Cavitation Characteristics of Ultrapure Water (Behavior of Cavitation Nuclei in Vibratory Erosion Tests)

In order to establish the necessary conditions for cavitation tests using ultrapure water, relative air content rates, cavitation noises and bubbles rising from a vibratory cavitation test apparatus are carefully measured with respect to time. The bubble diameters are measured by the ascending velocities of the bubbles using an LDV. It is note worthy that the relative air content rates of ultrapure water are considerably scattered and the bubbles induced by vibration are smaller than those of tap and still water. The bubble sizes are comparable to the size of cavitation nuclei. The cavitation noises are always changing with time, especially the number of high amplitude acoustic pulses, however, there is no effect on water quality in the changes with time.