New method for monitoring and correlating cavitation noise to erosion capability

Individual cavitation pressure pulses are monitored by measuring peak pulse amplitudes in a cavitating venturi, in order to obtain a correlation between cavitation noise and damage, using a pressure bar probe. Acoustic power derived from the pulse height spectra was found to vary with the nth power of venturi throat velocity, for n in the 6.8-10.5 range, the major component in the variation being the number of collapsing bubbles. Acoustic power has also been found to correlate linearly, with a small threshold, with the cavitation damage rate of an aluminum alloy. The feasibility of using cavitation erosion efficiency, or ratio between acoustic and erosion powers, in predicting eventual cavitation erosion rates in various geometries is investigated.