Collapse Dynamics of Hemispherical Cavitation Bubble in Contact with a Solid Boundary

The dynamics of electrochemically produced hemispherical bubble at solid-liquid interface is investigated experimentally. Time-resolved photography is applied to measure the position of bubble wall as a function of time. By means of stroboscope schlieren photography with 1 mu s exposure time it is shown that the development of instabilities of the bubble shape are general feature of the bubble dynamics in contact with the solid boundaries. The acoustic transients emitted after cavitation bubble collapse were registered with the laser beam deflection technique. Duration of the transient of 50-60 ns enables to estimate maximum pressure as 2.5 kbar, when the maximum bubble radius is 1 mm.