Extreme environment of the hypersonic regime of planetary entry flights prompts great challenges on the assessment of surface aeroheating and aerothermal prediction of the boundary layers over spacecrafts, leading to conservatism in design of the Thermal Protection System (TPS) of entry vehicles. Using ablative materials for the heat shield of TPS is the only viable choice to mitigate extreme heat fluxes of such high-enthalpy environments. To better model ablation process in the high-enthalpy hypersonic flow simulations, setting up the correct boundary conditions at the material surface is of paramount importance. We here investigate the role of the boundary condition on the surface aeroheating utilizing Direct Numerical Simulations (DNS) of the hypersonic flow over a flat plate subject to ablation. We also address how the extent of this investigation would differ in the cases of the significant out-gassing rates compared to that in the absence of out-gassing.     «

Extreme environment of the hypersonic regime of planetary entry flights prompts great challenges on the assessment of surface aeroheating and aerothermal prediction of the boundary layers over spacecrafts, leading to conservatism in design of the Thermal Protection System (TPS) of entry vehicles. Using ablative materials for the heat shield of TPS is the only viable choice to mitigate extreme heat fluxes of such high-enthalpy environments. To better model ablation process in the high-ent...     »