Kinetics of intense evaporative mass transfer through a porous layer

A kinetic problem of mass transfer in a model porous body in the process of intense evaporation (condensation) and vapour escape into a vacuum is considered. Two computational methods have been used: the mean free path method and the method of direct statistical simulation. With the aid of the first method the location of the condensation zone within a porous body is determined as a function of the evaporating surface-to-porous layer temperature difference and also of the condensation coefficient. The second method is employed in a one-dimensional case to obtain (without condensation) the density, velocity and temperature distributions for a gas in a porous layer and in a gas medium behind the porous body. It is shown that the agreement between the parameters obtained by both methods for the gas flow escaping the porous layer is quite satisfactory