Contribution of Cavitation Generation to Shock Wave Sterilization Effects in a Narrow Water Chamber
The paper reports on the generation mechanism of cavitation bubbles in a narrow water chamber and the sterilization effects of these cavitation bubbles on marine bacteria. Underwater shock waves are generated by electric discharge. Propagation behaviors of the waves in the water chamber are investigated using an optical method. On the other hand, a bio-experiment with marine bacteria is also carried out to examine sterilization effects. It is found that the shear wave is produced in the wall material of the water chamber by the energy release of underwater electric discharge and results in the tensile stress arising in the water, and thereby cavitation bubbles are induced with the propagation of the shear wave. From the results of the bio-experiments, we confirm a high sterilization effect of the cavitation bubbles.
A part of this work was supported by JSPS KAKENHI Grant Number 16H04600 and 16 K14512. We also would like to sincerely thank Nac Image Technology Inc. for the supply of high-speed camera, i-SPEED 7.