Abstract

Contributed Talk - Splinter CompQuantum   (MW-2050)

Divergence-free magnetohydrodynamics on a moving mesh

Volker Springel
Max Planck Institute for Astrophysics

Numerically solving the ideal magnetohydrodynamic (MHD) equations involves the well-known complication that the discretized equations do not readily prevent the appearance of unphysical magnetic monopoles. Such div(B) errors can either be coped with through a variety of cleaning techniques, or prevented manifestly through so-called constrained transport methods. However, on fully dynamic unstructured meshes like the one used by the AREPO code, a stable constrained transport approach has so far been elusive, so that production calculations needed to rely on Powell or Dedner cleaning, seeding nagging concerns about their reliability. In this talk I discuss a novel approach to realize a divergence-free magnetohydrodynamics algorithm on a moving and unstructured mesh. I will also compare the outcome of various test problems with this new method both to a Powell divergence-cleaning scheme and constrained transport on a stationary Cartesian mesh.