Broadband liner impedance eduction for multimodal acoustic propagation in the presence of a mean flow

Troian, Renata; Dragna, Didier; Bailly, Christophe; Galland, Marie‐Annick

doi:10.1016/j.jsv.2016.10.014

Cited by 55 publications

(24 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this sub-section, the implementation of the TDIBC based on the ADE method is explained, which is built upon methodologies proposed by Dragna et al (2015) and Troian et al (2017). All TDIBC formulations involving the dependency on angular frequency ω assume time harmonic behaviour e iωt .…”

Section: Ade Methods Based On Multi-oscillator Wall Softnessmentioning

confidence: 99%

“…(2015) and Troian et al. (2017). All TDIBC formulations involving the dependency on angular frequency assume time harmonic behaviour .…”

Section: Time-domain Impedance Boundary Conditionsmentioning

confidence: 96%

“…However, the method is limited to second-order temporal accuracy. To address this issue, Dragna, Pineau & Blanc-Benon (2015), Troian et al (2017) replaced the convolution integral with a set of auxiliary variables, each governed by a first-order ODE. This method is usually referred to as the auxiliary differential equation (ADE) method that originates from the field of electromagnetism (Joseph, Hagness & Taflove 1991).…”

Section: Time-domain Impedance Boundary Conditionsmentioning

confidence: 99%

See 2 more Smart Citations

Trapped waves in supersonic and hypersonic turbulent channel flow over porous walls

Chen

Scalo

2021

J. Fluid Mech.

View full text Add to dashboard Cite

show abstract

Section: Ade Methods Based On Multi-oscillator Wall Softnessmentioning

confidence: 99%

“…(2015) and Troian et al. (2017). All TDIBC formulations involving the dependency on angular frequency assume time harmonic behaviour .…”

Section: Time-domain Impedance Boundary Conditionsmentioning

confidence: 96%

Section: Time-domain Impedance Boundary Conditionsmentioning

confidence: 99%

See 1 more Smart Citation

Trapped waves in supersonic and hypersonic turbulent channel flow over porous walls

Chen

Scalo

2021

J. Fluid Mech.

View full text Add to dashboard Cite

show abstract

“…High-order moments or even the probability density functions, as obtained by Ehrhardt et al 32 for plane wave propagation through a turbulent medium, are not investigated as it would require to have a much higher number of realizations. Finally, the implementation of the time-domain admittance boundary condition is based on a generalized recursive convolution method, described in Troian et al 33 Numerical simulations have been performed for the two ground types presented in Sec. II D. For the parameters of the admittance fluctuations chosen here, the randomness has only a small influence for the semi-infinite ground: typically, the SPL for a particular realization deviates from the unperturbed SPL by at maximum 2 dB over the frequency bandwidth of interest.…”

Section: A Numerical Specificationmentioning

confidence: 99%

Sound propagation over the ground with a random spatially-varying surface admittance

Dragna

Blanc‐Benon

2017

The Journal of the Acoustical Society of America

Self Cite

View full text Add to dashboard Cite

Sound propagation over the ground with a random spatially-varying surface admittance is investigated. Starting from the Green's theorem, a Dyson equation is derived for the coherent acoustic pressure. Under the Bourret approximation, an explicit expression is deduced and an effective admittance that depends on the correlation function of the admittance fluctuations is exhibited. An asymptotic expression at long range is then obtained. Influence of the randomness on the amplitude of the reflection coefficient and on the wavenumbers of the surface wave component is analyzed. Afterwards, numerical simulations of the linearized Euler equations are carried out and the coherent pressure obtained by an ensemble-averaging over 200 realizations of the admittance is found to be in good agreement with the analytical solution. In the considered examples of grounds, the mean intensity is shown to be similar to the intensity in the non-random case, except near interferences that are smoothened out due to randomness. It is however exemplified that the intensity fluctuations can be large, especially near destructive interferences.

show abstract

“…In [7] numerical tools to solve sound propagation in acoustic liners are reviewed, starting from the Navier-Stokes equations [5], very accurate but expensive from the computational viewpoint to some reduced formulations that even that are less accurate, they are computationally more efficient. The suppression of the diffusive term in the Navier-Stokes equations leads to the linearized Euler equations [8,9] and finally the Helmholtz equation implies the use of the hypothesis of a hometropic and irrotational flow. Finally, a check of the boundary condition can be performed.…”

Section: Introductionmentioning

confidence: 99%

Empowering Design Based on Hybrid TwinTM: Application to Acoustic Resonators

Martin

Méndez

Sainges

et al. 2020

Designs

View full text Add to dashboard Cite

In the framework of civil aviation noise levels are becoming restricted every year, on one hand to provide comfort to the passengers and on the other hand to be compliant with regulations protecting airports surroundings. New technologies are required to reduce noise to cope with this restrictions as well as to guarantee a comfortable flight for passengers. For technological industries it is compulsory to stay competitive and keep improving the technology related to air intake acoustic liners. With an unceasingly growing market, for industries it is key to stay in the vanguard of air inlet technologies, ensuring innovation and establishing a proactive environment for future product generations. One of the main objectives in this framework is the reduction of the development time of these new technologies in all the stages of the process. In this work we focus on the design stage of a new prototype and we propose a hybrid technique enabling faster design and the reduction of development time. When designing new technologies or prototypes there are usually two constraints. On one hand, more innovative prototypes may present unconventional shapes are not accurately represented by conventional physical models. On the other hand, the available data is scarce, thus limiting the use of most innovative techniques based on the state-of-art of Artificial Intelligence. In this paper we propose a solution laying in the hybrid twin paradigm, combining both, data in the low limit and physics to provide a hybrid model able to represent unconventional and innovative acoustic solutions.

show abstract

Broadband liner impedance eduction for multimodal acoustic propagation in the presence of a mean flow

Cited by 55 publications

References 42 publications

Trapped waves in supersonic and hypersonic turbulent channel flow over porous walls

Trapped waves in supersonic and hypersonic turbulent channel flow over porous walls

Sound propagation over the ground with a random spatially-varying surface admittance

Empowering Design Based on Hybrid TwinTM: Application to Acoustic Resonators

Contact Info

Product

Resources

About