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A segmented Rayleigh-Ritz method for predicting sound transmission in a dissipative exhaust silencer of arbitrary cross-section

✍ Scribed by A. Cummings


Publisher
Elsevier Science
Year
1995
Tongue
English
Weight
557 KB
Volume
187
Category
Article
ISSN
0022-460X

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✦ Synopsis


Dissipative vehicle exhaust silencers often have cross-sectional geometries that defy straightforward analytical solution of the acoustic eigenproblem; some kind of solution is, however, required as a part of the basis for computational silencer design methods. As a useful alternative to some of the more widely used numerical schemes such as finite element methods, a ''segmented Rayleigh-Ritz'' formulation is described here. It has the advantages of being simple in concept and implementation, and making very modest computational demands. It has obvious drawbacks in terms of a loss of accuracy in computing the eigenvalues and eigenfunctions, though these can be minimized by an appropriate choice of trial functions, segmentation geometry and number of segments. A trial function is proposed here, for the fundamental mode in an oval-section silencer. Favourable-comparisons are made between the predicted and measured axial attenuation rate and phase speed.