Pressure distribution outside a single cavitation bubble
空化单气泡外围压强分布

Shape instabilities and diffusive instability are generally employed to investigate the stability of a single sonoluminescencing bubble, but the effect of the pressure outside a cavitation bubble is seldom studied. This paper particularly gives the pressure distribution outside a nonlinear resonance bubble by solving the Navier-Stokes equation outside the bubble. Numerical simulation shows that a negative pressure region appears in the vicinity of the bubble wall for those bubbles with a larger maximum radius, when the bubble is in its compressed phase, and which makes the bubble in the position of unstable equilibrium. We find that when the collapsing bubble approaches its minimum radius, a high pressure layer just outside the bubble is generated which gradually moves outward and subsequently forms a shock wave. Analysis indicates that the shock wave affects the measurement of the minimum radius of the bubble by Mie scattering; however, the effect is not dominant.