A Peculiar Behavior of Cavitation-Nuclei-Size Distributions in Sample Water Under Vibratory Erosion Tests

In order to clarify the necessary conditions for cavitation-erosion tests with a vibratory apparatus, we carefully measure the cavitation-nuclei-size distributions and the relative air content rate of test water with respect to time by means of a Coulter counter and a van Slyke apparatus, respectively. It is found that the exponent of the distribution curve and the volume concentration of nuclei characterizing the nuclei-size distributions do not fluctuate with time during the equilibrium period, and that the relative air content rate first decreases monotonously with time and then reaches a definite equilibrium value after 40min which is longer than the 15min recommended by the ASTM.