Subproblems Applied to a 3-D Magnetostatic Facet FEM Formulation

The Facet finite-element method (FFEM) requires a source field solution that is commonly obtained by the Biot–Savart (BS) equation that can be time-consuming. The subproblem modeling is applied to the FFEM in order to minimize the computational effort and time necessary to obtain the solution. The volume sources, which allow solving the BS equation only along the active regions, are presented, as well as the BS boundary condition correction.