Variable-geometry ducted fan

Patent metadata

Field	Value
Publication number	US-10570926-B2
Application number	US-201514958154-A
Country	US
Kind code	B2
Filing date	Dec 3, 2015
Priority date	Dec 3, 2015
Publication date	Feb 25, 2020
Grant date	Feb 25, 2020

Abstract

A variable-geometry ducted fan may include an air duct having a longitudinal axis, the air duct including an inlet of the variable-geometry ducted fan, a fan rotatably mounted within the air duct downstream from the inlet, the fan including fan blades defining a fan area, and a variable-area nozzle coupled to the air duct downstream from the fan, the variable-area nozzle including an exhaust of the variable-geometry ducted fan having a variable exhaust area.

First claim

What is claimed is:

1. A variable-geometry ducted fan comprising:
an air duct having a longitudinal axis, said air duct comprising an inlet of said variable-geometry ducted fan;
a fan rotatably mounted within said air duct downstream from said inlet, said fan comprising fan blades defining a fan area;
a variable-area nozzle coupled to said air duct downstream from said fan, said variable-area nozzle comprising an exhaust of said variable-geometry ducted fan having a variable exhaust area, wherein said variable-area nozzle comprises a circumferential array of pedals,
wherein a first pedal of the circumferential array of pedals comprises a first inner skin and a first outer skin, wherein said first pedal includes a first moment arm rigidly coupled between said first inner skin and said first outer skin and a first ring fitting coupled to said first moment arm, said first ring fitting encircling an first opening,
wherein a second pedal of the circumferential array of pedals comprises a second inner skin and a second outer skin, wherein said second pedal includes a second moment arm rigidly coupled between said second inner skin and said second outer skin and a second ring fitting coupled to said second moment arm, said second ring fitting encircling a second opening; and

an actuation system, said actuation system comprising:
an actuator ring passing through said first opening and through said second opening, wherein said actuator ring extends circumferentially around said variable-area nozzle, wherein expansion of said actuator ring expands said variable-area nozzle and contraction of said actuator ring contracts said variable-area nozzle; and
an actuator that drives expansion and contraction of said actuator ring.

2. The variable-geometry ducted fan of claim 1 wherein said variable-area nozzle expands relative to said longitudinal axis to increase said exhaust area of said exhaust for vertical flight.

3. The variable-geometry ducted fan of claim 2 wherein a ratio of said exhaust area to said fan area is approximately 1.30.

4. The variable-geometry ducted fan of claim 1 wherein said variable-area nozzle contracts relative to said longitudinal axis to decrease said exhaust area for horizontal flight.

5. The variable-geometry ducted fan of claim 4 wherein a ratio between said exhaust area and said fan area is approximately 0.98.

6. The variable-geometry ducted fan of claim 1 wherein said circumferential array of pedals are pivotably coupled to said air duct and circumscribe said longitudinal axis.

7. The variable-geometry ducted fan of claim 6 wherein said pedals pivot radially outward relative to said longitudinal axis to increase said exhaust area of said exhaust for vertical flight.

8. The variable-geometry ducted fan of claim 7 wherein said pedals pivot radially outward at an angle of approximately positive ten degrees relative to said longitudinal axis to increase said exhaust area of said exhaust for said vertical flight.

9. The variable-geometry ducted fan of claim 6 wherein said pedals pivot radially inward relative to said longitudinal axis to decrease said exhaust area of said exhaust for horizontal flight.

10. The variable-geometry ducted fan of claim 9 wherein said pedals pivot radially inward at an angle of approximately negative three degrees relative to said longitudinal axis to decrease said exhaust area of said exhaust for said horizontal flight.

11. The variable-geometry ducted fan of claim 1 wherein:
said variable-geometry ducted fan comprises an overall length,
said fan comprises a fan diameter, and
a ratio of said overall length to said fan diameter is approximately 0.875.

12. The variable-geometry ducted fan of claim 11 further comprising stators mounted within said air duct downstream from said fan blades.

13. The variable-geometry ducted fan of claim 12 wherein:
said fan blades are located at a position approximately 25 percent of said overall length of said variable-geometry ducted fan downstream from said inlet, and
said stators are located a minimum distance downstream from said fan blades approximately equal to a chord dimension of said fan blades.

14. The variable-geometry ducted fan of claim 1 wherein said first inner skin and said first outer skin converge at an end of said first pedal.

15. The variable-geometry ducted fan of claim 1 wherein said first inner skin is associated with an inner wall of said air duct, and wherein said first outer skin is associated with an outer wall of said air duct.

16. The variable-geometry ducted fan of claim 15 wherein, when pivoted in a radially inward direction, said first outer skin of said first pedal is aligned with and/or abuts with said outer wall of said air duct.

17. The variable-geometry ducted fan of claim 1 wherein said actuator comprises an electric actuation device, a pneumatic actuation device, a hydraulic actuation device, or a combination thereof.

18. The variable-geometry ducted fan of claim 1 wherein said actuator drives a first end and a second end of said actuating ring together and apart in order to contract and expand said actuating ring, respectively.

19. The variable-geometry ducted fan of claim 18 wherein said actuator comprises:
a first actuating linkage coupled to said first end of said actuating ring;
a second actuating linkage coupled to said second end of said actuating ring; and
a piston coupled to said first actuating linkage and said second actuating linkage such that actuation of said piston drives said first end and said second end of said actuating ring together and apart.

20. The variable-geometry ducted fan of claim 19 wherein said first actuating linkage, said second actuating linkage, and said piston form a scissor-linkage assembly.

21. The variable-geometry ducted fan of claim 1 wherein said first ring fitting is positioned directedly between said first inner skin and said first outer skin.

22. The variable-geometry ducted fan of claim 1 wherein said first ring fitting is rigidly coupled to said first moment arm.

23. The variable-geometry ducted fan of claim 1 wherein said an actuator ring comprises a single unitary structure passing through said first opening and through said second opening.

24. An aircraft comprising:
a vehicle body; and
at least one variable-geometry ducted fan coupled to said vehicle body, wherein said variable-geometry ducted fan is rotatable between an approximately vertical orientation and an approximately horizontal orientation, and wherein said variable-geometry ducted fan comprises:
an air duct having a longitudinal axis, said air duct comprising an inlet of said variable-geometry ducted fan;
a fan rotatably mounted within said air duct downstream from said inlet, said fan comprising fan blades defining a fan area;
a variable-area nozzle coupled to said air duct downstream from said fan, said variable-area nozzle comprising an exhaust of said variable-geometry ducted fan having a variable exhaust area, wherein said variable-area nozzle comprises a circumferential array of pedals,
wherein a first pedal of the circumferential array of pedals comprises a first inner skin and a first outer skin, wherein said first pedal includes a first moment arm rigidly coupled between said first inner skin and said first outer skin and a first ring fitting coupled to said first moment arm, said first ring fitting encircling an first opening,
wherein a second pedal of the circumferent

Assignees

• Boeing Co

Inventors

• Maciolek Robert F

Classifications

• B64D29/02 Primary

  associated with wings · CPC title

• B64D35/04

  characterised by the transmission driving a plurality of propellers or rotors · CPC title

• B64C29/0033

  the propellers being tiltable relative to the fuselage · CPC title

• B64C7/02

  Nacelles · CPC title

• F05B2240/123

  Nozzles · CPC title