Laminar Film Condensation of Gravity-Controlled Convection for Ternary Vapor Mixtures on a Vertical Flat Plate

Laminar film condensation of gravity-controlled convection for ternary vapor mixtures is theoretically treated. Similarity solutions for methanol-ethanol-water mixtures on an isothermal vertical flat plate are numerically obtained. The effects of mutual intervention of buoyant forces due to temperature and concentration differences on convective heat and mass transfer in the vapor boundary layer are revealed. The dimensionless expressions for heat and mass-transfer coefficients are derived from the numerical results. These expressions approach the characteristics of simultaneous heat and mass transfer in free convection of ternary vapor mixtures with the decrease in condensate mass flux. Heat and mass-transfer characteristics are calculated from the simultaneous algebraic equations which are composed of these expressions, phase equilibrium conditions and the continuity conditions of heat flux and mass transfer at a vapor-liquid interface.