Using the Schur Complement to Reduce Runtime in KULL's Magnetic Diffusion Package

Brunner, T A; Kolev, T V

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DOE OSTI · 1018784

Using the Schur Complement to Reduce Runtime in KULL's Magnetic Diffusion Package

Brunner, T A·Kolev, T V

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Abstract

Recently a Resistive Magnetohydrodynamics (MHD) package has been added to the KULL code. In order to be compatible with the underlying hydrodynamics algorithm, a new sub-zonal magnetics discretization was developed that supports arbitrary polygonal and polyhedral zones. This flexibility comes at the cost of many more unknowns per zone - approximately ten times more for a hexahedral mesh. We can eliminate some (or all, depending on the dimensionality) of the extra unknowns from the global matrix during assembly by using a Schur complement approach. This trades expensive global work for cache-friendly local work, while still allowing solution for the full system. Significant improvements in the solution time are observed for several test problems.

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70 PLASMA PHYSICS AND FUSION TECHNOLOGY 97 MATHEMATICS AND COMPUTING DIFFUSION FLEXIBILITY HYDRODYNAMICS MAGNETOHYDRODYNAMICS NUCLEAR EXPLOSIVES

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BibTeX RIS

Brunner, T A, Kolev, T V. 2010-12-15. Using the Schur Complement to Reduce Runtime in KULL's Magnetic Diffusion Package. https://www.osti.gov/biblio/1018784

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