Use of reciprocity principle in a hybrid modeling technique (HMT) based on inverse boundary element method (IBEM) for the determination of the optimal spectral characteristics of a complex radiating noise source

摘要

A robust hybrid modeling technique (HMT) based on near field acoustic measurements combined with numerical results derived from an Inverse Boundary Element Method (IBEM) is presented. The developed hybrid technique takes advantage from reciprocity principle to efficiently determine the optimal spectral characteristics of very complex noise sources, typically encountered in transportation industries. The first section of the paper reminds the direct link between reciprocity principle and integral representations of the acoustic field radiated by a noise source at finite number of discrete points located outside a closed surface enveloping the source. The second section discribes the parameters chosen to describe the radiating source and the numerical optimization procedure used to determine the optimal spectral characteristics of source parameters. The third and last section of the paper gives successful practical applications of the method in automobile industry to characterize the noise radiated by a car engine.