Cetane Rating and Load Effects on Combustion Noise in Diesel Engines

Abstract

Experiments have been performed on a single cylinder air-cooled direct injection four stroke Diesel engine to determine the connection between combustion randomness and radiated noise. The tests reported have carried the engine to its maximum fuel flow condition and investigated the effects of Cetane rating. The tests have conclusively demonstrated that a substantial anount of the radiated noise is causally related to the randomness (turbulence) of the combustion process and not the mean pressure-time history. However, the higher the load, the less the effect of the randomness on total noise output.