Numerical study on the gravity-capillary bubble jet

Abstract

A gravity-capillary bubble jet is calculated by numerically with an axisymmetric Boundary Element Method (BEM). The bubble jet means a rising of a free surface induced by the growth and collapse of an oscillating bubble under the free surface. Based on the assumption of inviscid, incompressible, and irrotational fluid flow, the Laplace equation is used as the governing equation. In previous researches, the dynamic behavior of a bubble is main focus. Here, calculating the motion of the free surface, which occurs after the bubble removed in the numerical model, is main focus. The motion and shape of the bubble is verified by a theoretical approach and an experimental result. Assuming that the bubble size is small, the surface tension is considered. Two kinds of bubbles, a vapor bubble and a gas bubble, are used here. The results of the calculation are verified through theory and experiment. The relationship between the initial position of the bubble and the bubble jet was examined.