Numerical Calculation of Transonic Potential Flow about Wing-Body Combinations

Abstract

A method is presented for numerically calculating the transonic potential flow about rather general geometries. It is based upon a particularly simple form of the usual quasilinear potential equations and is formulated in terms of local representations of the solution and the mapping functions used to generate the finitedifference grid. Thus, all derivatives are generated numerically and there is no need to transform the equation—a formidable task when using boundary-conforming coordinate systems for complex geometries. The solution is stabilized by adding upwind bias in supersonic regions, and the difference equations are solved by relaxation. Sample results for wing-cylinder and simple wing-fuselage combinations are presented.