Effect of nuclei concentration on cavitation cluster dynamics.

Cavitation cluster dynamics after the passage of a single pressure wave is studied for different concentrations of artificial cavitation nuclei (30 to 3x10(5) nuclei/ml). With increasing concentration of cavitation nuclei the lifetime of the cavitation cluster is prolonged. Additionally, it is found that the spatial extent of the cluster decreases with higher nuclei concentration. The experimental data for concentrations less than 400 nuclei/ml are compared to simulations with a Rayleigh-Plesset-type equation, taking into account bubble-bubble interaction. For higher concentrations (more than 1000 nuclei/ml) the observed radial cluster dynamics is compared with calculations from an axisymmetric cavity-collapse model.