Multibubble cavitation inception

Ida, Masato

The inception of cavitation in multibubble cases is studied numerically and theoretically to show that it is different from that in single-bubble cases in several aspects. By examining in detail the dynamics of interacting cavitation bubbles, we found that (a) a relatively large bubble can significantly decrease the cavitation threshold pressure of a nearby small bubble and (b) the explosive expansion of a bubble under negative pressure can be interrupted and turn into collapse even though the far-field liquid pressure well exceeds the bubble's threshold pressure. When we extended the discussion to systems of larger numbers of bubbles, we found that (c) a larger number of bubbles decrease the magnitude of the negative pressure of the surrounding liquid by a greater degree. The present findings would be useful in understanding the complex behavior of cavitation bubbles in practical applications where in general many cavitation nuclei exist and may interact with each other.