Heat Flux Predictions for High Speed Flows with an Immersed Boundary Method

The accurate prediction of surface heating loads on atmospheric entry vehicles is crucial in the design of thermal protection systems (TPS) and in improving our understanding of the surface response, such as ablation, surface kinetics, and recession. The use of an immersed boundary method (IBM) solver provides a distinct advantage in the study of coupled fluid ablation interaction (FAI) problems due to the use of stationary grids which allows for straightforward modeling of surface recession effects. However, one of the main drawbacks of Cartesian IBM solvers is the lack of shock-aligned and wall-aligned grids for resolving the boundary layer which results in significant reconstruction errors of surface temperature gradients heat loads, particularly for blunt body configurations. The work presented here investigates the formulation of a body-conformal near body solver (NBS) which has been coupled to a sharp IBM solver to accurately capture the surface heat flux while avoiding prohibitively small grid spacings near the wall. The newly developed NBS-IBM solver has been formulated to handle both perfect gas and chemically-reacting flows so as to be applicable to a wide range of high-enthalpy environments where FAI problems are actively investigated.