Local modeling of the aerodynamic heating of the blunt body surface in subsonic high-enthalpy air flow. Theory and experiment on a high-frequency plasmatron

Abstract

The concept of the local similarity of nonequilibrium boundary layers in high-enthalpy gas flows past blunt bodies is briefly described. The technical possibilities of the VGU-4 induction high-frequency plasmatron in modeling the aerodynamic heating of the hypothetical Pre-X (CNES) spacecraft in the vicinity of the stagnation point of a high-enthalpy air flow are presented. The engineering approach to quantitatively reproduce the thermochemical effect of a dissociated air flow on the vehicle surface in the high-heat region of the terrestrial entry trajectory is developed. In this approach the full-scale values of the total enthalpy, the stagnation pressure, and the velocity gradient at the stagnation point near the surface are reproduced in the experiment. The effective coefficients of O and N atom recombination on a silicone carbide (SiC) surface are determined under the conditions similar with those of the peak heating of the Pre-X vehicle surface in the vicinity of the flow stagnation point.