Acoustical and Flow Behaviour Analysis of Various Muffler Designs through CFD Analysis

Mufflers are installed within the exhaust system of most internal combustion engines, although the muffler is not designed to serve any primary exhaust function. The muffler is engineered as an acoustic soundproofing device designed to reduce the loudness of the sound pressure created by the engine by way of acoustic quieting. Pressure contour and Velocity contours have been obtained for the Five muffler models using CFD analysis. Acoustic Power levels, Transmission losses are also determined for each of the five models. As Shown by results, we can observe Model number one i.e. Muffler design with no extended inlet and outlet pipes inside the chamber has the least Acoustic power level of 45.32 dB. But for Model number one the Transmission loss is at low rate (3.72) as a result the efficiency of the muffler will be poor. For Model number four i.e. Three chambered muffler (with inlet and outlet pipe ends closed) the Transmission loss is at a high rate (9.92) as a result the efficiency will be great for this model but for Model number four the Sound emission is at a large rate 70.9dB which is not preferable. Taking the considerations of back pressure, as back pressure in Model number three is less. Model number three is the best optimum muffler model with an acoustic power level of 51.08 dB.