Nonlinear magnetohydrodynamics simulation using high-order finite elements.

Journal Article · Wed Jun 01 04:00:00 UTC 2005 · Proposed for publication in the Journal of Computational Physics.

OSTI ID:970734

Plimpton, Steven James; Schnack, D D ^[1]; Tarditi, A ^[2]; Chu, M S ^[3]; Gianakon, T A ^[4]; Kruger, S E ^[1]; Nebel, R A ^[4]; Barnes, D C ^[4]; Sovinec, C R ^[5]; Glasser, A H ^[4]

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1. Science Applications International Corporation, San Diego, CA
2. National Aeronautics and Space Administration-Johnson Space Center, Houston, TX
3. General Atomics Corporation, San Diego, CA
4. Los Alamos National Laboratory, Los Alamos, NM
5. University of Wisconsin-Madison, Madison, WI

A conforming representation composed of 2D finite elements and finite Fourier series is applied to 3D nonlinear non-ideal magnetohydrodynamics using a semi-implicit time-advance. The self-adjoint semi-implicit operator and variational approach to spatial discretization are synergistic and enable simulation in the extremely stiff conditions found in high temperature plasmas without sacrificing the geometric flexibility needed for modeling laboratory experiments. Growth rates for resistive tearing modes with experimentally relevant Lundquist number are computed accurately with time-steps that are large with respect to the global Alfven time and moderate spatial resolution when the finite elements have basis functions of polynomial degree (p) two or larger. An error diffusion method controls the generation of magnetic divergence error. Convergence studies show that this approach is effective for continuous basis functions with p {ge} 2, where the number of test functions for the divergence control terms is less than the number of degrees of freedom in the expansion for vector fields. Anisotropic thermal conduction at realistic ratios of parallel to perpendicular conductivity (x{parallel}/x{perpendicular}) is computed accurately with p {ge} 3 without mesh alignment. A simulation of tearing-mode evolution for a shaped toroidal tokamak equilibrium demonstrates the effectiveness of the algorithm in nonlinear conditions, and its results are used to verify the accuracy of the numerical anisotropic thermal conduction in 3D magnetic topologies.

• Research Organization: Sandia National Laboratories
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 970734
• Report Number(s): SAND2005-3534J
• Journal Information: Proposed for publication in the Journal of Computational Physics., Journal Name: Proposed for publication in the Journal of Computational Physics.
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACCURACY
ALGORITHMS
ALIGNMENT
CONVERGENCE
DEGREES OF FREEDOM
DIFFUSION
FLEXIBILITY
MAGNETOHYDRODYNAMICS
POLYNOMIALS
SIMULATION
SPATIAL RESOLUTION
THERMAL CONDUCTION
VECTOR FIELDS