The movement and shape change characteristics of a bubble passing through a liquid-liquid interface

Abstract

In order to study the movement and shape change characteristic of bubble when passing through the interface of two kinds of liquids with different viscosity, the free rising process of a single bubble in static stratified liquids was numerically simulated with the volume-of-fluid method. The results show that, when the initial height of bubble rising is the same, the rising velocity, deformation increase with the increase of bubble radius. When the maximum intensity of the vortex in the bubble is distributed at the top of the bubble, the top of the left and right sides and the bottom of the left and right sides, the bubble shape is spherical, ellipsoid and spherical cap shape respectively. At different initial heights, the bubble trajectory shows three different shapes ? linear, spiral, and C-shaped. The relation-ship between the bubble aspect ratio and rising height is predicted when different radius bubble passing through the interface. The amount of liquid B (lower layer) carried by the bubble increases with the increase of the bubble?s initial radius, and the amount of liquid carried by bubbles in C-shaped trajectory is higher than that in spiral trajectory.