Research On Full-Band Noise Prediction And Control Technology Of Passenger Ro-Ro Ship Cabins

Noise prediction and noise control in the cabins of ro-ro vessels was one of the key aspects of ship construction,as ship noise not only harms the physical and mental health of passengers and crew members but also affects the service life of ship equipment.Predicting and controlling the whole ship cabin noise in the ship design stage can help improve the comfort of passengers,reduce the construction period and lower the ship construction cost.The thesis proposed a full-band cabin noise prediction method based on statistical energy analysis,hybrid finite element-statistical energy analysis and finite element analysis,and conducts research on ship noise control technology in view of the deviation of traditional single noise prediction analysis methods.In this thesis,the following work was carried out with passenger roll-on/roll-off ships as the research object:(1)According to the research status of domestic and foreign ship cabin noise forecasting methods,the applicable characteristics of cabin noise forecasting methods were analyzed,and the idea of full-band noise forecasting in the cabin of passenger ro-ro vessels was determined.The basic principles,main parameters and kinetic equations of statistical energy analysis,hybrid finite element-statistical energy analysis and finite element method analysis were introduced in detail,and the idea of full-band noise prediction of passenger-roaming ship cabins was proposed.(2)The acoustic software VA ONE is used to simplify the model,improve the calculation efficiency on the basis of retaining the calculation accuracy,and establish the SEA acoustic model of passenger-ro-boat.The main parameters of statistical energy analysis were calculated according to the empirical formula,the absorption coefficient of ship cabin interior was determined,the main excitation source was determined based on the decibel superposition principle,and the excitation input value of the passenger-roaming ship was calculated.Set the boundary conditions semi-wireless fluid to simulate the external environment,calculate the modal number of each subsystem,and divide the analysis frequency band according to the modal number.(3)Based on statistical energy analysis,hybrid finite-element-statistical energy analysis and finite element analysis,full-band noise prediction was performed for passenger-ro-boat cabins,noise sound pressure level distribution was studied,and total sound pressure level was calculated.The sound pressure level of the main compartments was compared with the noise specification value,and the noise exceeding compartments were identified.The noise contribution and the maximum energy transfer path analysis were carried out for the exceeded compartment,and the main input excitation of the noise of the exceeded compartment was derived.(4)In response to the problem of excessive noise in some cabins,the research on the noise control technology of ship cabins was carried out.Firstly,the basic principles of noise reduction design and application scope were introduced.Secondly,sound absorption,sound insulation and vibration isolation technologies were studied,and simulation models were established for numerical analysis to study their influencing factors.Finally,the cabin structure was improved,and the noise control was carried out for the over-standard cabin by designing the acoustic package structure combined with the research laws of sound absorption and sound insulation,so that the noise over-standard cabin can meet the IMO cabin noise standard.