SPH Simulations of MHD Shocks Using a Piecewise Constant Smoothing Length Profile

Concerns regarding efficiency and accuracy of Smoothed Particle Hydrodynamics (SPH) compared to modern grid-based methods have been raised. Likewise, the extension of SPH to MHD problems has proven to be a challenge. In an attempt to improve the ability of SPH to treat shocks in general, and MHD shocks in particular, a modified version of SPH called Regularized Smoothed Particle Hydrodynamics (RSPH) has been presented [1]. This method allows a piecewise constant smoothing length profile to be used. Furthermore, the smoothing length profile is optimized at temporal intervals using a mass, momentum and internal erergy conserving regularization process. In this paper, we examine more closely the abilities of the RSPH method to treat MHD shocks. We present a simple stability analysis, as well as results from MHD shock tests in one and two dimensions.