A Multidimensional Radiation Magnetohydrodynamics Code Based on Flux-Limited Diffusion and HLLD

We present a multidimensional radiation magnetohydrodynamics (MHD) code based on the high-resolution shock capturing schemes (HRSC), the flux-limited diffusion (FLD) approximation, and the assumption of local thermodynamic equilibrium (LTE). The HRSC, employing a conservative algorithm that accurately ensures conservation of the total energy of MHD is implemented using a third-order Runge-Kutte scheme and the HLLD Riemann solver. In the FLD approximation, because the evolution equations of the radiation energy flux are neglected, this code is easily implemented, though the FLD approximation is less accurate when dealing with highly anisotropic radiation fields in an optically thin region. We carried out classical tests for the MHD and for the subcritical and supercritical radiating shocks. The results show that this code can achieve the necessary accuracy and efficiency to solve the radiation-dominated astrophysical processes with the FLD approximation