Interfacial evaporation of falling liquid films with wall heating

The interfacial evaporation of falling water films with wall heating was experimentally studied and analyzed. The results presented in this paper showed that the capillary-induced interfacial evaporation played an important role in heat transfer of a falling liquid film. It would be independent of the wall heat flux and somewhat lower than that without wall heating for impure fluids such as water-air system. The thermodynamic analysis conducted gave a theoretical basis for the experimental observations. The effective capillary radius was correlated with the mass flow rate. The experimental results and analysis showed that the interfacial evaporation should be taken into account in the study of falling liquid film heat transfer.