Slug Self-Propulsion in a Capillary Tube Mathematical Modeling and Numerical Simulation. (27th October 2016)

• Record Type: Journal Article
• Authors: Khodabocus, M. I.; Sellier, M.; Nock, V.
• Other Names: Leoncini Xavier Academic Editor.
• Is Part Of: Advances in mathematical physics. Volume 2016(2016)
• Publication Date: 2016-10-27
• Subjects: Mathematical physics -- Periodicals; Mathematical physics; Periodicals; 530.15
• DOI: 10.1155/2016/1234642
• Languages: English
• ISSNs: 1687-9120

Abstract

Abstract : A composite droplet made of two miscible fluids in a narrow tube generally moves under the action of capillarity until complete mixture is attained. This physical situation is analysed here on a combined theoretical and numerical analysis. The mathematical framework consists of the two-phase flow phase-field equation set, an advection-diffusion chemical concentration equation, and closure relationships relating the surface tensions to the chemical concentration. The numerical framework is composed of the COMSOL Laminar two-phase flow phase-field method coupled with an advection-diffusion chemical concentration equation. Through transient studies, we show that the penetrating length of the bidroplet system into the capillary tube is linear at early-time regime and exponential at late-time regime. Through parametric studies, we show that the rate of penetration of the bidroplet system into the capillary tube is proportional to a time-dependent exponential function. We also show that this speed obeys the Poiseuille law at the early-time regime. A series of position, speed-versus-property graphs are included to support the analysis. Finally, the overall results are contrasted with available experimental data, grouped together to settle a general mathematical description of the phenomenon, and explained and concluded on this basis.