Cavitation phenomena generated by a lithotripter shock wave

Abstract

A focused electromagnetic acoustic transducer (EMAT) has been used to produce high-intensity shock waves in water. Schlieren imaging of the field has shown the complex structure of not only the main shock transient but also that associated with cavitation in the field. The primary source of cavitation is, as expected, due to the rupture and subsequent collapse of bubbles generated in the water by the main shock. The images give evidence for the interaction of these primary cavitation shocks with bubbles in the field. The collapse of some of these bubbles gives rise to additional or secondary cavitation shock transients which expand symmetrically. This appears not to be the case for the primary events and some bubbles, which look highly distorted.