The design and test of exhaust silencing duct for the auto engine bench system

In this paper the design and performance of expanding silencing exhaust duct for the test bed of automotive engines are discussed. The frequency characteristics of sound attenuation and formula for the calculation of the transmission loss in the multi-stage expansion exhaust duct are given, The test result indicates that the exhaust noise is significantly attenuated and can be effectively controlled by using this Kind of silencing exhaust duct.