Abstract

The propagation of sound waves in an infinite circular cylindrical pipe with an inserted perforated screen is investigated rigorously through the mode matching technique. The pipe walls are assumed to be rigid for \( - \infty < z < - l\) and coated for \( - l < z < 0,{\text{ }}0 < z < \infty \) with different linings. An analytical solution for the field terms are determined in form of eigenmodes which are matched across the boundary of each junction discontinuity. Numerical results are performed to show the effect of the different parameters such as waveguide radius, length of the partial lined part and acoustic absorbing lining properties on the propagation phenomenon. The use of such components is effective in reducing noise effects from various sources. The results of the mode matching technique are also compared graphically with the results of the Wiener–Hopf technique which is more difficult to implement and perfect agreement are observed.

中文翻译：

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多孔屏无限管中声波的模式匹配分析

摘要

通过模式匹配技术，严格研究了声波在带有插入式穿孔屏的无限圆柱管中的传播。假定管壁对于\（-infty <z <-l \）是刚性的，并且对于\（-l <z <0，{\ text {}} 0 <z <\ infty \）是刚性的有不同的衬里。场项的解析解以本征模的形式确定，本征模在每个结点不连续的边界上都匹配。数值结果表明了不同参数如波导半径，部分衬里部分的长度和吸声衬里特性对传播现象的影响。使用此类组件可有效减少各种来源的噪声影响。模式匹配技术的结果也与Wiener-Hopf技术的结果进行了图形比较，后者更加难以实现并且观察到了完美的一致性。