Numerical Simulations of Bubble Growth and Detachment in Microgravity and Normal Gravity Shear Flows

Abstract

The three-dimensional level set method is used to simulate the experiments for bubble growth and detachment in a shear flow under microgravity and normal gravity conditions by Misawa et al. The gas flow inside the opening is solved in addition to the main liquid shear flow to consider the deformation of interface induced by the interaction between the gas flow and the liquid shear flow. The numerical simulations are quantitatively in good agreement with the experiments. It is shown that the stronger the gravity acceleration becomes, the more easily bubble detachment occurrs. It is also shown that the initiation of constriction of the bubble surface is significantly affected by the interaction between the gas flow and the shear flow; the liquid shear separates the interface from the edge of the opening and the liquid flow into the opening induces a reduction of the gas flow area, which results in early constriction of the interface and subsequent bubble detachment.