Comparison between Nested and Non-Nested Multigrid Methods for Magnetostatic Field Analysis

A comparision of the efficiency of the multigrid solution method for magnetostatic field analysis using nested and non-nested finite element meshes is presented, Two types of multigrid algorithms are investigated; The V-cycle and the W-cycle multigrid method. For the generation of nested meshes a simple halving procedure is employed resulting in fine meshes strongly dependent on the initial coarse mesh and with uniform mesh densities. NOn-nested meshes are generated using adaptive meshing with a suitable error estimator. The result show that both methods provide faster solution than the ordinary ICCG method. The speed-ups range from 2 to 10 mainly depending on the type of the cycle and the number of unknowns.