プロペラ単独性能に及ぼす鳴音防止加工形状の影響

抄録

Generally, propeller is applied with anti-singing device for the prevention of irregular noise resulted from Karman vortices generated from the trailing edges of propeller. It is well known that the anti-singing device exercises a greater effect on propeller open characteristics (P.O.C.) and propeller shaft speed, the effect of which is to be taken into account when propeller pitch is decided accordingly. On the other hand, in the propeller open test (P.O.T.), the finished accuracy of the trailing and leading edges greatly influences test results; however, it is difficult to attain higher accuracy on the very thin trailing edges of the propeller sized 250mm, which is popularly used for the model test. As a result, the effect of the anti-singing device is frequently studied experientially without adequate accuracy in spite of a greater effect of the anti-singing device upon the P.O.C.. This paper is based on the P.O.T. using 400mm diameter model propeller, supported by such a verification procedure that the P.O.C. performance was calculated by a simple method and applied with some corrections by comparing with the model test results, followed by a consistency having been finally confirmed upon comparison with the test results on full-scale vessel.