Influence of a Side Walls on Dryout of Falling Liquid Film Flowing Down on a Plate

Abstract

A theoretical and experimental study was conducted to investigate the influence of side wall on the dryout of liquid film flowing on an inclined plate. The film surface forms a meniscus having a minimum thickness near the side wall. The thin film causes the decline of dynamic pressure of flow and the dryout may happen at higher flow rate. In this study, the meniscus profile near the side wall was theoretically analyzed from the energy minimum principle under the condition of force balance between gravitational and viscous forces. Here we considered the system energy contributed from the work related to wetting behavior, the work resulted from the increase of gas-liquid interfacial area, the kinetic energy of film flow, as well as the liquid potential energy. The calculated results of meniscus radius and minimum film thickness roughly agree with the results of experimental measurement and CFD.