Shear-Driven Liquid Film in a Duct

Abstract

Two-dimensional flow simulations of shear-driven thin liquid film by turbulent air flow in a duct is performed using the Reynolds Averaged Navier Stokes and continuity equations along with the Volume of Fluid (VOF) model that is part of the FLUENT-CFD code. The purpose of this study is to determine the suitability of using this code/model for predicting reported measurements of shear driven liquid film in a duct. Both a laminar and a turbulent flow models were examined for the liquid film flow region to assess their impact on film thickness and velocity. The Low Reynolds number k-ε turbulence model is utilized for simulating the turbulent air and film flow. Simulated results for the distributions of the air velocity, liquid film velocities along with the liquid film thickness as a function of inlet air and liquid film flow rates are presented. Simulated results show that the film thickness decreases but surface film velocity increases with increasing air flow rate; film thickness and surface film velocity increase with increasing film flow rate; the imposed laminar film flow model produces linear velocity distribution inside the film but the turbulence film flow model produces a nonlinear velocity distribution; the developing thin film influences significantly the air velocity distribution; and these results compare favorably with measured behavior.