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Abstract

Research on new techniques of multi-chamber mufflers equipped with a side inlet and an internal non-perforated tube has been well addressed and developed; however, the research work of multi-chamber mufflers in conjunction with side inlet and internal perforated tubes which may efficiently increase the acoustical performance is rare. Therefore, the main purpose of this paper is to not only analyze the sound transmission loss (STL) of three-chamber side mufflers with a perforated tube but also to optimize their best design shape under a limited space. In this paper, both the generalized decoupling technique and plane wave theory in solving the coupled acoustical problem are used. The four-pole system matrix in evaluating the acoustic performance is also deduced in conjunction with a simulated algorithm (SA). To verify the liability of the SA technique, the noise minimization of muffles at a targeted frequency is exemplified first. To appreciate the acoustical performance of various multi-chamber mufflers with/without inner perforated tube, three kinds of multi-chamber mufflers ― a one-chamber side muffler, a two-chamber side muffler hybridized with a non-perforated tube, and a three-chamber side muffler hybridized with a perforated tube are introduced and assessed. In eliminating the broadband exhausted noise emitted from an air compressor’s inlet. Before the SA operation can be carried out, the accuracies of the mathematical models have to be checked by experimental data. The result reveals a three-chamber side muffler hybridized with a perforated tube exhibits an excellent acoustical ability beyond the other mufflers. Consequently, the approach used seeking the optimal design of the STL proposed in this study is indeed easy, economical and quite effective.

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