Combustion Induced Noise in Single Cylinder Diesel Engines

In this paper, the potential of noise reduction of a small single cylinder diesel engine is analysed. The attention is addressed towards the combustion-induced noise that substantially contributes to the engine radiation. Different settings of the injection equipment are investigated, since they influence to a great extent the pressure increase during the combustion process, which in turn determines the level and the spectral characteristics of the noise emission. The cylinder pressure signal is processed in time and frequency domains and is analysed in order to relate the radiation to the rate of pressure rise during the combustion process and then to the engine settings. The effect of different engine operative conditions is investigated.