Scattered electromagnetic field of a re-entry vehicle

Abstract

Scattered electromagnetic fields around the X24C lifting body illuminated by both transverse electric and transverse magnetic incident plane waves are simulated. The refractive and diffractive phenomena are studied in the resonant and the optical regimes. The numerical solutions are generated by solving the three-dimensional Maxwell equations in the time domain using an upwind-biased finite-volume algorithm. The numerical results are third order accurate in space and second order accurate in time. The simulations are validated on simpler shapes, including a cylinder and a sphere, for which the solutions are well known. The scattered field is then described for the re-entry vehicle in the resonant and optical regimes. The numerical results demonstrate that accurate radar cross sections can be obtained by implementation of consistent boundary conditions developed for a perfectly conducting scatterer. Nomenclature B = magnetic flux density, Wb/m 2 D = electric displacement, C/m 2 E = electric field intensity, V/m 2 / = wave frequency, s" 1 H = magnetic flux intensity, A/m i, 7, k = index of discretized volume J = electric current density, A/m 2 n = outer normal of a surface R = numerical residual r, 0, $ = spherical coordinates t -time, s U = dependent variables V = elementary cell volume, m 3 € = electric permittivity, F/m X = wavelength, m 41 = magnetic permeability, H/m §» *?» £ = general curvilinear coordinates a) = angular frequency of wave, s" 1 Subscripts ch = characteristic time required for wave to traverse one body length = incident field property Superscripts +, -= flux vector associated with positive and negative eigenvalue

A scalable HPF implementation of a finite‐volume computational electromagnetics application on a CRAY T3E parallel system

“…Computational electromagnetics (CEM) in the time domain is the most general numerical approach for describing dynamic or wide-band frequency electromagnetic phenomena. Computational simulations are derived from discretized approximations to the time-dependent Maxwell equations [1][2][3][4][5][6][7][8][9][10]. High numerical efficiency of CEM simulation procedures can be attained either by algorithmic improvements to solve the Maxwell equations or by using scalable parallel distributed memory computer systems.…”