Investigation of the Effect of Leading Edge Tubercles on Wingsail Performance

Abstract

In this study, effects of leading edge tubercles on a 2013 America's Cup boat wingsail are investigated by viscous Computational Fluid Dynamics (CFD). Adding tubercles on the leading edge of the sail is inspired by humpback whales, which are fast and maneuverable animals along baleen whales thanks to their distinctive flippers. It has been seen from the examined studies that tubercles on the leading edge of the wings delay stall and provide better lift/drag ratio in high angle of attacks (AoA) compared to the plain wing, which might be beneficial for wingsails. A 2013 America's Cup boat wingsail geometry is developed for measuring the effects of tubercles on its performance. Sinusoidal tubercles are placed on leading edge with different wave lengths and amplitudes varying as a function of chord length. Post-stall performance of the wingsail has been improved whereas onset of stall has been observed to be identical to that of the base wingsail.