THE ZEUS-3D CODE

Summary

ZEUS-3D is a computational fluid dynamics code developed at the Laboratory for 
Computational Astrophysics (NCSA, University of Illinois at Urbana-Champaign) 
for the simulation of astrophysical phenomena. ZEUS-3D solves problems in one, 
two, or three spatial dimensions with a wide variety of boundary conditions. A 
source-code preprocessor allows the user to customize the ZEUS-3D algorithm 
for the desired physics, geometry, and output. 

Physics Included

ZEUS-3D solves the equations of ideal (non-resistive), non-relativistic, 
magnetohydrodynamics, including externally applied gravitational fields and 
self-gravity. The gas can be adiabatic or isothermal, and the thermal pressure 
is isotropic. Boundary conditions may be specified as reflecting, periodic, 
inflow, or outflow.

Geometries

ZEUS-3D solves problems in Cartesian (x, y, z), cylindrical-polar (z, r, phi), 
and spherical-polar (r, theta, phi) coordinate systems.

Algorithm

¥ ZEUS-3D is a finite difference code with a fixed or moving orthogonal Eulerian mesh. 

¥ 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 the
 choice of coordinate systemson the structure of the code. 

¥ One- and two-dimensional simulations are treated efficiently by reducing the
 unused coordinates to symmetry axes.

¥ von-Neumann-Richtmyer artificial viscosity is 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). 

¥ The DADI (Dynamical Alternating Direction Implicit) scheme solves Poisson's
 equation for the gravitational potential.

Graphical Output

¥ Metacodes for 1- and 2-D NCAR graphics line, contour, and vector plots,
 including annotation.

¥ Line-of-sight integration is performed for a variety of variables, including
 Stokes parameters.

¥ Pixel, Voxel dumps in raw raster or HDF format.

¥ Various scalar quantities can be plotted as a function of time.

For more information, see the ZEUS-3D User Manual in ../codes/zeus3d/manuals/.

General inquiries, user registration, and bug reports are handled by electronic 
mail.  The LCA may be contacted by several means:

   E-mail: lca@ncsa.uiuc.edu
   Anonymous ftp: ftp to ftp.ncsa.uiuc.edu (signon:anonymous); cd lca/zeus3d
   World Wide Web: http://zeus.ncsa.uiuc.edu:8080/lca_home_page.html
.