Measurement of vibrational/rotational temperatures of gas molecules behind high Mach number shock waves by CARS spectroscopic system

When a space vehicle reenters onto the atmosphere with high velocity, radiative heating from the shocked air ahead of the vehicle plays an important role on the heat flux to the wall surface as well as convective heating. In the laboratory, the spectroscopic system has been developed for temperature measurement of radiation behind strong shock waves. In this paper, CARS method (Coherent Anti-Stokes Raman Spectroscopy) for radiative flow behind strong shock waves of high Mach number has been developed. The CARS measurement system consists of a YAG laser, a dye laser, optical system, and high-sensitivity I.I.-CCD camera systems with spectroscopy. The preliminary tests have been performed for the purpose of detecting CARS signal from strong shock waves with velocity range over 5 km/s. Finally, both vibrational and rotational temperatures could be estimated by fitting of the CARS spectra obtained from experiment and analytical calculation over Mach 15.
資料番号: AA0048089018