METHOD OF PROVIDING A SIGNAL FOR CONTROLLING BLADE VORTEX INTERACTION NOISE OF A ROTORCRAFT

Title:

METHOD OF PROVIDING A SIGNAL FOR CONTROLLING BLADE VORTEX INTERACTION NOISE OF A ROTORCRAFT

Document Type and Number:

WIPO Patent Application WO2000037310

Kind Code:

A3

Abstract:

A method of providing a signal representative of blade vortex interaction (BVI) noise for a multi-blade rotorcraft. The fluid (air) pressure at one, two, or more predetermined locations on a rotor blade is measured during at least one predetermined azimuthal segment of blade rotation during operation to provide respective pressure measurements. The pressure measurements are processed to provide a signal for use as a control variable in a control system for the active control of BVI noise. The pressure measurements are made within 10 % blade chord length of the blade leading edge and preferably two or more are made between 65 % and 95 % of blade radial-length. The pressure measurements are filtered and the band of retained frequencies is between 20 and 48 times the rotor rotation frequency. An algorithm operative over a determined blade frequency range optimizes the signal for control use.

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Inventors:

LORBER PETER F

Application Number:

PCT/US1999/030152

Publication Date:

November 09, 2000

Filing Date:

December 17, 1999

Export Citation:

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Assignee:

SIKORSKY AIRCRAFT CORP (US)

International Classes:

G01M99/00; B64C27/00; B64C27/467; B64C27/615; (IPC1-7): B64C27/00

Foreign References:

US5711651A	1998-01-27
US5588800A	1996-12-31
FR2782307A1	2000-02-18

Other References:

LORBER, PETER F: "Aerodynamic Results of a Pressure-Instrumented Model Rotor Test at the DNW", JOURNAL OF THE AMERICAN HELICOPTER SOCIETY, vol. 36, no. 4, October 1990 (1990-10-01), pages 66 - 76, XP000915794
YU Y H ET AL: "Reduction of Helicopter Blade-Vortex Interaction Noise by Active Rotor Control Technology", PROGRESS IN AEROSPACE SCIENCES, September 1997 (1997-09-01), XP002101523
PATENT ABSTRACTS OF JAPAN vol. 1998, no. 06 30 April 1998 (1998-04-30)

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