The Study Of Cylindrical Shell Acoustic Radiation And Wave Sound Propagation Characteristics Based On Equivalent Source

Reducing the underwater vibration sound radiation of elastic cylindrical structure which is an important part of JT vibration and noise reduction and quantitative acoustic design is a significant research in the field of underwater acoustic.However,the envir onment in which the radiator located is often not a free field,which involves the coupling vibration of the structure with the water and the presence of reflected sound in the process of acoustic propagation.This makes the elastic cylindrical shell structure in the underwater bounded space sound radiation prediction have become a central research.Firstly,the equivalent source method based on elastic cylindrical shell is put forward.An array of sources which are different shape distributed with sphere,cylinder and axis are interior to the radiator.The relationship between the intensity of the point source and the normal velocity of the radiator is constructed.Then the acoustic and vibration coupling properties of the elastic cylindrical shell are studied by modal function method.The normal velocity of the shell surface and the radiated sound power which determine the source intensity are calculated.Distribution form of Point source,the number of point sources and the conformal ratio which have affected on the calculation accuracy of the equivalent sound source method have been discussed.The equivalent sound source method when meets certain conditions has good accuracy to calculate the elastic cylindrical shell acoustic radiation characteristics in the range of medium low frequency(0~1200Hz).Finally,the eigenfunction method is used to calculate the acoustic propagation characteristics of the equivalent point source in the ideal waveguide.