Wing/winglet configurations and methods for aircraft

In an aircraft having a longitudinal axis, a vertical axis, a transverse axis, and a wing/winglet configuration comprising:

• a. a wing having upper and lower wing surfaces, a wing leading edge, a wing trailing edge, and a wing tip, where a wing chord is defined for any given portion of the wing which extends between the wing leading and trailing edges;
• and
• b. a winglet having upper and lower winglet surfaces, a winglet leading edge, a winglet trailing edge, and winglet root, where
• i. a winglet chord is defined for any given portion of the winglet, the winglet chord extending between the winglet leading and trailing edges, and
• ii. the winglet root is attached to the wing tip at a wing/winglet intersection;
• a method of increasing the performance of the wing and winglet comprising the steps of:
• c. defining a corner flow region as the portions of the wing upper surface and winglet upper surface near the wing/winglet intersection at which flow separation is likely to occur;
• d. defining first and second reference planes for the wing and winglet, respectively, where
• i. the first reference plane extends through the wing leading and trailing edges just outside the corner flow region, and
• ii. the second reference plane extends through the winglet leading and trailing edges just outside the corner flow region;
• e. defining wing and winglet chord planes for any given wing chord and any given winglet chord, respectively, where
• i. the wing chord plane is parallel to the longitudinal axis and perpendicular to the first reference plane, and
• ii. the winglet chord phase is parallel to the longitudinal axis and perpendicular to the second reference plane;
• and
• f. flattening the upper surface in the corner flow region such that for any given wing chord plane which intersects the wing upper surface in the corner flow region, a wing reference point is defined as a point on the wing upper surface that is furthest from the first reference plane, and a vertical distance between the wing reference point and an uppermost point on the wing trailing edge furthest from the first reference plane and in the given wing chord plane is less than 4.5% of the length of the wing chord associated with the given wing chord plane.

A wing/winglet configuration for an aircraft having a longitudinal axis, a vertical axis, and a transverse axis, comprising:

• a. a wing having upper and lower wing surfaces, a wing leading edge, a wing trailing edge, and a wing tip;
• and
• b. a winglet having upper and lower winglet surfaces a winglet leading edge, a winglet trailing edge, and a winglet root, where
• i. a winglet chord is defined for any given portion of the winglet which extends between the winglet leading and trailing edges, and
• ii. the winglet root is attached to the wing tip at a wing/winglet intersection;
• wherein
• c. a corner flow region is defined as the portions of the wing upper surface and winglet upper surface near the wing/winglet intersection at which flow separation is likely to occur;
• d. a reference plane is defined for the winglet, where the reference plane extends through the winglet leading and trailing edges just outside the corner flow region;
• e. a winglet chord plane is defined for any given winglet chord, where the winglet chord plane is parallel to the longitudinal axis and perpendicular to the reference plane;
• and
• f. for any given chord plane which intersects the wing upper surface in the corner flow region, a winglet reference point is defined as a point on the winglet upper surface that is furthest from the reference plane, where a vertical distance between the winglet reference point and an uppermost point on the winglet trailing edge furthest from the reference plane and in the given winglet chord plane is less than 4.0% of the length of the winglet chord associated with the given winglet chord plane.

IN an aircraft having a longitudinal axis, a vertical axis, a transverse axis, and a wing/winglet configuration comprising:

• a. a wing having upper and lower wing surfaces, a wing leading edge, a wing trailing edge, and a wing tip, where a wing chord is defined for any given portion of the wing which extends through the wing leading and trailing edges;
• and
• b. a winglet having upper and lower winglet surfaces, a winglet leading edge, a winglet trailing edge, and a winglet root, where
• i. a winglet chord is defined for any given portion of the winglet, the winglet chord extending between the winglet leading and trailing edges, and
• ii. the winglet root is attached to the wing tip at a wing/winglet intersection;
• wherein
• a method of increasing the performance of the wing and winglet comprising the steps of:
• c. a corner flow region is defined as the portions of the wing upper surface and winglet upper surface near the wing/winglet intersection at which flow separation is likely to occur;
• d. defining a reference plane for the winglet, where the reference plane extends through the winglet leading and trailing edges just outside the corner flow region;
• e. defining a winglet chord plane for any given winglet chord, where the winglet chord plane is parallel to the longitudinal axis and perpendicular to the reference plane;
• and
• f. flattening the upper winglet surface in the corner flow region such that for any given winglet chord plane which intersects the winglet upper surface in the corner flow region, a winglet reference point is defined as a point on the winglet upper surface that is furthest from the reference plane, and a vertical distance between the winglet reference point and an uppermost point on the winglet trailing edge furthest from the reference plane and in the given winglet chord plane is less than 4.0% of the length of the winglet chord associated with the given winglet chord plane.