Behavior of transmission loss in muffler with the variation in absorption layer thickness

This paper reveals the acoustic performance of packed dissipative muffler with the variation in thickness of absorption material. It researches the sound absorbing capacity of different mufflers on application of this absorption material and also predicts one of the suitable designs of muffler for application in automobile industry. Delany-Bazley equations are used for the application of properties to the absorption materials. This study is performed to reduce the noise coming out of the exhaust system of vehicles as noise pollution and excessive exhaust smoke affect the environment. Transmission Loss (TL) which is the main acoustic performance parameter is evaluated as it determines the reduction in exhaust noise. This is performed in the 3D linear pressure acoustic module of Comsol Multiphysics. Polyester, Ceramic Acoustic Absorber and Rockwool are the materials taken for study