Comparison of two configurations to improve heat and mass transfer in evaporating two-component liquid film flow

This paper deals with a numerical analysis of comparison of two configurations to improve heat and mass transfer by the evaporation of two-component liquid film in a vertical channel under mixed convection. The liquid mixture falling down on one plate of the channel consists of water and ethanol. Two configurations are considered in this study, the first one consists in applying a uniform heat flux density to the wetted wall while in the second case, the same quantity of heat, was used for preheating the liquid mixture at inlet. The model solves the coupled governing equations in both phases together with the boundary and interfacial conditions. The systems of equations obtained by using an implicit finite difference method are solved by Tridiagonal Matrix Algorithm. The main purpose of this study is to compare the heat and mass transfer in two studied configurations. The result shows that the configuration with preheated film at the inlet of channel is the best technique to obtain a significant average evaporated mass flux density.