HYPERSONIC AERODYNAMICS ON THIN BODIES WITH INTERACTION AND UPSTREAM INFLUENCE

In the fundamental configuration studied here, a steady hypersonic fre e stream flows over a thin sharp aligned airfoil or flat plate with a leading-edge shock wave, and the flow field in the shock layer (contai ning a viscous and an inviscid layer) is steady laminar and two-dimens ional, for a perfect gas without real and high-temperature gas effects . The viscous and inviscid layers are analysed and computed simultaneo usly in the region from the leading edge to the trailing edge, includi ng the upstream-influence effect present, to determine the interactive flow throughout the shock layer and the positions of the shock wave a nd the boundary-layer edge, where matching is required. Further theore tical analysis of the shock layer helps to explain the computational r esults, including the nonlinear breakdown possible when forward marchi ng against enhanced upstream influence, for example as the wall enthal py increases towards its insulated value. Then the viscous layer is co mputed by sweeping methods, for higher values of wall enthalpies, to p revent this nonlinear breakdown for airfoils including the flat plate. Thin airfoils in hypersonic viscous flow are treated, for higher valu es of the wall enthalpies and with the upstream-influence effect, as a re hypersonic inviscid flows, by modifying the computational methods u sed for the flat plate. Also, the behaviour of the upstream influence for bodies of relatively large thickness, and under wall velocity slip and enthalpy jump for flat plates, is discussed briefly from a theore tical point of view.Subsequent to the present work, computations based on the Navier-Stokes and on the parabolized Navier-Stokes equations h ave yielded excellent and good agreement respectively with the present predictions for large Mach and Reynolds numbers.