Steady drainage in emulsions: corrections for surface Plateau borders and a model for high aqueous volume fractionN. Péron, S.J. Cox, S. Hutzler and D. Weaire
School of Physics, Trinity College Dublin, Ireland
(Received 23 November 2006 / Received in final form 3 April 2007 / Published online 26 May 2007 )
We compare extensive experimental results for the gravity-driven steady drainage of oil-in-water emulsions with two theoretical predictions, both based on the assumption of Poiseuille flow. The first is from standard foam drainage theory, applicable at low aqueous volume fractions, for which a correction is derived to account for the effects of the confinement of the emulsion. The second arises from considering the permeability of a model porous medium consisting of solid sphere packings, applicable at higher aqueous volume fractions. We find quantitative agreement between experiment and the foam drainage theory at low aqueous volume fractions. At higher aqueous volume fractions, the reduced flow rate calculated from the permeability theory approaches the master curve of the experimental data. Our experimental data demonstrates the analogy between the problem of electrical flow and liquid flow through foams and emulsions.
47.57.Bc - Foams and emulsions.
82.70.Kj - Emulsions and suspensions.
47.61.Jd - Multiphase flows.
47.15.G- - Low-Reynolds-number (creeping) flows.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2007