Comparison of DEIM and BPIM to Speed Up a POD-Based Nonlinear Magnetostatic Model

Proper orthogonal decomposition (POD) has been successfully used to reduce the size of linear finite-element (FE) problems, and thus the computational time associated with. When considering a nonlinear behavior law of the ferromagnetic materials, the POD is not so efficient due to the high computational cost associated with the nonlinear entries of the full FE model. Then, the POD approach must be combined with an interpolation method to efficiently deal with the nonlinear terms, thus obtaining an efficient reduced model. An interpolation method consists in computing a small number of nonlinear entries and interpolating the other terms. Different methods have been presented to select the set of nonlinear entries to be calculated. Then, the (discrete) empirical interpolation method [(D)EIM] and the best points interpolation method (BPIM) have been developed. In this paper, we propose to compare two reduced models based on the POD-(D)EIM and on the POD-BPIM in the case of nonlinear magnetostatics coupled with electric equation.