The Application of Idealization and Response Analysis to Diesel Engine Noise Assessment 750836

A method of determining the contributions to noise radiated by a diesel engine using idealization and response analysis is described. An idealization of the engine surface as a set of flat plates is used to calculate radiation efficiency from physical properties and edge constraints of each plate, and the velocity response of the engine surface is measured using accelerometers. This data is used in a simple acoustical power relationship to determine 1/3 octave sound pressure levels under free field conditions for the engine and individual noise sources on the engine. The theory is discussed and an example of the application of the method is given, and compared briefly with the more traditional noise source identification technique of lead cladding.