Formulation and implementation of the current filament method for the analysis of current diffusion and heating in conductors in railguns and homopolar generators

The authors present the formulation of the current filament model and show how the method was applied to the diffusion problems in railguns and homopolar generators (HPGs). Some computational results are included. The method was used to investigate railgun current diffusion and heating at the gun breech as well as the proximity effect eddy current in a self-excited air-core HPG. It is concluded that the current filament method is a conceptually simple and useful method for analyzing two-dimensional linear magnetic diffusion problems in which the direction of the current density can be assumed. The method is easy to program and incorporate into lumped-parameter system models on the computer