2-DIMENSIONAL AND 3-DIMENSIONAL ANALYSIS OF HYPERSONIC NONEQUILIBRIUMLOW-DENSITY FLOWS

Flowfield results have been obtained for hypersonic, low-density, two- and three-dimensional, nonequilibrium viscous shock-layer flows, Thre e-dimensional calculations are performed for sphere-cone-shaped bodies at various angles of attack. Recently obtained surface and shock-slip boundary conditions are implemented to account for the low-density ef fects. These boundary conditions may also be employed with the Navier- Stokes equations with or without a shock-fitting solution technique, A method is suggested for obtaining the input shock shape for the three dimensional nonequilibrium viscous how. This approach gives superior convergence of results, especially under low-density flow conditions, and makes the VSL method self-starting, The analytic algebraic grid im plemented with the equations does not add any numerical dissipation. O btained results show the effect of low density on the surrounding flow fieid and surface quantities for a hypervelocity vehicle. Good agreeme nt is obtained with the available numerical results (including the dir ect simulation Monte Carlo predictions) and experimental data for the low-density flight conditions.