Krylov et al Proc ISMA 2016 - preliminary.pdf (990.61 kB)
Periodicity-enhanced structures for efficient sound absorption
conference contribution
posted on 2016-10-13, 09:50 authored by Victor V. Krylov, Abdelhalim Azbaid El OuahabiIn the present work, an overview of experimental investigations of the two types of periodicity-enhanced acoustic absorbing structures is given. In the first type of structures, the performance of acoustic absorbing materials is improved by providing a smooth transition from the impedance of air to the impedance of the absorbing material in question. This smooth change in the impedance is materialised using gradient index metamaterial layers formed by quasi-periodic arrays of solid cylinders. In the second type of performance improving devices, the principle of acoustic black holes has been implemented. To achieve the required power-law decrease in sound velocity with propagation distance the cylindrical inhomogeneous acoustic waveguides enhanced by quasi-periodic systems of concentric rings have been used. Measurements of the reflection coefficients for both types of structures have been carried out. The results show the possibility of substantial reduction of the acoustic reflections in both cases.
Funding
The research reported here has been supported by EPSRC grant EP/K038214/1.
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Aeronautical and Automotive Engineering
Published in
27th International Conference on Noise and Vibration Engineering, 'ISMA 2016' Proceedings of the ISMA 2016Pages
2057 - 2070Citation
KRYLOV, V.V. and AZBAID EL OUAHABI, A.,2016. Periodicity-enhanced structures for efficient sound absorption. Presented at the 27th International Conference on Noise and Vibration Engineering, (ISMA 2016), Leuven, Belgium, 19th-21st Sept., pp. 2057-2070.Publisher
KU LeuvenVersion
- AM (Accepted Manuscript)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Acceptance date
2016-08-21Publication date
2016Notes
This is a conference paper.Publisher version
Language
- en