The implications of three-dimensional mesh generation on the calculation of mechanical forces in magnetic devices

The implications of the methods used in mesh generation for force calculation in three-dimensional magnetic device analysis are discussed. Virtual-work and single-solution methods are compared, and the usefulness of the element topological information is considered. It is concluded that because the virtual work approach is somewhat independent of the meshing system used and the coenergy values may be derived easily in the solution process, the approach may be the method of choice for many applications requiring low-cost force calculation in three dimensions. It must be noted, however, that it can generate large errors, and the exact method of generating the models for the multiple solutions, i.e., moving nodes or changing labels, can have major effects on the overall accuracy. In general, it is more difficult to separate postprocessing functions in three dimensions from the underlying topological structures created in the postprocessor and solver, and further work in both areas is needed to develop effective calculation techniques