Study On The Noise Prediction Of The Cruise Ship Cabin And Vibration Attenuation Characteristic Of The Floating Floor

With the rapid development of cruise industry and the particularity of ships with high added value,the study of cruise ship cabin's vibration and noise becomes more and more important.This paper takes a certain type of cruise ship as the research object.Based on statistical energy analysis method,the noise prediction analysis of the cruise ship cabin is carried out by numerical simulation,and the noise value of the cruise ship typical cabin is compared with the IMO standard,and the reasons for the cabin's noise exceeding the standard are analyzed.In order to control the noise of the superscale cabin,the vibration and noise attenuation characteristic of the floating floor is studied,and some measures is carried out.First of all,the basic principle of statistical energy analysis method and its application scope and assumptions are expounded.The basic parameters of statistical energy analysis method,including modal density,damping loss factor,coupling loss factor and input power,are introduced.Secondly,the structure and main parameters of the cruise ship are introduced,and the main noise sources and characteristics of the upper and lower floors of the cruise ship are analyzed.In order to study the acoustic vibration characteristics of the cruise ship,the SEA model of the cruise ship was established by using the vibration and acoustic integration software VA ONE,and the basic parameters of each model were determined,and the noise prediction and analysis of the cruise ship were carried out.The prediction results were compared with the IMO standard limits,and the related noise exceeded the cabin was obtained,and the main reasons for the noise exceeding the standard are analyzed.Then,the structural type and application of floating floor which is used to control cabin's noise are mainly introduced.The vibration and noise attenuation characteristic of the floating floor is studied based on the wave model and the four terminal parameter model respectively,and the experimental results are compared and analyzed with the theoretical result.At the same time,the dynamic stiffness and damping of the floating floor are obtained by the experimental test.Finally,the vibration attenuation characteristic of the single and double floating floor is compared and analyzed by using the four terminal parameter method.Then,the principles and methods of noise control for ship cabins are briefly introduced,and the measures for cabin's noise control are also introduced.The contribution rate and input power of the engine room and input power of the living rooms is analyzed,and the main transmission path of noise energy is determined.The acoustic enclosure of diesel engine is designed,and the noise attenuation effect under different excitation is compared and analyzed.The noise control of the floating floor with different structures to the over standard cabin is studied,and the thickness of the mineral wool of the floating floor is optimized.On this basis,the noise attenuation effect of floating floor structure on the each source cabin is analyzed.Finally,the characteristics of the underwater radiation noise of the cruise ship and the basic prediction process are introduced.Then the simulation analysis was carried out based on the SEA.The results show that the sound pressure level of underwater radiation noise decreases first,then increases and finally decreases with the increase of frequency.In order to estimate the main noise sources,the effective values of underwater radiated noise of cruise ships under different excitation sources are analyzed.According to the underwater radiation noise control method,the vibration isolation design of the diesel engine was carried out.The study shows that the underwater radiation noise of the cruise ship is reduced after the vibration isolation treatment,and the reduction degree is about 3dB~5dB.