Leading edge structure for a flow control system of an aircraft

Patent metadata

Field	Value
Publication number	US-11040769-B2
Application number	US-201816030261-A
Country	US
Kind code	B2
Filing date	Jul 9, 2018
Priority date	Jul 11, 2017
Publication date	Jun 22, 2021
Grant date	Jun 22, 2021

Abstract

A leading edge structure (1) for a flow control system of an aircraft, including a double-walled leading edge panel (3) that surrounds a plenum (7), wherein the leading edge panel (3) includes an inner wall element (21) facing the plenum (7) and an outer wall element (23) in contact with the ambient flow (25), wherein between the inner and outer wall elements (21, 23) the leading edge panel (3) includes elongate stiffeners (27) spaced apart from one another, so that between each pair of adjacent stiffeners (27) a hollow chamber (29) is formed between the inner and outer wall elements (21, 23), wherein the outer wall element (23) includes micro pores (31) forming a fluid connection between the hollow chambers (29) and an ambient flow (25), and wherein the inner wall element (21) includes openings (33) forming a fluid connection between the hollow chambers (29) and the plenum (7).

First claim

The invention claimed is:

1. A leading edge structure for a flow control system of an aircraft, the leading edge structure comprising
a double-walled leading edge panel that surrounds a plenum in a curved manner, the plenum extending in a span direction,
wherein the leading edge panel has a first side portion extending from a leading edge point to a first attachment end,
wherein the leading edge panel has a second side portion opposite the first side portion, extending from the leading edge point to a second attachment end,
wherein the leading edge panel comprises an inner wall element facing the plenum and an outer wall element in contact with the ambient flow, wherein at least the inner wall element includes layers of fiber reinforced plastic,
wherein between the inner and outer wall elements, the leading edge panel comprises a plurality of elongate stiffeners spaced apart from one another, so that between each pair of adjacent stiffeners a hollow chamber is formed between the inner and outer wall elements,
wherein the outer wall element comprises a plurality of micro pores forming a fluid connection between the hollow chambers and an ambient flow,
wherein the inner wall element comprises openings forming a fluid connection between the hollow chambers and the plenum,
wherein the elongate stiffeners are formed integrally with the inner wall element, and
wherein each of the elongate stiffeners includes a core sandwiched between the layers of fiber reinforced plastic of the inner wall element.

2. The leading edge structure according to claim 1 , further comprising a back wall connecting the first attachment end to the second attachment end of the leading edge panel, thereby enclosing the plenum on a side opposite the leading edge point.

3. The leading edge structure according to claim 1 , wherein the openings are formed as throttle holes each having a predefined diameter adapted for a predefined mass flow rate through the throttle holes in order to achieve a predefined fluid pressure in the hollow chambers.

4. The leading edge structure according to claim 1 , wherein each of the stiffeners has a solid shape in cross section and the solid shape is one of a square or a trapezoid.

5. The leading edge structure according to claim 1 , wherein the stiffeners extend in the span direction.

6. The leading edge structure according to claim 1 , wherein the core of each of the stiffeners is a solid structure.

7. The leading edge structure according to claim 6 , wherein the cores of the stiffeners are formed of a foam material.

8. The leading edge structure according to claim 1 , wherein support ribs are attached to the inner wall element in such a way that the support ribs face the plenum and extend across the span direction along the inner wall element.

9. The leading edge structure according to claim 8 , wherein the support ribs are formed integrally with the inner wall element to form a single piece molded component.

10. The leading edge structure according to claim 8 , wherein the support ribs are formed of a fiber reinforced plastic (FRP).

11. The leading edge structure according to claim 1 , wherein the outer wall element is formed as a titanium sheet.

12. The leading edge structure according to claim 1 , wherein the outer wall element comprises multiple sections, wherein the porosity varies from one section of the multiple sections to another section of the multiple sections and the variation in porosity is in terms of pore diameter and/or pore pitch of the micro holes in the outer wall element.

13. A vertical tail plane for an aircraft comprising
a vertical tail plane box having a first lateral panel with a first attachment portion and an opposite second lateral panel with a second attachment portion,
a leading edge structure comprising
a double-walled leading edge panel that surrounds a plenum in a curved manner, the plenum extending in a span direction,
wherein the leading edge panel has a first side portion extending from a leading edge point to a first attachment end,
wherein the leading edge panel has a second side portion opposite the first side portion, and the second side portion extends from the leading edge point to a second attachment end,
wherein the leading edge panel comprises an inner wall element facing the plenum and an outer wall element configured to contact with ambient air flow over the vertical tail plane,
wherein between the inner and outer wall elements, the leading edge panel comprises a plurality of elongate stiffeners spaced apart from one another, so that between each pair of adjacent stiffeners a hollow chamber is formed between the inner and outer wall elements,
wherein the outer wall element comprises a plurality of micro pores forming a fluid connection between the hollow chambers and an ambient flow,
wherein the inner wall element comprises openings forming a fluid connection between the hollow chambers and the plenum,
wherein the elongate stiffeners are formed integrally with the inner wall element,

wherein the first attachment end is attached to the first attachment portion, and wherein the second attachment end is attached to the second attachment portion, so that the first side portion of the leading edge panel forms a continuous flow surface with the first lateral panel of the vertical tail plane box, and the second side portion of the leading edge panel forms a continuous flow surface with the second lateral panel of the vertical tail plane box,
wherein the plenum is in fluid connection with a rear-facing outlet flap for causing a vacuum in the plenum to draw air from the ambient flow through the micro pores and the hollow chambers into the plenum,
wherein the plenum is in fluid connection with a fore-facing inlet flap for causing an overpressure in the plenum to blow out air from the plenum through the hollow chambers and the micro pores to the ambient flow, and
wherein the vertical tail plane further comprises a connection duct connecting a lower end of the plenum to the outlet flap and/or to the inlet flap.

14. A leading edge structure for a vertical tail plane, the leading edge structure comprising:
a double-walled structure which extends in a spanwise direction of the vertical tail plane, and is U shaped in a cross section in a chordwise direction of the vertical tail plane;
an outer wall panel of the doubled-walled leading edge forms a leading edge of the vertical tail plane, wherein the outer wall panel is perforated with micro-pores which allow air to flow through the outer wall panel;
an inner wall panel of the doubled-wall leading edge, wherein the inner wall panel is seated within the outer-wall panel, is co-extensive in the spanwise direction with the outer wall panel, includes openings configured to allow air passing through the outer wall panel to flow into or out of a plenum within the doubled-walled structure, and the inner wall panel is formed of layers of fiber reinforced plastic; and
stiffeners sandwiched between the inner wall panel and the outer wall panel, wherein the stiffeners are oriented in the spanwise direction;
wherein the plenum is defined, in part, by the inner wall panel which forms an outer wall of the plenum;
wherein the inner wall panel and the stiffeners are an integral, single piece component and each of the stiffeners includes at least one of the layers of the inner wall panel and a core sandwiched between the layers of fiber reinforced plastic of the inner wall panel.

15. The leading edge structure of claim 14 wherein the inner wall panel and stiffeners are a molded component formed of a fiber reinforced plastic ma

Assignees

• Airbus Operations Gmbh

Inventors

• Schrauf Geza
• Heck Christian

Classifications

• Y02T50/10

  Drag reduction · CPC title

• F15D1/12

  by influencing the boundary layer · CPC title

• B64C2230/22

  by using a surface having multiple apertures of relatively small openings other than slots · CPC title

• B64C21/02 Primary

  by use of slot, ducts, porous areas or the like · CPC title

• B64C2230/08

  by influencing fluid flow by means of surface cavities, i.e. net fluid flow is null · CPC title