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

TL;DR

The paper introduces an extended multi-fluid MHD code called PIERNIK, based on the Relaxing TVD scheme, capable of simulating astrophysical phenomena involving multiple interacting fluids such as gas, dust, and cosmic rays.

Contribution

It presents a novel multi-fluid extension of the Relaxing TVD scheme, including modules for self-gravity, resistivity, and other astrophysical processes, with demonstrated application to dust migration in disks.

Findings

Dust drifts toward gas pressure maxima due to velocity differences and drag force.

The code successfully models multi-fluid interactions in astrophysical contexts.

Parallelized implementation enables large-scale simulations.

Abstract

We present a new multi-fluid, grid MHD code PIERNIK, which is based on the Relaxing TVD scheme (Jin and 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 introduce the multifluid extension of Relaxing TVD scheme and present a test case of dust migration in a two-fluid disk composed of gas and dust. We demonstrate that due to the difference in azimuthal velocities of gas and dust and the drag force acting on both components dust drifts towards maxima of gas pressure distribution.