Acoustical and optical tracking of the collapse of a laser-generated cavitation bubble near a solid boundary

A pulse from a Nd:YAG laser is used to generate a cavitation bubble near a plane solid boundary in deionised water. The different stages in the collapse of the bubble are followed using a high speed photographic technique involving sensitive Schlieren imaging and an ultra short pulse from a nitrogen laser pumped dye laser. The first collapse phase of the cavitation bubble is recorded with high spatial and temporal resolution. A thin film PVDF pressure transducer attached to the surface of the solid was used to study the development of the pressure on the surface during the bubble collapse and fluid flow was also directly observed. Both the optical and acoustical analysis techniques confirm the formation of a liquid jet and a shock wave which we believe are responsible for damage and erosion associated with cavitation near solid surfaces.