Fast finite-element solver for a reluctance mass accelerator

By choosing an appropriate method for partitioning and linearizing the system equations that describe a time-domain finite-element model of a reluctance mass accelerator, it is possible to reduce the computation time considerably over a traditional material reluctance model. In this work, we have constructed an axisymmetric magnetic field finite-element solver based on the induced magnetization of the saturable materials, instead of the more common field-dependent reluctance model. Eddy currents and driving circuit elements are also included in the model. Using this platform, we demonstrate how a well-conditioned set of field equations is produced and how a simple nonlinear iteration scheme can produce reliable results without repeated factorization of the finite-element matrix. Some comparisons with an established simplified model and experimental results help to verify the model.