MPI-AMRVAC 2.0 for Solar and Astrophysical Applications

Abstract

We report on the development of MPI-AMRVAC version 2.0, which is an open-source framework for parallel, grid-adaptive simulations of hydrodynamic and magnetohydrodynamic (MHD) astrophysical applications. The framework now supports radial grid stretching in combination with adaptive mesh refinement (AMR). The advantages of this combined approach are demonstrated with one-dimensional, two-dimensional and three-dimensional examples of spherically symmetric Bondi accretion, steady planar Bondi-Hoyle-Lyttleton flows, and wind accretion in Supergiant X-ray binaries. Another improvement is support for the generic splitting of any background magnetic field. We present several tests relevant for solar physics applications to demonstrate the advantages of field splitting on accuracy and robustness in extremely low plasma β environments: a static magnetic flux rope, a magnetic null-point, and magnetic reconnection in a current sheet with either uniform or anomalous resistivity. Our implementation for treating anisotropic thermal conduction in multi-dimensional MHD applications is also described, which generalizes the original slope limited symmetric scheme from 2D to 3D. We perform ring diffusion tests that demonstrate its accuracy and robustness, and show that it prevents the unphysical thermal flux present in traditional schemes. The improved parallel scaling of the code is demonstrated with 3D AMR simulations of solar coronal rain, which show satisfactory strong scaling up to 2000 cores. Other framework improvements are also reported: the modernization and reorganization into a library, the handling of automatic regression tests, the use of inline/online Doxygen documentation, and a new future-proof data format for input/output.

A Comprehensive Comparison of Relativistic Particle Integrators

“…Finally, charged particle motions in dipolar fields can be handled well by the GCA approximation and recover the azimuthal drift along with the mirror motion as estimated by theory. All of these methods are implemented in the open source MPI-AMRVAC framework (Porth et al 2014;Xia et al 2018) and can be used to analyze particle dynamics in evolving electromagnetic fields from MHD simulations. The extension of the methods presented here to general relativistic covariant formulations is planned for future work in the general relativistic MHD code BHAC (Porth et al 2017).…”

Ideal MHD instabilities for coronal mass ejections: interacting current channels and particle acceleration

“…In order to properly simulate the high magnetic Reynolds number regime, or accommodate for collisionless effects through coupled MHD-PIC simulations, modern open source software frameworks like MPI-AMRVAC [86,63,36] provide useful input to the scientific community. Indeed, several of our example applications [85,88,89,57,37,67,65,54] made use of MPI-AMRVAC.…”

Particle Orbits at the Magnetopause: Kelvin‐Helmholtz Induced Trapping

“…The test particle simulations presented in this article were realized using MPI-AMRVAC, the parallelized Adaptive Mesh Refinement Versatile Advection Code (Keppens et al, 2012;Porth et al, 2014;Xia et al, 2018). The resistive and Hall-MHD module (extension of MHD applicable to phenomena occurring on length scales shorter than the ion inertial length and time scales shorter than the ion cyclotron period) has been tested and validated by Porth et al (2014), and the test particle module has been introduced and further applied by Ripperda et al (2017aRipperda et al ( , 2017bRipperda et al ( , 2018.…”