Cavitation Erosion Prediction From Inferred Forces Using Material Resistance Data

Abstract

To improve cavitation erosion prediction based on induced vibrations, some experimental work has been carried out on two different materials, a stainless steel and a protective coating. First, the erosive characteristics of the materials have been analyzed in a cavitating vortex generator. Pit counting results have been correlated to inferred force intensities occurring on the eroded area from measured vibrations considering the transmissibility from the excitation location to the measuring position. The relationship between the pit area and the force intensity has been calculated. To validate these results, the same materials have been tested in a hydrodynamic tunnel where the force intensities have been inferred in the same way. Then, the eroded area has been calculated using the erosion characteristics previously determined. The results obtained compare well with with the actual erosion measured on the tunnel specimens. Next step is to apply this method to hydraulic machines.