## Abstract

A technique that combines the boundary element method (BEM) and the point collocation approach is proposed to calculate the transmission loss (TL) of silencers in the absence of mean flow and temperature gradient. A long silencer is first divided into several substructures for analysis purposes. The point collocation approach is applied to produce the impedance matrices of any long substructure that has an axially uniform cross section to produce its impedance matrix. On the other hand, the direct mixed-body BEM is used to produce the impedance matrices of any irregular sections. The point collocation approach employs a modal expansion of the cross-sectional modes extracted by the 2D finite element method (FEM), and then matches the sound pressures and particle velocities at the collocation points on both ends to calculate the impedance matrix. All the substructure impedance matrices are then combined to form the resultant impedance matrix of the whole silencer for TL computation. Several test cases are presented to valid the combined technique and to demonstrate its computational efficiency.

Original language | English |
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Pages (from-to) | 265-273 |

Number of pages | 9 |

Journal | Engineering Analysis with Boundary Elements |

Volume | 61 |

DOIs | |

State | Published - Dec 2 2015 |

### Bibliographical note

Funding Information:The authors would like to acknowledge the support of the research Grant 11174065 from National Natural Science Foundation of China . L. Yang was supported by China Scholarship Council while he was a visiting student at the University of Kentucky.

Publisher Copyright:

© 2015 Elsevier Ltd. All rights reserved.

## Keywords

- Boundary element method
- Mufflers
- Point collocation approach
- Silencers
- Transmission loss

## ASJC Scopus subject areas

- Analysis
- Engineering (all)
- Computational Mathematics
- Applied Mathematics