多气泡耦合作用下非球状特性数值研究

Numerical study on non-spherical bubble dynamics in multiple-bubble interactions

为了研究多个气泡相互耦合作用时其表现出的运动特性,采用基于势流理论的边界元方法对多气泡间耦合作用进行数值模拟。将数值解与Rayleigh-Plesset方程解析解对比,使得数值模型的有效性和收敛性得以验证;然后,建立3个气泡的数值模型,研究无量纲参数气泡间距d对气泡运动和形态的影响。等间距布置3个气泡,当d=1.8时,中间的气泡在抑制作用下呈现"圆柱状",随着气泡间距的增大,其最终趋于"球形",且气泡上、下2个气泡射流速度增大;不等间距布置3个气泡,距离远的气泡最先发生射流,射流完成时该气泡已开始回弹。

To study the complex bubble dynamic behaviors in multiple？bubble interactions, the boundary element method （ BEM ） based on the potential flow theory was adopted to perform numerical simulation of the coupling effect among multiple bubbles. Firstly, both the validity and convergence of the numerical model were confirmed by comparison between numerical results and the analytical solution derived from Rayleigh？Plesset equation. Next, the numerical model of three bubbles was established to study the effect of the dimensionless parameter？inter？bubble distance d on the bubble motion and shape. In the cases with identical inter？bubble distance, the bubble in the mid？dle assumes a cylinder？like shape when d=1.8, and it tends to be a sphere with the increase of d , besides the in？crease of the jet velocity of upper and lower bubbles;in the cases with different inter？bubble distances, the farther bubble forms jet earliest and it starts to rebound before the jet impact.