Aircraft winglet
Embodiments of the present invention relate to a winglet for an end or tip of an aircraft wing. The winglet includes an inner portion that curves upward having a large radius of curvature near the wing, a middle portion having a small radius of curvature forming a bend, and an outer portion having a large radius of curvature extending to a tip of the winglet. The winglet lowers induced drag of the wing and improves aircraft performance especially for wing tip extensions that extend upwards about equal to or slightly more than outwards.
1. An aircraft winglet, comprising:
a wing tip extension projecting outward from an end of a wing and curving upward from the wing, the winglet having an inner portion with a first radius of curvature near the wing, a middle portion having a second radius of curvature forming a bend, and an outer portion having a third radius of curvature extending to a tip of the winglet;
wherein the first and third radius of curvature are each larger than the second radius of curvature and the third radius of curvature is larger than the first radius of curvature.
2. The aircraft winglet of claim 1 , wherein the winglet comprises a tapered width extending from the bend towards the tip.
3. The aircraft winglet of claim 1 , wherein the winglet comprises a swept shape such that both a leading edge and a trailing edge are angled in an aft direction.
4. The aircraft winglet of claim 1 , wherein the winglet comprises a winglet sweep angle that mimics a sweep angle of the wing.
5. The aircraft winglet of claim 1 , wherein the winglet further comprises a cant angle of about 17.5 degrees and a dihedral angle of about 72.5 degrees.
6. The aircraft winglet of claim 1 , wherein the bend has a major axis of about 37 degrees above a wing surface reference plane.
7. The aircraft winglet of claim 1 , wherein the first radius of curvature at the inner portion has a maximum radius of about ninety-five inches nearest the wing, the second radius of curvature at the middle portion has a minimum radius of curvature of about fourteen inches, and the third radius of curvature at the outer portion has a maximum radius of curvature of about six-hundred inches.
8. The aircraft winglet of claim 1 , wherein a height of the winglet is about proportional to a given span increase, thereby providing less wetted area and less parasite drag.
9. The aircraft winglet of claim 1 , wherein the winglet has a ratio for a height of the tip above the wing compared to an extension of the tip from the end of the wing from about 1.0 to about 1.3.
10. A curved wing tip extension for an aircraft wing comprising:
an inner portion adjacent the aircraft wing and having a first radius of curvature;
a middle portion adjacent the inner portion, the middle portion having a second radius of curvature;
an outer portion adjacent the middle portion and extending to a winglet tip, the outer portion having a third radius of curvature;
wherein the first and third radius of curvature are each larger than the second radius of curvature and the third radius of curvature is larger than the first radius of curvature.
11. The curved wing tip extension of claim 10 , wherein the first radius of curvature has a radius up to approximately ninety-five inches at the inner portion adjacent the wing.
12. The curved wing tip extension of claim 11 , wherein the second radius of curvature has a radius of at least about fourteen inches.
13. The curved wing tip extension of claim 12 , wherein the third radius of curvature has a radius up to approximately six-hundred inches at the outer portion adjacent the winglet tip.
14. The aircraft winglet of claim 10 , wherein the curved wing tip extension further comprises a cant angle of about 17.5 degrees and a dihedral angle of about 72.5 degrees.
15. A compound curved wing tip extension for an aircraft wing comprising an airfoil body having a leading edge, a trailing edge spaced a distance from the leading edge, and a tip, the leading edge and trailing edge angled in an aft direction, the airfoil body having an inner portion adjacent the aircraft wing and having a first radius of curvature, a middle portion adjacent the inner portion, the middle portion having a second radius of curvature, and an outer portion adjacent the middle portion and extending to the tip, the outer portion having a third radius of curvature, with the first and third radius of curvature each larger than the second radius of curvature and the third radius is larger than the first radius of curvature.
16. The compound curved wing tip extension of claim 15 , wherein the leading edge and trailing edge are angled aft between approximately 20 and 65 degrees.
17. The compound curved wing tip extension of claim 16 , wherein the curved wing tip extension further comprises a cant angle of about 17.5 degrees and a dihedral angle of about 72.5 degrees.
18. The compound curved wing tip extension of claim 17 , wherein the first radius of curvature has a radius up to approximately ninety-five inches at the inner portion adjacent the wing and the third radius of curvature has a radius up to approximately six-hundred inches at the outer portion adjacent the winglet tip.
19. The compound curved wing tip extension of claim 18 , wherein the second radius of curvature has a radius of at least about fourteen inches.
20. The compound curved wing tip extension of claim 19 , wherein the second radius of curvature forms a bend having a major axis of about 37 degrees above a wing surface reference plane.