多泡相互作用对气泡溃灭的影响

INVESTIGATION OF BUBBLE-BUBBLE INTERACTION EFFECT DURING THE COLLAPSE OF MULTI-BUBBLE SYSTEM

通过直接数值模拟方法对多泡在压力驱动下的溃灭过程进行了研究.气相满足理想气体正压模型,液相为不可压流体,采用基于压力的方法求解多泡的两相流场.数值研究表明,在多泡流场中,中心气泡的溃灭过程明显不同于单泡,存在总体溃灭延迟现象和后期加速现象.随着周围气泡数的增多或气泡间距的减小,中心气泡的溃灭时间增长,溃灭时的压力峰值增大.结合理论定性分析发现,气泡运动不仅受远场压力的驱动,还受周围气泡诱导压力场的影响.周围气泡的诱导压力经历先减小后增大的过程,从而使受其影响的中心气泡产生先延迟后加速的特征.

The collapse stage of 3D bubbles in higher surrounding pressure is studied using direct numerical simulation based on the volume of fluid （VOF） method. The numerical results show that the collapse of central bubble in multi- bubble system is different from single bubble collapse significantly, which contains delay stage and acceleration stage. Increasing the number of neighboring bubbles or decreasing the distance between bubbles leads to a longer collapse time and a higher pressure peak of central bubble. According to theoretical analysis, the bubble＇s radial motion is driven not only by the liquid pressure in the far field but also by the pressures emitted from the neighboring bubbles. The pressures from the neighboring bubbles first decrease and then increase. This leads to the delay and acceleration characteristics of central bubbles.