The effect of the addition of tubercles on the performance of Moth-T-foil

Tubercles have proven, in the nature (e.g., the humpback whale) as well as in engineering (e.g., rudders, wind and tidal turbine blades, propellers, etc.), to be an efficient device to control the flow and to delay stall. This study focusses on the implementation of tubercles on the main lifting foil of a moth sailing dinghy. To do so, a "Bladerider" flapped T-foil with and without tubercles was tested in the Kelvin Hydrodynamics Laboratory in Glasgow, at a range of speeds, angles of attack, flap angles but also immersions. The results of these full-scale tow-tests, including the lift and drag data of the bare foil, are presented in this paper. The measurement data was used to investigate the effect of the addition of tubercles on the performance of a T-foil