Quantitative Evaluation of Cavitation Erosion

Abstract

In order to evaluate the quantitative cavitation-erosion resistance of materials, a pressure-detector-installed specimen was developed, which can measure both the impact load produced by cavitation bubble collapse and the volume loss simultaneously. Test specimens (pressure-detection rod) used were nine kinds of metals and were exposed to vibratory cavitation. A linear relation was obtained for all materials between the accumulated impact energy ∑Fi2 calculated from the distribution of impact loads and the volume loss, independent of test conditions. Impact energy accumulated during the incubation period and the energy for a unit material removal in steady-state period were obtained from the relation. These values are very Important concerning quantitative erosion resistance evaluation. That is, when the distribution of impact loads is acquired for different cavitation conditions, the volume loss can be estimated. This idea was applied to the venturi cavitation erosion. The experimental results for venturi test corresponds well with the prediction using these impact energy values. It was concluded that the quantitative impact energy values of materials can be determined independent of the apparatus and the test condition by using the newly developed pressure-detector-installed specimen.