Viscous Shock-Layer Simulation of Airflow past Ablating Blunt Body with Carbon Surface

A kinetic model for air-carbon surface interaction is suggested. The model is based on the langmuir approach to the kinetics of catalytic reactions. It yields a reasonable agreement with published experimental data on graphite oxidation. A viscous shock-layer code has been developed to simulate hypersonic flows of the 19-species mixture containing air and carbon products. Numerical analysis of ablation and strong ionization processes is carried out with different ablation and ionization models. Calculations show that 1) the maximal drop of the heat flux because of ablation, compared with that obtained for the fully catalytic (chemical-equilibrium) wall in the 11-species air, is within 26% under the conditions discussed; 2) mass loss rate strongly depends on the adsorption type (mobile/immobile); 3) ionization model may have a substantial influence on the shock thickness in the case of re-entry with a hyperbolic velocity; and 4) the effect of the wall catalycity with respect to charged particles on the heating rate is small