MODELING OF DIESEL ENGINE NOISE USING COHERENCE

A diesel engine can be modeled as a multiple-input, single output system, sometimes known as a coherence model.

Theoretical models for multi-input, single output systems are quite well developed, but only recently have attempts been made to apply these models to practical noise cases such as diesel engines. The results of these models can be used to predict changes in engine noise as cylinder pressure - time history is varied or to attempt to identify sources of noise in the engine. Practical difficulties and simplifying assumptions which must be made are discussed.