Start-up of an elastico-viscous liquid draining from a vertical surface

Abstract

The free drainage of thin films of non-Newtonian liquids from vertical surfaces occurs in a variety of industrial processes. Consideration is given in this paper to the effect of liquid elasticity on the much neglected “start-up” phase of the flow. The analysis utilizes the solution derived in 1970 by Waters and King for the generation of plane Poiseuille flow, to show that the presence of elasticity has a profound effect on the initial and the subsequent drainage profile.