Proceedings of the 10th Convention of the
European Acoustics Association
Forum Acusticum 2023


Politecnico di Torino
Torino, Italy
September 11 - 15, 2023





Session: A01-05: Active metamaterials
Date: Friday 15 September 2023
Time: 11:40 - 12:00
Title: Advection Boundary Law for sound transmission attenuation of plane and spinning guided modes
Author(s): E. De Bono, Université Bourgogne Franche-Comté, FEMTO-ST, 24 rue de l'Épitaphe, 25000 Besançon, France
M. Collet, École Centrale de Lyon, LTDS, 36 avenue Guy de Collonge, 69130 Écully, France
É. Salze, École Centrale de Lyon, LMFA, 36 avenue Guy de Collonge, 69130 Écully, France
M. Ouisse, Université Bourgogne Franche-Compté, FEMTO-ST, 24 rue de l'Épitaphe, 25000 Besançon, France
M. Gillet, Université Bourgogne Franche-Compté, FEMTO-ST, 24 rue de l'Épitaphe, 25000 Besançon, France
H. Lissek, EPFL, Signal processing laboratory LTS2, acoustic group, Sation 11, 1015 Lausanne, Switzerland
J. Mardjono, Safran Aircraft Engines, Rond-point René Ravaud, 77550 Moissy-Cramayel, France
K. Billon, École Centrale de Lyon, LTDS, 36 avenue Guy de Collonge, 69130 Écully, France
M. Volery, EPFL, Route Cantonale, 1015 Lausanne, Switzerland
Pages: 6065-6069
DOI: https://www.doi.org/10.61782/fa.2023.0573
PDF: https://dael.euracoustics.org/confs/fa2023/data/articles/000573.pdf
Conference proceedings
Abstract

Sound attenuation along a waveguide is a highly demanded research field, for applications ranging from heating and air-conditioning ventilation systems, to aircraft turbofan engines. Electroacoustic devices and digital control have provided the tools for crafting innovative liners where the boundary condition can be programmed. The most straightforward idea is to program classical local impedance operators. Nevertheless, it might be worthy to navigate off the beaten track, and try to target boundary operators which could never be physically produced by purely passive treatments. In this contribution, we focus the attention on a particular boundary law, called advective, as it possesses a convective character achieved thanks to the introduction of the first spatial derivative. After introducing such special boundary condition, we implement it on an electroacoustic liner and demonstrate its potentialities in enhancing the transmission loss in acoustic waveguides with flow. We present results for both plane and spinning modes attenuation. Numerical simulations and experimental implementations demonstrate the potentiality of this boundary law, opening the doors toward boundary operators involving spatial derivatives for wave propagation control.