A device for reducing the resistance of transom stern hulls

OCEAN ENGINEERING

卷:235

Article

Eslamdoost, Arash¹  Larsson, Lars¹  Brown, Matz² 

[1] Chalmers Univ Technol, Dept Mech & Maritime Sci, Gothenburg, Sweden

[2] SSPA Sweden AB, Gothenburg, Sweden

关键词: Transom flow;    Transom clearance;    Recirculation zone;    Resistance reduction;    High-speed;   

DOI  :  10.1016/j.oceaneng.2021.109351

来源: Elsevier

【 摘 要 】

A novel idea to reduce the resistance of a transom stern hull in displacement and semi-planing modes is investigated. By placing a spoon-shaped device in the recirculating zone behind the transom, the momentum of the forward-moving water will be absorbed, and a pushing force generated on the device. Numerical and experimental techniques are applied on a transom stern hull to optimize the shape and position of the device and to explore in detail the physics behind the gain. For the towed hull at a Froude number of 0.4, the maximum measured resistance reduction is 11%, while the computed maximum reduction is 17%. In self-propulsion with one propeller, the measured power reduction is 15%. The power cannot be computed with the applied propeller model, which is an axial body-force distribution in the propeller disk, but the reduction in thrust using the device is 11%. More significant gains are possible at smaller Froude numbers, while the effect is reduced at higher Froude numbers. Larger gains are achieved by splitting the thrust on two propellers.

【 授权许可】

Free