水中气泡溃灭的理论与数值研究

Theoretical and numerical studies on the bubble collapse in water

从理论和数值两个方面研究了单个气泡在自由流场中的溃灭。采用Rayleigh方程推导出一个新的球形气泡演变的解析解。基于流体体积法(VOF),在考虑表面张力、粘度和可压缩性效应的情况下,对单个纯气体泡的运动进行了三维模拟。在第一次溃灭阶段,气泡体积演变的数值结果与解析解保持一致。数值结果表明气泡体积到达最小值后开始回弹,气泡的形状、速度场和压力场在回弹点附近发生剧烈变化。

The collapse of a bubble in free flow field has been investigated theoretically and numerically.The Rayleigh equation is adopted to derive a new analytical solution of the evolution of a spherical bubble.A three-dimensional simulation of the behavior of a gas-filled bubble based on the Volume of Fluid（VOF） method is also performed,considering the effects of surface tension,viscosity and gas compressibility.The numerical result of the volume evolution of the bubble is in good agreement with the analytical solution during its first-stage collapse.Numerical results also show that the volume of the gas-filled bubble reaches its minimum value and then rebounds.Dramatic changes of bubble shape,field velocity and pressure occur in the vicinity of the turning point.