Effect of physical and chemical nonequilibrium processes on the parameters of the near wake downstream of a spacecraft

The axisymmetric laminar flowfield and heat transfer characteristics of the RAM-C experimental spacecraft moving in the Earth’s atmosphere at an altitude of 61 km and a velocity of 7.65 km/s are investigated on the basis of a numerical solution of the Navier-Stokes equations. In studying the effect of the physical and chemical nonequilibrium processes on the flow parameters two approximations are employed for describing the gas properties, namely, that of a perfect gas with a constant adiabatic exponent and a model of dissociating and vibrationally-relaxing air. Emphasis is placed on the study of the spacecraft’s near-wake parameters. The results obtained are compared with experimental data on the electron concentration in the shock layer on the lateral surface and the calculated results of other authors.