Gas Flow and Thermocapillary Effects on Fluid Flow Dynamics in a Horizontal Layer

The study of convective processes caused by impact of various forces on the fluid and gas media is actual nowadays. The increased interest to these problems is determined by preparation of the new experiments on the International Space Station in the frame of the scientific project CIMEX of the European Space Agency. They are the experiments to investigate the convective flows of the fluids with a thermocapillary interface between liquid and gas phases. In the case, when a co-current gas flux generates the tangential stresses on a free boundary the additional characteristics of the convective flows should be detected. In this paper the exact solutions of a stationary problems of convection and of gas flow in the horizontal layers with a free thermocapillary interface are constructed. An evaporation through the fluid-gas flow interface is modeled qualitatively with the help of a heat exchange condition. It is determined that the velocity on the fluid-gas interface can be positive and negative. The equal-zero condition for the interface velocity is found, as well. In the experiments an open horizontal fluid layer is studied so that the closed flux condition is not needed. Although the closed flux requirement is not set explicitly a parameters relation is found, when this condition is fulfilled. The paper presents the velocity and temperature profiles in the conditions, which correspond qualitatively to the CIMEX experiment.