Study On The Noise Of The FPSO's Living Cabin With SEA

More and more attention has been paid to deepwater oil exploitation with the increase of the oil requirement all over the world. At the same time, the advantages of FPSO provide excellent chance for the development of deepwater exploitation. Considering the living condition of FPSO, the noise prediction of cabins and working environment in design process must be provided and then the procedures for vibration suppression and noise control treatment should be adapted in order to satisfy the relevant rules.The theory of statistical energy analysis was developed at sixties in the 20th century in spaceflight industry. From the view of statistic and energy, the response of complex structures functioned by exterior loads can be drawn up with the application of statistic energy analysis method, which can efficiently and accurately simulate the characteristic of middle and high frequency acoustics as well as the vibration of the structure. This paper gives the noise prediction of the living cabins of FPSO based on statistic energy analysis method, and the method of noise control treatment are studied after analyzing the noise transmission path.Firstly, the parameters of the SEA method such as the damping loss factor (DLF), coulpling loss factor (CLF), modal density and power input are studied by theory and experiment method.Secondly, the noise source equipments are confirmed. The noise source equipments which can affect the noise level of the FPSO's living cabins are selected to load in the SEA model. They are confirmed by analyzed the comparison of the sound pressure level (SPL) the equipments emitted which are gotten by estimated the experience formular.Thirdly, according to the arragement drawing and structure drawing, the SEA model of FPSO is established by the vibro-acoustic software AutoSEA. The complexity of the subsystem and the computational complexity and computational accuracy should be considered while dividing the model subsystems.Then, the SEA parameters of each cabin are gotten by solving the SEA model, such as SPL, modes, modal density, energy density, wave number and so on.The cabins which the SPL doesn't meet the requirement of rules and those with different locations are analyzed according to the characters of noise radiation. Then the units' contribution to the noise level of the cabins is found by studying on the noise transmission path, and the noise level is improved after the noise treatment on the units.The task that have been accomplished is summarized, and the problems which have been done deficiently in either theory or practise are expounded. And there are still a lot of work to...