Modelling electromagnetic rail launchers at speed using 3D finite elements

A formulation which allows the simulation of railguns and other devices incorporating moving conductors which are of constant cross-section in the direction of motion has been described. The formulation is believed to be as economic in terms of computer resources as possible. One important feature is that the final set of equations which has to be solved appears to be well-conditioned, and can be solved efficiently using the preconditioned biconjugate gradient technique. It is important that the mesh used in the moving region does not contain any large jumps in element size in the direction of motion. The application of the method to railgun launchers is illustrated