Use of characteristics for boundaries in time dependent finite difference analysis of multidimensional gas dynamics

Abstract
Relations form the theory of characteristics are used to connect boundary and interior points in the numerical analysis of multidimensional, unsteady gas dynamics.Since specification of all variables on the boundaries does not occur, it is necessary to employ at least some of the differential equations for boundary points. The objective is to avoid the use of non‐central finite differences and the subsequent generation of a pseudo‐boundary layer.Boundaries consisting of a moving shock wave, a solid wall and a surface in a supersonic, downstream region are considered. The numerical procedure for determining variables on boundaries is described in datail for the hypersonic, blunt body problem.