The SSOR-preconditioned inner-outer flexible gmres method for the FEM analysis of em problems

When solving electromagnetic problems by finite element method, the resulting linear systems are ill-conditioned when the PML absorbing layers are adopted. Traditional Krylov iterative algorithms usually converge slowly or may even stagnate. In this paper, the combination of the inner-outer Flexible Generalized Minimum Residual Method (GMRES) and the symmetric successive overrelaxation (SSOR) preconditioning scheme is used to accelerate the iteration for solving a large sparse system of linear equations resulting from the analysis of EM problems by use of edge-based finite element method (FEM). The numerical results show that tens of times convergence improvement can he achieved compared with the conventional GMRES solver. © 2006 Wiley Periodicals, Inc.