Stagnation-Point Heat Transfer Rates for Pioneer-Venus Probes

Summary The convective and radiative heat transfer rates are calculated for the stagnation region of the Pioneer- Venus Probe vehicles during their entry flights into the planet Venus. The nonequilibrium thermochemical state of the flow is calculated using a viscous shock layer method accounting for oxidation of heatshield surface by atomic oxygen and for pyrolysis-gas injection. Radiative transport along the stagnation streamline is calculated using a lineby-line technique and tangent-slab approximation. For both radiative and convective heating rates, the present results are substantially smaller than the earlier values obtained assuming equilibrium.