Indicator Probe Methods of Measuring Turbulent Micromixing
{'Code': '07020000', 'Directorate': {'Abbreviation': 'ENG', 'LongName': 'Directorate For Engineering'}, 'Division': {'Abbreviation': 'CBET', 'LongName': 'Div Of Chem, Bioeng, Env, & Transp Sys'}}
{'SignBlockName': 'Robert M. Wellek', 'PO_EMAI': None, 'PO_PHON': None}
Research Summary:  The diffusion process occurring at small                     scales of turbulence is probed by forcing instantaneous                         diffusion controlled chemical reactions to drive indicator                      reactions.  The resulting reactions, whose rates are controlled                 by turbulent micromixing, cause color changes which are                         measured with a fiber optic light probe.  The theoretical                       relationship between the light absorption and micromixing is                    validated by varying the chemical species and their                             concentration levels.  Measurement at one reactant                              concentration ratio yields the intensity of segregation, a                      measure of the micromixing, while measurements at various                       reactant ratios gives a more detailed measure of micromixing in                 terms of a tracer probability density function.  Additionally,                  the position of a visible color border itself contains                          micromixing information because the visible cut-off point of                    the eye corresponds to a certain color intensity.                               Consequently, the exciting possibility is explored that visual                  observation alone can be used to determine such an elusive                      quality as intensity of segregation.                                                                                                                            Uniqueness/Innovation:  The theoretical underpinning for this                   work, the use of a fiber optic light probe with an indicator                    and the technique of using the location of a visual border to                   obtain micromixing information are all unique and novel.                                                                                                        Significance:  Micromixing is vitally important in processes as                 diverse as reaction injection molding, combustion, chemical                     lasers and reactor design for fast chemical reactions.  The                     common characteristics of these technologies which depend upon                  reactive mixing is that the rate at which chemical reactants                    are brought together at the molecular level controls or                         strongly affects the process.  Measurement of micromixing in                    the conventional manner with an inert tracer is not only                        difficult because of the need to measure fluctuations around                    the mean, but unreliable in principle because a tracer probe                    measures an average concentration over a finite probe volume.                   Hence part of the signal is always lost.                                                                                                                        An important characteristic of this novel indicator probe                       method is that it is not limited by probe resolution; it is                     capable of capturing the entire signal.  This ability to                        measure micromixing in liquids can have an important impact on                  the understanding of turbulent micromixing.  Furthermore,                       rational design with reactive mixing is now severely limited by                 lack of knowledge of the micromixing in the industrial                          situations.  In most cases, knowledge of the intensity of                       segregation would allow such design and the ability to measure                  this quantity in industry with a simple, inexpensive, visual                    experiment can significantly improve design capability in the                   diverse processes which depend upon reactive mixing.
{'FirstName': 'Herbert', 'LastName': 'Toor', 'PI_MID_INIT': 'L', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'Herbert L Toor', 'EmailAddress': None, 'NSF_ID': '000207786', 'StartDate': '07/15/1987', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'Carnegie-Mellon University', 'CityName': 'PITTSBURGH', 'ZipCode': '152133815', 'PhoneNumber': '4122688746', 'StreetAddress': '5000 FORBES AVE', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'Pennsylvania', 'StateCode': 'PA', 'CONGRESSDISTRICT': '18', 'CONGRESS_DISTRICT_ORG': 'PA18', 'ORG_UEI_NUM': 'U3NKNFLNQ613', 'ORG_LGL_BUS_NAME': 'CARNEGIE MELLON UNIVERSITY', 'ORG_PRNT_UEI_NUM': 'U3NKNFLNQ613'}
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[{'Code': '1403', 'Text': 'Proc Sys, Reac Eng & Mol Therm'}, {'Code': '1414', 'Text': 'INTERFAC PROCESSES & THERMODYN'}]
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1987&All=true', 'xml': '8703890.xml'}