Noise Excitation by Auxiliary Units of Internal Combustion Engines

For modern low noise I.C. engines, the noise excitation of auxiliary units becomes more and more important. The paper gives an overview about the authors experience in noise of engine oil pumps, generators, reciprocating air compressors and hydraulic oil pumps. The dominating noise excitation mechanisms were dealt with. Examples of typical shares of auxiliary unit noise were shown for different engines classes. Future noise reduction strategies were discussed.