Evaporation Mass Flux: A Predictive Model and Experiments

Evaporation is a fundamental and core phenomenon in a broad range of disciplines. Despite its importance, the current theories on evaporation suffer from fitting coefficients with reported values varying in a few orders of magnitude. Lack of a sound model impedes simulation and prediction of characteristics of many systems in these disciplines. Here, we studied evaporation at a planar liquid-vapor interface. Our experimental set-up provides the ability to probe thermodynamic properties in liquid-vapor interface. Through analysis of these properties in a wide range of evaporation mass fluxes, we cast a predictive model of evaporation based on non-equilibrium thermodynamics with no fitting parameters. In this model, only the interfacial temperature of liquid and vapor phases along with vapor pressure are needed to predict evaporation mass flux. The model was validated by reported study of an independent research group. The developed model provides a foundation for all liquid-vapor phase change studies.