Study On The Acoustic Attenuation Performance Of Diesel Engine Exhaust Catalytic Silencers

The diesel catalytic silencers installed in the diesel exhaust system have the abilities dual of emission control and noise reduction. It saves the space as one after-treatment device in the exhaust pipe.According to the structure of the monolith in the catalytic silencer, the acoustic calculation model is build up by using transfer matrix method and finite element method (FEM) respectively. The monolith part and the other part of the silencer which calculated by FEM are coupled to obtain the whole catalytic silencer's acoustic characteristics. The monolith's acoustic attenuation performance is processed, and the tow methods are compared.The transmission loss measurement of the catalytic converter is carried out by using the B&K impedance tube. The comparison of the measurement results and the software calculations; validated that the calculated method of catalytic silencer is correct. Consequently, the acoustic attenuation performance can be calculated and analyzed.In modeling the complex catalytic silencer, the method of element to element match is used. And the transmission loss and the acoustic characteristics are analyzed and discussed.