Title:
FAN NOISE REDUCTION FROM TURBOFAN ENGINES USING ADAPTIVE HERSCHEL-QUINCKE TUBES
Document Type and Number:
WIPO Patent Application WO2000020748
Kind Code:
A3
Abstract:
An array of adaptive or fixed Herschel-Quincke tubes (1) aligned in a circumferential or helical array about an inlet (38) of a turbofan engine. The array of tubes effectively divide the acoustic energy generated by the engine. One of the energy components propagates within the tubes while the other propagates within the engine compartment. The acoustic energy within the tubes is reintroduced into the engine compartment to cancel the acoustic energy remaining in the engine as it propagates from the fan (36) towards the inlet and the outlet (34) openings.
Inventors:
BURDISSO RICARDO
SMITH JEROME P
SMITH JEROME P
Application Number:
PCT/US1999/021297
Publication Date:
July 27, 2000
Filing Date:
September 16, 1999
Export Citation:
Assignee:
VIRGINIA TECH INTELL PROP (US)
International Classes:
F02C7/045; F04D29/66; G10K11/175; (IPC1-7): F02K3/02; F01N1/02
Foreign References:
| US3951566A | 1976-04-20 | |||
| US4255083A | 1981-03-10 | |||
| US5732547A | 1998-03-31 |
Other References:
See also references of EP 1115967A4
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