Study of the Influence of the Injection Parameters on Combustion Noise in a Common Rail Diesel Engine Using ANOVA and Neural Network

The influence of some injection parameters (as main injection timing, pilot injection timing, pilot injection duration) on noise emissions and combustion noise level of a Diesel engine has been evaluated. The noise emissions of an in-line, four cylinder, turbocharged FIAT 1929 cm3 TDI engine were measured using an ambient microphone and accelerometers. The injection system of the engine used was the high-pressure Common Rail system. The experimental results were elaborated using an ANOVA (analysis of variance) technique, to evaluate the influence of the control parameters on the controlled ones. Moreover, a multi-layer neural network was used to predict noise emissions and vibration level. It was found that the accelerometer mounted on the top of the engine bolt, which clamped the head of the cylinder to the crankcase, gave the best coherence of the results. The timing of the main injection influences on noise, while the influence of timing and duration of the pilot injection on noise shows different behavior for different fuel injected quantities.