Siberian Federal University

The relations for the fields of temperature, concentration, speeds and pressure at the interface of two regions occupied by a liquid and gas phases are derived from the conservation laws. The substance of a liquid can evaporate (condense) and the vapor is transferred in the gas phase as an impurity. The obtained conditions differ from the conditions traditionally used because the additional terms appear in the equations of forces balance and energy streams balance. These additional terms are responsible for the physical phenomena at interface such as dynamic influence on a liquid of evaporating (condensed) substance, the waste of energy on deformation of the boundary, on overcoming of the surface tension etc. Usually these terms are neglected, but it is not always correct. As an example the problem of evaporation of a spherical layer of a liquid is considered. The calculations are carried out. It should be noted that the additional terms in some conditions can play a significant role at calculation of the process parameters.