Heat Flux Predictions using a 3D Near Body Solver on an Adaptive Block-Structured Cartesian Off-Body Grid

The pre-processing step for simulating hypersonic flows including the material response around complex flight vehicles can be very time-consuming using traditional body-conformal grids. The generation of high quality grids while maintaining shock alignment and wall orthogonality becomes extremely problematic for geometries of increasing complexity. Furthermore, accurate heat flux predictions are known to be very sensitive to the employed numerical scheme and the quality of the grid. The use of Cartesian grid solvers in this respect, provides a number of advantages such as automatic volume mesh generation processes and hands-off shock tracking with adaptive mesh refinement. Cartesian solvers have difficulty in achieving adequate flux reconstruction in the near-wall region and generally do not contain wall-aligned grids for most geometries making hypersonic viscous flow applications difficult to model. A near body solver is used as a body-conformal solver to capture these viscous interactions and couple them back into the Cartesian solution. This NBS-Cart solver has previously been validated for perfect gas and high-enthalpy flows for 2D and axisymmetric flows. The work shown here seeks to extend the solver to arbitrarily complex 3D geometries to demonstrate the feasibility of this solver under a wide range of hypersonic viscous flow applications. Validation of the perfect gas solver is presented for a scale MSL capsule and the Orion CEV, while the thermo-chemical non-equilibrium solver is validated with a scale MSL capsule using a 5-species air model based on computed surface heating and pressure profiles at various angles of attack.