The inexact Newton method applied for the solution of a magnetostatic problem

Inexact Newton solvers can offer many attractive features for the solution of non linear problem in the field of electromagnetics. A critical point for the optimal set up of the solver is the choice of the best algorithm for the evaluation of the approximate solutions of the linear systems at each Newton step, and the most effective preconditioning strategy. In this paper, the NITSOL method is proposed for the solution of a non linear linear magnetostatic problem. The problem has been discretized by means of a finite element approach. The GMRES method has been adopted as linear solver, and four preconditioners have been tested. The performance of the procedure are evaluated for different meshes with increasing number of discretization points.