Improved sound transmission loss of glass wool with acoustic metamaterials
Improved sound transmission loss of glass wool with acoustic metamaterials
Fibrous absorbers, such as glass wool, are widely applied as thermo-acoustic insulation. The lightweightness and good fire-smoke-toxicity properties of glass wool makes this material a well proven insulation material, e.g. in aircraft cabins. However, since the sound absorption of fibrous materials is governed by viscous losses, their sound insulation performance is reduced at low frequencies. Acoustic metamaterials, on the other hand, have emerged in the recent years as new sound insulation materials with particular efficiency in the low-frequency regime. Due to the dispersive properties of most acoustic metamaterials, however, this efficiency typically is limited to relatively narrow frequency bands. Therefore, it seems to be reasonable to combine the strengths of both types of sound insulation materials in order to achieve good sound insulation characteristics at low and high frequencies with low additional weight and/or installation space. In this contribution, first results from investigations of how the low-frequency acoustic performance of glass wool can be improved by adding acoustic metamaterials are presented. The investigated concept employs a thin plate-type acoustic metamaterial (PAM), which exhibits tunable anti-resonance frequencies with transmission loss values much larger than the corresponding mass law. The PAM is combined with lightweight aircraft grade glass wool and attached to a plate in order to improve the sound transmission loss of the plate. An analytical model is used to predict the acoustic performance of this design. Finally, the concept is validated using a 1.2 m2 test sample, which is experimentally characterized using sound intensity measurements in a laboratory
Acoustic metamaterial, Glass wool, Plate, Transmission loss
Canadian Acoustical Association
Langfeldt, Felix
2bf86877-f2cd-4c35-be0f-e38a718a915c
Gleine, Wolfgang
6b99025f-b44a-46a8-b699-ec25962c7e75
2019
Langfeldt, Felix
2bf86877-f2cd-4c35-be0f-e38a718a915c
Gleine, Wolfgang
6b99025f-b44a-46a8-b699-ec25962c7e75
Langfeldt, Felix and Gleine, Wolfgang
(2019)
Improved sound transmission loss of glass wool with acoustic metamaterials.
In Proceedings of the 26th International Congress on Sound and Vibration, ICSV 2019.
Canadian Acoustical Association..
Record type:
Conference or Workshop Item
(Paper)
Abstract
Fibrous absorbers, such as glass wool, are widely applied as thermo-acoustic insulation. The lightweightness and good fire-smoke-toxicity properties of glass wool makes this material a well proven insulation material, e.g. in aircraft cabins. However, since the sound absorption of fibrous materials is governed by viscous losses, their sound insulation performance is reduced at low frequencies. Acoustic metamaterials, on the other hand, have emerged in the recent years as new sound insulation materials with particular efficiency in the low-frequency regime. Due to the dispersive properties of most acoustic metamaterials, however, this efficiency typically is limited to relatively narrow frequency bands. Therefore, it seems to be reasonable to combine the strengths of both types of sound insulation materials in order to achieve good sound insulation characteristics at low and high frequencies with low additional weight and/or installation space. In this contribution, first results from investigations of how the low-frequency acoustic performance of glass wool can be improved by adding acoustic metamaterials are presented. The investigated concept employs a thin plate-type acoustic metamaterial (PAM), which exhibits tunable anti-resonance frequencies with transmission loss values much larger than the corresponding mass law. The PAM is combined with lightweight aircraft grade glass wool and attached to a plate in order to improve the sound transmission loss of the plate. An analytical model is used to predict the acoustic performance of this design. Finally, the concept is validated using a 1.2 m2 test sample, which is experimentally characterized using sound intensity measurements in a laboratory
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Published date: 2019
Additional Information:
Funding Information:
This work has been performed under the framework of the German-Canadian joint research project New Acoustic Insulation Metamaterial Technology for Aerospace (NAIMMTA), funded by the Federal Ministry of Education and Research (grant number: 03INT504AB). The financial support is gratefully acknowledged by the authors. Furthermore, the authors would like to thank Hutchinson Aerospace GmbH for providing the glass wool blankets and fixation elements for the assembly of the laboratory test sample.
Publisher Copyright:
© Proceedings of the 26th International Congress on Sound and Vibration, ICSV 2019. All rights reserved.
Venue - Dates:
26th International Congress on Sound and Vibration, ICSV 2019, , Montreal, Canada, 2019-07-07 - 2019-07-11
Keywords:
Acoustic metamaterial, Glass wool, Plate, Transmission loss
Identifiers
Local EPrints ID: 469336
URI: http://eprints.soton.ac.uk/id/eprint/469336
PURE UUID: 2f2cdb12-aacc-4a3d-a4a4-acaf9fe0764e
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Date deposited: 13 Sep 2022 16:47
Last modified: 18 Mar 2024 04:05
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Author:
Wolfgang Gleine
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