The life and fate of a bubble in a geometrically perturbed Hele-Shaw channel
| Autor: | Jack S. Keeler, Alice B. Thompson, Grégoire Le Lay, Anne Juel, Andrew L. Hazel, Grégoire Lemoult, Antoine Gaillard |
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| Přispěvatelé: | University of Manchester [Manchester], University of Warwick [Coventry], École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL), Laboratoire Ondes et Milieux Complexes (LOMC), Centre National de la Recherche Scientifique (CNRS)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Normandie Université (NU), Soft Matter (WZI, IoP, FNWI) |
| Rok vydání: | 2021 |
| Předmět: |
bubble dynamics
Physics Coalescence (physics) Plane (geometry) Mechanical Engineering Bubble Hele-Shaw flows Perturbation (astronomy) Mechanics Viscous liquid Condensed Matter Physics Breakup 01 natural sciences 010305 fluids & plasmas Volumetric flow rate Physics::Fluid Dynamics Mechanics of Materials 0103 physical sciences [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] Transient (oscillation) 010306 general physics |
| Zdroj: | Journal of Fluid Mechanics Journal of Fluid Mechanics, Cambridge University Press (CUP), 2020, Special JFM volume in celebration of the George K. Batchelor centenary, 914, pp.A34-1-A34-40. ⟨10.1017/jfm.2020.844⟩ Journal of Fluid Mechanics, 914:A34. Cambridge University Press |
| ISSN: | 1469-7645 0022-1120 |
| DOI: | 10.1017/jfm.2020.844 |
| Popis: | International audience; Motivated by the desire to understand complex transient behaviour in fluid flows, we study the dynamics of an air bubble driven by the steady motion of a suspending viscous fluid within a Hele-Shaw channel with a centred depth perturbation. Using both experiments and numerical simulations of a depth-averaged model, we investigate the evolution of an initially centred bubble of prescribed volume as a function of flow rate and initial shape. The experiments exhibit a rich variety of organised transient dynamics, involving bubble breakup as well as aggregation and coalescence of interacting neighbouring bubbles. The long-term outcome is either a single bubble or multiple separating bubbles, positioned along the channel in order of increasing velocity. Up to moderate flow rates, the life and fate of the bubble are reproducible and can be categorised by a small number of characteristic behaviours that occur in simply connected regions of the parameter plane. Increasing the flow rate leads to less reproducible time evolutions with increasing sensitivity to initial conditions and perturbations in the channel. Time-dependent numerical simulations that allow for breakup and coalescence are found to reproduce most of the dynamical behaviour observed experimentally, including enhanced sensitivity at high flow rate. An unusual feature of this system is that the set of steady and periodic solutions can change during temporal evolution because both the number of bubbles and their size distribution evolve due to breakup and coalescence events. Calculation of stable and unstable solutions in the single- and two-bubble cases reveals that the transient dynamics is orchestrated by weakly unstable solutions of the system that can appear and disappear as the number of bubbles changes. |
| Databáze: | OpenAIRE |
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