Computational aspects of a nonlinear problem involving electromagnetic transients in ferromagnetic shields

Abstract

Previously, an analytical procedure was developed to characterize the nonlinear electric field transients induced at the inner surface of long, thin-walled, cylindrical, electrically conductive, ferromagnetic shields by short-duration, surface current pulses directed axially along the outer surface. The analytical procedure uses mathematical analysis supplemented with numerical calculations. Previous papers emphasized the mathematical aspects of the problem. This paper considers the computational aspects. Some practical aspects associated with the implementation of a finite difference time-domain (FDTD) formulation are discussed. The effects of spatial and time increments on numerical results are investigated. A method for estimating the residual error in benchmark calculations is proposed and demonstrated, and results of example calculations are presented.