A patched-grid algorithm for complex aircraft configurations

A patched-grid algorithm for the analysis of complex configurations with an implicit, upwind-biased Navier-Stokes solver is presented. Through the use of a generalized coordinate transformation at the zonal interface between two or more blocks, the algorithm can be applied to highly stretched viscous grids and to arbitrarily-shaped patch boundaries. Applications are made to the SR71 reconnaissance aircraft in a high-altitude environment at a supersonic speed and to the F/A-18 forebody-strake configuration at subsonic, high-alpha conditions, in support of the NASA High-Alpha Research Program.