Modelling Heat Transfer at Low-Density Hypersonic Spacecraft Flight Regimes

Abstract The effects of rarefaction and nonequilibrium processes on hypersonic rarefied-gas flows over blunt bodies are studied by the Direct Simulation Monte-Carlo technique (DSMC) and by solving the full Navier–Stokes equations and the equations of a thin viscous shock layer (TVSL) under the conditions of wind-tunnel experiments and hypersonic-vehicle flights in the Earth atmosphere at altitudes from 60 to 110 km. The nonequilibrium, equilibrium and “frozen” flow regimes are examined for various physical and chemical processes in air and hydrogen. The influence of similarity parameters (Reynolds number, temperature factor, catalysis parameters, and gas injection rates) on the flow structure near the blunt bodies (a sphere and a cylinder) and on their heat transfer characteristics in hypersonic streams of ionizing air is studied.