Experimental investigations of cavitation bubble collapse by a water shock tube

This paper deals experimentally with the mechanism of an impulsive pressure generated by a collapsing bubble. In a water filled shock tube, an expansion wave and a subsequent compression wave are applied to single, twin, and triadic bubbles. The growth, collapse, and rebound of bubbles situated at various distances from a solid boundary are observed by means of high-speed photography and in-line Fraunhofer holography using a pulsed dye laser. The results indicate that the impulsive pressure is caused by a shock wave radiated at the instant of the rebound of a collapsing bubble, and that the subsequent jet impingement does not produce any detectable effects. The pressure pulse is found to be of the order 10,000 to 100,000 atm, and its duration 2 to 3 microsec.