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

TL;DR

PIERNIK is a new multi-fluid MHD code extending the Relaxing TVD scheme to include dust, cosmic rays, and additional physics, enabling advanced astrophysical fluid simulations.

Contribution

It introduces a multi-fluid, non-ideal extension of the Relaxing TVD scheme with new modules for cosmic rays, self-gravity, and resistivity, tailored for astrophysical applications.

Findings

Implemented a multi-fluid MHD code with cosmic-ray diffusion.

Enabled simulations of cosmic-ray propagation in the ISM.

Parallelized the code using MPI for large-scale simulations.

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) and Pen et al. (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.