In convergent-divergent tunnel the erosion effects of cavitation on an aluminium hydrofoil of raf61 was studied. The images of the cavitation erosion on the hydrofoil were gained using SEM. The digital image processing technique was applied to direct measure the cavitation erosions by evaluating the damage on the hydrofoil’s surfaces. It detected the edge of the pits and statistical the values of pit-number, size and area etc. It’s more reliable to characterize cavitation intensity and lead to a better understanding of cavitation erosion phenomenon.
