Experimental study on the combustion, emissions and fuel consumption of elliptical nozzle diesel engine

A series of experiments are carried out to investigate the combustion, emissions characteristics and fuel con-sumption of a diesel engine equipped with elliptical nozzle. The elliptical holes, which are made with an aspect ratio of 1.5, have a similar flow area as that of the references. In-cylinder pressure, exhaust emissions and fuel consumption are measured with varied fuel injection timing under a constant speed and different loads. The elliptical nozzles are characterized by shorter ignition delays, lower maximum rates of heat release and in -cylinder average temperature, and longer combustion durations. The NOx emission of the ICE with an ellip-tical nozzle is lower and while Soot emission higher. Under variable fuel injection timing, the NOx-Soot trade-off are affected by the nozzle shape. A substantial improvement in the fuel consumption-NOx emission trade-off is obtained for elliptic nozzles at three different loads. Employing moderate earlier injection couple with elliptical nozzle can reduce fuel consumption 2.5% while NOx and Soot emission remain unchanged at 25% load, and NOx emission reduce by 8.3% and 12.7%, and Soot emission reduce by 5.7% and 10.9%, and fuel consumption reduce by 2.4% and 1.7% at 50% and 75% load respectively.