechanics community. How can I do?(Are there any specific community of fluid mechanics?) Thanks.
  10. Mechanics Corner A Journal of Applied Mechanics and Mathematics by DrD, #55 Planetary Gear Challenge Introduction Back in the mid-1990s, I worked as the "in-house consultant" for a small aerospace manufacturing firm in the Chicago suburbs (500 employees). The general rule was simply that any engineer in the company could bring me any problem, and I would try to give them a solution. It was one of the happiest jobs I've ever had because I was constantly being given new problems to work on. Some of the problems were simple, the sort that could be solved in 20 minutes with pencil and paper. Others took many days and lots of computer work, but I had a free hand and I really enjoyed it. For the figure and the remainder of this challenge, please see the PDF file. I am unable to save the figure in a format that will allow me to upload it here. -- DrD Planetary Gear Challenge.pdf
  11. This is not the sort of question Mechanical Engineers typically look at. We focus on macroscopic phenomena, not sub-atomic questions. DrD
  12. Good morning. Could you recommend me computer programs for the design of a combustion engine to know the real performance of this? Thanks a lot
  13. Refrigeration cycle Refrigeration cycle is a cycle of mechanical system in which transmission of heat allow from one place at a lower temperature (the source ) to another place at a higher temperature ( the sink or heat sink ) by continuously circulating, evaporating, and condensing a fixed supply of refrigerant in a closed system. Or,Refrigeration cycle is thermodynamic cycle to generate refrigerating effect with the use of evaporator, compressor, condenser & expansion valve. Thus, a heat pump is called as a "heater" if the objective is to warm the heat sink (as when warming the inside of a home on a cold day), or a "refrigerator" or “cooler” if the objective is to cool the heat source (as in the normal operation of a freezer). In both case, the operating principles are close.Heat is removed from a cold place to a warm place. Note :- Refrigeration cycle is also called heat pump cycle. Diagram of refrigeration cycle. Vapour compression cycle Vapour Compression Refrigeration Cycle is the most widely used refrigeration system. Vapor-compression cycle refrigeration is a process that uses the physics of phase change heat transfer and the unique properties of a refrigerant to transfer heat from a relatively cold source to a hot medium. Basic Refrigetion cycle The basic components of any refrigeration system working on the vapour compression cycle,are the compressor,condenser, expansion valve and evaporator and the refrigerant fluid which is alternatively vaporized and liquefied during the refrigeration cycle. The temperature at which a fluid boils or condeses,is known as the saturation temperature and it varies with temperature. Basic components of refrigeration cycle The 4 main Components of Refrigeration cycle 1.Compressor 2.Condenser 3.Expansion valve 4.Evaporator
  14. What is your name? Where and what company are you currently working on? What is your role? How long have you been in this company/role? What are the most important skills you’ve identified that are helpful and needed in your profession? In your opinion, what are the most important skills that mechanical engineering students should possess and develop to be effective professionals in their future workplaces? What do you think are the future opportunities for mechanical engineers in the next 5-10 years? *Name and company is optional, in case of concerns of privacy.
  15. Centrifugal pump is a rotodynamic pump which transfer liquids from suction to discharge by converting kinetic energy of liquid into potential energy.
  16. Hello, I'm working on a fun sport court project and can use help. EXISTING: The current sport court is built on a raised wooden deck (30yr old; 12' tall at highest point) supported by 2x12 PT floor joists 16" OC. The existing 2x6 redwood surface is old, warped and rotted. Above the 2x6 surface is an old plastic sport court material similar to www.versacourt.com. We are removing the 2x6 redwood surface deck and the old plastic sport court material. QUESTION: What is the ideal product to replace the 2x6' redwood substrate surface with? A new versacourt plastic sport court material will float over this new surface. GOAL: Goal is to pick a strong and cost effective substrate surface under the sport court material that will not warp over time and will allow pickleballs, tennis balls and basketballs to bounce well without dead spots. The product needs to drain, not be sloped and be under 1.5" thick. Concrete is the ideal base for a sport court but we can't use concrete in this application (will not drain unless sloped and over 1.5" thick). Ideas?
  17. This made me Smile! As I said in my post, I have discussed this and had the detail in the "Seapower" sketches expanded on in the past, so I understand where the diagram is coming from and the idea itself...it is a little "unclear" from the above but the concept IS the "Seapower" diagram, the umbrella, a potential drive facilitator for the bubbles.
  18. I've just perused this again and had a thought....you're making a punch...have you calculated whether the force required to punch through the metal can be achieved? It's a CSA calculation (circumference x thickness) and the shear strength of the material in Pa Take the CSA (in m^2) and multiply by the shear strength in Pa to get the required force in N. Good Luck!
  19. Hello All, FYI: DN2600 Butterfly valve flange mounting hole diameter = 62mm. Bolt size = M56. Doubt: By mistake we have manufactured water pipeline flange with mounting hole diameter = 60mm. Now we don't have option to increase hole size to 62mm. Does it create any problem if I use this 60mm mounting hole pipeline flange to install such a big valve? Is it make difficult to allign valve with pipeline flange? Please help me with your onsite experiences.
  20. Hi Jake, This is abit late. Hope it will be of assistance.
  21. Hi Govardhanan, Allow me to answer equally simply. 1. I can see the setup has two main phases; the motor, rack and pinion phase, and the piston food in a cylinder phase. 2. To size the motor you need to determine the load required to desirably dispense the food. This can be achieved through determining the required load at the piston. The exercise may be approached in varied ways including; using physical loads on piston. 3. Upon determining the required load range, work it backward to size the motor. Remember energy input at motor rack phase = energy output at piston * efficiencies(may start with 80%). Best of lack
  22. Hi Pablo, Have to deal with case by case of each shaft diameter, General rule is use the Yield strength as it defines the onset of plastic deformation. Two, work with the outer most diameter as for any shaft plasticity start at the outer most layer of the shaft. Therefore if the shear stress of outer most layer of the shaft is below the yield shear strength, then your shaft is safe. (Assumption; we are dealing with torque loads). Regards. Michael Given the tensile strength is important to get the appropriate shear strength for your analysis. Different materials have differing relations between tensile and shear stress.
  23. If Mr. Reid wants to work with you, you better take him up on it. I suggest that all others are going to ask for a drawing as that is the standard way for engineers to communicate. Who knows? It might even clarify your own thinking. DrD
  24. I'm glad you are getting something useful from these posts. Alban, I have to say that I do no know enough about Kane's method to have a useful opinion. Sorry about that! DrD
  25. Hi Govardhanan! You will likely have problems with this design due to the foodstuffs not flowing sufficiently. If the foodstuff is too viscous, it will not exit through the holes at the bottom...in fact in some instances, the container will fail before it does. If you look at dispensers available commercially, you will find that the majority have a cone at the bottom to facilitate exiting of the material. Whilst you acknowledge that you are a student of mechanics, I am sure you will be familiar with the phrase "every action has an equal and opposite reaction." (Isaac Newton) . Basically, in this situation, all of the force from the piston is reflected back into the piston with nothing facilitating flow through the exit holes. If this exit was altered to a cone of - say - 60 degrees (radially), 86.6% of the force would push down and 50% of the force would be deflected to "feeding" the material through towards the target exit. [Yes that does exceed 100%, but that's trigonometric mechanical advantage] Note: I have not sketched this out and checked as have no paper at the moment, so it's a "finger in the air" calc. but at very least the principle is right if the figures are wrong... Good luck! Bruce
  26. Failing the accelerometer - which would be very successful if on a drum - you could connect a microphone to a transistor to switch on the light. It is a very simple circuit and is reproduced on a number of differing electronics websites. Basically the "switch" would be the microphone. They generally have a resistor in the circuit...if this was a variable resistor, it could be adjustable. daisy chain this to a timer circuit and you're laughing....or drumming! Good luck!
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