A numerical analysis for radiation profile behind strong shock waves about 10 km/s in low-density air

The double-peak characteristic of radiation intensity behind shock waves above 10 km/s in a low-density air are studied by carrying out a numerical analysis for one-dimensional, steady hypersonic flows with nonequilibrium chemical reactions. The gas model is based on 11 gas species, 3 temperatures and 47 chemical reactions. The radiation model includes all possible types of emissions from bound-bound, free-bound and free-free transitions. The result indicates that the double-peak characteristic of the radiation profile can be attributed to the increase of the radiation intensity of the atomic line spectra and the continuum spectra from the free-bound and free-free transitions in the near equilibrium region far downstream of the shock front