Modelling of ducted noise sources in the proximity of acoustic liners

This paper focuses on modelling and predicting the acoustic field generated by ducted point sources in close proximity to an acoustic liner. Two analytical models are presented. The first model comprises a point monopole or dipole source in an infinite lined duct based on an existing Green's function. The predictions are compared with classic solutions for a source over an infinite lined plane and with a high frequency asymptotic duct approximation. The second model extends the Green's function to include a liner section of finite length connected to hard-wall extensions by using mode-matching techniques. The new model features the inclusion of point sources in the vicinity of an impedance discontinuity. The accuracy of this model is demonstrated by comparison with reference FE solutions. Both models indicate a significant impact of the source proximity to the liner surface in the source power output. These models offer insight on the source modification effects beyond the conventional approach in the design of liners solely based on acoustic absorption.

Duct acoustics, Mode-matching, Noise reduction, Source proximity liners

10.1016/j.jsv.2021.116548

0022-460X

Palleja-Cabre, S.

b841a96c-05d1-4f08-a197-8693cb3a3f90

Tester, B.J.

1bd4a793-131b-4173-93cc-3eca70b2d116

Astley, R.J.

cb7fed9f-a96a-4b58-8939-6db1010f9893

20 January 2022

Palleja-Cabre, S.

b841a96c-05d1-4f08-a197-8693cb3a3f90

Tester, B.J.

1bd4a793-131b-4173-93cc-3eca70b2d116

Astley, R.J.

cb7fed9f-a96a-4b58-8939-6db1010f9893

Palleja-Cabre, S., Tester, B.J. and Astley, R.J. (2022) Modelling of ducted noise sources in the proximity of acoustic liners. Journal of Sound and Vibration, 517 (116548), [116548]. (doi:10.1016/j.jsv.2021.116548).

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Modelling_of_ducted_noise_sources_in_the_proximity_of_acoustic_liners - Accepted Manuscript

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Published date: 20 January 2022

Additional Information: Funding Information: This project was funded by the European Union's Horizon 2020 research and innovation programme under a Marie Sklodowska-Curie Innovative Training Network (ITN) grant (Agreement No 722401) within the SmartAnswer consortium. The authors thank Prof. Rienstra for the use of his eigenvalue solver routine, and Dr. Hadrien Beriot for his support in obtaining the numerical solutions using the FE software Simcenter 3D Acoustics. Funding Information: This project was funded by the European Union’s Horizon 2020 research and innovation programme under a Marie Sklodowska-Curie Innovative Training Network (ITN) grant (Agreement No 722401 ) within the SmartAnswer consortium. The authors thank Prof. Rienstra for the use of his eigenvalue solver routine, and Dr. Hadrien Beriot for his support in obtaining the numerical solutions using the FE software Simcenter 3D Acoustics. Publisher Copyright: © 2021 Elsevier Ltd Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

Keywords: Duct acoustics, Mode-matching, Noise reduction, Source proximity liners