COUPLED RADIATION EFFECTS IN THERMOCHEMICAL NONEQUILIBRIUM SHOCK-CAPTURING FLOWFIELD CALCULATIONS

Lunar and Mars return conditions are examined using the Langley aeroth ermodynamic upwind relaxation algorithm flowfield code and the Langley optimized radiative nonequilibrium radiation code to assess the effec t of radiative coupling on axisymmetric thermochemical nonequilibrium flows. Coupling of the two codes is achieved iteratively. Special trea tment required to couple radiation in a shock-capturing method is disc ussed. Results indicate that while coupling effects are generally the same as occur in equilibrium flows, under certain conditions radiation can modify the chemical kinetics of a nonequilibrium flow, and thus a fter relaxation processes. Coupling effects are round to be small for all cases considered, except for a 5-m-diam aerobrake returning from M ars at 13.6 km/s.