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Molecular Rayleigh Scattering Diagnostic for Dynamic Temperature, Velocity, and Density MeasurementsA molecular Rayleigh scattering technique is developed to measure dynamic gas temperature, velocity, and density in unseeded turbulent flows at sampling rates up to 16 kHz. A high power CW laser beam is focused at a point in an air jet plume and Rayleigh scattered light is collected and spectrally resolved. The spectrum of the light, which contains information about the temperature and velocity of the flow, is analyzed using a Fabry-Perot interferometer. The circular interference fringe pattern is divided into four concentric regions and sampled at 1 and 16 kHz using photon counting electronics. Monitoring the relative change in intensity within each region allows for measurement of gas temperature and velocity. Independently monitoring the total scattered light intensity provides a measure of gas density. A low speed heated jet is used to validate the measurement of temperature fluctuations and an acoustically excited nozzle flow is studied to validate velocity fluctuation measurements. Power spectral density calculations of the property fluctuations, as well as mean and fluctuating quantities are presented. Temperature fluctuation results are compared with constant current anemometry measurements and velocity fluctuation results are compared with constant temperature anemometry measurements at the same locations.
Document ID
Document Type
Conference Paper
Mielke, Amy R.
(NASA Glenn Research Center Cleveland, OH, United States)
Elam, Kristie A.
(Jacobs Sverdrup Technology, Inc. Cleveland, OH, United States)
Sung, Chi-Jen
(Case Western Reserve Univ. Cleveland, OH, United States)
Date Acquired
August 25, 2013
Publication Date
June 5, 2006
Subject Category
Report/Patent Number
AIAA Paper-2006-2969
Meeting Information
Meeting: 25th AIAA Aerodynamic Measurement Technology and Ground Testing Conference
Location: San Francisco, CA
Country: United States
Start Date: June 5, 2006
End Date: June 8, 2006
Sponsors: American Inst. of Aeronautics and Astronautics
Funding Number(s)
WBS: WBS 561581.02.08.03
Distribution Limits
Public Use Permitted.
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