Experimental and Numerical Analyses of Performances and Noise Emission of a Common Rail Light Duty D.I. Diesel Engine

This paper illustrates a numerical and experimental analysis of performances and overall noise radiated from a common rail light duty diesel engine. The engine was equipped with two different injection systems: an under development low-cost fuel injector and a commercial Bosch one, employed for automotive applications. The injectors behaviour was compared throughout an experimental investigation that was carried out on a naturally aspirated, four strokes, two valves, single cylinder engine (225 cm³ displacement). Both engine performances, pollutant and noise emissions were measured at different operating conditions for two injection strategies. Concerning the acoustic analysis, both structure born and gasdynamic noise contributions were estimated using different experimental techniques. Contemporarily to the above campaign, a one-dimensional simulation of the investigated engine was performed, finalized to provide some information on the spray combustion and heat release realized by the two fuel injection systems (FIS). The numerical results were then compared to the experimental ones, in terms of heat release fraction, in-cylinder pressure signal and gas dynamic noise emissions.