A method for the computation of open-boundary non-linear transient magnetic fields in axisymmetry

摘要

This paper describes an iterative finite element method to evaluate numerically axisymmetric magnetic fields in a ferromagnetic material in the presence of external time-varying current sources and in an open-boundary geometry. A fictitious boundary delimiting a bounded domain is introduced. At each discrete time, two algebraic systems are set up and solved for the predictor and corrector solutions. Both these systems are solved iteratively by assuming a first guess for the Dirichlet condition on the fictitious boundary and improving it by making use of the free-space Green's function until convergence takes place. A great reduction in computing time is obtained with respect to the solution with a Newton-Raphson solver. Examples of application are also given.