Determination of mass transfer coefficient for condensation simulation

Abstract

Mass transfer calculation through vapor-liquid interface is the most important key issue for condensation simulation. However, it is a challenge to determine the coefficient of mass transfer model and the uncertain coefficient leads to unclear physics of the calculated results. Up to now, the coefficient is generally chosen based on numerical trial and errors or empirical parameters. A new mass transfer model for condensation is proposed. And a calculation method for the coefficient in this model is derived, which correlates the coefficients with the measurable interfacial temperature difference. The simulation results of the proposed model agree well with the theoretical results of Nusselt theory for laminar film condensation. The convergence analysis of the proposed model illustrates the mechanism that smaller coefficient causes serious deviations between the calculated interfacial temperature and the saturated temperature, while overlarge coefficient causes convergence difficulties. The convergence analysis is also applicable to the Lee model and the Schrage model.