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arXiv · 1407.3884

Action Principles for Extended MHD Models

I. Keramidas Charidakos·M. Lingam·P. J. Morrison·R. L. White·A. Wurm
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Abstract

The general, non-dissipative, two-fluid model in plasma physics is Hamiltonian, but this property is sometimes lost or obscured in the process of deriving simplified (or reduced) two-fluid or one-fluid models from the two-fluid equations of motion. To ensure that the reduced models are Hamiltonian, we start with the general two-fluid action functional, and make all the approximations, changes of variables, and expansions directly within the action context. The resulting equations are then mapped to the Eulerian fluid variables using a novel nonlocal Lagrange-Euler map. Using this method, we recover Lüst's general two-fluid model, extended MHD, Hall MHD, and electron MHD from a unified framework. The variational formulation allows us to use Noether's theorem to derive conserved quantities for each symmetry of the action.

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I. Keramidas Charidakos, M. Lingam, P. J. Morrison, R. L. White, A. Wurm. 2014-07-15. Action Principles for Extended MHD Models. https://doi.org/10.1063/1.4896336

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