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Conference Paper: Active tonal noise control for a computer cooling fan

TitleActive tonal noise control for a computer cooling fan
Authors
Issue Date2005
Citation
Proceedings Of The American Society Of Mechanical Engineers Fluids Engineering Division Summer Conference, 2005, v. 1 PART A, p. 465-474 How to Cite?
Abstract
The noise sources on a blade can be divided into a thrust force component along the rotating axis, and a drag component on the fan rotational plane. The radiated noise is a result of acoustic interference among all blades, and the two source components. For a sample fan with B=7 blades, and S=7 struts, the drag noise is expected to cancel themselves out. The result is a simple thrust dipole along the fan axis. When B=7 and S=4, however, the dominant noise is a rotating drag dipole. This paper demonstrates, experimentally, the global elimination of the blade passing frequency tones from the thrust dipole and the rotating drag dipole for the two sample fans, respectively, by using a simple open-loop, feedforward control scheme. The rig consists of a miniature electret microphone used as a rotation sensor, ordinary loudspeakers, and a bandpass filter with adjustable amplitude and phase delay. The electret microphone is installed flush with the inlet bellmouth of the fan. It picks up the fluctuating aerodynamic pressure caused by the passing rotor blades, and is shown to perform much better than a normal optical tachometer. Copyright © 2005 by ASME.
Persistent Identifierhttp://hdl.handle.net/10722/158953
References

 

Author Affiliations
  1. Hong Kong Polytechnic University
DC FieldValueLanguage
dc.contributor.authorWang, Jen_US
dc.contributor.authorHuang, Len_US
dc.date.accessioned2012-08-08T09:04:45Z-
dc.date.available2012-08-08T09:04:45Z-
dc.date.issued2005en_US
dc.identifier.citationProceedings Of The American Society Of Mechanical Engineers Fluids Engineering Division Summer Conference, 2005, v. 1 PART A, p. 465-474en_US
dc.identifier.urihttp://hdl.handle.net/10722/158953-
dc.description.abstractThe noise sources on a blade can be divided into a thrust force component along the rotating axis, and a drag component on the fan rotational plane. The radiated noise is a result of acoustic interference among all blades, and the two source components. For a sample fan with B=7 blades, and S=7 struts, the drag noise is expected to cancel themselves out. The result is a simple thrust dipole along the fan axis. When B=7 and S=4, however, the dominant noise is a rotating drag dipole. This paper demonstrates, experimentally, the global elimination of the blade passing frequency tones from the thrust dipole and the rotating drag dipole for the two sample fans, respectively, by using a simple open-loop, feedforward control scheme. The rig consists of a miniature electret microphone used as a rotation sensor, ordinary loudspeakers, and a bandpass filter with adjustable amplitude and phase delay. The electret microphone is installed flush with the inlet bellmouth of the fan. It picks up the fluctuating aerodynamic pressure caused by the passing rotor blades, and is shown to perform much better than a normal optical tachometer. Copyright © 2005 by ASME.en_US
dc.languageengen_US
dc.relation.ispartofProceedings of the American Society of Mechanical Engineers Fluids Engineering Division Summer Conferenceen_US
dc.titleActive tonal noise control for a computer cooling fanen_US
dc.typeConference_Paperen_US
dc.identifier.emailHuang, L:lixi@hku.hken_US
dc.identifier.authorityHuang, L=rp00119en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.scopuseid_2-s2.0-28844436415en_US
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-28844436415&selection=ref&src=s&origin=recordpageen_US
dc.identifier.volume1 PART Aen_US
dc.identifier.spage465en_US
dc.identifier.epage474en_US
dc.identifier.scopusauthoridWang, J=9639054400en_US
dc.identifier.scopusauthoridHuang, L=7404735514en_US

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