Design Analysis of Automobile Muffler with Cavity

The reduction of the emitted noise pollution from the exhaust system of the enginesisa realchallenge for various industries. Inthis regard, mufflers have been used to reduce thetransmitted noise from the automobile engineinto the surroundingenvironment.Mufflers are designed to reflect the soundwavesproduced by the engine in such a waythattheypartially cancel themselves out. Noise transmission loss performance in mufflerdepends on itsgeometry. Therefore, maximization of noise transmission loss in mufflersusingshape modification concept is an important research area.In thisstudy, threeapproaches have been followed for the maximization of noise transmission loss in mufflers by using of shape modification concept i.e.including the resonatorsoutside the expansion chamber, performance comparison for the mufflerswith and without the resonators, calculations for transmission loss and modal analysiscarried out in AnsysMechanicalAPDL. Finally, the optimum shape of mufflerbased on the design variables for having maximum noise transmission lossisconsideredbetter