Finite element solution of unbounded magnetic field problem containing ferromagnetic materials

The strategic dual image method for obtaining the finite-element solution of unbounded magnetic field problems can be applied to any complex magnetic field distributions with unbounded boundary. However, a difficulty in generalizing the method to magnetic field problems involving ferromagnetic materials has been pointed out. It is shown that this difficulty can be removed by utilizing the B=μ0(H +M) formulation instead of B=μH, where B , H, M, μ₀, and μ are, respectively, the flux density, field intensity, magnetization, permeability of air, and permeability of the ferromagnetic material. The resulting method can be used to obtain the finite-element solution of unbounded saturable magnetic field problems