초록 ▼

An improved winglet design is presented for aircraft wherein the winglet configuration is well suited for aircraft wings having moderate to no aft swept, or wings having forward swept. The winglets (302) are located at the outer end of each wing (300) and curve upwardly as they extend outwardly from

An improved winglet design is presented for aircraft wherein the winglet configuration is well suited for aircraft wings having moderate to no aft swept, or wings having forward swept. The winglets (302) are located at the outer end of each wing (300) and curve upwardly as they extend outwardly from their intersection (304) with the wings (300). The curvature profile (303) of the winglets (302) when viewed from the rear (or front) of the aircraft at least approximates a specified curve profile made up of more than one curved section, e.g. the winglet trailing edge profile (305) having a perpendicular projection onto a plane normal to the winglet inner or root chord (342), said projection creating a winglet profile curve approximating a compound curve composed of two arc segment (306, 307). The two arc segments are tangent to each other at there point of connection (306b, 307a) wherein the arc segment (306) at the lower portion of the winglet connects to the outer end of the wing (300) and is tangent with the wing's reference plane (331). This lower arc segment (306) of the winglet profile connects to and is tangent with a second and arc segment (307) forming the profile of the upper portion of the winglet (302). A unique design specification for the plan form or developed shape of the winglet that is suitable for wings having nominal (less than 15 degrees) aft sweep, or have neutral, or forward sweep is also provided.

대표청구항 ▼

1. A wing for an aircraft, the wing forming an airfoil and comprising: an inner end, and outer end, an upper surface, a lower surface, a leading edge, and a trailing edge; and a winglet having an inner end, an outer end tip, an upper surface, a lower surface, a leading edge and a trailing edge;where

1. A wing for an aircraft, the wing forming an airfoil and comprising: an inner end, and outer end, an upper surface, a lower surface, a leading edge, and a trailing edge; and a winglet having an inner end, an outer end tip, an upper surface, a lower surface, a leading edge and a trailing edge;wherein the inner end, or root, of said winglet is connected to the outer end of said wing, and the upper and lower surfaces of the winglet and the leading and trailing edges of the winglet are continuations of the upper and lower surfaces of the wing and leading and trailing edges of the wing, respectively; the winglet having a transition region and a sail section, the transition region extending from the outer end oft wing the sail section and the sail section extending from the end of the transition region to the winglet end tip;such that the leading and trailing edges of the winglet each have a profile that defines at least two curves along each of their entire length, from their inner end at the root of the winglet, to the outer end of the tip of the winglet;wherein the curves defining the winglet edge profile at any point are generated through a locus of points projected onto a plane substantially normal to the winglet inner end, or root, chord line, and conforms to the following criteria;the lower end of the profile curve is approximately tangent to the wing reference plane at the junction of the winglet to the outer end of the wing;each profile curve is approximately monotonic, with constantly increasing radius of curvature from the curve lower end to the curve upper end;the upper end point of the profile curve, at the winglet end tip, is tangent to a line parallel with a line oriented at the cant angle, phi, at the winglet end tip;the upper end point of the lower profile curve is positioned at a height above the wing reference plane having a value of between 65 percent and 105 percent of the wing outer end chord length;the location of the upper end of the transitions section, or start or lower end of the sail section, is positioned at a specified distance along the length of said alternate curve form measured from the lower end of the curve; andthe winglet profile curve from root to tip excludes both a single conic curve and the combination of a lower are segment connected and tangent to an upper linear segment. 2. The wing for an aircraft of claim 1, wherein the locus of points defining the curve to be projected lie along the winglet trailing edge curve (100 percent section chord locations). 3. The wing for an aircraft of claim 1 wherein the locus of points defining the curve to be projected lie along the winglet leading edge curve (0 percent section chord locations). 4. An aircraft of claim 1 wherein the profile curve is a composite curve comprised of a lower rho conic curve segment connected and tangent to an upper arc segment curve. 5. The wing for an aircraft of claim 4 wherein the curve length of the rho conic curve segment is substantially the same as the are curve length of the are having a radius, R1 over an angle equal to Beta, where Beta is the design arc segment angle specifying the upper end point location of the lower arc segment measured from the curve lower or root end and the wing tip XZ-plane. 6. The wing for an aircraft of claim 1, wherein the profile is a composite curve comprised of a lower a rho conic curve segment connected and tangent to an second or upper rho conic segment curve, wherein the rho value of the lower segment curve is greater than the rho value of the upper segment curve. 7. A wing for an aircraft, the wing comprising: an inner end, and outer end, an upper surface, a lower surface, a leading edge, and a trailing edge; anda winglet having an inner end, an outer end tip, an upper surface, a lower surface, a leading edge and a trailing edge;wherein the inner end of said winglet is connected to the outer end of said wing, and the upper and lower surfaces of the winglet and the leading and trailing edges of the winglet are continuations of the upper and lower surfaces of the wing and leading and trailing edges of the wing, respectively;such that said winglet edge profile always defines a curve as it extends from its inner end to its outer end tip;wherein a curve defining the winglet profile is generated through a locus of points of constant percent chord positions on airfoil section chord lines or extensions thereof, such that each profile curve is approximately monotonic, with constantly increasing radius of curvature from the curve lower end to the curve upper end;the upper end of the profile curve, at the winglet end tip, is tangent to a line parallel with a line oriented at the cant angle, phi, at the winglet end tip;said winglet profile curve when projected onto a plane substantially normal to the winglet inner end, or root chord line, closely approximates a composite curve composed of two arc segments. 8. The aircraft of claim 7, wherein the radius defining the lower portion of the winglet's projected contour has a value less than the radius defining the upper portion of the winglet's projected contour and the arc center of the two arc segments are located inboard of the winglet upper portion. 9. The wing for an aircraft of claim 7, wherein the radius defining the lower portion of the winglet's projected contour has a value less than the radius defining the upper portion of the winglet's projected contour and the are center of the lower are segment is located at a point inboard of the winglet upper portion and the arc center of the upper arc segment is located at a point outboard of the winglet upper portion such that the winglet profile has a reflex in curvature at the junction of the two arc segments. 10. The wing for an aircraft of claim 7, wherein the two arc segments are tangent to each other at their point of connection, and the arc segment of the lower portion of the winglet connects to the outer end of the wing and is tangent with the wing's outer reference plane. 11. The wing for an aircraft of claim 10, wherein the a tangent line at the outer tip of the arc segment defining the upper portion profile of the winglet forms a cant angle of between 12 and 20 degrees to a plane that is both normal to the wing tip reference plane and is through the wing outer tip chord line. 12. The wing for an aircraft of claim 7, wherein the wing has a maximum aft sweep angle of less than 15 degrees, the are section radius of curvature, R1 for the lower portion of the winglet has a range in values defined by the following: R1/h=Kr*cos(phi/2+pi/4)/cos(phi)where: Kr=curvature parameter, where 0.35