Sheet Cavitation and Cavitating Performance of a Hydrofoil with Non-uniform Leading-edge Protuberances

Cavitation remains a major limitation for marine propulsors, turbines, and lifting surfaces due to its significant impact on performance, stability, and structural integrity. Conventional hydrofoils typically exhibit early cavitation onset and large vapor structures, which increase drag, reduce lift, and induce unsteady pressure fluctuations. Bio-inspired leading-edge protuberances have shown potential for delaying separation in non-cavitating flows; however, their influence on cavitation dynamics remains poorly understood. This study investigates whether non-uniform leading-edge protuberances can improve the cavitating performance of a NACA ۶۳۴-۰۲۱ hydrofoil. Three-dimensional steady RANS simulations were carried out using the Schnerr–Sauer cavitation model and the SST k-ω turbulence model. The analysis focused on lift, drag, lift-to-drag ratio, pressure-coefficient distributions, and vapor-volume fields. Results show that the leading-edge protuberances alter the near-edge flow, generate streamwise vortices, and slightly delay cavitation onset. For angles of attack ranging from ۶° to ۲۴° under cavitating conditions, the bionic hydrofoil produces shorter and weaker vapor structures than the baseline. At an angle of attack of ۲۴°, lift increases by ۷% while drag rises by ۲%, resulting in a ۴% improvement in the lift-to-drag ratio. Pressure recovery is enhanced, with the recovery coefficient increasing from ۰.۰۷۸ in the baseline to ۰.۰۸۱–۰.۱۳۰ across the span of the bionic configuration. The normalized cavity length decreases from ۰.۷ in the baseline to ۰–۰.۱۲ for the bionic hydrofoil. These findings highlight the potential of nature-inspired designs for improving the performance of marine lift surfaces and propulsive systems.

کلیدواژه ها:

Computational fluid dynamics ، Hydrodynamic performance ، Non-uniform leading-edge protuberances ، Schnerr&ndash ، Sauer model ، Sheet cavitation