COMPUTATION OF HIGH-SPEEDJNVISCID FLOWS ABOUT REAL CONFIGURATIONS* By Frank Marconi, Larry Yaeger, Grumman Aerospace Corporation and H. Harris Hamilton NASA Lahgley Research Center SUMMARY A numerical procedure for computing the three-dimensional inviscid flow about complex geometries is described. A second-order accurate finite-difference marching technique is used to integrate Euler's equations. ^Analytic conformal mappings are employed to develop a computational grid. All shocks in the flow field are treated explicitly as discontinuities satisfying the Rankine-Hugoniot jump conditions. Computa- tional difficulties associated with blunt-nose entropy layers are avoided by explicitly fol- lowing a stream surface located at the layer's outer edge and disallowing numerical derivatives of certain flow variables across this surface. Equilibrium air thermody- namics are included using curve fits of Mollier charts. A computer code which utilizes these computational procedures and a geometry package which simplifies the description of complex vehicles have been developed. This code has been used extensively to com-, pute flow fields about a variety of complex vehicles and results are presented herein. Agreement with experimental data is shown to be good. INTRODUCTION Most of the flow-field data necessary in the development of high-speed vehicles have been obtained through wind-tunnel tests which are expensive, slow, and some- times inadequate. The accurate and efficient calculation of the three-dimensional super/hypersonic flow about these vehicles would be very useful in supplementing these test programs. Techniques for calculating these flow fields are currently available, of course, but previous codes have not had so wide a range of applicability in terms of Mach number, angle of attack, and vehicle geometry as the technique described herein. Specific examples are small perturbation techniques (accurate for slender bodies at low This research was performed under Contract No. NAS 1-11525, NASA Langley Research Center. 1411