A permanent C-magnet in the air. The example demonstrates how to model curved permanent magnet using the equivalent surface currents.
Plane problem of DC magnetics.
Geometry of the magnet:
Relative permeability of the air μ = 1;
Relative permeability of the magnet μ = 1000;
Coercive force of the magnet Hc = 10000 A/m.
The magnet polarization is along its curvature.
To avoid the influence of the boundaries while modeling the unbounded problem, we'll enclose the magnet in a rectangular region of air and specify zero Dirichlet boundary condition on its sides.
Magnetization of straight parts of the magnet is specified in terms of coercive force vector. Effective surface currents simulate magnetization in the middle curved part of the magnet.
Flux density in ferromagnetic C-magnet: