TY - JOUR
T1 - Variational formulation of relaxed and multi-region relaxed magnetohydrodynamics
AU - Dewar, R. L.
AU - Yoshida, Z.
AU - Bhattacharjee, A.
AU - Hudson, S. R.
N1 - Publisher Copyright:
© 2015 Cambridge University Press.
PY - 2015/12/1
Y1 - 2015/12/1
N2 - Ideal magnetohydrodynamics (IMHD) is strongly constrained by an infinite number of microscopic constraints expressing mass, entropy and magnetic flux conservation in each infinitesimal fluid element, the latter preventing magnetic reconnection. By contrast, in the Taylor relaxation model for formation of macroscopically self-organized plasma equilibrium states, all these constraints are relaxed save for the global magnetic fluxes and helicity. A Lagrangian variational principle is presented that leads to a new, fully dynamical, relaxed magnetohydrodynamics (RxMHD), such that all static solutions are Taylor states but also allows state with flow. By postulating that some long-lived macroscopic current sheets can act as barriers to relaxation, separating the plasma into multiple relaxation regions, a further generalization, multi-region relaxed magnetohydrodynamics (MRxMHD) is developed.
AB - Ideal magnetohydrodynamics (IMHD) is strongly constrained by an infinite number of microscopic constraints expressing mass, entropy and magnetic flux conservation in each infinitesimal fluid element, the latter preventing magnetic reconnection. By contrast, in the Taylor relaxation model for formation of macroscopically self-organized plasma equilibrium states, all these constraints are relaxed save for the global magnetic fluxes and helicity. A Lagrangian variational principle is presented that leads to a new, fully dynamical, relaxed magnetohydrodynamics (RxMHD), such that all static solutions are Taylor states but also allows state with flow. By postulating that some long-lived macroscopic current sheets can act as barriers to relaxation, separating the plasma into multiple relaxation regions, a further generalization, multi-region relaxed magnetohydrodynamics (MRxMHD) is developed.
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U2 - 10.1017/S0022377815001336
DO - 10.1017/S0022377815001336
M3 - Article
AN - SCOPUS:85016795549
SN - 0022-3778
VL - 81
JO - Journal of Plasma Physics
JF - Journal of Plasma Physics
IS - 6
M1 - 515810604
ER -