Analytical and Experimental Study on Noise Attenuation of Multi-Cylinder Diesel Engine with Existing and Modified Muffler

Man's desire for a pollution free atmosphere entails control of air pollution and noise pollution. The principal sources of noise in automotive engines are intake noise, radiator noise, combustion noise, exhaust noise etc. Out of these, exhaust noise is predominant and has to be controlled. Noise pollution affects human beings physiologically and psychologically. In this paper on reactive muffler for a multi-cylinder diesel engine is designed and modified. More attenuation is given by making some changes in its configuration. The Bond graph technique has been applied for the analytical results of the muffler. The modelling of acoustic and other systems are easily and logically achieved through Bond graph technique[1,2,3]. Bond graph, invented by Paynter, is a method or representation of a physical system by means of symbols and lines, identifying power flow paths and lumped parameter elements of resistance, capacitance and inductance. The Bond graph model is created by taking wave propagation in acoustic material into consideration. The analysis of the Bond Graph model was carried out by using software COSMO-KGP. These results were compared with the experimental results and found to be in close agreement.