Method of designing a winglet and a winglet designed thereby

Patent metadata

Field	Value
Publication number	US-2018237162-A1
Application number	US-201815899788-A
Country	US
Kind code	A1
Filing date	Feb 20, 2018
Priority date	Feb 22, 2017
Publication date	Aug 23, 2018
Grant date	—

Abstract

A method of designing a winglet (3) for an aircraft (7) including: defining the location of the winglet root; defining a maximum height for the winglet tip; defining a maximum span for the winglet; creating the winglet shape by locating the winglet root (13′), locating the winglet tip (15′) at the location of maximum height and maximum span, and connecting the winglet root (13′) to the winglet tip (15′) using a winglet shape. The winglet shape includes a curved transition region (17′) extending away from the root, and a wing-like region extending from the distal end of the transition region (17′) to the winglet tip (15′). The step of creating the winglet shape includes iteratively changing the curvature and/or the location of the center of the curvature of the transition region, whilst maintaining the locations of the winglet root and winglet tip.

First claim

1 . A method of designing a winglet for an aircraft, the method comprising the steps of:
i. defining the location of a root for the winglet; ii. defining a maximum height of a tip for the winglet; iii. defining a maximum span for the winglet; iv. creating a winglet shape by locating a winglet root at the location of the root, locating a winglet tip at a location no higher than the maximum height, and defining a span of the winglet shape which is no greater than the maximum span, and connecting the winglet root to the winglet tip using the winglet shape; wherein the winglet shape comprises a curved transition region extending away from the winglet root, and a wing-like region extending from a distal end of the curved transition region to the winglet tip, and wherein the step of creating the winglet shape comprises iteratively changing a curvature and/or location of a center of curvature of the curved transition region, while maintaining the location of the winglet root and maintaining the location of the winglet tip, such that a total length of the winglet shape from the winglet root to the winglet tip is increased while keeping the winglet shape in compliance with the maximum height and the maximum span.

2 . The method according to claim 1 , wherein the total length of the winglet is optimized to minimize an overall drag coefficient of the wing tip of the winglet shape.

3 . The method according to claim 1 , wherein the location of the center of curvature of the transition region is changed by progressively moving that center of curvature outboard.

4 . The method according to claim 1 , wherein the changing of the curvature of the transition region comprises increasing a radius curvature of the curvature of the transition region.

5 . The method according to claim 1 , wherein the wing-like region is substantially planar.

6 . The method according to claim 5 , wherein the wing-like region extends vertically downward from the winglet tip.

7 . The method according to claim 1 , wherein the maximum height and span of the winglet are defined for when an aircraft, having the winglet fitted, is stationary on the ground.

8 . The method according to claim 7 , wherein the winglet is designed such that the wing-like region is substantially vertical when the aircraft is stationary on the ground under worst-case static loading, and when the aircraft is in flight under 1-g flight conditions the wing-like region is designed to be canted inboard such that the winglet tip is moved inboard of the point of maximum span of the winglet.

9 . A method of manufacturing a winglet comprising the steps of:
designing a winglet using the method according to claim 1 ; and manufacturing the winglet to conform to the design of the winglet.

10 . A winglet designed using the method of claim 1 .

11 . A winglet manufactured using the method of claim 9 .

12 . A winglet comprising: a winglet root, a curved transition region extending from the root to a distal end, and a wing-like region extending from the distal end of the transition region to a winglet tip;
wherein the winglet has a shape formed by fixing a location of the winglet tip at a maximum height and a maximum span whilst moving the location of the center of the curvature of the transition region outboard such that the length of the winglet from root to tip is increased, whilst keeping the winglet within the maximum height and span constraints.

13 . A method to design a winglet shape for an aircraft, wherein the winglet shape includes a root, a tip, a curved transition region extending from the root towards the tip, and a wing-like region extending from the curved transition region to the tip, wherein the method comprises:
defining a location for the root of the winglet shape; defining a maximum height of the tip of the winglet shape; defining a maximum span of the winglet shape; iteratively changing a curvature and/or location of a center of curvature of the curved transition region, wherein the iterative changes progressively increase a total length of the winglet shape and do not change the location of the root, and during and/or after the iterative changes, conforming that the winglet shape complies with the maximum height and the maximum span.

14 . The method of claim 13 wherein the step of iteratively changing includes progressively moving the center of the curvature away from the root.

15 . The method of claim 13 wherein the step of iteratively changing includes progressively increasing a radius of the curvature.

16 . The method of claim 13 wherein the step of iteratively changing includes maintaining the wing-like region parallel to a plane.

17 . The method of claim 13 wherein the steps of defining the maximum height and the maximum span incorporate an assumption that the aircraft is on the ground and the winglet shape corresponds to a winglet mounted to a wing of the aircraft.

18 . The method of claim 13 wherein the step of iteratively changing includes maintaining the wing-parallel to a vertical plane.

Assignees

• Airbus Operations Ltd
• Airbus Operations Gmbh

Inventors

• Wright Christopher
• Commis Ben
• Leoviriyakit Kasidit
• Heller Gerd

Classifications

• B64F5/00 Primary

  Designing, manufacturing, assembling, cleaning, maintaining or repairing aircraft, not otherwise provided for; Handling, transporting, testing or inspecting aircraft components, not otherwise provided for · CPC title

• B64C23/069

  using one or more wing tip airfoil devices, e.g. winglets, splines, wing tip fences or raked wingtips · CPC title

• Y02T50/10

  Drag reduction · CPC title

• B64C23/065 Primary

  at the wing tips · CPC title

• B64C3/10

  Shape of wings · CPC title