Radiatively and Collisionally Structured Shock Waves Exhibiting Large Emission-Convection Ratio

Radiatively and collisionally structured, normal shock waves in a monatomic, nonequilibrium, ionizing gas are solved for waves in which the emission-convection ratio varies from a small value in the preshock flow to a very large value in the postshock flow. The gas model adopted for the mixture allows nonequilibrium ionization and spectral radiative emission and absorption. Two sequential regions are identified: (1) One which displays far upstream an abrupt isothermal “ionization front” and then subsequent heating and adjustment, and next (2) a uniform asymptotic region in which occurs a thick, hot, unusual precursor, a frozen and adiabatic discontinuity, and a very thin tail. The second region permits asymptotic simplifications leading to rational uncoupling of precursor and tail and simplification of spectral difficulties. The first region affords no spectral simplification, and nonrational spectral approximations are employed.