The University of Southampton
University of Southampton Institutional Repository

High frequency multimode radiation from ducts with flow

High frequency multimode radiation from ducts with flow
High frequency multimode radiation from ducts with flow
Multimode sound radiation from hard-walled semi-infinite ducts with uniform subsonic flow is investigated theoretically. An analytic expression, valid in the high frequency limit, is derived for the multimode directivity function in the forward arc for a general family of mode distribution functions. The multimode directivity depends on the amplitude and directivity function of each individual mode. The amplitude of each mode is expressed as a function of cut-off ratio for a uniform distribution of incoherent monopoles, a uniform distribution of incoherent axial dipoles and for equal power per mode. The modes' directivity functions are obtained analytically by applying a Lorentz transformation to the zero flow solution. The analytic formula for the multimode directivity with flow is derived assuming total transmission of power at the open-end of the duct. This formula is compared to the exact numerical result for an unflanged duct, computed utilizing a Wiener-Hopf solution.The agreement is shown to be excellent.
Sinayoko, S.
4ef613be-ccf6-44ea-84e5-8d48ee47d3d2
Joseph, P.F.
9c30491e-8464-4c9a-8723-2abc62bdf75d
McAlpine, A.
aaf9e771-153d-4100-9e84-de4b14466ed7
Sinayoko, S.
4ef613be-ccf6-44ea-84e5-8d48ee47d3d2
Joseph, P.F.
9c30491e-8464-4c9a-8723-2abc62bdf75d
McAlpine, A.
aaf9e771-153d-4100-9e84-de4b14466ed7

Sinayoko, S., Joseph, P.F. and McAlpine, A. (2008) High frequency multimode radiation from ducts with flow. Proceedings of the 14th AIAA/CEAS Aeroacoustics Conference (29th AIAA Aeroacoustics Conference). 05 - 07 May 2008. 12 pp .

Record type: Conference or Workshop Item (Paper)

Abstract

Multimode sound radiation from hard-walled semi-infinite ducts with uniform subsonic flow is investigated theoretically. An analytic expression, valid in the high frequency limit, is derived for the multimode directivity function in the forward arc for a general family of mode distribution functions. The multimode directivity depends on the amplitude and directivity function of each individual mode. The amplitude of each mode is expressed as a function of cut-off ratio for a uniform distribution of incoherent monopoles, a uniform distribution of incoherent axial dipoles and for equal power per mode. The modes' directivity functions are obtained analytically by applying a Lorentz transformation to the zero flow solution. The analytic formula for the multimode directivity with flow is derived assuming total transmission of power at the open-end of the duct. This formula is compared to the exact numerical result for an unflanged duct, computed utilizing a Wiener-Hopf solution.The agreement is shown to be excellent.

Full text not available from this repository.

More information

Published date: May 2008
Venue - Dates: Proceedings of the 14th AIAA/CEAS Aeroacoustics Conference (29th AIAA Aeroacoustics Conference), 2008-05-05 - 2008-05-07

Identifiers

Local EPrints ID: 57779
URI: https://eprints.soton.ac.uk/id/eprint/57779
PURE UUID: 7bad06ec-4e8e-4a7d-b05f-4b046f9281d9
ORCID for A. McAlpine: ORCID iD orcid.org/0000-0003-4189-2167

Catalogue record

Date deposited: 20 Aug 2008
Last modified: 14 Mar 2019 01:49

Export record

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×