Research On The Acoustic Convergence Technology Of Distributed Sound Sources

In the situation which the and power of a single sound source can not meet thedemand, the research on acoustic convergence technology of distributed sound sourcesplays an irreplaceable role in promoting the energy of sound field. On the basis of thestudy of different vibration types of piston sound source,the uniform vibrating pistonsound source is selected to study acoustic convergence of multiple sound sources, whichis vertified by experiment.The main contents of the thesis including:1)Based on the point source radiation theory, the theoretical results and directivityfunction of the acoustic radiation of different vibration types of piston sound source arederived using Rayleigh integral method. And some guiding significant conclusionsabout the choice of different types of sound source are obtained by the comparison ofthe directivity and radiation field separately.2)The theoretical result of multiple sound sources radiation field is deduced fromuniform vibrating piston sound source. The research on the radiation sound field of thelinear distributed sound sources shows that the directivity is better when the spacing isequal to wavelength of sound source. Moreover, a comparison between the sound fieldof single and multiple sound sources is made under the condition of equal radiationpower, which demonstrates that mulitipule sound sources distribution only inhibits theacoustic energy in some directions.The impact of the ratio of the spacing and the wavelength of the sound source ofthe curvilinear distributed sound sources and the number of the sound sources upon thesound focusing effect and acoustic focal position. Study shows that when the spacing ofthe sound sources is the same as the wavelength, the effect of sound focusing is the best;and the more sound source number is, the higher SPL and the smaller the focus spot are.When the sound sources is less than10,the SPL of the focus spot would increase by atleast1dB in case of adding one more sound source.3) Two treble sources are used to testify the conclusion that when the spacing ofthe sound sources is the same as the wavelength, the focusing intensity is higher.4)The radiating sound field of nonuniform distributed sound sources is focusedwell in the conditions of ideal and complex by the time reversal method which need notthe apriori knowledge such as medium properties et al. The number increase of thesound sources and the existance of scatterers would promote the focus gainsignificantly.