The Effects of Air Content on Unsteady Tip Vortex Cavitation

The phenomena of tip vortex cavitation (TVC) in unsteady incoming flows were studied experimentally in this paper. An elliptic hydrofoil with section NACA 66₂-415 was adopted as test model and high-speed video camera was employed to observe the tip vortex cavitation inception in the fixed foil with oscillation incoming flows. The effect of air content was considered in this investigation. The results show that the cavitation inception is delayed by the decrease of the non-dimensional frequency. The effect of air content in water is still very important in the case of unsteady tip vortex cavitation. The results indicate that the unsteady effect should be further considered in the scale effect study of TVC inception.