BROADBAND AND QUASI-PERFECT ACOUSTIC ABSORPTION WITH BIO-INSPIRED HIERARCHICAL METAMATERIALS FOR AIR AND SURFACE TRANSPORTATION SYSTEMS

Aircraft noise has become a major concern for communities around airports giving rise to stacked legislations and regulations at various levels. Current noise reduction technologies do not seem to achieve the targeted reductions set by the EC experts by the ACARE Flightpath 2050. Classical control methods can provide significant noise reduction but may add additional mass causing excess drag and degradation of the aircraft aerodynamic performance. The general goal of this proposal is to create meta-structures able to efficiently dissipate flow-induced noise without requiring increasing area or added weight. We have proposed a novel type of high performance acoustic treatment made up of Micro-Capillary Plate (MCP) absorbers. MCPs consist of highly porous panels made up of leaded glass, of high porosity (greater than 60%) since their surface contains millions of micro-channels per centimeter square, the holes or square channel dimensions varying between 5µm and 50µm. These characteristics provide them with exceptional acoustical properties compared to other classical absorbers or MPPs. For instance, if rigidly backed by an air cavity of 24 mm, a MCP device provides a half-bandwidth absorption over 12 octaves whereas a MPP device works only over two-three octaves. The project outcomes allow practical selection of the meta-material architecture that best suits specific applications. For instance, they can be used for duct geometries in air-conditioning and ventilations systems.

Publicaciones
Revistas JCR
GAA The use of microperforations to attenuate the cavity pressure fluctuations induced by a low-speed flow
Cédric Maury, Teresa Bravo, Daniel Mazzoni
Journal of Sound and Vibration Volume 439, 20 January 2019, Pages 1-16
https://doi.org/10.1016/j.jsv.2018.09.045
GAA Wideband sound absorption and transmission through micro-capillary plates: Modelling and experimental validation
Cédric Maury, Teresa Bravo
Journal of Sound and Vibration, Volume 478, 2020, 115356
https://doi.org/10.1016/j.jsv.2020.115356
GAA Causally-guided acoustic optimization of single-layer rigidly-backed micro-perforated partitions: Theory
Teresa Bravo, Cédric Maury,
Journal of Sound and Vibration, Volume 520, 2022, 116634
https://doi.org/10.1016/j.jsv.2021.116634
GAA Causally-guided acoustic optimization of rigidly-backed micro-perforated partitions: Case studies and experiments
Teresa Bravo, Cédric Maury
Journal of Sound and Vibration, Volume 523, 2022, 116735
https://doi.org/10.1016/j.jsv.2021.116735
GAA Enhanced modal matching method for macro- and micro-perforated plates
Cédric Maury, Teresa Bravo
Journal of Sound and Vibration, Volume 500, 2021, 116042
https://doi.org/10.1016/j.jsv.2021.116042
Proceedings
GAA Cost-efficient characterization of the aeroacoustic performance of micro-perforated wall-treatments in a wind tunnel
Cedric Maury, Teresa Bravo, Daniel Mazzoni, Muriel Amielh and Laurence Pietri
Proc. Mtgs. Acoust. 42, 040001 (2020)
https://doi.org/10.1121/2.0001378
GAA Assessing the broadband absorption properties of micro-capillary plates through modelling and experimental studies
Teresa Bravo and Cedric Maury
Proc. Mtgs. Acoust. 42, 040002 (2020)
https://doi.org/10.1121/2.0001380
Libros y Capítulos de Libro
GAA Absorption and Transmission of Boundary Layer Noise through Micro-Perforated Structures: Measurements and Modellings
Cédric Maury, Teresa Bravo & Daniel Mazzoni
Flinovia—Flow Induced Noise and Vibration Issues and Aspects-III. FLINOVIA 2019. Springer, Cham
https://doi.org/10.1007/978-3-030-64807-7_11
Congresos y reuniones, conferencias
2022
GAA Sound absorption through micro-capillary plates: modelling and experimental studies
Conferencia invitada

T. Bravo and C. Maury

24th Internationa Congress on Acoustics

Del 24 al 28 de octubre de 2022, Gyeongju, Corea del Sur.

GAA Causal-based acoustic optimization of microperforated structures with rigid backing
Conferencia invitada

T. Bravo and C. Maury

Internoise 2022

August 2022, Glasgow, UK.

2021
GAA Low-frequency broadband dissipation using Micro-Capillary Plates
Conferencia invitada

T. Bravo and C. Maury

Symposium on the Acoustics of Poro-Elastic Materials, SAPEM 2020+I

E-congress celebrado del 29 de marzo al 2 de abril de 2021.


Comunicación presentada
2020
GAA Investigation of Micro-Capillary Plates to Enhance Low-Frequency Sound Absorption
Conferencia invitada

C. Maury and T. Bravo

FORUM ACUSTICUM 2020, FA2020/35,

E-congress celebrado del 7 al 11 de diciembre de 2020, Lyon, Francia.


Comunicación presentada
GAA The Effect of a Micro-Perforated Cavity Floor on the Propagation of Tunnel-Cavity Modes in a Low-Speed Duct Flow
Conferencia invitada

C. Maury, T. Bravo and D. Mazzoni

FORUM ACUSTICUM 2020, FA2020/35,

E-congress celebrado del 7 al 11 de diciembre de 2020, Lyon, Francia.


Comunicación presentada
GAA Micro-capillary plate absorbers for broadband dissipation in the low frequency range
Conferencia invitada

T. Bravo and C. Maury

Internoise 2020.

E-congress celebrado del 23 al 26 de agosto de 2020, Seúl, Corea.

2019
GAA Optimised micro-perforated panels for broadband absorptivity
Conferencia invitada

T. Bravo and C. Maury

26th International Congress on Sound and Vibration

Del 7 al 11 de julio de 2019, Montreal, Canada.

GAA Absorption and Transmission through Functionally-Graded Micro Perforated Panels
Conferencia invitada

T. Bravo, C. de la Colina and C. Maury

The 48th International Congress and Exhibition on Noise Control Engineering. INTERNOISE 2019.

Del 16 al 19 de junio de 2019, Madrid, España.


Comunicación presentada
GAA The Attenuation of Flow-Induced Cavity Noise in a Wind-Tunnel by Micro-Perforations
Conferencia invitada

C. Maury, T. Bravo and D. Mazzoni

The 48th International Congress and Exhibition on Noise Control Engineering. INTERNOISE 2019.

Del 16 al 19 de junio de 2019, Madrid, España.


Comunicación presentada
2018
GAA Sound Attenuation in a Flow Duct Periodically Loaded with Micro-Perforates Backed by Helmholtz Resonators
Conferencia invitada

T. Bravo and C. Maury

The 47th International Congress and Exhibition on Noise Control Engineering. INTERNOISE 2018.

Del 26 al 29 de agosto de 2018, Chicago, Illinois, EE.UU.