Evaporation of a thin binary liquid film covering one plate of a vertical Channel

Abstract

The present work is a numerical study of the heat and mass transfer in a vertical channel with isothermal plates. The first plate is covered with an extremely thin binary film of water and ethylene glycol. The second one is dry. Due to the heating effects and the forced (mixed) convection flow of air containing the respective vapors of film constituents, phase change can occur. The mathematical formulation of the problem is based on the conservation equations of mass, momentum, energy and species subjected to the appropriate boundary conditions. The variability of the thermo physical properties of the liquid and the gas mixtures as well as the effect of the buoyancy forces in the momentum equations were taken into account. A numerical model using the finite difference method was developed and tested systematically. A detailed parametric analysis on the effects of several operating variables such as the temperatures of the plates and the inlet conditions of the gas mixture on the phase change process and on the heat and mass transfers was conducted.