Accession Number : AD0623405

Title :   A METHOD OF CHARACTERISTICS SOLUTION IN THREE INDEPENDENT VARIABLES.

Descriptive Note : Final rept. for May 65,

Corporate Author : NORTHROP CORP HAWTHORNE CALIF NORAIR DIV

Personal Author(s) : Brown,B. N. Pridmore ; Franks,W. J.

Report Date : JUN 1965

Pagination or Media Count : 76

Abstract : An improved method for the solution of hyperbolic partial differential equations in three independent variables is presented, with application to supersonic steady flow of an inviscid ideal gas. A finite difference method of characteristics is used. New approaches which improve accuracy and efficiency in a three dimensional numerical solution are discussed for solving the shock singularities, for controlling finite difference meshes in three dimensional space so that stability conditions are satisfied, and for interpolation. A major departure from previous approaches to this problem is the choice of local coordinates and base point configurations with reference to directions of maximum variation of the dependent variables on the initial value surface. While this condition is automatically satisfied in methods of characteristics solutions in two independent variables it has apparently been ignored in previous approaches to the problem in three variables. It is of sufficient importance to make the difference between meaningless and accurate results. Results illustrating the behavior of the numerical solutions are presented. (Author)

Descriptors :   (*PARTIAL DIFFERENTIAL EQUATIONS, NUMERICAL METHODS AND PROCEDURES), (*NUMERICAL METHODS AND PROCEDURES, PARTIAL DIFFERENTIAL EQUATIONS), (*SUPERSONIC FLOW, NUMERICAL ANALYSIS), PERTURBATION THEORY

Distribution Statement : APPROVED FOR PUBLIC RELEASE