Radiation temperature measurement of optical thick hypersonic combustion flow

Temperature is a critical parameter to diagnose the high temperature hypersonic combustion flow. A fiber-spectrometer based measurement system and the correlated theoretical models to measure the radiation temperature of the “optical thick” hypersonic combustion flow were established in this paper. The spectral responsivity of the fiber-spectrometer based measurement system was measured at NIM in lab condition, and the spectral radiance and emissivity of the hypersonic combustion flow were measured in-situ at the combustion wind tunnel of BISLMV. Preliminary experimental results showed the spectral emissivity of the combustion flow was about 0.1 in the spectral range 500-800nm without strong spectral selection, which resulted in the radiation temperature about 2200 K, with relative standard uncertainty about 10%.