A propeller for propulsion of an electric boat. we ate here for example, a boat ride, 5 meters, powered by an electric motor supplied by a source of 300 w . this low power required quality and efficiency to the screw propeller!. In the case of naval propellers, the way to go is starting from the boat total drag and looking for a propeller which thust could overcome that drag and able to be moved with the less torque, avoiding cavitation effects at the same time.. Figure 1. illustration of terms used to describe propellers. the radius, r, of the propeller, is the distance from the center to the tip, along the center line.the chord length, c, is the straight-line width of the propeller at a given distance along the radius.the twist angle, β, is the local angle of the blade at a given distance along the radius (hepperle, 2006)..
Boat propellers defined. a boat propeller is a fan mechanism that transmits power by converting rotational motion into thrust. usually consisting of 3 or more blades, a boat prop spins around a central shaft to create dynamics similar to a rotating screw or airfoil. when blades spin, a pressure difference between the forward and rear surfaces. Based on the theory of the optimum propeller (as developed by betz, prandtl, glauert), only a small number of design parameters must be specified. these are the number of blades b, the axial velocity v of the flow (flight speed or boat speed), the diameter d of the propeller,. The ‘propeller handbook’ by dave gerr is a top resource, with 176 pages dedicated to explaining (in relatively understandable terms) how to choose, install and understand your boat’s prop. at around £15, it’s a very worthwhile reference..
