Flow Transition Behavior of the Wetting Flow Between the Film Flow and Rivulet Flow on an Inclined Wall

Abstract

Gas-liquid two-phase interfacial flows, such as the liquid film flows (also known as wetting flows on walls), are observed in many industrial processes including absorption, desorption, distillation, and so on. The present study focuses on the characteristics of wetting flows, in particular the drastic transition between the film flow and rivulet flow, as the liquid flow rate and the wall surface texture treatments are varied. The three-dimensional gas-liquid two-phase interfacial flow (wetting flow) simulation is based on the volume of fluid (VOF) model. As the liquid flow rate is increased and then decreased, a hysteresis of the transition between the film flow and rivulet flow is discovered, which implies that the transition phenomenon depends primarily on the history of the change of interfacial surface shape (which affects the process of the flow pattern transition). The applicability and accuracy of the present numerical simulation is validated by using the existing experimental and theoretical studies. Further study on the effect of texture geometry shows that the surface texture treatments added on the wall can impede liquid channeling and increase the wetted area.