Shock study with extended-MHD model using a Discontinuous Galerkin Scheme

Summary form only given. We apply a positivity-preserving semi-implicit Discontinuous Galerkin Scheme with Lax-Friedrichs flux on solving extended-MHD equations. The scheme is shock-capturing as further verified by slow shock and fast shock tests. The method is applied to the study of 2-dimensional interaction of magnetized flow with obstacles. Results with different orientations of magnetic field are presented. A magnetic field perpendicular to the plane will give a result comparable to the hydrodynamic case, where a bow shock in front of the obstacle is observed if the flow is super-magnetosonic. When the magnetic field is in plane but perpendicular to the flow direction, the phenomena change dramatically depending on the Alfven and flow Mach numbers. This study can facilitate the diagnosis of the outflow jet in the two-wire reconnection experiments performed on the 1MA, 100ns COBRA generator at Cornell University. We also present MHD results for comparison to the extended-MHD results. The differences are pronounced due to the effect of the Hall term. The observations of a Biermann battery effect in the extended-MHD results during this flow-obstacle interaction process are also presented.