Prediction On The Noise Level Of Ship Superstructure Cabin

With the improvement of knowledge, testing technique and higher requirement of people's life quality, the ship, as the land on the sea, has good performance not only in security, fastness, but also in comfortableness. The noise of ship superstructure cabin has becoming a more and more important problem because of many negative factors caused by ship vibration and noise, such as the fatigue and breakage of ship structure, failure performance of the instrument and device and the uncomfortable feeling, even the health weakening of passengers and crew.The prediction of the noise level in the cabin and work space at design stage is aiming to make effective measurement to control the noise level in advance to meet the regulations and ship owner's needs, which can avoid incidental expanses in the remediation and modification, so as to shorten the period and cut the construction cost of ship.In order to predict the noise levels in the ship superstructure cabin, the two methods are discussed in this paper, such as the Grey Prediction method and the acoustics analysis in FEM method. The research work are summarized as follows:(1) The prevalent prediction method in noise level of ship used nowadays is discussed, in order to put forward the advantage of the Grey Prediction method and the acoustics analysis in FEM method.(2) Introduce the basic knowledge of acoustics, the main sources of ship noise, the transmit route and characteristic, aiming to provide the basic knowledge of noise.(3) Introduce the essence, method, content and feature of Grey System, present the method and process the Grey Relevancy Analysis and GreyPrediction.(4) Establish the Grey Model on the basis of the actual sound pressure level of 27000DWT bulk carrier superstructure cabin as a sample and extend the Grey Model through comparing the prediction values with the actual values, aiming to predict the noise level of superstructure cabin of 74500DWT bulk carrier and 5618TEU container ship.(5) Introduce the theory of acoustic FEM analysis and the method of acoustic FEM analysis by using of ANSYS software.(6) Use the method of acoustic FEM analysis to predict the noise level of superstructure cabin of 74500DWT bulk carrier and 5618TEU container ship.(7) In order to predict the noise level of superstructure cabin of the 5618TEU container ship effectively, use these two methods to predict the noise level of superstructure cabin of 74500DWT bulk carrier and verify the method by comparing the predict results and actual noise level of 74500DWTbulk carrier.