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

TL;DR

The paper introduces an extended multi-fluid MHD code, PIERNIK, based on the Relaxing TVD scheme, incorporating additional physics like dust, cosmic rays, self-gravity, and resistivity for astrophysical simulations.

Contribution

It presents a new multi-fluid MHD code with extensions for resistivity, self-gravity, and additional fluids, enhancing capabilities for astrophysical fluid dynamics modeling.

Findings

Demonstrated magnetic reconnection with uniform resistivity.

Showcased current-dependent resistivity effects.

Validated code features with example 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 Ohmic resistivity extension of the original Relaxing TVD MHD scheme, and show examples of magnetic reconnection in cases of uniform and current-dependent resistivity prescriptions.