Eur. Phys. J. E (2006) 20: 317-325
https://doi.org/10.1140/epje/i2005-10131-6

Regular Article

Air bubbles under vertical vibrations

¹ LML, Université de Lille 1, UMR 8107 CNRS, Bd Paul Langevin, F-59655, Villeneuve d'Ascq, France
² Institut de Physique B5, GRASP - Université de Liège, B-4000, Liège, Belgium
³ PMMH, École Supérieure de Physique et Chimie Industrielles (ESPCI), UMR 7636 CNRS, 10 rue Vauquelin, F-75231, Paris Cedex 05, France

^* e-mail: Farzam.Zoueshtiagh@univ-lille1.fr
^** e-mail: herve.caps@ulg.ac.be

Received: 14 November 2005
Accepted: 4 July 2006
Published online: 28 July 2006

Abstract

This paper reports on an experimental study of the splitting instability of an air bubble a few centimetres in diameter placed in a sealed cylindrical cell filled with liquid and submitted to vertical oscillations. The response of the bubble to the oscillations is observed with a high-speed video camera. It is found that the bubble dynamics is closely associated with the acceleration of the cell Γ. For small acceleration values, the bubble undergoes minor shape deformations. With increasing acceleration values, these deformations are amplified and for sufficiently large Γ the bubble becomes toroidal. The bubble may then become unstable and split into smaller parts. The onset of bubble division is studied and its dependency on physical parameters such as the fluid viscosity, the fluid surface tension and the initial size of the bubble is presented. It is found that the criterion for the bubble splitting process is associated with a threshold based on the acceleration of the oscillations. Above this threshold, the number of bubbles present in the cell is observed to grow until a final steady state is reached. Data analysis reveals that the final bubble size may be characterized in terms of Bond number.