PIERNIK MHD code – a multi–fluid, non–ideal extension of the relaxing–TVD scheme (IV)

Toruń Centre for Astronomy, Nicolaus Copernicus University, Toruń, Poland ;
e-mail: mhanasz@astri.uni.torun.pl

Abstract

We present a new multi–fluid, grid MHD code PIERNIK, which is based on the Relaxing TVD scheme (Jin & Xin 1995). The original scheme (see Trac & Pen 2003; Pen 2003) has been extended by an addition of dynamically independent, but interacting fluids: dust and a diffusive cosmic ray gas, described within the fluid approximation, with an option to add other fluids in an easy way. The code has been equipped with shearing–box boundary conditions, and a selfgravity module, Ohmic resistivity module, as well as other facilities which are useful in astrophysical fluid–dynamical simulations. The code is parallelized by means of the MPI library. In this paper we present an extension of PIERNIK, which is designed for simulations of diffusive propagation of the Cosmic–Ray (CR) component in the magnetized ISM.