Numerical study of radiative heating influence on aerothermal environment over a reentry capsule

The computational means are developed to predict the radiative heating influence of high-temperature nonequilibrium gas on the aerothermal enviroment in order to meet the requirement of aerothermal enviroment understanding over hypersonic reentry vehicles. The high-temperature air flowfeild over a reenrty capsule after the lunar-earth transfer orbital flight are simulated by solving Navier-Stokes equations with chemical source terms, the parameters, such as temperature and mass fraction of species in the flowfilds, are obtained. Based on radiation transfer equation, considering the major radiative mechanisms of atoms and molecules in high temperature air, radiative heating influences on aerothermal environment of reentry capsule are studied numerically. The investigation indicates that the nose radius of the capsule has significant infulence on aeroheating with the given trajectory condition, and the radiative heat flux at local surface contributes over 30 percent of the total heat flux for those mostly severe aero-heating region. It also shows that catalytic effects on radiative heat flux is not so evident, the major radiative sources are the continual and line spectra of O and N, together with the first positive band of N₂.