Solution of the Wang-Chang-Uhlenbeck master equation

Nonequilibrium processes in a gas with internal degrees of freedom of molecules can be studied by using the generalized Boltzmann equation, the WangChang–Uhlenbeck equation, where the internal and translational degrees of freedom are considered in the framework of quantum and classical mechanics, respectively. For small deviations from local thermodynamic equilibrium, an asymptotic method developed for this equation yields hydrodynamic equations including the effect of the internal degrees of freedom on the viscosity and thermal conduction of the gas [1].