Application of a reciprocity technique for measurement of acoustic transfer functions to the prediction of road vehicle pass-by noise

Abstract

A technique based on the principle of acoustic reciprocity has been developed for measuring acoustic transfer functions of sound radiation from vibrating surfaces of the engine, power train, exhaust system and tires. In many realistic cases of sound radiation, reciprocal measurements of transfer functions are usually more convenient and mostly more accurate than the corresponding direct measurements. This paper explain the basic acoustic reciprocity and experimental setup and illustrate its benefits by application to measurements of transfer functions of sound radiation from the engine of a fully trimmed vehicle.