Regularisation of the equivalent source method for robust numerical modelling of acoustic scattering
The equivalent source method can be used to model acoustic scattering, by representing the scattering object with a set of equivalent sources that satisfy a boundary condition. The equivalent source strengths are optimised by a least-squares method. When the equivalent sources are positioned furt...
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| Format: | Conference Paper |
| Language: | English |
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2025
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| Online Access: | https://hdl.handle.net/10356/182895 http://www.scopus.com/inward/record.url?eid=2-s2.0-84947606523&partnerID=MN8TOARS https://eprints.soton.ac.uk/380528/1/Bhan.pdf https://www.proceedings.com/27574.html |
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| author | Lam, Bhan Elliott, Stephen Cheer, Jordan Gan, Woon-Seng |
| author2 | School of Electrical and Electronic Engineering |
| author_facet | School of Electrical and Electronic Engineering Lam, Bhan Elliott, Stephen Cheer, Jordan Gan, Woon-Seng |
| author_sort | Lam, Bhan |
| collection | NTU |
| description | The equivalent source method can be used to model acoustic scattering, by representing the
scattering object with a set of equivalent sources that satisfy a boundary condition. The
equivalent source strengths are optimised by a least-squares method. When the equivalent
sources are positioned further from the boundary to reduce the boundary condition error,
the optimisation becomes ill-conditioned. This limits the application of the equivalent
source method in irregularly-shaped objects as boundary condition error is highly sensitive
to equivalent source placement. To overcome the problem of ill-conditioning, a
regularisation parameter is introduced, which increases the robustness to errors in the
modelled acoustic field by limiting the power of overdriven equivalent sources. Simulations
of a rigid infinite wall with an equivalent dipole line-array, reveal that regularisation
reduces boundary condition error in all ill-conditioned cases. Good trade-offs between
boundary condition error and regularisation are achieved for a wide range of regularisation parameter values. This allows the results to be calculated for varying
frequencies and distances between the equivalent sources and the boundary. Regularisation
reduces the sensitivity of boundary condition error to equivalent source placement, thereby
increasing the flexibility of the equivalent source method for irregularly-shaped scattering
objects. |
| first_indexed | 2025-03-09T10:04:13Z |
| format | Conference Paper |
| id | ntu-10356/182895 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2025-03-09T10:04:13Z |
| publishDate | 2025 |
| record_format | dspace |
| spelling | ntu-10356/1828952025-03-07T15:43:44Z Regularisation of the equivalent source method for robust numerical modelling of acoustic scattering Lam, Bhan Elliott, Stephen Cheer, Jordan Gan, Woon-Seng School of Electrical and Electronic Engineering 44th International Congress and Exposition on Noise Control Engineering (Inter-Noise 2015) Digital Signal Processing Laboratory Engineering Acoustics Scattering Numerical modelling Equivalent source method The equivalent source method can be used to model acoustic scattering, by representing the scattering object with a set of equivalent sources that satisfy a boundary condition. The equivalent source strengths are optimised by a least-squares method. When the equivalent sources are positioned further from the boundary to reduce the boundary condition error, the optimisation becomes ill-conditioned. This limits the application of the equivalent source method in irregularly-shaped objects as boundary condition error is highly sensitive to equivalent source placement. To overcome the problem of ill-conditioning, a regularisation parameter is introduced, which increases the robustness to errors in the modelled acoustic field by limiting the power of overdriven equivalent sources. Simulations of a rigid infinite wall with an equivalent dipole line-array, reveal that regularisation reduces boundary condition error in all ill-conditioned cases. Good trade-offs between boundary condition error and regularisation are achieved for a wide range of regularisation parameter values. This allows the results to be calculated for varying frequencies and distances between the equivalent sources and the boundary. Regularisation reduces the sensitivity of boundary condition error to equivalent source placement, thereby increasing the flexibility of the equivalent source method for irregularly-shaped scattering objects. Ministry of National Development (MND) National Research Foundation (NRF) Submitted/Accepted version This material is based on research/work supported by the Singapore Ministry of National Development and National Research Foundation under L2 NIC Award No. L2NICCFP1-2013-7. 2025-03-06T06:27:17Z 2025-03-06T06:27:17Z 2015 Conference Paper Lam, B., Elliott, S., Cheer, J. & Gan, W. (2015). Regularisation of the equivalent source method for robust numerical modelling of acoustic scattering. 44th International Congress and Exposition on Noise Control Engineering (Inter-Noise 2015), 5, 3831-3842. 9781510810822 https://hdl.handle.net/10356/182895 2-s2.0-84947606523 http://www.scopus.com/inward/record.url?eid=2-s2.0-84947606523&partnerID=MN8TOARS https://eprints.soton.ac.uk/380528/1/Bhan.pdf https://www.proceedings.com/27574.html 5 3831 3842 en L2NICCFP1-2013-7 © 2015 Institute of Noise Control Engineering - USA (INCE-USA). All rights reserved. This article may be downloaded for personal use only. Any other use requires prior permission of the copyright holder. application/pdf |
| spellingShingle | Engineering Acoustics Scattering Numerical modelling Equivalent source method Lam, Bhan Elliott, Stephen Cheer, Jordan Gan, Woon-Seng Regularisation of the equivalent source method for robust numerical modelling of acoustic scattering |
| title | Regularisation of the equivalent source method for robust numerical modelling of acoustic scattering |
| title_full | Regularisation of the equivalent source method for robust numerical modelling of acoustic scattering |
| title_fullStr | Regularisation of the equivalent source method for robust numerical modelling of acoustic scattering |
| title_full_unstemmed | Regularisation of the equivalent source method for robust numerical modelling of acoustic scattering |
| title_short | Regularisation of the equivalent source method for robust numerical modelling of acoustic scattering |
| title_sort | regularisation of the equivalent source method for robust numerical modelling of acoustic scattering |
| topic | Engineering Acoustics Scattering Numerical modelling Equivalent source method |
| url | https://hdl.handle.net/10356/182895 http://www.scopus.com/inward/record.url?eid=2-s2.0-84947606523&partnerID=MN8TOARS https://eprints.soton.ac.uk/380528/1/Bhan.pdf https://www.proceedings.com/27574.html |
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