Summary

ZEUS-2D is a computational fluid dynamics code developed at the Laboratory for Computational Astrophysics (NCSA, University of Illinois at Urbana-Champaign) for astrophysical radiation magetohydrodynamics problems. ZEUS-2D solves problems in one or two spatial dimensions with a wide variety of boundary conditions. The C language preprocessor allows the user to define various macros to customize the ZEUS-2D algorithm for the desired physics, geometry, and output.

Physics Included

ZEUS-2D solves the equations of ideal (non-resistive), non-relativistic, hydrodynamics, including radiation transport, (frozen-in) magnetic fields, rotation, and self-gravity. Boundary conditions may be specified as reflecting, periodic, inflow, or outflow.

Geometries

ZEUS-2D solves problems in Cartesian (x, y), cylindrical-polar (r, phi), and spherical-polar (r, theta) coordinate systems.

Algorithm

• ZEUS-2D is a finite difference code with a fixed or moving orthogonal Eulerian mesh.

• MHD Time integration is fully explicit, with the time step controlled by the Courant condition.

• The mesh is staggered, with zone-centered scalar quantities (density, energy) and face-centered vector components (velocity, magnetic field) to increase accuracy.

• The algorithm is written in a "covariant" form to minimize the effect of coordinate systems, translations, and changes of scale.

• One-dimensional simulations are treated efficiently by reducing the unused coordinate to a symmetry axis.

• Either von-Neumann-Richtmyer or a tensor artificial viscosity may be used to spread shocks over several mesh zones.

• The upstream weighted, monotonicity-preserving advection schemes are exactly conservative. The Donor Cell (first order), van Leer (second order), or Piecewise Parabolic (third order) method may be selected.

• The magnetic field components are evolved in a manner that ensures that the divergence vanishes and that all possible MHD modes propagate accurately and stably (Evans and Hawley Constrained Transport scheme modified by Stone and Norman using the Method of Characteristics).

• A conjugate gradient technique employing incomplete Cholesky preconditioning is used to solve Poisson's equation for the gravitational potential. A multipole expansion of the potential is used to compute boundary conditions of the Dirichlet type.

Graphical Output

• ZEUS-2D writes HDF format Scientific Data Sets. These files can be read and visualized using a variety of graphics packages.

• Various scalar quantities may be output as a function of time.

• A post-processor is included to read the HDF data and plot it as 1- or 2-D NCAR Graphics metacode files.

The Code

The Zeus-2D code can be downloaded here.

Benchmarks

Benchmarks for Zeus-2D can be found here.

For More Information

• See the documentation The ZEUS-2D Code for Astrophysical Fluid Dynamics Simulations (LCA Technical report #14)

• See also the companion paper on the ZEUS-2D Radiation Hydrodynamics Module (LCA Technical report #13)

• See the series of 3 papers in the Astrophysical Journal Supplement Series, vol. 80, 1992:

  1. Stone and Norman (I . HYDRO), p. 753

  2. Stone and Norman (II. MHD ), p. 791

  3. Stone, Mihalas, and Norman (III. RHD ), p. 819