The reduction of noise emitted from the exhaust of an internal combustion engine is a real challenge for all automotive industries. Mufflers are designed to reflect sound waves produced by the engine in such a way as to cancel the effect of each other by destructive interference between the incoming waves from the engine cylinder and reflected waves from the muffler of 2 stroke motorbike engine. Numerical simulation is carried out to study the sound pressure level (SPL) and flow variables like velocity and pressure of conventional and proposed modified reactive muffler. In the numerical investigation of Conventional muffler and modified muffler, the path of exhaust gases in which it flows is analyzed through large eddy simulation and then Fflowcs Williams and Hawking model are utilized to predict the Sound pressure level of the conventional muffler and modified mufflers by using the time flow history of large eddy Simulation at the receiver location and the result of proposed modified muffler is compared with the conventional muffler. By comparing the Sound pressure level (SPL) results of conventional and modified mufflers show that the sound pressure level of the modified muffler - 01 are 5dB less than the conventional muffler and the sound pressure level of the modified muffler - 02 are 15dB less than the conventional muffler which produces sound pressure level of 80dB. The output velocity of exhaust gases is also drop down from 259.1 m/s of the conventional muffler to 182 m/s in modified design-2. So the stack pressure inside the expansion chamber of modified muffler-02 is less than the conventional muffler which creates high backpressure so our objective is achieved.
Zahoor Ullah Hassan Ahmed Dr. Kareem Akhtar “Comparison of Sound pressure Level of Conventional and Modified Mufflers by International Journal of Engineering Works Vol. 8 Issue 01 PP. 63-67 January 2021 https://doi.org/10.34259/ijew.21.8016367.
. Selvaraj, N.V., and N.N. Deshmukh, Experimental and Simulation Study to Reduce Engine Noise. Indian Journal of Science and Technology, 2016. 9(34).
. Tutunea, D., M. Calbureanu, and M. Lungu, The computational fluid dynamics (CFD) study of fluid dynamics performances of a resistance muffler. Recent Advances in Fluid Mechanics and Heat & Mass Transfer, 2013: p. 31-34.
. Liu, K., et al., Flow-induced noise simulation using detached eddy simulation and the finite element acoustic analogy method. Advances in Mechanical Engineering, 2016. 8(7): p. 1687814016655683.
. Puneetha, C., H. Manjunath, and M. Shashidhar. Backpressure Study in Exhaust Muffler of Single Cylinder Diesel Engine using CFD Analysis.
. P. B. p. D. Suyog s.Mane, "CFD analysis of Backpressure of the reactive muffler," IJIERT, December 2016.
. A. L. V. prof Amar pandhare, "CFD Analysis of flow through muffler to Selectoptimium muffler model of Ci engine," IJLTET, May 2014.
. K. Pradyumna saripalli, "Cfd Analysis on flow through a resistive muffler of LCV engine," IJSTS, June 2015.
. Pangavhane, S. D. ( Oct-Nov 2013). Experimental and CFD Analysis of a Perforated Inner Pipe Muffler for the Prediction of Backpressure. International Journal of Engineering and Technology (IJET) 11.
. Mr. Sumit Surveet all M. S. (2014).Acoustics and Flow Field Analysis of Perforated muffler design
. Kai Liu et all. Flow-induced noise simulation using detached eddy simulation and the finite element acoustic analogy method (2016).Advances in Mechanical Engineering,
Sileshi kore et all.Performance evaluation of reactive muffler using cfd Department of mechanical engineering Addis Ababa institute of technology Addis Ababa university.
 Mr.Zahoor Ullah received a degree in B.SC Mechanical engineering from the University of engineering & technology in Peshawar Pakistan in 2015. Currently, he is pursuing an M.S degree in dynamic System engineering from the University of engineering & technology in Peshawar Pakistan.His main research interest in the field of acoustic.