• Ujjal Kalita
• Dr. Manpreet Singh

Now a day’s noise and pollution free environment is the most important aspect as the number of vehicles is increasing day by day. Noise control is the most important criteria as it will lead to friendly environment. It can be achieved by various techniques of which absorbing the sound coming out of the exhaust system of vehicles by using muffler is the most important technique. Porous and fibrous materials are widely used as sound absorbing materials. In this paper the different sound absorbing materials that are used are light weight acoustic absorber with silicon carbide fibers, polyester, Rockwool are used and the amount of transmission loss occurring because of the absorption materials are compared. Air flow resistivity which is one of the physical properties of absorption material is taken for the transmission loss calculation in muffler. In this paper the different mufflers are modeled in Solidworks and these are analyzed in Comsol Multiphysics where the transmission loss is determined at various frequencies. From the analysis it is found that increase in air flow resistivity and increases in thickness of absorptive lining increases the transmission loss and light weight ceramic acoustic absorber is favorable and could be used in muffler for sound attenuation. This paper also reveals one of the effective designs of muffler that could be fitted in automobile industry.

Muffler, transmission loss, light weight ceramic acoustic absorber (SiC fibers), Analysis in Comsol

"PREDICTION OF TRANSMISSION LOSS IN MUFFLER ON VARYING THE FLOW RESISTIVITY OF ABSORPTION MATERIAL", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 3, page no.674-679, March-2019, Available :http://www.jetir.org/papers/JETIREL06105.pdf

"PREDICTION OF TRANSMISSION LOSS IN MUFFLER ON VARYING THE FLOW RESISTIVITY OF ABSORPTION MATERIAL", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 3, page no. pp674-679, March-2019, Available at : http://www.jetir.org/papers/JETIREL06105.pdf