Simulation of Moving Electromagnetic Parts with Finite- and Boundary Elements

  • Zechner, Jürgen (TAILSIT GmbH)
  • Rüberg, Thomas (TAILSIT GmbH)
  • Kielhorn, Lars (TAILSIT GmbH)

Please login to view abstract download link

For the simulation of electromagnetic fields, we combine the Finite Element Method (FEM) with the Boundary Element Method (BEM) [1]. With this approach, only the workpiece needs to be discretized, and its often nonlinear material behavior is captured by the FEM. The electromagnetic fields in the surrounding domain are represented by the BEM, eliminating the need for an air mesh or artificial boundary conditions. This enables the simulation of moving workpieces without the burden of meshing and re-meshing the air domain. The analysis of electromagnetic fields typically forms part of a broader multiphysics problem in which the mechanical and thermal behavior is incorporated, too. This motivates the use of coupling libraries such as preCICE [2]. For the FEM-BEM coupling, we implemented a preCICE adapter to enable the simulation of a wide range of multiphysics applications involving electromagnetic effects, such as eddy-current brakes, magnetic latches in smart covers and headphones, or induction heating. The adapter for our in-house solver computes the electromagnetic forces based on the current configuration. We chose LS-DYNA as the structural solver and implemented a preCICE adapter for it (see [3] for an alternative approach). This adapter provides nodal displacements and velocities of the structural components. The electromagnetic forces exchanged via preCICE are applied as additional loads using user-subroutines. We discuss the advantages and challenges of the electromagnetic FEM-BEM coupling, including MPI-parallel and scalable Fast Multipole Methods, as well as the capabilities and the current state development of the preCICE adapter for LS-DYNA. Finally, we present benchmarks and practical examples that demonstrate the accuracy and applicability of the proposed multiphysics setup. [1] T. Rüberg, L. Kielhorn, and J. Zechner. Electromagnetic devices with moving parts — simulation with FEM/BEM coupling. Mathematics, 9(15):1804, 2021. [2] G. Chourdakis, et al. preCICE v2: A sustainable and user-friendly coupling library. Open Research Europe, 2022, 2. Jg., S. 51. [3] S. Scheiblhofer, S. Jäger, and A. M. Horr. Coupling FEM and CFD solvers for continuous casting process simulation using preCICE. COUPLED VIII: proceedings of the VIII International Conference on Computational Methods for Coupled Problems in Science and Engineering. CIMNE, 2019.