Effects on cavitation inception of leading and trailing edge flaps on a high-performance hydrofoil

Abstract

For the high-performance foiling yachts, cavitation is often a limiting factor for take-off and top speed. The present work investigates solutions to delay the onset of cavitation thanks to a combination of leading edge and trailing edge flaps. Both numerical studies based on a potential code and experiments in a hydrodynamic tunnel are conducted in order to assess the effect of specific geometric parameters on the hydrodynamic performance and cavitation inception. Experimentally the effect on the hydrodynamic performances and cavitation buckets of a 70% chord trailing edge flap and a 20% chord leading edge flap of NACA 0012 is investigated. The hydrofoils are manufactured using a 3D printer technique at IRENav and tested in the cavitation tunnel of the institute at an inflow velocity of 6.67 m/s (Re = 10⁶). The results show that the lift coefficient increases and the cavitation bucket gets larger with the flaps deflection. The experimental results are in good agreement with the numerical ones by highlighting the capacity of the flaps to enlarge both the operating domain and the cavitation bucket of the hydrofoil.