A Photographic Study of the Dynamics and Damage Capabilities of Bubbles Collapsing Near Solid Boundaries

Abstract

The effect of proximal rigid boundaries on the motion and damage capabilities of spark bubbles is investigated by means of a qualitative photographic study. It is determined that an axially symmetric bubble collapsing nonhemispherically against a solid boundary can form a liquid jet which impinges against the solid boundary, but the jet has little or no damage capability. Observations of the toroidal minimum volume and associated damage to the boundary in the form of circular dents on indium indicate a pressure pulse damage mechanism.