A Kinetic Model for Vapor-Liquid Flows

The evaporation of a liquid slab into vacuum is studied by numerical solutions of the Enskog-Vlasov equation for a fluid of spherical molecules interacting by Sutherland potential. The main aim of this work is to obtain the structure of the vapor-liquid interface in non-equilibrium conditions as well as the distribution function of evaporating molecules. The results show that the distribution function of molecules crossing a properly defined vapor-liquid boundary is almost Maxwellian and that the vapor phase is reasonably well described by the Boltzmann equation with diffusive boundary condition