Change search
ReferencesLink to record
Permanent link

Direct link
In-duct identification of a rotating sound source with high spatial resolution
KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Vibration monitoring.ORCID iD: 0000-0002-8474-8563
2015 (English)In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 357, 51-73 p.Article in journal (Refereed) Published
Abstract [en]

To understand and reduce the flow noise generation from in-duct fluid machines, it is necessary to identify the acoustic source characteristics precisely. In this work, a source identification technique, which can identify the strengths and positions of the major sound radiators in the source plane, is studied for an in-duct rotating source. A linear acoustic theory including the effects of evanescent modes and source rotation is formulated based on the modal summation method, which is the underlying theory for the inverse source reconstruction. A validation experiment is conducted on a duct system excited by a loudspeaker in static and rotating conditions, with two different speeds, in the absence of flow. Due to the source rotation, the measured pressure spectra reveal the Doppler effect, and the amount of frequency shift corresponds to the multiplication of the circumferential mode order and the rotation speed. Amplitudes of participating modes are estimated at the shifted frequencies in the stationary reference frame, and the modal amplitude set including the effect of source rotation is collected to investigate the source behavior in the rotating reference frame. By using the estimated modal amplitudes, the near-field pressure is re-calculated and compared with the measured pressure. The obtained maximum relative error is about -25 and -10 dB for rotation speeds at 300 and 600 rev/mm, respectively. The spatial distribution of acoustic source parameters is restored from the estimated modal amplitude set. The result clearly shows that the position and magnitude of the main sound source can be identified with high spatial resolution in the rotating reference frame.

Place, publisher, year, edition, pages
[Heo, Yong-Ho; Ih, Jeong-Guon] Korea Adv Inst Sci & Technol, Dept Mech Engn, Ctr Noise & Vibrat Control NoViC, Taejon 305701, South Korea. [Boden, Hans] KTH, Marcus Wallenberg Lab Sound & Vibrat Res MWL, Aeronaut & Vehicle Engn, S-10044 Stockholm, Sweden., 2015. Vol. 357, 51-73 p.
National Category
Fluid Mechanics and Acoustics
URN: urn:nbn:se:kth:diva-174202DOI: 10.1016/j.jsv.2015.07.015ISI: 000360965200005ScopusID: 2-s2.0-84940891185OAI: diva2:860047

QC 20151009

Available from: 2015-10-09 Created: 2015-10-02 Last updated: 2015-10-21Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Bodén, Hans
By organisation
MWL Vibration monitoring
In the same journal
Journal of Sound and Vibration
Fluid Mechanics and Acoustics

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 27 hits
ReferencesLink to record
Permanent link

Direct link