Title: A parallel adaptive mesh refinement algorithm of an unsplit staggered mesh scheme for magnetohydrodynamics

Speaker: Dongwook Lee, Ph.D. Candidate, University of Maryland at College Park

Date/Time: Monday, December 5, 2005, 9:00-10:00 am

Location: Building 980, Room 95 (Sandia NM)

Brief Abstract: Many numerical solutions of multidimensional MHD problems have been solved using operator splitting, which is simply an extension of the one-dimensional formulation in Godunov type finite-volume schemes.  Although the formal accuracy of such schemes has been shown to be second order, there are generally unphysical errors due to the inherent dimensional splitting in numerical time integration.

To avoid there errors we have developed a new operator unsplit staggered mesh algorithm (USM-MHD) that has been implemented on massively parallel computers. The USM-MHD scheme has shown to efficiently ensure the divergence-free magnetic fields constraint up to computer round-off error. The method is a second order finite-volume Godunov algorithm which has a TVD version of the MUSCL-Hancock scheme, and also incorporates a full consideration of multidimensional structures in MHD. The development of a parallel adaptive mesh refinement (AMR) version of this scheme is ongoing and is being implemented in the FLASH code computational framework using the PARAMESH library.

We will discuss the formulation of the USM-MHD scheme, and as well as results of several numerical test problems.