Study On The Cabin Noise Prediction And Control Method With The International New Criterion

With the development of ships in large size, the noise induced by large size powerequipment is increasingly obvious. The noise is damage for crew’s sleep and work, evenmake them lost hearing forever. Moreover, it is also harmful to marine organism. So thecontradiction between higher requirements of the comfort and the old standard attractsmore attention recently. Therefore, a new noise standard (DE53) is advanced by27European Union Member States to improve the standard requirement and restraint. Inorder to face the impact of the new standard to Chinese shipbuilding, the different of newand old standard is researched, and a method of cabin noise prediction and control designwith SEA and the standards is researched. So, the research of this paper as follows:1. The development of the ship noise standards, prediction and control technology arebriefly explained.2. Each key point of the of new standard is detailed interpretation according to theSOLAS and IMO A.468(XII), and the different of conventional and new standard iscompared, more, the real distance to conventional standard and the suitability to newstandard are all identified by research of the implement situation of IMO standard and thetechnical defects in domestic conventional noise design proceed. And then, the answeringattitude and methods are determined.3. The basic theory of statistical energy analysis(SEA) used in cabin noise predictionis described. At first, the basic hypothesis condition and fundamental principleare introduced, and then, the building and the solving of the power current equation isexplicated; and the determination method of the SEA parameters(model density, dampingloss factor and coupling loss factor) is detailed introduced. At last, the form of input powerand the conversion method of the responses are indicated.4. Basic on the SEA method, and according to the plans of a45,000ton bulk carrier, aSEA model is build by shell, beam, acoustic cavity, semi-infinite field(SIF) and so on. Andthen, calculating the noise level of each cabin by considering the excitation such as mainengine, propeller, auxiliary machine, air condition, pumps and so on. And then assess theresults with the standards and determine the cabin which must take measures to control thenoise to meet the requirement of the standards. At last, there key problems which wouldeffect the accuracy of the prediction result are also researched. 5. The basic principle of noise control is indicated at first, and the common noisecontrol measures were researched start with four aspects: structure design, noise sources,transmission routes and noise receiver. And then, the noise control design method usingsoftware VA one is researched, which include the detail process of noise control design,and the influence degree to take difference measures to difference cabin. At last, somereasonable and effective measures are taken to those cabins which not satisfy the standardand ensure all of the cabin noise meets the new requirement.