Conference Agenda

Computational strategies improvements for the inductive and capacitive unstructured PEEC formulation are presented in order to address efficiently a large frequency range of electromagnetic problems. Good accuracy on results is ensured thanks to the use of an adaptive Gauss integration procedure while multi-threaded Adpatative Multi Level Fast Multipole Method (AMLFMM) matrix compression algorithm allows to speed-up far interactions computation. This article focuses on the following two points: on the one hand, allowing good convergence for iterative linear systems at any frequency by the choice of an efficient preconditioner coupled with a suitable PEEC circuit solver and, on the other hand, the use of Model Order Reduction (MOR) techniques for solving multi frequency problems, allowing fast computing time. An example illustrates the performances of these approaches.

Eddy current testing (ECT) is an efficient non-destructive testing technique for inspection of defect in conductive structural components. The eddy current field problem of ECT is usually treated as a quasi-static field by ignoring the displacement current term in the Maxwell equations, as the metallic inspection target usually has a large electrical conductivity but a dielectric constant close to the air. Recently, high frequency ECT is adopted to the NDT of composite material structures of the carbon fiber reinforced plastics (CFRP), and show good performance in potential applications. However, the conventional numerical method for simulation of ECT signals, which is indispensable for the probe optimization and defect reconstruction, is not suitable for the high frequency ECT problem because the effect of displacement current was not taken into account. In this study, an efficient numerical solution method for high-frequency ECT problem considering the displacement current effect is proposed, and a corresponding numerical code is developed based on the FEM-BEM hybrid program developed by authors for conventional ECT. The validity and efficiency of the numerical method and code are verified through simulating high-frequency ECT signals of benchmark problems and compared with results of both the full FEM software and experiments.

In this work an isogeometric Nitsche formulation is used for the simulation of non-conforming electromagnetic problems. Isogeometric Analysis is especially well suited when coupling non-conforming curved domains, as -in contrast to the classical finite element method- it allows for the exact representation of the interface on both domains. For the simulation of electric machines this is very convenient due to their circular shape. The convergence of the isogeometric Nitsche method is investigated.

In electromagnetic field analysis, the Darwin model allows us to consider the effects of inductance and capacitance. In this paper, we examine two interrelated Darwin model methods for accelerating the convergence of an iterative solution. One method enlarges the size of the coefficient matrix, whereas the other method does not.

A Method–of–Moments (MoM) is coupled with PEEC in order to compute Joule and hystheresis losses in the armor, shields and moisture barriers of a submarine tripolar cable. The large size and complex structure of the linear algebraic system resulting from the problem discretization, demand for a suitably tailored solver. We describe a block–Gauß–Seidel preconditioner for Krylov subspace methods that allows for a matrix–free solver implementation, resulting in a dramatic reduction of computation time and memory requirements w.r.t. to other brute–force modeling approaches.