DEPENDENCE OF HEAT EXCHANGE IN AN EVAPORATING LIQUID FILM IN A MICROCHANNEL ON HEATER SIZE

Heat exchange in a liquid film moving along the microchannel bottom is calculated using the developed three-dimensional steady-state model of the liquid film motion. The liquid moves under the action of a cocurrent gas flow in the channel, with a square heater located at its bottom. In this case, the action of all the main physical factors during their interaction is taken into account: diffusive/convective heat transfer, dependence of the liquid properties on temperature, thermocapillary effect, occurrence/growth of surface deformations, and evaporation/condensation of the liquid. It is revealed that heater size significantly affects temperature fields, surface deformations, and temperature extremes. An equation for calculating the greatest excess of mean temperature achieved on the substrate is derived.