Aerothermodynamics Simulation for the ARD Capsule Under the Equilibrium Flow.

Kurzfassung

The present study discusses the flow simulation of two points of the reentry trajectory for the European "Atmospheric Reentry Demonstrator" (ARD) obtained by the solution of the thin-layer Navier-Stokes equations. The computations are done with the DLR CEVCATS code. A laminar and a turbulent hypersonic flow are considered. In both cases the flow is assumed in thermochemical equilibrium. The emphasis of the study is put on the validation of the computed results. The numerical accuracy is addressed throughout grid topology and grid density studies and also by comparing the results with numerical solutions from other sources. Furthermore, for the laminar case the hypothesis of perfect gas is also considered, while for the turbulent case two algebraic turbulence model are tested. While grid convergence is clearly demonstrated, no grid independent solutions are achieved due to large areas of separated flow which varies from grid to grid. Also, the study shows that for simple capsule geometries a minimum of 230000 points are required for.