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

Abstract

For high-performance foiling yachts, cavitation is often a limiting factor for take-off and top speed. The present work investigates solutions to control the onset of cavitation thanks to a combination of leading edge and trailing edge flaps. Numerical 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. The hydrofoils are manufactured using an additive 3D printing technique and tested in the cavitation tunnel of IRENav at an inflow velocity of 6.67m/s (Re=106). 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 results show that the lift coefficient increases and the cavitation bucket shifts up and decreases with the flaps deflection. The experimental results are in good agreement with the numerical ones by highlighting the capacity of the flaps to modify both the operating domain and the cavitation bucket of the hydrofoil. Eventually, the PLA 3D printed foils prove to be a fast, unexpensive and reliable technologies for cavitation studies.