Negative Verification of the Inverted Temperature Profile in Condensation. Application of New Boundary Conditions Based on Molecular Dynamics Study.

The direct simulation Monte Carlo (DSMC) method is used to examine the inverted temperature profile in condensation. In order to analyze the temperature jump at a liquid-vapor interface, new boundary conditions obtained by the molecular dynamics study are applied for one dimensional condensing flow of argon. Here, condensation/evaporation coefficient is considered to be a function of surface-normal component of kinetic energy of molecules, and the velocity distributions for evaporated and reflected molecules are given by modified Maxwellian using the condensation/evaporation coefficient. The results show that the temperature decreases gradually as approaching the condensing surface and that the inverted temperature profile disappears for the new boundary conditions. It is also found that the dependence of condensation/evaporation coefficient on kinetic energy plays an important role in the temperature profiles in the vicinity of condensing surface.