Ground Effect Vanes Arrangement

• US 20090084907A1
• Filed: 03/01/2007
• Published: 04/02/2009
• Est. Priority Date: 03/01/2006
• Status: Active Grant

• Current Assignee: Urban Aeronautics Ltd.
• Original Assignee: Urban Aeronautics Ltd.
• Inventors: Yoeli, Raphael
• Granted Patent: US 8,020,804 B2
• Time in Patent Office: Days
• US Class Current: 244/23.R
• CPC Class Codes: B64C 15/02 the jets being propulsion jets
• CPC Class Codes: B64C 27/20 Rotorcraft characterised by having shrouded rotors, e.g. flying platforms

Abstract

A vehicle, particularly a VTOL air vehicle, includes a duct carried by the vehicle frame with the longitudinal axis of the duct perpendicular to the longitudinal axis of the vehicle frame; a propeller rotatably mounted within the duct about the longitudinal axis of the duct to force an ambient fluid therethrough from its inlet at the upper end of the duct through its exit at the lower end of the duct, and thereby to produce an upward lift force applied to the vehicle, and a plurality of spaced vanes mounted to and across the inlet and exit ends of the duct about axes substantially perpendicular to the longitudinal axis of the duct and selectively operational to produce a desired horizontal control force in addition to the lift force applied to the vehicle.

Claims

1. A method of improving aerodynamic flow through a ducted fan of a VTOL vehicle when the VTOL vehicle is in proximity to the ground, the ducted fan comprising an open-ended duct, having an inlet end and an outlet end;

a propeller mounted within said duct between said inlet and outlet ends; and

a first plurality of vanes extending across the inlet end of the duct;

the method comprising;

(a) adding a second plurality of vanes across the outlet end of the duct, said second plurality of vanes being pivotally adjustable about axes parallel to longitudinal axes of said second plurality of vanes; and

(b) pivotally adjusting at least some of said second plurality of vanes to substantially match angularity of flow exiting the duct caused by the flow impinging on the ground.

2. The method of claim 1, wherein step (a) is carried out by arranging all of said second plurality of vanes parallel to each other.

3. The method of claim 1 wherein step (a) is carried out by arranging said second plurality of vanes in pie-slice-shaped segments about a center axis through the duct.

4. The method of claim 3 wherein said second plurality of vanes are arranged in 4 to 8 segments.

5. The method of claim 3 wherein step (b) is carried out by adjusting vanes of said segments concentrically.

6. The method of claim 1 further comprising:

(c) twisting at least some of said first plurality of vanes in areas adjacent a peripheral edge of the duct to adjust their respective planes of symmetry to local variations in flow into the inlet end of the duct.

7. The method of claim 1 wherein each of said second plurality of vanes is provided with an individual adjustment actuator.

8. The method of claim 1 wherein said second plurality of vanes are adjustable in clusters.

9. The method of claim 3 wherein, for each segment, the vanes are substantially perpendicular to a bisecting radius of the segment.

10. The method of claim 1 wherein step (b) is carried out by adjusting plural vanes in each of said first and second pluralities of vanes.

11. The method of claim 3 wherein step b) is carried out by pivotally adjusting said second plurality of vanes up to a degree sufficient to enable said second plurality of vanes to substantially align with a combined velocity of incoming free-stream air and velocity induced by said duct when said duct is moving forward or sideward.

12. The method of claim 11 wherein step (a) is carried out by also arranging said first plurality of vanes in pie-slice-shaped segments about said center axis and wherein step (b) is carried out by pivotally adjusting both said first and second pluralities of vanes up to at least about 45°

to thereby enhance sideward and forward flight capability of said vehicle.

13. The method of claim 3 wherein step (b) is carried out by selectively rotating vanes of said second plurality of vanes to concentrically control expansion or contraction of the diameter of a slipstream wake downstream of said duct.

14. A method of improving aerodynamic flow through a ducted fan of a VTOL vehicle when the VTOL vehicle is in proximity to the ground, the ducted fan comprising an open-ended duct, having an inlet end and an outlet end;

a propeller mounted within said duct between said inlet and outlet ends and a first plurality of vanes extending across the inlet end of the duct;

the method comprising;

(a) adding a second plurality of vanes across the outlet end of the duct; and

(b) providing means for adjusting flow along said second plurality of vanes to substantially match angularity of flow exiting the duct caused by the flow impinging on the ground.

15. A vehicle comprising:

a vehicle frame;

a duct carried by the vehicle frame with the longitudinal axis of the duct perpendicular to the longitudinal axis of the vehicle frame;

a propeller rotatably mounted within the duct about the longitudinal axis of the duct to force an ambient fluid therethrough from its inlet at the upper end of the duct through its exit at the lower end of the duct and thereby to produce an upward lift force applied to the vehicle;

a first plurality of spaced vanes mounted to and across the inlet end of the duct about pivot axes perpendicular to the longitudinal axis of the duct and selectively operational to produce a desired horizontal control force in addition to the lift force applied to the vehicle; and

a second plurality of vanes across the outlet end of the duct selectively rotatable to align substantially with the transverse outflow stream lines to prevent separation of the flow on said vanes and retain the control effectiveness of the vanes near ground.

16. The vehicle of claim 15 wherein said first and second plurality of vanes are arranged substantially parallel to a longitudinal axis of the vehicle.

17. The vehicle of claim 15 wherein one of said first and second plurality of vanes are arranged in pie-slice-shaped segments about a center axis of the duct.

18. The vehicle of claim 17 wherein said one of said first and second plurality of vanes comprises said second plurality of vanes.

19. The vehicle of claim 15 wherein said second plurality of vanes are individually adjustable.

20. The vehicle of claim 15 wherein clusters of said second plurality of vanes are separately adjustable.

21. The vehicle of claim 17 wherein vanes of each segment are substantially perpendicular to a bisecting radius of the segment.

22. The vehicle of claim 17 wherein said second plurality of vanes are arranged in 4 to 8 segments.

23. A vehicle comprising:

a vehicle frame;

a duct carried by the vehicle frame with the longitudinal axis of the duct perpendicular to the longitudinal axis of the vehicle frame;

a propeller rotatably mounted within the duct about the longitudinal axis of the duct to force an ambient fluid therethrough from its inlet at the upper end of the duct through its exit at the lower end of the duct, and thereby to produce an upward lift force applied to the vehicle;

a first plurality of spaced vanes mounted to and across the inlet end of the duct about pivotal axes perpendicular to the longitudinal axis of the duct and selectively operational to produce a desired horizontal control force in addition to the lift force applied to the vehicle;

a second plurality of vanes across the outlet end of the duct; and

means for influencing flow across said second plurality of vanes to reduce separation of flow from said vanes as required by local streamline direction near each said vane under conditions when flow exiting the duct impinges on the ground.

24. The vehicle of claim 23 wherein vanes in said second plurality of vanes are non-pivotal.

25. The vehicle of claim 23 wherein said first and second plurality of vanes are arranged substantially parallel to a longitudinal axis of the vehicle.

26. The vehicle of claim 23 wherein one of said first and second plurality of vanes are arranged in pie-slice-shaped segments about a center axis of the duct.

27. The vehicle of claim 26 wherein said one of said first and second plurality of vanes comprises said second plurality of vanes.

28. The vehicle of claim 26 wherein vanes of each segment are substantially perpendicular to a bisecting radius of the segment.

29. The vehicle of claim 26 wherein vanes of said second plurality of vanes are each pivotally adjustable at least to about 45°

.

30. The vehicle of claim 26 wherein both said first and second plurality of vanes are arranged in pie-slice-shaped segments about a center axis of the duct, and wherein vanes of said first and second plurality of ducts are each pivotally adjustable at least to about 45°

.