Prediction of Sound Attenuation Characteristics of Mufflers

Internal combustion engines are fitted with exhaust muffler to attenuate the pressure pulsation generated during combustion process. Effective prediction of sound pressure loss of hot gases as it flows through the muffler greatly helps in the design of mufflers. An attempt has been made here to predict the transmission loss through modal analysis, followed by acoustic analysis using finite element analysis for three different configurations of mufflers under different fixing conditions. It was found that three chamber muffler provides higher attenuation of sound pressure compare to one and two chamber mufflers and also fixing the muffler at the center provides further helps in sound pressure attenuation.