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DINAME2019
DINAME2019
Analysis in Acoustic Duct with a Periodic Side-Branch Tubes Array
Submission Author:
BRENNO VICTOR LIMA CAMPOS , SP
Co-Authors:
BRENNO VICTOR LIMA CAMPOS, Jose Maria Campos dos Santos
Presenter: BRENNO VICTOR LIMA CAMPOS
doi://10.26678/ABCM.DINAME2019.DIN2019-0211
Abstract
The proposed paper presents the behavior of a duct with periodic side-branch tubes commonly used as a device for noise control. They increase the resonance bandwidth to improve the transmission loss in the duct-tube assembly. One way to obtain a greater attenuation range is to place the tubes periodically along the duct. It generates forbid frequency bands commonly known as bandgaps, where the propagating harmonic waves are attenuated. These band gaps are generated based on the spatial frequency of areas of incompatible impedance that produce Bragg scattering effect and local resonance effect on the tubes. This work investigates the band gaps created in the duct-tube system using three methods: transfer matrix method (TMM), finite element method (FEM) and wave finite element (WFE) method. A system duct-tube is simulated with the intention to obtain the dispersion diagrams and forced response. The results are compared between the methods (TMM and WFE) to evaluate their accuracy and efficiency. Simulations using different unit-cell geometries and the number and length of tubes in the unit-cell are under way and will be presented in the full paper.
Keywords
metamaterial, bandgaps, duct, Noise control
