A 3D MHD model of astrophysical flows: Algorithms, tests and parallelisation

Astronomy Division, Department of Physical Sciences, PO Box 3000, 90014 University of Oulu, Finland

Corresponding author: M. J. Korpi, Maarit.Korpi@oulu.fi

Received: 22 December 2000
Accepted: 24 January 2001

Abstract

In this paper we describe a numerical method designed for modelling different kinds of astrophysical flows in three dimensions. Our method is a standard explicit finite difference method employing the local shearing-box technique. To model the features of astrophysical systems, which are usually compressible, magnetised and turbulent, it is desirable to have high spatial resolution and large domain size to model as many features as possible, on various scales, within a particular system. In addition, the time-scales involved are usually wide-ranging also requiring significant amounts of CPU time. These two limits (resolution and time-scales) enforce huge limits on computational capabilities. The model we have developed therefore uses parallel algorithms to increase the performance of standard serial methods. The aim of this paper is to report the numerical methods we use and the techniques invoked for parallelising the code. The justification of these methods is given by the extensive tests presented herein.