Cavitation Inception in Turbulent Flows Around a Hydrofoil

The phenomenon of cavitation inception around a hydrofoil is studied experimentally. The flow ve-locities around the foil are measured by a laser doppler velocimetry (LDV). The inception cavitation aspects are observed by using a high-speed video camera. In the experiment, the Reynolds number is fixed at a value of 7.0×10⁵. The boundary layer around the foil undergoes turbulent flow under the experiment condition. The LDV measurement results show that the flow in the boundary layer around the foil doesn't separate from the surface. It is found that the cavitation inception in non-separated turbulent flow is related to the coherent structures in the boundary layer. It is clear that the turbulent bursting and the hairpin-shaped vortex structure accompany the incipient cavitation.