Characterization of the Noise Emitted by a Single Cylinder Diesel Engine: Experimental Activities and 1D Simulation

The paper summarizes the activities related to the characterization of the noise sources and related sound emission levels emitted by a single cylinder diesel engine. A deep analysis is carried out aiming to clearly define the various noise sources, through the employment of numerical and experimental techniques. In particular, an intensimetric analysis is carried out to define a bi-dimensional noise level map around the engine. In addition, the gasdynamic noise, at the different engine speeds, is measured through a microphone mounted near the intake and exhaust mouth. Contemporarily to the experimental activity, a theoretical one dimensional simulation of the whole engine, is also carried out. The presented one-dimensional analysis is able to characterize the wave propagation phenomena in the external ducts and provide the estimation of both engine performance and gasdynamic noise emission too. The presented techniques allow to fully describe the noise emission behaviour of the tested engine.