Abstract
The multigrid method has been applied to electromagnetic field problems to show that it can reduce computational time in comparison with conventional linear solvers. However the convergence of the multigrid method depends on the iteration number of smoothing. Thus it is important to estimate the optimum iteration number of smoothing. This paper discusses the convergence of the geometric multigrid method against the iteration number of smoothing in edge-based finite element analysis. Numerical results show that the optimum number of smoothing can be estimated using the aspect ratio of elements.