Theoretical and numerical studies on the bubble collapse in water

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.