Some Characteristics of Recent Propeller Singing and Its Preventive Measures

So far a cause of propeller singing could be explained by the resonance between Karman vortex street from the trailing edge of 0.55R∿0.6R and the natural frequency of the blade. The revision of the trailing edge mentioned above by grinding could almost arrest the singing. However there are many cases where recent propeller singing cannot be extinguished by the usual measure. In this study, the characeristics of recent singing and its preventive measures are considered using FFT analysis of noise occured in some large ships. In consequence, we developed a new anti-singing design which leads to good results on some applied ships