Calculation of three-dimensional flowfields by the unsteady method of characteristics

Abstract

A numerical algorithm based on the unsteady three-dimensional method of characteristi cs is presented for calculating unsteady three-dimensional subsonic/transonic inviscid flowfields. The flowfield unit processes are based on a local network consisting of six bicharacteristics and the pathline. The algorithm is an explicit secondorder accurate predictor-corrector procedure. An inverse-march ing method is employed, wherein the solution grid in physical space is prespecified. Steady flow solutions are obtained as the asymptotic solution in time. Results are presented for spherical supersonic source flow, for axisymmetric supersonic flow in a conical nozzle, for three-dimensional supersonic flow in a superelliptical nozzle, and for three-dimensional subsonic/transonic flow in a superelliptical nozzle. Solutions obtained by the present method agree well with solutions obtained by steady flow method of characteristi cs algorithms and experimental data.