Optimization Design And Performance Study Of Floating Raft Vibration Isolation Device For Diesel Generator Set

With the development of society and the progress of science and technology,the demand of environmental vibration and noise index is higher and higher.Especially,the requirement of vibration and noise index is higher and higher.The floating raft vibration isolation device is the most widely used method to control the vibration of naval ships.With the improvement of the comfort of civil ships and the vibration requirements of military ships under special working conditions,the optimization design of the floating raft vibration isolation device and the analysis of its vibration isolation performance,as well as the introduction of new vibration reduction measures,have gradually become a hot topic of current research.More than a decade ago,relevant researchers participated in the design and calculation of XX2 boat,including the design and calculation of floating raft vibration isolation device for two diesel generator sets.According to the experimental data,it has achieved good vibration isolation effect.In recent years,the new-generation XX3 boat has been developed in China,and its vibration and impact resistance index has been further improved.According to relevant requirements,the floating raft vibration isolation device of the diesel generator set of XX3 boat was optimized,mainly including raft structure optimization design,vibration isolator selection and layout optimization.Based on the finite element method and the finite element software ANSYS,the finite element model of the floating raft vibration isolation device was established.In order to further study the vibration transfer characteristics of the floating raft system,the vibration isolation performance of the floating raft system and the main parameters affecting the vibration isolation performance of the floating raft system were calculated and studied through the harmonic response analysis module,including the dynamic stiffness and damping ratio of the vibration isolator,the thickness and structural stiffness of the raft body,and the thickness and structural stiffness of the base plate.Based on the three basic ideas of vibration control,on the premise of ensuring the small change of the weight of the raft,the main measures to improve the structure of the raft are studied,and the vibration isolation performance of the improved raft system is calculated and analyzed,which provides some ideas for improving the design of the raft structure.Considering the special working environment requirements of XX3 boat,the underwater radiated noise of the cabin where the floating raft vibration isolation device of the diesel generator set is located is calculated.At the same time,the dynamic stiffness and damping ratio of the vibration isolator,the thickness and structural stiffness of the raft body,and the influence of the thickness and structural stiffness of the cabin on the underwater radiated noise of the floating raft cabin are studied.The new concept of acoustic black hole in wave and acoustics is introduced into the floating raft isolation system,and the concept of acoustic black hole is briefly introduced.In this paper,a small floating raft vibration isolation device is set up,and several acoustic black hole schemes are designed for the raft.