Experimental and Simulation Study to Reduce Engine Noise

The silencer or muffler is used to reduce the engine exhaust noise and also to reduce the exhaust flue gas temperature. To achieve this, a proper design of silencer is very important. The aim of this study is to find the effect of radial jets at the upstream of muffler on temperature and acoustic pressure. The radial jets were introduced at different reservoir pressure at the downstream of muffler. The simulation study has been carried out to determine the temperature and pressure distribution inside the silencer with and without radial jets and experiments were carried out to validate the result. It is observed that around 10 dB reduction in OASPL with interaction of jets in cross flow. These jets also reduces the exhaust gas temperature by 80 0C for engine speed 4000 rpm with jets at 2 bar reservoir pressure. Thus, this study concludes that the technique is effective to reduce the temperature of exhaust and noise. This technique can be applied easily to all vehicle mufflers where air at higher pressure is readily available as well as stationary engine mufflers using high pressure from small compressor.