Kinetic simulation of the non-equilibrium effects at the liquid-vapor interface

Abstract

Phase change phenomena at microscale is important for novel cooling microsystems with intensive evaporation, so the development of reliable models and simulations are challenging. The vapor behaviors near its condensed phase are simulated using the non-linear S-model kinetic equation. The pressure and temperature jumps obtained numerically are in good agreement with the analytical expressions derived from the appropriate Onsager-Casimir reciprocity relations. The results of the evaporation flux are close to those given by the Hertz-Knudsen-Schrage formula, only when the values of the pressure and temperature at the upper boundary of the Knudsen layer are used. Comparison with recently measured temperature jumps are provided and disagreement with some experiments are discussed.