Recent experiences on mixed finite elements for 2D simulations of magneticfields

A mixed formulation of two-dimensional magnetostatic problems, where both B and H are unknowns, is considered. The solution is obtained by minimizing the residual of the constitutive law, imposing Maxwell's equations as const raints by means of Lagrange multipliers, When a finite element discretizati on involving face and edge elements is applied, we have to solve a linear s ystem whose algebraic treatment presents some difficulties. In the paper, t he attention is focused on the computational aspects of the proposed method ology with special emphasis on the choice of algebraic solvers and of possi ble preconditioning techniques. A case study, concerning the field analysis of a magnetic screen, is presented and discussed.