Towards quantitative assessment of material resistance to cavitation erosion

The progress in developing a new method of assessing material resistance to cavitation erosion is reported. The method proposed incorporates procedures for determining cavitation impingement structure, superposing erosive effects of various cavitation impingement fractions and determining the set of parameters needed to describe material performance under cavitation load of given amplitude distribution. The experimental techniques applied and results obtained in the process of validating and developing the method are presented. At the moment, the Sitnik model of erosion progress under uniform cavitation impingement seems especially well suited for further work on erosion modeling. No evidence of cavitation macropulses due to collective phenomena acting simultaneously on a major part of a specimen has been identified in the IMP PAN cavitation tunnel. It is shown that cavitation pulses distribution can be approximated by means of a power-exponential distribution. The mean erosion rates of PA2 aluminium alloy and E04 Armco iron have been found almost proportional to the ME cavitation intensity index even after a test of 10 h duration.