Title:
HIGH PERFORMANCE OUTBOARD SECTION FOR ROTOR BLADES
Document Type and Number:
WIPO Patent Application WO2008091299
Kind Code:
B1
Abstract:
Blades for rotorcraft are designed and/or implemented with rotor blades having a swept portion that occupies at least 20-40% of a length of the blade. Forward and aft sweeps are contemplated, with up to 20° or more of sweep. The swept portion preferably has a thickness ration of at least 10-20% at R80, and can have a tapered planform with a relatively outboard section having a smaller chord than a relatively inboard section. Contemplated design methods include optimizing or otherwise designing the rotor blade planform and lift distribution along the blade for efficiency in various flight conditions without taking into account the detrimental effects of high Mach numbers, and then using sweep angle, airfoil thickness and transonic airfoil shaping to maintain the lift distribution, low drag and low noise level at real Mach numbers at the various blade stations at the various flight conditions.
More Like This:
Inventors:
KAREM ABE (US)
Application Number:
PCT/US2007/017846
Publication Date:
November 27, 2008
Filing Date:
August 10, 2007
Export Citation:
Assignee:
KAREM ABE (US)
International Classes:
B64C27/467
Download PDF:
Previous Patent: UPPER ROTOR CONTROL SYSTEM FOR A COUNTER-ROTATING ROTOR SYSTEM
Next Patent: TILT OUTBOARD WING FOR TILT ROTOR AIRCRAFT
Next Patent: TILT OUTBOARD WING FOR TILT ROTOR AIRCRAFT