Evaporation Heat Transfer in Thin-Film Region With Bulk Vapor Flow Effect

Abstract

An extra high evaporating heat transfer coefficient can be obtained by thin-film evaporation. In the current investigation, a new detailed mathematical model is developed by considering the effects of bulk flow and interfacial thermal resistance on fluid flow and heat transfer in the thin-film region of an evaporating meniscus. In addition to the interfacial thermal resistance occurring at the liquid–vapor interface, the pressure difference between liquid and vapor is considered to the bulk flow effect. The results show that the bulk flow, which depends on the pressure difference between the interfacial pressure and vapor pressure, significantly affects thin-film profile, heat flux distribution, interfacial temperature, meniscus radius, mass flow rate, and average flow velocity in the evaporating thin-film region. While the interfacial thermal resistance occurring at the liquid–vapor interface affects fluid flow and heat transfer in the evaporating thin-film region, the bulk flow effect is more important than the interfacial thermal resistance.