Final version Horner Hu Applie Acoustics May 2012.pdf (2.18 MB)
A hybrid modal decomposition approach for higher-order modes in circular ducts
journal contribution
posted on 2012-08-08, 07:47 authored by Jane L. Horner, Y. HuBefore it is possible to determine the effect over a wide frequency range of different
aperture devices on the sound field in a duct, the contribution from the individual
higher-order modes must be established. Two approaches to decompose the sound
field may be taken which are either to use a large number of microphone locations to
reconstruct the sound field, or to use a hybrid method involving a reduced set of
microphone locations and a model of the sound field in the system. Modelling the
higher-order modes in a duct is itself a numerically intensive procedure if fully
coupled calculations are required. It is possible to simplify the process for modelling
the sound field by using uncoupled calculations for the higher order modes. Results
are presented for such a hybrid approach, combining a limited number of microphone
locations with an uncoupled model, to establish the sound field in a circular duct.
Both point source and plane wave sources are considered and direct measurement of
the sound field is compared to the reconstructed field for a normalised wave number
range up to 7. Results show acceptable agreement between the hybrid approach and
direct measurement with the greatest errors occurring around cut-on of the axially
anti-symmetric modes. Thus, it is demonstrated that a hybrid approach may be
applied to ducts with simple sources and that the approach can be used to deconstruct
the in-duct sound field into the individual higher-order mode contributions
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Aeronautical and Automotive Engineering
Citation
HORNER, J.L. and HU, Y., 2012. A hybrid modal decomposition approach for higher-order modes in circular ducts. Applied Acoustics, 74 (1), pp.122–133.Publisher
© ElsevierVersion
- AM (Accepted Manuscript)
Publication date
2012Notes
This is the author’s version of a work that was accepted for publication in the journal, Applied Acoustics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published at: http://dx.doi.org/10.1016/j.apacoust.2012.06.018ISSN
0003-682XPublisher version
Language
- en