Marine Propellers

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Non-Confidential Description - PSU No. 0851 Keywords: Marine propulsor, efficiency, propeller, hub vortex Background Most marine propellers consist of a central hub with attached blades in the form of helicoidal surfaces that acts as “screws” into the water to generate thrust. The rotation of the blades usually results in the formation of a strong vortex in close proximity to the propeller hub. This vortex can cause reductions in shaft torque, induce damage to the propeller, and lead to an overall loss of efficiency of a ship’s propulsion system. Invention Description This invention describes a device that can be fit to new marine propellers or retro-fit to existing marine propellers, and can significantly reduce or eliminate the hub vortex created by the propeller. The device acts to counter the vorticity or “swirl” introduced into the water by the action of the propeller, thus reducing the strength of the hub vortex. The device leads to significant propulsive improvement, better fuel efficiency, and improved propeller operational life span. Advantages/Applications Manufacturing processes are well known and economical Improves propeller efficiency and cuts fuel usage Lightweight compared to comparable devices Compatible with variable pitch propellers May be retro-fit to existing propellers Proper positioning of device provides anti-fouling benefits