Effect of simple shear on liquid drainage within foams
- 29 June 2006
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review E
- Vol. 73 (6), 061408
- https://doi.org/10.1103/physreve.73.061408
Abstract
This paper examines the impact of shear on the drainage of liquid through a foam. The effect on drainage of changes in the Plateau border network brought about by shear is examined. This effect of shear was modeled using both a detailed three-dimensional simulation of foam structure, and an idealized two-dimensional hexagonal foam. The main phenomenon that has been discovered is that shear induces an anisotropy in the drainage of liquid through the foam. If the foam is strained and liquid flows under gravity either perpendicular or parallel to the shear direction, a net liquid flow in the direction perpendicular to the direction of gravity is induced. It was found that the degree of anisotropy increases nearly linearly with increasing strain until the foam yields, after which the degree of flow anisotropy remains roughly constant. This is not a small effect, with the flow in the direction perpendicular to gravity being up to about 20% of the flow in the direction of gravity at the yield strain. This shear-induced anisotropy provides a potential explanation for the hitherto puzzling phenomenon of the convective roll in foam. The other two effects examined are the effect of shear on the length of Plateau borders per volume of foam, which increases as strain increases, and the resistance of the foam to flow in the direction of gravity, which increases if the strain direction is perpendicular to gravity, but decreases if the strain is parallel to gravity.Keywords
This publication has 15 references indexed in Scilit:
- Elastic dilatancy in wet foams: A simple modelColloids and Surfaces A: Physicochemical and Engineering Aspects, 2005
- Dilatancy in liquid foamsPhilosophical Magazine, 2003
- Structure of random monodisperse foamPhysical Review E, 2003
- Dynamics of yielding observed in a three-dimensional aqueous dry foamPhysical Review E, 2003
- Simple shearing flow of dry soap foams with tetrahedrally close-packed structureJournal of Rheology, 2000
- The Surface Evolver and the stability of liquid surfacesPhilosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 1996
- The foam drainage equationJournal of Physics: Condensed Matter, 1996
- Rheology of foams and highly concentrated emulsionsJournal of Colloid and Interface Science, 1986
- Rheology of foams and highly concentrated emulsionsJournal of Colloid and Interface Science, 1983
- A study of interstitial liquid flow in foam. Part I. Theoretical model and application to foam fractionationAIChE Journal, 1965