WIT Press


BEM Analysis Of Sound Wave Propagation In Ducts With Obstacles, Cross-section Variations And Bypass Elements.

Price

Free (open access)

Paper DOI

10.2495/BT010121

Volume

27

Pages

10

Published

2001

Size

700 kb

Author(s)

G. Rosenhouse and O. Findling

Abstract

Defect, variation of cross-section and branching influence sound fields within ducts. The analysis of such effects has been performed in two-dimensions. Rectangular and semi-circular shapes simulated the defects. In the case of semi- circular obstacles strong dependence on frequency appeared. The transmission loss was increased at specific frequencies, while it weakened at others (even up to a negative transmission loss), as compared to the response in a duct clean of obstacles. Generally, a change in the size of the defect did not effect the acoustic response pattern, while the intensity of the response varied. In ducts with rectangular obstacles the analysis is similar, but certain additional phenomena, such as an additional peak, and a change in the fre

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