(459g) Effect of the Wall Surface Texture Treatments On the Wetting Flows

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. Efficient control of these wetting flows is one of the key design factors for ensuring the performance of such devices. For the optimum design of packed columns widely used in these kinds of processes, it is very important to predict the detailed behavior of wetting flows in packing elements, such that the mass transfer between the gas and liquid may be enhanced and the flooding and channeling of the liquid flow may be prevented.

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 flow (which affects the variation trend of surface tension). Further study on the effect of texture geometry shows that the surface texture treatments added on the wall can improve the wetted area on the wall and mixing flow in the liquid film.