Prediction of gas–liquid interface in oscillatory period

Abstract

A new theoretical expression was developed to predict the bubble shape under nonequilibrium conditions by considering damping and inertial forces. Nonequilibrium bubble formation may happen during the bubble departure and bubble oscillation and when shear stress between liquid and gas phases are relatively high. The new theoretical expression can be used to predict the bubble shape and variation of force and pressure across the liquid–gas interface along the perimeter. To enhance the accuracy of prediction of the new theoretical model, the bubble was divided into several parts, k (k = 1:N), and the new expression was solved separately for each individual part. The theoretical prediction was compared with experimental data, and a good agreement was observed. The new model can predict the fluctuation force across the liquid–gas interface along the perimeter of the bubble during the oscillatory period.