Unconventional Propeller Tip Design - Hydrodynamic Study

Winglets have been successful in the aircraft industry, but have not yet seen widespread use on marine propellers.\n\nThree different propellers (one conventional and two equipped with winglets) have been modelled and analysed with the CFD software STAR-CCM+. The winglet propellers achieved up to 40 % greater thrust than the conventional propeller at the operational propulsion point, but the torque increased even more - meaning that the overall open water efficiency was reduced by as much as 8.7 percentage points. The cavitation performance was also worse.\nMuch of the negative effects are assumed to be caused by an unfavourable winglet design.\n\nIt is concluded that this type of propellers may have a potential for better efficiency if the winglets are carefully designed.