A numerical investigation on the drainage of a surfactant-modified water droplet in paraffin oil - Aix-Marseille Université
Article Dans Une Revue Advances in Colloid and Interface Science Année : 2015

A numerical investigation on the drainage of a surfactant-modified water droplet in paraffin oil

Résumé

A volume of fluid approach is used in numerical simulations of the settling motion of a surfactant modified water droplet in a continuous paraffin oil phase. The droplet is millimeter-sized and confined in a square two dimensional domain. The surfactant interfacial and bulk concentration-equations are solved together with the incompressible Navier-Stokes equation. The role of boundary walls in the overall settling dynamics is described. As the droplet moves downwards the interfacial shear creates non-homogeneous interfacial surfactant concentrations and Marangoni driven phenomena come into play. A decrease of the drainage velocity is then evidenced indicating that buoyancy forces are counter balanced by Marangoni induced lift-forces. The lateral migration of the droplet due to boundary wall proximity is discussed. It is shown to increase with wall proximity and to decrease when increasing the interfacial concentration. Finally, a simplified model is used to investigate the evolution of the bulk concentration assuming the surfactant is insoluble in paraffin oil and poorly soluble in water. (C) 2015 Elsevier B.V. All rights reserved.

Domaines

Matériaux
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Dates et versions

hal-01416720 , version 1 (14-12-2016)

Identifiants

Citer

Adil Lekhlifi, Abdelaziz Fanzar, Mickaël Antoni. A numerical investigation on the drainage of a surfactant-modified water droplet in paraffin oil. Advances in Colloid and Interface Science, 2015, 222, pp.446 - 460. ⟨10.1016/j.cis.2015.02.005⟩. ⟨hal-01416720⟩
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