Kinetic theoretical studies of the half-space problem of evaporation and condensation

This article is the combination of a review and some new results of kinetic theoretical studies on the half-space problem of evaporation and condensat ion. A semi-infinite expanse of a gas uniform at infinity and bounded by it s plane condensed phase is considered. Steady flow, evaporating from or con densing onto the condensed phase depending on the parameters of the condens ed phase and the infinity, and the relation among the parameters that allow s a steady solution are studied. Special attention is paid to the differenc e of the character of the relation, depending on evaporation, subsonic cond ensation, or supersonic condensation. and analytic structure of the transit ion of the relation and solution from evaporation to subsonic condensation or from subsonic condensation to supersonic one.