
The Library
Experimentally testing impedance boundary conditions for acoustic liners with flow : beyond upstream and downstream
Tools
Spillere, André Mateus Netto, Bonomo, Lucas Araujo, Cordioli, Júlio Apolinário and Brambley, Edward James (2020) Experimentally testing impedance boundary conditions for acoustic liners with flow : beyond upstream and downstream. Journal of Sound and Vibration . 115676. doi:10.1016/j.jsv.2020.115676 ISSN 0022-460X.
|
PDF
WRAP-Experimentally-testing-impedance-boundary-conditions-acoustic-liners-Bramley-2020.pdf - Accepted Version - Requires a PDF viewer. Available under License Creative Commons Attribution Non-commercial No Derivatives 4.0. Download (1443Kb) | Preview |
Official URL: https://doi.org/10.1016/j.jsv.2020.115676
Abstract
Impedance eduction experiments on acoustic liners with flow have systematically shown the educed impedance depending on the direction of the incident wave. Recent attempts to model this dependence include impedance boundary conditions with an additional degree of freedom. In this case, both upstream and downstream acoustic sources must be used to educe both the liner impedance and the extra degree of freedom of the model, which implies two different axial wavenumber conditions are used, and always result in a perfect collapse of the educed impedances; this would be true whether or not the model itself is correct. In this work, we describe a novel experimental setup that allows for four different axial wavenumbers per frequency to be measured: two upstream and two downstream. We use this experiment to investigate three different impedance boundary conditions, namely inviscid sheared, viscous, and momentum transfer conditions, in addition to the classical Ingard–Myers boundary condition, using an inverse eduction technique based on the mode matching method. The additional degree of freedom in each of the first three models is best fitted to experimental data, and then compared to the theoretically predicted values. Unphysical or unrealistic values are found at certain frequencies for each model, and therefore the validity of such models is questionable. The predictive capabilities of the models are tested and compared by means of the plane-wave scattering matrix, and no model is found to be truly predictive. Under certain conditions, educed impedances using the Ingard–Myers boundary condition show similar accuracy in terms of transmission coefficients when compared to the other models.
Item Type: | Journal Article | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Subjects: | Q Science > QA Mathematics Q Science > QC Physics |
||||||||||||
Divisions: | Faculty of Science, Engineering and Medicine > Science > Mathematics Faculty of Science, Engineering and Medicine > Engineering > WMG (Formerly the Warwick Manufacturing Group) |
||||||||||||
SWORD Depositor: | Library Publications Router | ||||||||||||
Library of Congress Subject Headings (LCSH): | Acoustic impedance, Boundaries, S-matrix theory | ||||||||||||
Journal or Publication Title: | Journal of Sound and Vibration | ||||||||||||
Publisher: | Elsevier Ltd. | ||||||||||||
ISSN: | 0022-460X | ||||||||||||
Official Date: | 28 August 2020 | ||||||||||||
Dates: |
|
||||||||||||
Article Number: | 115676 | ||||||||||||
DOI: | 10.1016/j.jsv.2020.115676 | ||||||||||||
Status: | Peer Reviewed | ||||||||||||
Publication Status: | Published | ||||||||||||
Access rights to Published version: | Restricted or Subscription Access | ||||||||||||
Copyright Holders: | © 2020 Elsevier Ltd. All rights reserved. | ||||||||||||
Description: | A preliminary version of some parts of this paper was presented as AIAA Paper 2019–2488 at the 25th AIAA/CEAS Aeroacoustics Conference in Delft, The Netherlands |
||||||||||||
Date of first compliant deposit: | 15 October 2020 | ||||||||||||
Date of first compliant Open Access: | 28 August 2021 | ||||||||||||
RIOXX Funder/Project Grant: |
|
Request changes or add full text files to a record
Repository staff actions (login required)
![]() |
View Item |
Downloads
Downloads per month over past year