Assessment of the statistical rate theory expression for evaporation mass flux

Abstract

A series of 72 steady-state evaporation experiments in which water evaporated from a spherical liquid-vapor interface have been conducted. In each experiment, the interfacial temperatures, the temperature profile across the liquid-vapor interface, and the pressure in the vapor phase were measured. When the interfacial parameters were used in the statistical rate theory (SRT) expression for evaporation flux, the vapor-phase pressure could be predicted to a reasonable degree of accuracy in all experiments. In all 72 experiments, the interfacial temperature of the vapor was always higher than that of the liquid phase and in certain cases, the difference was measured to be 7.1 K. Measurement of the vapor-phase pressure near the cool liquid-vapor interface and far from the interface did not show a significant difference, indicating that the density (concentration) in the bulk vapor phase may not be uniform.