Application of the Weis-Fogh mechanism to a ship propulsion system (Analysis based on the two-dimensional potential flow on the opening and closing stages)

Journal of Fluid Science and Technology

卷:12

Masahiko SAKAMOTO¹  Michihisa TSUTAHARA² 

[1] Department of Mechanical Engineering, National Institute of Technology, Nara College;

[2] Kobe University;

关键词: two-dimensional potential flow;    ship propulsion system;    weis-fogh mechanism;    fluid dynamic forces;    unsteady flow;   

DOI  :  10.1299/jfst.2017jfst0017

来源: DOAJ

【 摘 要 】

A two-dimensional ship propulsion model using the Weis-Fogh mechanism is analyzed by the potential flow theory and the conformal mapping. The purpose of this study is to clarify the most effective operating condition in which the loss is minimum. The opening and the closing stages are carefully studied. In both stages, a fixed point of the wing moves in the direction perpendicular to the flow direction. The condition to prevent the vortex shedding when the wing separates from the wall is to equalize the both sides pressure at the trailing edge of the wing, and the acceleration of the wing motion satisfying the condition is clarified. On the other hand, in the closing stage the condition to satisfy the so-called Kutta condition is applied at the wing edge. This condition means that the wing prevents the separation nor generation of the jet which produces high thrust but more loss. The unsteady forces and the moment on the wing are also shown.

【 授权许可】

Unknown