Study On Noise Prediction And Control Of Platform Support Vessel On Sailing Condition

In order to protect the crew's physical and mental health,the International Maritime Organization has improved the ship noise standard.PSV(Platform Support Vessel)is the ship which provides anchor handing,tug,supply and other support for offshore platform.It has complex structure and lots of heavy equipment.Because the excitation source is close to the living cabin,noise control situation is serious.At present,the PSV constructed in domestic is easy to have the problem of excessive noise in ship cabin.It is difficult to apply the noise control measures to the excessive noise cabins after the sea trial,and it will increase the construction period and cost of ship.Facing this situation,this paper uses the Statistical Energy Analysis method and the acoustic-vibration analysis software VA One to study a 85 m PSV,the noise control strategy is put forward for general ship.Research contents are as follows:(1)According to the drawings of general arrangement,structure and lines,the three-dimensional model of the 85 m PSV is established.Based on this,the Statistical Energy Analysis model is established considering ship outboard water,cabin fluid,stiffened plate and other factors.(2)The influence of engine radiated noise,structure noise and propeller structure noise of PSV is studied.It is verified that engine structure noise is the largest noise source of ship cabins in main deck and above in the PSV.The influence of radiated noise and structural noise is equally important in the cabin where the noise source is located.(3)Comparing noise prediction value with measured value considering decoration materials and no decoration materials under the condition of 100% MCR,it is found that deviation is large for the ship cabin near the noise source when decoration materials are not considered.For the PSV,decoration materials factors must be considered for the cabin near the noise source.(4)It is verified that noise level of cabin is positively correlated with the level of the excitation source by simulating noise level on different sailing conditions.The software is used to forecast the cabin noise on 85% MCR and 50% MCR conditions.(5)The attenuation of the noise in superstructure of the PSV is analyzed,and the energy of superstructure noise is mainly in the range of 100Hz-4000 Hz,among which it is the most in 250Hz-2000 Hz.(6)According to the overproof value and the location of the cabin,different noise control measures are developed.For the engine control room exceeding seriously,noise spectrum is analyzed to find the main energy of the noise band.Noise input path is analyzed,combination types of sound absorption,sound insulation,vibration isolation and damping and other noise control measures are taken to control cabin noise.Finally,the noise control strategy for general ship is summarized.