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Rayleigh Scattering Diagnostic for Measurement of Temperature, Velocity, and Density Fluctuation SpectraA molecular Rayleigh scattering technique is developed to measure dynamic gas temperature, velocity, and density in unseeded turbulent flows at sampling rates up to 10 kHz. A high power CW laser beam is focused at a point in a heated air jet plume and Rayleigh scattered light is collected and spectrally resolved. The spectrum of the light, which contains information about the temperature, velocity, and density 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 10 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. Power spectral density calculations of temperature, velocity, and density fluctuations, as well as mean and fluctuating quantities are demonstrated for various radial locations in the jet flow at a fixed axial distance from the jet exit plane. Results are compared with constant current anemometry and pitot probe measurements at the same locations.
Document ID
Document Type
Conference Paper
Mielke, Amy F.
(NASA Glenn Research Center Cleveland, OH, United States)
Elam, Kristie A.
(Jacobs Sverdrup Technology, Inc. Cleveland, OH, VA, United States)
Sung, Chih-Jen
(Case Western Reserve Univ. Cleveland, OH, United States)
Panda, Jayanta
Date Acquired
August 25, 2013
Publication Date
January 9, 2006
Subject Category
Report/Patent Number
AIAA Paper-2006-837
Meeting Information
44th AIAA Aerospace Sciences Meeting(Renov, NV)
Funding Number(s)
WBS: WBS 22-781-30-61
Distribution Limits
Public Use Permitted.
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