A General Code for Modeling MHD flows on Parallel Computers:
Versatile Advection Code

Gábor Tóth

Astronomical Institute, Utrecht Univ., The Netherlands

Astrophysical Letters and Communications, 34, 245 (1996)

A general tool for solving MHD and hydrodynamical problems typical of astrophysical applications is designed and implemented. The code allows the user to solve a hyperbolic system of partial differential equations with a variety of modern high resolution numerical schemes on 1, 2 or 3D grids with slab or axial symmetry. The equations may contain fluxes and source terms. The initial and boundary conditions can be chosen from a number of implemented types, but the code is structured in a manner that allows the user to write his/her own subroutines for a new type of initial or boundary condition, or -- as a matter of fact -- for a new set of equations. Alternative numerical schemes can be added with relatively small effort. The choice of algorithms allows the user to find the optimal one for the application at hand and/or to compare results of different schemes thus gaining insight into the numerical effects. An emphasis is put on independence of computer platforms, which is very important in parallel computational environments, where standardization has not taken place yet. Efficiency of the code is also a high priority, the options available for the user should not compromise the performance.