Condensation Effects on Rayleigh Scattering Measurements in a Supersonic Wind Tunnel
نویسندگان
چکیده
Rayleigh and Raman scattering measurements have been performed i n the 20-inch, Mach 6 wind tunnel at the NASA Langley Research Center . Rayleigh results show signal levels which are much higher than expected f o r molecular scattering in the tunnel, while densities deduced from s p o n t a n e o u s Raman scattering of molecular nitrogen are in good agreement with t h e expected nitrogen densities in the facility. The apparent discrepancy in t h e Rayleigh result is attributed to cluster formation as a result of expansion i n the tunnel. The dependence of the Rayleigh signal on the stagnation p r e s s u r e and temperature is also discussed.
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