The fluid mechanics of phase change

Abstract

The phenomena of evaporation and condensation are subject to the laws of fluid mechanics. While the usual continuum equations hold in the bulk of the vapour, the exchange processes near the interfaces have to be modelled more accurately by the laws of molecular dynamics. When an inert gas is present, the mass fluxes are diffusion-controlled and tend to be small; the fluxes are much greater in the kinetic-controlled pure vapour case. Strange phenomena, namely, jumps in the temperature and possible inversion in the temperature field, are predicted by the theory for the pure vapour case. While the jumps have been found experimentally, the whole phenomenon has yet to be fully understood and remains an interesting field for fluid mechanical investigations.