Momentum and energy exchange in nonequilibrium multicomponent media

In multicomponent media, the equilibrium states are defined by thermodynamic equilibrium conditions in the form of the equalities between the pressures and temperatures of the components, the maximum entropy principle (or the free-energy minimum) for the mixture, and the equality of the velocities of the components. The conservation laws for the components allow for their interaction with each other in the form of forces and energy fluxes containing the differences of the velocities, pressures, and temperatures of the components. The form of momentum and energy exchange between each component and the continuum expressing the collective properties of the ensemble of components, is also considered. It is shown that these momentum and energy fluxes are different from zero only for the states of multicomponent media with velocity nonequilibrium.