Wing airfoil stiffening for solar powered aircraft

• US 10,640,221 B2
• Filed: 12/15/2014
• Issued: 05/05/2020
• Est. Priority Date: 10/19/2011
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Grip, Robert Erik, Kutzmann, Aaron J., Rawdon, Blaine Knight
• Primary Examiner(s): Hutchens, Christopher D
• Application Number:
  US14/571,170
• Publication Number:
  US 20160167764A1
• Time in Patent Office: 1,968 Days
• CPC Class Codes: B64C 3/18 Spars; Ribs; Stringers
• CPC Class Codes: B64C 3/182 Stringers, longerons
• CPC Class Codes: B64C 3/185 Spars
• CPC Class Codes: B64C 3/187 Ribs
• CPC Class Codes: B64C 3/22 Geodetic or other open-frame structures
• CPC Class Codes: B64C 3/26 Construction, shape, or attachment of separate skins, e.g. panels
• CPC Class Codes: B64D 27/24 using steam or spring force jet aircraft B64D27/16
• CPC Class Codes: B64D 27/353 using solar cells
• CPC Class Codes: Y02T 50/40 Weight reduction
• CPC Class Codes: Y02T 50/50 On board measures aiming to increase energy efficiency
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor

Abstract

A light-weight stiffened wing airfoil includes at least one wing segment (52). The wing segment comprises an upper (53b) and a lower skin assembly (53a), wherein each of the upper and lower skin assemblies incorporates a plurality of inwardly facing stringers (74); a first rib (64-1) at a distal end of the wing segment and a second rib (64-2) at a proximal end of the wing segment; a plurality of rib trusses (70) extending from the first and second ribs to the opposing skin assembly (53); and a plurality of support members extending from the inwardly facing stringers to the opposing skin assembly.

Claims

1. A stiffened wing airfoil including at least one wing segment of a plurality of wing segments together comprising the wing airfoil, each wing segment rotatable about a longitudinal axis of the wing airfoil, the wing segment comprising:

a first skin assembly and a second skin assembly, wherein each of the first skin assembly and second skin assemblies incorporates a plurality of inwardly facing stringers extending in a direction of the longitudinal axis of the wing airfoil and conforming to an inner surface of the first skin assembly and the second skin assembly, each of the stringers comprising a groove;

a first rib at a distal end of the wing segment and a second rib at a proximal end of the wing segment, wherein the first rib and second rib are supported by a plurality of rib trusses extending between a first rib cap and a second rib cap of each of the first rib and the second rib at nodes proximate a first subset of the stringers; and

a plurality of support members including a plurality of rib support members (76a) and a plurality of skin support members (76b), wherein;

each of the rib support members extend between the first rib cap and the second rib cap of the first rib from one of the nodes proximate the first subset of stringers to a node proximate a stringer other than the first subset of the stringers;

each of the skin support members extend from the second rib cap of the first rib at one of the nodes proximate the first subset of stringers to one of a series of predefined locations along the groove of one of the plurality of stringers on the first skin assembly, wherein a plurality of the skin support members comprise wires or rods;

at least one of the skin support members extends from the second rib cap of the first rib at the one of the nodes proximate the first subset of stringers to a predefined location along a groove of a stringer other than the first subset of stringers; and

at least one of the plurality of skin support members is affixed between the one of the plurality of inwardly facing stringers and a rib flange of one of the first rib and the second rib, the rib flange substantially perpendicular to the longitudinal axis of the wing airfoil.

2. The stiffened wing airfoil of claim 1, wherein the one of the predefined locations is along a same groove of the first subset of stringers.

3. The stiffened wing airfoil of claim 2, wherein the series of predefined locations are evenly spaced between the first rib and second rib.

4. The stiffened wing airfoil of claim 1, wherein at least one of the second skin assembly and the first skin assembly bows away from the other of the second skin assembly and the first skin assembly.

5. The stiffened wing airfoil of claim 4, wherein the at least one of the first skin assembly and the second skin assembly is pulled inward by tension supplied by at least some of the support members.

6. The stiffened wing airfoil of claim 1, wherein the support members extending from the inwardly facing stringers of the second skin assembly to the first skin assembly comprise wires, and wherein the support members extending from the inwardly facing stringer grooves of the first skin assembly to the second skin assembly comprise rods.

7. The stiffened wing airfoil of claim 1, wherein a group of the plurality of support members contact the inwardly facing stringers of the first skin assembly and the second skin assembly via a connector in contact with the rib flange of one of the first rib or the second rib.

8. The stiffened wing airfoil of claim 7, wherein at least one of the plurality of rib trusses is mounted to the connector.

9. The stiffened wing airfoil of claim 7, wherein a blade of the connector contacts one of the first skin assembly and the second skin assembly.

10. The stiffened wing airfoil of claim 1, further comprising:

a solar panel located on the first skin assembly opposite the inwardly facing stringers.

11. The stiffened wing airfoil of claim 1, wherein a portion of the plurality of support members attached to an aft portion of one of the first skin assembly and the second skin assembly comprise shape-memory alloy, wherein the portion of support members controls a shape of a trailing edge of at least one of the first skin assembly and the second skin assembly.

12. The stiffened wing airfoil of claim 1, wherein the skin support members are secured to the groove of the stringer at the series of predefined locations via a plurality of connectors, formed to the grooves of the stringers.

13. The stiffened wing airfoil of claim 1, wherein the stringers are integrally formed from the same material as the respective first and second skin assemblies.

14. The stiffened wing airfoil of claim 1, wherein the at least one of the plurality of skin support members is affixed between one of the plurality of inwardly facing stringer and a rib flange of one of the first rib and the second rib via a connector having a surface bonded to a matching surface of the rib flange of the one of the first rib and the second rib.

15. The stiffened wing airfoil of claim 14, wherein at least one of the rib support members is affixed between the first rib cap and the second rib cap via the connector.

16. The stiffened wing airfoil of claim 15, wherein the at least one of the plurality of skin support members and the at least one of the plurality of rib support members is inserted into a corresponding hole of the connector and bonded to the connector.