Passage of a gas bubble through a liquid-liquid interface

The present study aims at investigating the passage of a gas bubble at a plan liquid-liquid interface both experimentally by using a high-speed video camera and numerically through the volume-of-fluid (VOF) approach. A Newtonian silicone oil was used for the light phase while two different liquids, a Newtonian Emkarox (HV45) solution and a non-Newtonian poly(acryl amide) (PAAm) solution, were employed as the heavy phase. The passage of a gas bubble, generated from a submerged orifice, was followed during its rise in each liquid phase and in particular at the liquid-liquid interface. The original curve of the bubble's position vs time gave interesting insight into the dynamic behavior of the interface. Experimental results show the effect of the bubble size as well as the rheological properties of the heavy phase on the bubble's retention time at the liquid-liquid interface. The preliminary numerical results obtained by the VOF approach are in qualitative agreement with the experimental data.