Irreversible Thermodynamics of a Fluid System with Spin

The linear irreversible processes occurring in a fluid system whose molecules possess internal angular momentum are completely classified by means of irreducible Cartesian tensors in terms of the symmetry properties of the local equilibrium state of the fluid. It is assumed that this local thermodynamic state is characterized by the specific internal angular momentum s as well as by the mass density ρ and the specific entropy S. Even with the resulting tensorial phenomenological coefficients, it is found, for example, that there can be no contribution to the heat flux from the velocity gradient.