experimental study of the effects of air-injection, injection timing and cooled egr on the combustion, emissions and performance of a nature aspirated direct injection diesel engine

in this literature, a combined method has been employed to simultaneously reducesmoke (soot) and oxide of nitrogen (nox) and maintain the performance parameters of dieselengine. this includes creating an air jet by designing an air-cell inside the piston body, advancedinjection timing and using cold exhaust gas recirculation. the tested engine was an mt4.244engine that worked as natural aspiration. the air-cell causes reduction in both soot and noxemissions. furthermore, applying cold egr had a noticeable effect on nox emission reduction.advancing injection timing, the performance parameters of the engine could be improved. thetests were done in 25%, 50%, 75% and 100% load conditions, for the engine speed of 2000 rpm.the results showed that by simultaneous reduction of soot and nox emissions, performanceparameters can be kept in a suitable range. the greatest reductions in nox and soot emissionshave been observed in 100% load. there have been no considerable changes in bsfc (brakespecific fuel consumption and power) while injection timing advances have been applied for5° ca and 5% egr.