HL-20 COMPUTATIONAL FLUID-DYNAMICS ANALYSIS

The essential elements of a computational fluid dynamics analysis of t he HL-20/personnel launch system aerothermal environment at hypersonic speeds including surface definition, grid generation, solution techni ques, and visual representation of results are presented. Examples of solution technique validation through comparison with data from ground -based facilities are presented, along with results from computations at flight conditions. Computations at flight points indicate that real -gas effects have little or no effect on vehicle aerodynamics and, at these conditions, results from approximate techniques for determining surface heating are comparable with those obtained from Navier-Stokes solutions.