Time-dependent motion of a confined bubble in a tube: transition between two steady states. (29th October 2018)

• Record Type: Journal Article
• Authors: Yu, Yingxian Estella; Zhu, Lailai; Shim, Suin; Eggers, Jens; Stone, Howard A.
• Is Part Of: Journal of fluid mechanics. Volume 857(2018)
• Publication Date: 2018-10-29
• Subjects: bubble dynamics, -- lubrication theory, -- thin films; Fluid mechanics -- Periodicals; 532.005
• DOI: 10.1017/jfm.2018.835
• Languages: English
• ISSNs: 0022-1120

Abstract

Abstract : When a confined bubble translates steadily in a cylindrical capillary tube, without the consideration of gravity effects, a uniform thin film of liquid separates the bubble surface and the tube wall. In this work, we investigate how this steady state is established by considering the transitional motion of the bubble as it adjusts its film thickness profile between two steady states, characterized by two different bubble speeds. During the transition, two uniform film regions coexist, separated by a step-like transitional region. The transitional motion also requires modification of the film solution near the rear of the bubble, which depends on the ratio of the two capillary numbers. These theoretical results are verified by experiments and numerical simulations.