Efficient wing tip devices and methods for incorporating such devices into existing wing designs
AssigneeThe Boeing Company
InventorJames D. McLean
Life of this patent
Estimating the term…
Abstract
Efficient wing tip devices for use with aircraft wings. In one embodiment, an aircraft wing/winglet combination includes a wing having a wing root portion and a wing tip portion spaced apart from the wing root portion. The wing tip portion can have a wash-out twist relative to the wing root portion. The aircraft wing/winglet combination can further include a winglet extending from the wing tip portion of the wing. The winglet can be swept at least generally forward relative to the wing to favorably change the lift distribution on the wing and in turn reduce the induced drag on the wing.
Claims33
An airfoil/winglet combination comprising:
- an airfoil having an airfoil root portion and an airfoil tip portion spaced apart from the airfoil root portion, the airfoil tip portion having a wash-out twist relative to the airfoil root portion;
- and
- a winglet extending outwardly from the airfoil tip portion of the airfoil, the winglet being swept forward relative to the airfoil and fixedly attached directly to the airfoil tip portion in the absence of a second winglet extending outwardly from the airfoil tip portion, wherein the airfoil includes an airfoil trailing edge portion and the winglet includes a winglet trailing edge portion, the winglet trailing edge portion being positioned forward of the airfoil trailing edge portion defining a space therebetween.
An aircraft system comprising:
- a wing having a wing tip portion and a wing root portion, the wing root portion defining a wing root chord, the wing tip portion defining a wing tip chord, the wing tip chord having a wash-out twist relative to the wing root chord and being offset from the wing root chord along a wing quarter-chord line;
- and
- a winglet having a winglet tip portion and a winglet root portion, the winglet root portion defining a winglet root chord and being fixedly attached directly to the wing tip portion of the wing in the absence of a second winglet extending outwardly from the wing tip portion, the winglet tip portion defining a winglet tip chord and being offset from the winglet root chord along a winglet quarter-chord line, the winglet quarter-chord line being swept at least generally forward relative to the wing quarter-chord line wherein the wing includes a wing trailing edge portion and the winglet includes a winglet trailing edge portion, the winglet trailing edge portion being positioned forward of the wing trailing edge portion defining a space therebetween.
A method for manufacturing an aircraft wing/winglet combination, the method comprising:
- providing a wing having a wing root portion and a wing tip portion, the wing root portion configured to be attached toward a fuselage of an aircraft and defining a wing root chord, the wing tip portion defining a wing tip chord and being offset from the wing root chord along a wing quarter-chord line, the wing tip chord having a wash-out twist relative to the wing root chord;
- providing a winglet having a winglet root portion and a winglet tip portion, the winglet root portion defining a winglet root chord, the winglet tip portion defining a winglet tip chord, the winglet tip chord being offset from the winglet root chord along a winglet quarter-chord line;
- and
- fixedly attaching the winglet root portion directly to the wing tip portion in the absence of a second winglet extending outwardly from the wing tip portion and such that the winglet quarter-chord line is swept at least generally forward relative to the wing quarter-chord line wherein the wing includes a wing trailing edge and the winglet includes a winglet trailing edge, the winglet trailing edge being positioned forward of the wing trailing edge defining a space therebetween.
A method for manufacturing a second wing from a first wing, the first wing having a wing root portion and a wing tip portion, the wing root portion configured to be attached toward a fuselage of an aircraft and defining a wing root chord, the wing tip portion defining a wing tip chord and being offset from the wing root chord along a wing quarter-chord line, the wing tip chord having a wash-out twist relative to the wing root chord, the method comprising:
- providing a winglet having a winglet root portion and a winglet tip portion, the winglet root portion defining a winglet root chord, the winglet tip portion defining a winglet tip chord and being offset from the winglet root chord along a winglet quarter-chord line;
- and
- fixedly attaching the winglet root portion directly to the wing tip portion in the absence of a second winglet extending outwardly from the wing tip portion and such that the winglet quarter-chord line is swept at least generally forward relative to the wing quarter-chord line wherein the first wing includes a wing trailing edge and the winglet includes a winglet trailing edge, the winglet trailing edge being positioned forward of the wing trailing edge defining a space therebetween.
A method for improving the drag characteristics of a wing having a wing root portion and a wing tip portion, the wing root portion defining a wing root chord and being configured to be attached toward a fuselage of an aircraft, the wing tip portion defining a wing tip chord offset from the wing root chord along a wing quarter-chord line, the method comprising:
- changing the planform of the wing by:
- providing a winglet having a winglet root portion and a winglet tip portion, the winglet root portion defining a winglet root chord, the winglet tip portion defining a winglet tip chord, the winglet tip chord being offset from the winglet root chord along a winglet quarter-chord line;
- and
- fixedly attaching the winglet to the wing by fixing the winglet root portion directly to the wing tip portion in the absence of a second winglet extending outwardly from the wing tip portion, wherein when the winglet is fixedly attached to the wing, the winglet quarter-chord line is swept at least generally forward relative to the wing quarter-chord line wherein the wing includes a wing trailing edge and the winglet includes a winglet trailing edge, the winglet trailing edge being positioned forward of the wing trailing edge defining a space therebetween.
A winglet for use with an aircraft, the winglet comprising:
- a winglet root portion, wherein the winglet root portion is configured to fixedly attached directly to a wing tip portion of a wing of the aircraft in the absence of a second winglet extending outwardly from the wingtip portion, the wing having a washout twist;
- and
- a winglet tip portion, wherein the winglet tip portion is swept forward relative to the winglet root portion a winglet trailing edge portion, wherein the winglet trailing edge portion is configured to be positioned forward of a trailing edge portion of the wing defining a space therebetween.
Dependencies are inferred from the claim text.