Effective computational models for anisotropic soft B-H curves

The flux density B for a magnetic field H in a soft magnetic material is given by the derivatives of the stored coenergy density with respect to the components of H. Any single-valued nonlinear tensor permeability may therefore be stored compactly, and retrieved with little computation, by storing its coenergy density as a function of position in H-space. In a dual form, H can be found by differentiating the stored energy density with respect to the components of B. Computational experiments show that sufficient accuracy can be achieved using cubic splines or other C²-continuous approximating functions.