초록 ▼

A capped winglet comprising a helical portion having a smooth vertical curvature of 180°±approximately 20° from the plane of the unbounded end of a wing, and a generally planar cap contiguous with the helical portion of the winglet at the end of its curvature away from the wing, the c

A capped winglet comprising a helical portion having a smooth vertical curvature of 180°±approximately 20° from the plane of the unbounded end of a wing, and a generally planar cap contiguous with the helical portion of the winglet at the end of its curvature away from the wing, the cap having a free inboard end and a chord tapered toward the free end.

대표청구항 ▼

The invention claimed is: 1. A blended winglet having a free inboard end having an outer wing end with leading and trailing edges defining a plane, said winglet comprising a vertically curved, helical portion having a smooth vertical curvature of 180°±approximately 20° from the plane

The invention claimed is: 1. A blended winglet having a free inboard end having an outer wing end with leading and trailing edges defining a plane, said winglet comprising a vertically curved, helical portion having a smooth vertical curvature of 180°±approximately 20° from the plane of the outer wing end, wherein said helical portion of said winglet has substantially parallel, aft-extending leading and trailing edges and a longitudinal axis substantially parallel to the plane of the wing adjacent the winglet. 2. The winglet of claim 1, further comprising a generally planar cap contiguous with said helical portion of said winglet, said cap extending in the inboard direction away from said helical portion and having a free inboard end. 3. The winglet of claim 2, wherein said helical portion has a leading edge defining a helix angle in the range of 20-50°. 4. The winglet of claim 2, wherein substantially all of said helical portion has a symmetrical airfoil shape with variable thickness along each chord line. 5. The winglet of claim 4, wherein said helical portion has a substantially constant radius of curvature in the range of 0.1-0.5 times the chord of the outer wing end at a point adjacent to said winglet. 6. The winglet of claim 5, wherein said winglet cap has a spanwise length in the range of 1-3 times said chord. 7. The winglet of claim 1, wherein said helical portion has a leading edge defining a helix angle in the range of 20-50°. 8. The winglet of claim 7, wherein said helix angle is approximately 30°. 9. The winglet of claim 1, wherein substantially all of said helical portion has a symmetrical airfoil shape with variable thickness along each chord line. 10. The winglet of claim 1, wherein said helical portion has a substantially constant radius of curvature in the range of 0.1-0.5 times the chord of the outer wing end at a point adjacent to said winglet. 11. The winglet of claim 10, wherein the radius of curvature of said helical portion is approximately one-fourth of the chord of the outer wing end at a point adjacent to said winglet. 12. The winglet of claim 1, wherein said winglet cap has a spanwise length in the range of 1-3 times the chord of the outer wing end at a point adjacent to said winglet. 13. A blended winglet for a wing having an outer wing end with leading and trailing edges defining a plane, said winglet comprising: a vertically curved helical portion having a smooth vertical curvature of 180°±approximately 20° from the plane of the outer wing end wherein said helical portion of said winglet has substantially parallel, aft-extending leading and trailing edges and a longitudinal axis substantially parallel to the plane of the wing adjacent the winglet; and a generally planar cap contiguous with said curved portion of said winglet at the end of its curvature away from the wing, said cap extending in the inboard direction away from said curved portion and having a free inboard end. 14. The winglet of claim 13, wherein said cap has a leading edge which is aft of the leading edge of the wing adjacent its wingtip, and wherein said cap is within approximately 20° of parallel to said plane of said wing end. 15. The winglet of claim 14, wherein said curved portion of said winglet is helical with a longitudinal axis substantially centerline parallel to the plane of the wing adjacent the winglet. 16. A blended winglet for a wing having an outer wing end with leading and trailing edges defining a plane, said winglet comprising: a vertically curved, helical portion having a smooth vertical curvature of 180°±approximately 20° from the plane of the outer wing end; and a generally planar cap contiguous with said helical portion of said winglet and above the wing, said cap having a free inboard end; wherein said helical portion has a centerline parallel to the plane of the wing adjacent the winglet, and a leading edge defining a helix angle in the range of 20-50°; wherein substantially all of said helical portion has a symmetrical airfoil shape; wherein said helical portion has a substantially constant radius of curvature in the range of 0.1-0.5 times the chord of the outer wing end at a point adjacent to said winglet; wherein said winglet cap has a length in the range of 1-3 times said chord; wherein said helical portion has a substantially constant chord; and wherein said cap has a leading edge with approximately 1-10° of aft sweep and a relatively unswept trailing edge. 17. The winglet of claim 16, wherein the vertical curvature of said helical portion of said winglet from the plane of the wing adjacent the wingtip is approximately 180°. 18. The winglet of claim 17, wherein said helix angle is approximately 30°. 19. The winglet of claim 18, wherein the radius of curvature of said helical portion is approximately one-fourth of the chord of the outer wing end at a point adjacent to said winglet. 20. The winglet of claim 19, wherein the length of said winglet cap is approximately twice said chord. 21. A wing with a winglet for beneficially redirecting and reusing spanwise flow, comprising: a wing having a leading edge, a trailing edge and an outer wing end; and a curved winglet attached on one end to said outer wing end and having a free second end, said winglet having a helical portion with a longitudinal axis substantially parallel to the angle of attack of the wing, said helical portion having substantially parallel, aft-extending leading and trailing edges extending 180°±approximately 20° about said axis. 22. The wing of claim 21, further comprising a generally planar winglet cap connected between said helical portion and said free end of said winglet, said cap extending in the inboard direction away from said helical portion. 23. The wing of claim 22, wherein said helical portion has parallel leading and trailing edges defining a helix angle of approximately 30°. 24. The wing of claim 23, wherein said wing and said winglet cap have a normal camber and substantially all of said helical portion of said winglet has a symmetrical airfoil shape with variable thickness along each chord line. 25. The wing of claim 24, wherein said helical portion has a substantially constant radius of curvature of approximately one-fourth the chord of said outer wing end at a point adjacent to said winglet. 26. The wing of claim 25, wherein said winglet cap has a spanwise length of approximately twice said chord. 27. The wing of claim 21, wherein said helical portion has parallel leading and trailing edges defining a helix angle of approximately 30°. 28. The wing of claim 21, wherein said wing and said winglet cap have a normal camber and substantially all of said helical portion of said winglet has a symmetrical airfoil shape with variable thickness along each chord line. 29. The wing of claim 21, wherein said helical portion has a substantially constant radius of curvature of approximately one-fourth the chord of said outer wing end at a point adjacent to said winglet. 30. A wing with a winglet for beneficially redirecting and reusing spanwise flow, comprising: a wing having a leading edge, a trailing edge and an outer wing end; a curved winglet attached on one end to said outer wing end and having a free second end, said winglet having a helical portion with a longitudinal axis substantially parallel to the angle of attack of the wing, said helical portion extending 180°±approximately 20° about said axis and having parallel leading and trailing edges defining a helix angle of approximately 30°, said helical portion having a substantially constant radius of curvature of approximately one-fourth the chord of said outer wing end at a point adjacent to said winglet; and a generally planar winglet cap connected between said helical portion and said free end of said winglet; wherein said wing and said winglet cap have a normal camber and substantially all of said helical portion of said winglet has a symmetrical airfoil shape; wherein said winglet cap has a length of approximately twice said chord; wherein said helical portion has a substantially constant chord; and wherein said winglet cap has a leading edge with approximately 1-10° of aft sweep and a relatively unswept trailing edge. 31. The wing of claim 30, wherein said wing has an aspect ratio in the range of 15:1 to 30:1. 32. The wing of claim 31, wherein the length of said wing from its root to its tip is in the range of 5-20 feet. 33. The wing of claim 32, wherein said wing has an airfoil shape selected from the group consisting of the RG15 family of airfoils and SD-2048 airfoils. 34. The wing of claim 33, wherein said winglet cap is substantially horizontal in the spanwise direction in normal flight.