Astrophysical MHD simulations in two and three dimensions

Numerical methods are developed to study astrophysical plasma flows within the physical framework of compressible magnetohydrodynamics. Numerical finite-difference codes have been developed and applied to a variety of problems in two and three space dimensions. Key technical issues which arise in MHD simulations are discussed: (1) preservation of a divergence-free magnetic field, and (2) accurate and numerically stable treatment of all MHD wave modes. These difficulties, and the importance of incorporating upwind information in the Alfven wave characteristics into the numerical representations of the magnetic induction equation and Lorentz force term are described. Several astrophysical applications are presented which show the generality of the methods. 29 refs