Complementarity by “local corrections”

By using complementarity (solving for both potentials, scalar and vector), one often can provide bilateral bounds for some quantities of interest, like for instance the reluctance of a circuit. However, the vector potential method is expensive, and does not make use of information acquired in the first phase of solving for the scalar potetential. We show how to improve on this by a “local correction” process which, starting from h = grad φ, yields a divergence‐free b, close to μh, by a series of local and independent (parallel) problems.