Micro Perforation Plate-Honeycomb Sound Absorption Structure In The Noise Control Of The Ship’s Cabin Room

As human beings continue to explore the ocean,they have built a lot of equipment for ocean development,such as ships,ocean platforms and workstations,etc.These large structures are faced with huge noise problems.On the one hand,environmental noise and mechanical noise can cause harm to the health of crew and staff,on the other hand,it can also cause the normal and safe operation of equipment and structure.Therefore,noise control in Marine environment has become an important issue to be solved urgently.Microperforated sound absorbing material has become one of the solutions to noise control due to its simple structure,processing and meeting the environmental requirements.Although the sound absorbing band is not wide enough,the honeycomb structure is added in its rear to broaden the sound absorbing band,and it has gradually become the main scheme for noise control of ship cabins.In view of the short sound absorption bandwidth of the microperforated panel in the noise control of the ship cabin,the honeycomb structure was added on the back of the microperforated panel to form the microperforated honeycomb sound absorption structure.The acoustic characteristics of the microperforated honeycomb sound absorption structure were simulated and analyzed using COMSOL Multiphysics software based on impedance tube method to measure the sound absorption coefficient.Furthermore,genetic algorithm was selected to optimize the parameters of the sound absorption structure.Finally,the micro-perforated honeycomb sound absorption structure was laid into the cabin model for simulation analysis to test its sound absorption and noise reduction effects under different noise conditions.(1)Based on acoustic wave equation,acoustic and electric analogy method and Helmholtz resonance principle,COMSOL Multiphysics software was used to compare and analyze the acoustic characteristics of microperforation-honeycomb sound absorption structure with finite element method,focusing on exploring the influence of nine structural parameters of microperforation-honeycomb sound absorption structure on the sound absorption coefficient.Orthogonal experiment was further designed to study the cross influence of nine factors,and the primary and secondary relationship between factors was obtained.The optimal scheme of microperforation was 4mm aperture,11% porosity,1mm plate thickness,0mm back cavity and triangular shape of the hole.The optimal combination of honeycomb is30 mm in size,2.5mm in wall thickness,20 mm in height and triangular in shape.(2)using a genetic algorithm for micro perforated-cellular sound absorption structure parameter optimization,genetic algorithm parameters,it is concluded that the optimal structure parameters of the whole frequency band,the last to get the optimal micro perforated-cellular absorption structure impedance tube COMSOL simulation experiment,the maximum error is 1.98%,the reliability of the genetic algorithm to optimize the results.(3)Based on the drawing of a fishing boat,the parameters of statistical energy analysis(SEA)model are established,and the SEA model of fishing boat is established for simulation and solution by applying excitation in combination with the actual sailing situation.The sound pressure levels of the cabins before and after the laying of the microperforation-honeycomb sound absorption structure are compared.The results show that the micro-perforated honeycomb structure has a good effect on cabin sound absorption and can effectively reduce the sound pressure level of cabin noise,which provides a reference for the design of ship noise reduction.