A Numerical Study of the Behaviour of a Turbocharged Diesel Engine as a Noise Source

In this paper, a numerical model is used to study the influence of several relevant parameters on the behaviour of a turbocharged Diesel engine as an exhaust noise source, with two main objectives: first, determine if it is possible to reduce exhaust noise at the source itself, thus simplifying the task of exhaust system design; and secondly, to asses up to which extent simple linear source models may be used to predict exhaust noise in these engines. The results obtained indicate that, on the one hand, exhaust noise is sensitive to the variation of certain engine design parameters and, on the other hand, that for certain running conditions simple source models may give an acceptable estimation of the actual engine behaviour as a noise source.