Evaluation of the combustion noise of passenger car diesel engines

The present article is concerned with the investigation of the combustion noise of passenger car diesel engines, which, especially in part load conditions, is clearly perceptible for passengers and passers-by. On the one hand, the state-of-the-art is shown by comparing three actual passenger cars on an acoustic roller test bench. On the other hand, a profound analysis of the combustion process is performed on an engine test bed, with the main focus on the illustration of dependencies between several operation parameters and the combustion noise as well as the transmission from the combustion chamber to the environment. Beside steady-state operating points the transient behavior is also investigated.