A device for reducing the resistance of transom stern hulls

A novel idea to reduce the resistance of a transom stern hull in displacement and semi-planing modes is investigated. By placing spoon-shaped device recirculating zone behind transom, momentum forward-moving water will be absorbed, pushing force generated on device. Numerical experimental techniques are applied optimize shape position explore detail physics gain. For towed at Froude number 0.4, maximum measured reduction 11%, while computed 17%. In self-propulsion with one propeller, power 15%. The cannot propeller model, which an axial body-force distribution disk, but thrust using 11%. More significant gains possible smaller numbers, effect reduced higher numbers. Larger achieved by splitting two propellers. • Recirculating hulls considered as source energy loss. Transom Pushing Device (TPD) placed inside this region performance TPD has been verified computation techniques. more than 10% when not ventilated. can different (higher gain might achieved).