High-enthalpy aerothermodynamics of a Mars entry vehicle .2. Computational results

Numerical solutions for hypersonic flows of carbon dioxide and air around a 70-deg sphere-cone Mars entry vehicle configuration were computed using a laminar, axisymmetric, nonequilibrium Navier-Stokes solver with freestream flow conditions equivalent to those of aerothermodynamic tests conducted in a high-enthalpy impulse facility. The wake flowfield computations were found to be much more sensitive to both grid resolution and grid adaptation than the forebody results. The wake computations showed the existence of a region of separated, steady, recirculating flow behind the vehicle. Whereas the rapid expansion of the flow around the corner of the vehicle resulted in a wake that was mostly frozen both chemically and vibrationally, the degree of flow expansion was not great enough to produce noncontinuum flow behavior, Comparisons between computational and experimental surface heating distributions were within the estimated experimental uncertainty for both cases except around the forebody stagnation point and the free-shear-layer reattachment point for the air case and within a small portion of the wake recirculation vortex for the carbon dioxide case.