** Next:** Introduction

# Adaptive-Grid Methods for Plasma and Radiation Hydrodynamics

**Osman Yasar **

Oak Ridge National Laboratory

Center for Computational Sciences

Oak Ridge, TN 37831

### Abstract:

*An explicit adaptive-grid finite differencing method for one dimensional
radiation magnetohydrodynamics computations is described. Based on the
equidistribution principle, this explicit procedure moves the grid points
to regions with high spatial gradients in
physical quantities, such as temperature, mass density, pressure and
momentum. The governing magnetic field, radiative transfer and hydrodynamics
equations are transformed to the moving adaptive reference frame. The time and
spatially dependent radiation field is determined by solving the radiative
transfer equation with the multigroup discrete ordinate method with
implicit time differencing. The magnetic field is solved through a diffusion
equation resulted from Maxwell's equations and Ohm's law. The
fluid equations are solved using a first order upwind spatial differencing and
explicit time differencing scheme. The coupling between the fluid and radiation
field is treated explicitly by first solving for the radiation field and then
the fluid equations. A conservative differencing scheme based on the control
volume approach is chosen to retain the conservative nature of the governing
equations.
*

*Osman Yasar *

Thu Mar 21 14:48:13 EST 1996