Blunt body rarefied wakes for Earth entry

Direct simulation Monte Carlo (DSMC) and Navier-Stokes axisymmetric calculations are presented for hypersonic low-density flow about a 70-deg blunt cone afterbody configuration. The flow conditions simulated are those experienced by a space vehicle for an altitude range of 105-75 km during Earth entry. The entry velocity considered is 7 km/s. A steady vortex is predicted in the near wake for 75 and 85 km altitudes by both calculations. The flow remains attached for 95 and 105 km altitudes. Comparisons of DSMC and Navier-Stokes calculations for the wake flowfield become less and less favorable with increasing altitude. Comparisons of surface quantities show reasonable agreement between DSMC and Navier-Stokes calculations along the forebody. However, the surface quantities along the afterbody calculated from DSMC and Navier-Stokes calculations differ significantly at the higher altitudes. (Author)