ABSTRACT
The exhaust noise is the most main noise source of automobile and evenits internal combustion engine,often is about 10~15dB(A) higher than entire noise of the internal combustion engine in which exhaust noise isn’t included. At Present,it is the most effeetive and direct method to install the exhaust silencer to reduce the exhaus tnoise.Therefore,the researehed exhaust silencer have the vital significance to reduce the exhaust noise.
The present paper,summarized and infered transition matrix of acoustie primary element of silencer.By method of transition matrix,computed and analyzed effcet of structure paremeter in the simple expansion type silencer and insert tube expansion type silencer to acoustic performance:Computed and analysed effcet of designed parameter in Helmholtz wave resonating silencer and perforated pipe resonating silencer to noise elimination performance. The analysed conelusions show:When the stream veloeity is smaller than about 35m/s,the stream veloeity is not big effect to noise elimination Performance:When the stream velocity is bigger than about 35m/s,along with the stream velocity increasing noise elimination Performance Suddenly drop.In addition,the different design Parameter has the important influence to the noise elimination Performance as well.
Discusses the evaluation of the muffler (insertion loss, transmission loss, power loss), the establishment of exhaust muffler mathematical model of insertion loss. Application of MATLAB mathematical computing software programming structural parameters of different circumstances, the simple expansion-type silencer insertion loss, with expansion-type muffler tube insertion loss.
Key words: Exhaust-noise Muffler Simple-expansion Intubation-expansion Insertion-loss