A PARALLEL FINITE-VOLUME RUNGE-KUTTA ALGORITHM FOR ELECTROMAGNETIC SCATTERING

A 3D explicit finite volume algorithm has been developed to simulate s cattering from complex geometries on parallel computers using structur ed body conformal curvilinear grids. Most simulations for practical 3D geometries require a large number of grid points for adequate spatial resolution making them suitable to parallel computation. The simulati ons have been carried out using a multi-block/zonal approach in the me ssage passing paradigm on the SP-2. Each zone is placed on a separate processor and interprocessor communication is carried out using the Me ssage Passing Library/Interface (MPL/MPI). Integration of Maxwell's eq uations is performed using the four-stage Runge-Kutta time integration method on a dual grid. This method of integrating on a staggered grid gives enhanced dissipative and dispersive characteristics. A scattere d field formulation has been used and the Liao boundary condition is u sed at the outer nonreflecting boundary. The far zone transformation h as also been implemented efficiently, using specialized MPL functions to evaluate the far zone scattering results. Results show extremely go od comparisons for scattering from the sphere and the ogive with the e xact solution and standard FDTD type algorithms. Comparisons for nonax isymmetric targets like the NASA almond with experimental data has als o been found to be extremely good. (C) 1997 Academic Press.