关键词: 螺旋桨;振动;噪声;CFD;有限元;模态叠加法;边界元

Abstract: To study characteristics of ship propeller-shaft-rudder-stern coupled vibration noise，unsteady force derived from integral CFD calculation was used as excitation force，and loaded to finite element model in the form of distributed load. Combined with modal superposition and acoustic boundary element method，a numerical method to calculate propeller-shaft-rudder and stern coupled vibration noise was established．The analysis of vibration response results illustrates that the influence of working condition to vibration response is more obvious in lower-frequency spectrum than that in higher-frequency spectrum. Frequency of the maximum vibration response amplitude is influenced by structure characteristics and excitation resource. Propeller blade has the maximum vibration transmission loss in propeller-shaft system．The comparison of different model’s propeller blade vibration results illustrates that propeller-shaft model is more practical than single propeller model because of its closer results to propeller-shaft-hull model and simplicity．The analysis of vibration noise results illustrates that vibration characteristics can be reflected by frequency spectrum of vibration response and sound field distribution. Total sound pressure contributed by hull vibration accounts for above 90% while that of propeller blade is only about 1%，therefore vibration noise of hull should be considered when predicting propeller induced vibration noise．

Key words: Propeller;Vibration;Noise;CFD;Finite element;Modal superposition method;Boundary element