Energy related conservation law for fluids and multi-fluid plasmas with equilibrium flow

Abstract

Within the framework of dissipationless multi-fluid theory for plasmas, all nonlinear perturbations of a stationary equilibrium that could be created from the equilibrium without breaking local entropy conservation are considered. Describing the fluid perturbations by Eulerian displacement vectors reveals a general symmetry and through Noether’s theorem leads to a conservation law. Its relation to the law of energy conservation is discussed since it will be important for the generalization of the energy principle known for static equilibria in magnetohyrodynamics to an energy principle of stationary equilibria in the framework of a multi-fluid theory.