Semi-Implicit Method for MHD Computations Without an Alfven Wave CFL Restriction

摘要

A semi-implicit method for solving the three-dimensional magnetohydrodynamic equations on long time scales is presented. Standard explicit methods must use time steps which are constrained by a Courant-Friedrichs-Lewy condition due to the fast compressional and shear Alfven motion. This semi-implicit method eliminates both of these restrictions so that very large time steps are permited. The method is simple to implement and the computation time for one time step is essentially the same as for explicit methods. Numerical test results in slab and cylindrical geometry are presented. (ERA citation 10:050491)