An Engineering Method For Interactive Inviscid-Boundary Layers In Three-Dimensional Hypersonic Flows

Abstract

An engineering method has been developed that couples an approximate three-dimensional inviscid technique with the axisymmetric analog and a set of approximate convective-heating equations. The displacement effect of the boundary layer on the outer inviscid flow is calculated and included as a boundary condition in the inviscid technique. This accounts for the viscous interaction present at lower Reynolds numbers. The method is applied to blunted axisymmetric and three-dimensional elliptic cones at angle of attack for the laminar hypersonic flow of a perfect gas. The method is also applied to turbulent and equilibrium-air conditions. The present technique predicts surface heating rates, pressures, and shock shapes that compare favorably with experimental (ground-test and flight) data and numerical solutions of the Navier-Stokes and viscous shock-layer equations. In addition, the inclusion of the viscous interaction significantly improves results obtained at lower Reynolds numbers. The new technique represents a major improvement over current engineering aerothermal methods with only a modest increase in computational effort.