The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 12, 2002
Filed:
Aug. 16, 2001
Bruce D. Charles, Mesa, AZ (US);
Ahmed A. Hassan, Mesa, AZ (US);
Hormoz Tadghighi, Scottsdale, AZ (US);
Ram D. JanakiRam, Mesa, AZ (US);
The Boeing Company, St. Louis, MO (US);
Abstract
An active control device for reducing blade-vortex interactions (BVI) noise generated by a rotorcraft, such as a helicopter, comprises a segmented trailing edge flap located near the tip of each of the rotorcraft's rotor blades. The various flap segments may be independently actuated according to flap deflections schedules which are tailored to address a particular operating regime with maximum efficiency and effectiveness. Through the careful azimuth-dependent independent actuation of the flap segments, blade tip vortices which are the primary source for BVI noise are (a) made weaker and (b) pushed farther away from the rotor disk (that is, larger blade-vortex separation distances are achieved), resulting in lower BVI noise.