Draining of films on a quasivertical plate using viscous dissipation

Abstract

This work focused on obtaining an improved and expanded general theoretical analysis of a two-dimensional film draining on a quasi-vertical plate, solving rigorous mass, momentum, and energy balances. A dimensional analysis and scaling was used to simplify the mathematical description and a generalized Newtonian fluid was assumed as the film-forming material. A new quantity that governs the draining flow and film characteristics, called viscous dissipation, was proposed as part of the novel analytical expressions obtained in this work. Velocity profile, average velocity, flow rate, and local and average film thickness expressions can be obtained, allowing to simplify the overall calculation complexity and to find new potential analytical expressions using more complex rheological models.