Physics

Dr Sudip K. Garain
University of Notre Dame, USA

Abstract:

Many of the space physics and astrophysics systems are spherical. The numerical simulations of all such systems use spherical polarcoordinate systems. However, computations are heavily affected because the mesh in this coordinate systems results in vanishingly small timesteps, and a loss of accuracy close to the poles. In this presentation, we describe a new meshing for spherical problems which is truly isotropic in angular space and thus, avoids the coordinate singularity present in the spherical coordinate systems. We also describe the numerical technique for achieving high order WENO reconstruction for the zone-centered variables as well as divergence free reconstruction of the face-centered magnetic field components. Using standard test problems, we demonstrate that our simulation technique achieves its design accuracies. Finally, as an application, we present results of the 3D numerical simulation for the advection of magnetic flux tube through sub-Keplerian accretion flow.