Hydrofoils with Differing Leading-Edge Protuberances: CFD and Experimental Investigations

Main Article Content

R Kant
A Bhattacharyya


Leading-edge protuberances on the pectoral fin of humpback whales have been widely adopted to the designs of foils to provide superior lifting characteristics in the post-stall regimes. The present work investigates the lift, drag and flow characteristics of finite-span rectangular hydrofoils having different configurations of two protuberances over the leading edge with NACA 634-021 as the base design section. The results obtained from CFD analyses are validated using lift and drag measurements from experiments. The influence of using a transition-sensitive turbulence model on the results is investigated. It is observed that, in general, a foil with smaller separation between protuberances has better post-stall lift characteristics whereas that with protuberances at larger separation have better pre-stall characteristics. Depending on the separation between them, streamwise vortices are generated from the leading-edge protuberances. The two protuberances can restrict the zone of separation between them at high angles of attack. The influence of Reynolds number on the lifting performance is also investigated.

Article Details