Film drainage of viscous liquid on top of bare bubble: Influence of the Bond number

Helena Kocarkova (1) , Florence Rouyer (2, 3) , Franck Pigeonneau (1)

1 SVI - Surface du Verre et Interfaces
2 LPMDI - Laboratoire de Physique des Matériaux Divisés et des Interfaces
3 Rhéophysique

We present experimental results of film drainage on top of gas bubbles pushed by gravity towards the free surface of highly viscous Newtonian liquid with a uniform interface tension. The temporal evolution of the thickness of the film between a single bubble and the air/liquid interface is investigated via interference method. Experiments under various physical conditions (range of viscosities and surface tension of the liquid, and bubble sizes) evidence the influence of the deformation of the thin film on the thinning rate and confirm the slow down of film drainage with Bond number as previously reported by numerical work of Pigeonneau and Sellier [Phys. Fluids 23, 092102 (2011)]. Considering the liquid flow in the cap squeezed by buoyancy force of the bubble, we provide an approximation of thinning rate as a function of Bond number that agrees with experimental and numerical data. Qualitatively, the smaller the area of the thin film compare to the surface of the bubble, the faster the drainage.

Mots clés: bubbles; buoyancy; film flow; liquid films; surface tension; thin films; two-phase flow; viscosity

Domaines: Dynamique des Fluides [physics.flu-dyn]

Helena Kocarkova, Florence Rouyer, Franck Pigeonneau. Film drainage of viscous liquid on top of bare bubble: Influence of the Bond number. Physics of Fluid, 2013, 25 (022105), pp.1. ⟨10.1063/1.4792310⟩. ⟨hal-00795487⟩