Cavitation bubble dynamics — new tools for an intricate problem

Abstract

With the help of laser produced bubbles in water and high speed photography and holography sophisticated experiments on cavitation bubble dynamics can be conducted. The observation of a bubble vortex ring after jet formation upon collapse of a spherical bubble in front of a plane solid boundary is reported. The vortex ring may expand and contract several times until it disintegrates into a ring of bubbles by some instability finally taking over. A critical discussion of our qualitative understanding of jet formation is included. In a second part the problem of the acoustic cavitation noise spectrum is discussed. Numerically obtained ‘visible cavitation noise’ plots from a single bubble already resemble those obtained experimentally from acoustic cavitation. A discussion shows that the theory should be extended to self-consistency.