Jumps in the density and temperature of one of the components of a binary gas mixture over the plane surface of a liquid

Abstract

We consider a problem concerning the vaporization (or condensation) of one of the components of a binary gas mixture situated over the plane surface of a liquid. The kinetic equation in the model form of [1] is used to describe the system. As is well known, this model agrees well with experiment and is simpler than the Boltzmann equation so far as mathematical relations are concerned. This model fails to describe a number of effects because it is assumed that the collision time of the particles is independent of their velocity. This relates primarily to the phenomenon of thermal diffusion of the gases. Thus the formulas given below are applicable to gas mixtures having a small thermal-diffusion coefficient. The model equation is solved by an approximate method developed in [2]. In [3] the temperature jump of a single-component gas at a solid wall is calculated by this method, and the method is also employed in [4] in the calculation of the slipping rate of a binary gas mixture in the field of a temperature gradient. In both cases the results agree with numerical calculations by other authors within an accuracy of 1.5%.