A simpler variational principle for stationary non-barotropic ideal magnetohydrodynamics

Variational principles for magnetohydrodynamics (MHD) were introdu- ced by previous authors both in Lagrangian and Eulerian form. In this paper we introduce simpler Eulerian variational principles from which all the relevant equa- tions of non-barotropic stationary magnetohydrodynamics can be derived for certain field topologies. The variational principle is given in terms of three independent func- tions for stationary non-barotropic flows in which magnetic field lines lie on entropy surfaces. This is a smaller number of variables than the eight variables which appear in the standard equations of non-barotropic magnetohydrodynamics which are the magnetic field B the velocity field v, the entropy s and the density ρ. The reduction of variables constraints the possible chaotic motion available to such a system.