Absorption Spectroscopy for Temperature Measurement Behind Shock Wave at Super-Orbital Velocity

摘要

The distribution of the translational temperature of atomic oxygen behind the strong shock wave in air produced in a shock tube was measured by means of an unique absorption spectroscopic technique. The translational temperature was determined by fitting a Voigt profile to the measured absorption spectral line shape. The translational temperature behind a shock wave with an initial pressure of 0.3 torr and a shock propagation velocity of 12 km/s showed a fairly good agreement with a numerical prediction, at least qualitatively, and enables confirmation of the phenomenon of the lower rotational temperature compared to the translational temperature, which was suggested previously. Simultaneously, the distribution of electron density was also determined from the absorption spectral profile and showed a reasonable agreement with the previous experimental result based on the emission spectroscopic technique for a Balmer line of hydrogen. This agreement suggests the validity of the present result.