Enhanced performance rotorcraft rotor blade

Patent metadata

Field	Value
Publication number	US-9446843-B2
Application number	US-201213430686-A
Country	US
Kind code	B2
Filing date	Mar 27, 2012
Priority date	Mar 27, 2012
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

An enhanced performance rotorcraft rotor blade system and methods are presented. A rotor blade comprises an inboard blade portion, and at least one controllable surface coupled to the inboard blade portion. The at least one controllable surface is operable to improve a lift of the inboard blade portion by altering an angle of attack of the inboard blade portion independent of the rotor blade.

First claim

The invention claimed is:

1. An enhanced performance rotorcraft rotor blade system for a rotorcraft, the system comprising:
a rotor blade comprising a blade tip and an inboard blade portion;
a swash plate configured to control a pitch of the entire rotor blade; and
at least one controllable surface coupled to the inboard blade portion in a region of low tangential velocity away from the blade tip, wherein the at least one controllable surface is movable to change the position of the at least one controllable surface to improve a lift of the inboard blade portion, wherein the at least one controllable surface is configured to move independent of motion of the entire rotor blade controlled by the swash plate;
wherein the enhanced performance rotorcraft rotor blade system is configured to:
(i) detect a high directional velocity of the rotorcraft, wherein detecting the high directional velocity comprises detecting that the rotorcraft is advancing at a high forward speed that results in retreating blade stall; and
(ii) in response to detecting the high directional velocity, (a) control the swash plate to reduce the angle of attack of the entire rotor blade when the rotor blade is retreating and (b) deploy the at least one controllable surface to improve a lift of the inboard blade portion when the rotor blade is retreating by (1) increasing an angle of attack of the inboard blade portion independent of the swash plate reducing the angle of attack of the entire rotor blade or (2) extending the at least one controllable surface to increase a distance from a leading edge to a trailing edge of the inboard blade portion.

2. The enhanced performance rotorcraft rotor blade system of claim 1 , wherein the at least one controllable surface comprises one of: a flap and an extendable flap.

3. The enhanced performance rotorcraft rotor blade system of claim 2 , wherein the extendable flap increases a distance from a leading edge to a trailing edge of the inboard blade portion.

4. The enhanced performance rotorcraft rotor blade system of claim 2 , wherein the flap is coupled to one of: a leading edge of the inboard blade portion, and a trailing edge of the inboard blade portion.

5. The enhanced performance rotorcraft rotor blade system of claim 1 , wherein the at least one controllable surface comprises a rotatable portion of the rotor blade operable to rotate about a neutral axis of the rotor blade.

6. The enhanced performance rotorcraft rotor blade system of claim 1 , further comprising a processor module operable to control the angle of attack of the at least one controllable surface.

7. The enhanced performance rotorcraft rotor blade system of claim 6 , wherein the processor module is further operable to control the angle of attack based on a rotation angle of the rotor blade.

8. The enhanced performance rotorcraft rotor blade system of claim 6 , wherein:
the rotor blade comprises a plurality of controllable surfaces; and
the processor module is operable to alter the angle of attack independently for each of the controllable surfaces.

9. The enhanced performance rotorcraft rotor blade system of claim 6 , wherein the processor module is further operable to control the angle of attack of the at least one controllable surface in response to one of: an input from a pilot and an input from the processor module.

10. The enhanced performance rotorcraft rotor blade system of claim 1 , wherein the at least one controllable surface comprises:
a flap coupled to a trailing edge of the inboard blade portion; and
an extendable flap coupled to the trailing edge of the inboard blade portion.

11. The enhanced performance rotorcraft rotor blade system of claim 10 , wherein the at least one controllable surface further comprises a leading edge flap coupled to a leading edge of the inboard blade portion.

12. The enhanced performance rotorcraft rotor blade system of claim 1 , wherein the at least one controllable surface comprises:
a leading edge controllable surface coupled to a leading edge of the inboard blade portion and operable to extend a chord of the rotor blade to provide a length change of an airfoil section of the rotor blade in an area near a root of the rotor blade.

13. The enhanced performance rotorcraft rotor blade system of claim 1 , wherein the at least one controllable surface further comprises two flaps coupled to a trailing edge of the inboard blade portion.

14. A method for operating an enhanced performance rotorcraft rotor blade system to reduce effects of retreating rotor blade stall, the method comprising:
detecting a high directional velocity of a rotorcraft comprising a rotor blade and a swash plate, the rotor blade comprising an inboard blade portion and a blade tip, and the swash plate configured to control a pitch of the entire rotor blade, wherein detecting the high directional velocity comprises detecting a high forward speed of the rotorcraft that results in retreating blade stall; and
in response to detecting the high directional velocity of the rotorcraft:
(i) the swash plate reducing an angle of attack of the entire rotor blade when the rotor blade is retreating;
(ii) deploying at least one controllable surface coupled to the inboard blade portion of the rotor blade located in a low velocity region of the rotor blade and away from the blade tip to improve a lift of the inboard blade portion when the rotor blade is retreating by (a) increasing an angle of attack of the inboard blade portion independent of the swash plate reducing the angle of attack of the entire rotor blade or (b) extending the at least one controllable surface to increase a distance from a leading edge to a trailing edge of the inboard blade portion; and
(iii) moving the at least one controllable surface independent of motion of the entire rotor blade controlled by the swash plate to reduce an angle of attack of the entire rotor blade when the rotor blade is retreating.

15. The method of claim 14 , further comprising moving the at least one controllable surface in response to one of: an input from a pilot, and an input from a processor module.

16. A method comprising:
configuring a rotor blade comprising a blade tip and an inboard blade portion in a region of low tangential velocity of the rotor blade;
configuring a swash plate to control a pitch of the entire rotor blade;
configuring the swash plate to reduce an angle of attack of the entire rotor blade when the rotor blade is retreating so as to alter a lift and a thrust of the entire rotor blade;
coupling at least one controllable surface to a leading edge of the inboard blade portion in the region of low tangential velocity away from the blade tip; and
configuring the at least one controllable surface to improve a lift of the inboard blade portion in the region of low tangential velocity when the rotor blade is retreating by increasing an angle of attack of the inboard blade portion independent of the swash plate reducing the angle of attack of the entire rotor blade when the rotor blade is retreating;
configuring a rotorcraft to (i) detect a high directional velocity of the rotorcraft, wherein detecting the high directional velocity comprises detecting that the rotorcraft is advancing at a high forward speed that results in retreating blade stall and (ii) in response to detecting the high directional velocity, (a) control the swash plate to reduce the angle of attack of the entire rotor blade when the rotor blade is retreating, and (b) deploy the at least one controllable surface to improve a lift of the inboard blade portion when the rotor blade is retreati

Assignees

• Perlman David L
• Boeing Co

Inventors

• Perlman David L

Classifications

• Y10T29/49336

  Blade making · CPC title

• B64C27/72 Primary

  Means acting on blades · CPC title

• B64C27/615 Primary

  including flaps mounted on blades · CPC title

• B64C2027/7266

  actuated by actuators · CPC title

• Y02T50/34

  Cross-Sectional Technologies · mapped topic