Author(s)

K. V. Meredith, A. Heather, J. de Vries & Y. Xin

Abstract

A model for simulating thin liquid film transport over solid surfaces has been developed. The film transport for mass continuity and momentumwere formulated as a two-dimensional set of equations using thin-film assumptions. These equations have been implemented in an open-source CFD code (OpenFOAM). Treatments for partial-wetting phenomena have been included in the model to account for the behavior near the contact-line. A surface-tangential force along the contact line has been developed to allow for the simulation of rivulets and dry patches in two-dimensional surface flow. An approach for applying contact angle effects to the model for a real stochastic surface is outlined. Additionally, experimental measurements were made for film flow over an inclined surface for a wide range of flow rates. Using these experimental results, the model has been validated for partially wetted flow over an inclined panel. The critical flow rate of a film over a given surface was used as validation for the model. Results show that for flow rates below the critical flow rate, the partially wetted behavior of the flow was reproduced. Comparisons to experimental flow patterns and wetted-area fractions were made. Keywords: thin-film assumption, partial wetting, contact line, critical flow rate. 1 Introduction The goal of this research was to develop a robust water-film transport model for use in simulating the partial wetting behavior of thin film flow in practical applications over realistic surfaces. To this extent, a thin film transport model has been developed in OpenFOAM®, an open source computational fluid dynamics (CFD) framework.

Keywords

thin-film assumption, partial wetting, contact line, critical flow rate