Heat and mass transfer through a vapor film in view of the motion of liquid-vapor interface and the rise of temperature at the interface

Unsteady-state processes of heat and mass transfer in a vapor film formed during the interaction of a highly heated body with a cold liquid are investigated using a numerical solution of the kinetic Boltzmann equation. Two options of formulation of the problem are treated, which are more complex compared to those treated in the previous study, namely, (a) the liquid surface moves at a constant velocity, and the liquid temperature is constant; and (b) the liquid surface is stationary, and the liquid is heated (heat is transferred by heat conduction alone). It is demonstrated that, in analyzing various applications (for example, problems on the evolution of vapor cavities under conditions of film boiling), the state of vapor in the film may be taken to be quasi-steady-state; it may be described by steady-state kinetic relations for which the effect of mass flux may be ignored.