GRAVITY EFFECT ON EVAPORATION AND INTERFACIAL DEFORMATIONS IN NONISOTHERMAL LIQUID FILM MOVED BY A GAS FLOWIN A MICROGAP

In the present paper, we investigate evaporating locally heated thin liquid film driven by the action of gas flow in a microgap. A two-sided three-dimensional mathematical model is used. For a deformable gas-liquid interface, convection heat transfer in the liquid and the gas phases as well as temperature dependence of surface tension and liquid viscosity are taken into account. Interaction and balancing of different effects on the evaporation process along the gas-liquid interface takes place. The influences of gravity force, the gas flow rate, and heating intensity on the evaporation rate and gas-liquid interface deformations have been investigated numerically using the developed model. It is shown that evaporation is governed substantially by the gravity and the relation is strongly nonlinear, which could be explained by smoothing of deformations at the gas-liquid interface with gravity changing. The qualitatively different effect of gas velocity on the evaporation rate has been found, depending on the thermal boundary condition on the heated substrate.