Combined Three-Dimensional Finite-Difference and Integral Method Alfred

Abstract

A combined integral, explicit finite-difference method is presented. The example calculation predicts the three-dimensional compressible blast wave loading on a rigid four-sided structure. Previous techniques for the inviscid slip flow pressure loading on such structures include a variety of linear interpolation and extrapolation techniques to predict the transient pressure distribution on the structure walls. The present approach introduced a combination of the finite-difference computation with an integral method which is confined to the irregular finite-difference cell volumes adjoining the walls, edges, and corners of the structure. Separate numerical techniques are applied inturn to the finite-difference computations and the integral regions, with an initial condition boundary overlap coupling at each discrete time step in the computations.