Simulation Analysis Of Underwater Acoustic Radiation Of Annular Rib Conical Shell And Research On Noise Reduction Measures

Noise pollution,air pollution and water pollution are called the three major pollution.In Marine engineering,Marine environmental noise is a prominent pollution problem.Due to the shallow draft of surface ships and the exposure of superstructure to air,the noise of surface ships is mainly transmitted by air,so the main source of Marine environmental noise is the noise generated by underwater vehicles.In order to reduce the pollution,benefit the concealment of underwater ships,and protect the normal rest of the ship's internal personnel,the design research on the structural noise performance is gradually emerging.This paper discusses in detail the effects of the geometric parameters of underwater structures and the laying methods of internal muffler materials on the external acoustic field noise of structures.At first,this paper aimed at a certain size of the ring rib conical shell,analyzes the geometric parameters on the outer ring rib conical shell structure of acoustic field effects and linear change,respectively,the ring rib conical shell is the most important geometric parameters: high rib,rib width and space,half cone Angle,calculate their underwater radiation sound field,and plug in different position in the radiation sound field of ISO(International Standardization Organization)standard sound pressure measurement point.By comparing the variation of sound pressure at the measuring point with the linear variation of the same geometrical parameter,the influence of the geometrical parameters on the radiating sound field of the circular conical shell is analyzed.Then,the paper changes the geometrical parameters of the ring-ribbed conical shell,analyzes the effect of the external acoustic radiation of the ring-ribbed conical shell when the geometrical parameters change synthetically,and explains the weak effect of the change of geometrical parameters on the underwater acoustic radiation of the ring-ribbed conical shell.This paper for the analysis of the geometrical parameters on the ring rib conical shell outer sound field effect,on the basis of internal installation must be according to certain proportion in the shell thickness of viscoelastic damping and sound material,porous and transverse compare three different kinds of materials,change the laying thickness of the best materials and installation location,a series of data obtained,the design scheme of the data base.Based on the new requirements for interior decoration materials in acoustics at present,this paper proposes a multi-layer interior decoration material which has not been used in underwater vehicles.Finally,the vibration excitation of the shell is changed to sound excitation to further verify the noise reduction effect of the multi-layer interior materials.