Abstract—Diesel engine exhaust system retrofit capable of suppressing the wave that offends the exhaust gas flow has been introduced in the vicinity of the exhaust port of a single cylinder naturally aspirated four stroke 7 HP 1500 rpm direct injection diesel engine and experimented. The retrofit considerably reduces the smoke, hydrocarbon, carbon monoxide and oxides of nitrogen levels while improving the thermal efficiency moderately (1% to 3%). The impact of retrofit on smoke and oxides of nitrogen are pronounced at higher loads. While the influence of retrofit on UBHC reduction is more or less uniform with increasing load, that on carbon monoxide is pronounced at lower loads. Exhaust gas temperature, cylinder peak pressure and peak heat release rate decline with the use of retrofit. Retrofit of area factor 7 (area factor is the ratio of flow dissipation area with retrofit to that with conventional straight exhaust pipe) is found better than those with 4 and 8.

Index Terms—Exhaust retrofit, Diesel engine, Emissions, Thermal performance, Exhaust system

Cite: Raja A, Ramanathan A R, and Vaidyanathan S, "On the Evaluation of Diesel Engine Exhaust System Retrofit for Improved Thermal Performance and Reduced Emissions," International Journal of Mechanical Engineering and Robotics Research, Vol.1, No.3, pp. 421-430, October 2012.