Research On Characteristics Of Underwater Acoustic Radiation And Cabin Noise Induced By Vibration Of Propeller-shaft-ship Coupling System

In the process of ship cruising,the structural vibration is produced under propeller excitation、main power equipment excitation and so on.The vibration of the ship structure is transmitted to the surrounding fluid through the hull,then the underwater radiation noise is generated;and the vibration of the ship structure is transmitted to the cabin,then the cabin noise is generated.Excessive underwater acoustic radiation and cabin noise are not only harmful to ship acoustic stealth performance,but also affect ship habitation and comfort.At present,the research of ship underwater acoustic radiation and cabin noise is relatively independent,and there is little research on ship acoustic optimization method.Therefore,it is urgent to further study ship noise characteristics and acoustic optimization on the basis of perfecting prediction system of ship acoustic radiation and cabin noise,in order to improve ship acoustic stealth,habitability and comfort.Therefore,in this paper,the prediction methods and acoustic optimization method of ship underwater acoustic radiation and full-frequency cabin noise、the characteristics of ship underwater acoustic radiation and full-frequency cabin noise under different excitation are studied.The main research contents are as follows:(1)Taking a large ship as the research object,the full-frequency simulation modeling method is established,and the full-frequency simulation analysis model of the ship is formed.(2)The ship vibration response and underwater acoustic radiation characteristics under different excitation are compared and analyzed,and the relationship among ship mode,vibration response and underwater acoustic radiation under different excitation is given,and the contribution rate of different excitation to underwater acoustic radiation of ship is given.(3)Taking a certain structural cabin as the research object,using the Finite Element Method/ Boundary Element Method(FEM/ BEM),the Hybrid Method(FE-SEA)and the Statistical Energy Method(SEA)to forecast the full-frequency cabin noise,and the accuracy of the simulation results and the effectiveness of the full-frequency cabin noise prediction method are verified by the experiment.(4)The typical cabin noise characteristics of the ship under different excitation are analyzed,the contribution rate of different excitation to cabin noise is given,and the contribution of cabin panels to cabin noise under different excitation is given,the relationship between the ship underwater acoustic radiation and cabin noise is given.The above research has perfected the prediction system of the ship underwater acoustic radiation and the full-frequency cabin noise,and provides the method guidance for the forecast and the acoustic optimization of ship underwater acoustic radiation and the full-frequency cabin noise.