Abstract - The internal combustion engine is the major source of noise pollution. The engines find a wide application base as in various manufacturing machines, locomotives, and automobiles. The maximum contribution to noise pollution is shared by exhaust noise and noise which is produced on account of friction of various parts. A muffler is a device used to decrease noise within the exhaust system. It is set along the exhaust pipe for the attenuation of noise. The reduction in the level of exhaust noise depends upon the construction and the working procedure of mufflers. Therefore, the design of the muffler plays an important role as it affects the noise characteristics and fuel efficiency of the engine .In the present work, an attempt has been made to study the effect of parameters such as different lengths of Extended Inlet for constant lengths of Extended Outlet elements in both chambers of Double Expansion Chamber reactive muffler with an external connecting tube on the muffler’s capacity of noise reduction (i.e. Transmission loss). The acoustic behavior of the muffler is studied in detail by: (1)the finite element method by using COMSOL Multi-Physics, (2) Experimental validationby using Two Load Method.
Keywords - Reactive muffler, Transmission Loss, Finite Element Analysis, Two Load Method.