Leading edge for an airfoil

Abstract

A leading edge for an airfoil comprising a torsion box, the leading edge comprising a leading plate and a first inflatable element suitable for being filled with air. The leading plate comprises a convex side and a concave side. The first inflatable element is in contact with at least part of the concave side, thus reinforcing the leading plate. An airfoil comprising such a leading edge is also provided.

Claims

1. A leading edge for an airfoil comprising a torsion box, the leading edge comprising: a leading plate with a convex side and a concave side; a first inflatable element fillable filled with air, the first inflatable contacting at least part of the concave side, thus reinforcing the leading plate, and an outer coverage forming a continuous surface covering the leading plate, configured to further cover the torsion box; wherein the outer coverage covers upper and lower surfaces of the torsion box and is attached to the torsion box, wherein an attachment of the outer coverage to the torsion box is located at a rear spar of the torsion box opposite a front spar of the torsion box; and wherein the leading plate is attached to the front spar of the torsion box.

2. The leading edge according to claim 1, further comprising: a second inflatable element fillable with air, the second inflatable element contacting at least part of the convex side of the leading plate; and an outer coverage covering the second inflatable element and the leading plate, configured to further cover the torsion box.

3. The leading edge according to claim 1, wherein the first inflatable element comprises at least one string attached to two different points of said first inflatable element, thus establishing a maximum distance between said points.

4. The leading edge according to claim 1, wherein the first inflatable element further comprises an inflation valve configured to control a pressure inside said first inflatable element.

5. The leading edge according to claim 1, wherein the first inflatable element is made of a material comprising fibers made of aramids, nylon or ultra-high-molecular-weight polyethylene and a matrix.

6. The leading edge according to claim 5, wherein the matrix comprises silicone, chlorosulfonated polyethylene or thermoplastic polyurethane.

7. An airfoil comprising: a torsion box and a leading edge, the leading edge comprising: a leading plate with a convex side and a concave side; a first inflatable element fillable with air; the first inflatable element contacting at least part of the concave side, thus reinforcing the leading plate, and an outer coverage forming a continuous surface covering the leading plate, configured to further cover the torsion box; wherein the outer coverage covers upper and lower surfaces of the torsion box and is attached to the torsion box, wherein an attachment of the outer coverage to the torsion box is located at a rear spar of the torsion box opposite a front spar of the torsion box; and wherein the leading plate is attached to the front spar of the torsion box.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other characteristics and advantages of the invention will become clearly understood in view of the detailed description of the invention which becomes apparent from preferred embodiments of the invention, given just as an example and not being limited thereto, with reference to the drawings.

(2) FIG. 1 This figure shows a side view of a first embodiment of a leading edge according to the invention.

(3) FIG. 2 This figure shows a side view of a second embodiment of a leading edge according to the invention.

(4) FIG. 3 This figure shows a side view of a third embodiment of a leading edge according to the invention.

(5) FIG. 4 This figure shows an airfoil comprising a leading edge according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) Once an object of the invention has been outlined, specific non-limitative embodiments are described hereinafter.

(7) FIG. 1 shows a side view of a first embodiment of a leading edge (1) according to the invention. This leading edge (1) comprises:

(8) a leading plate (2) with a convex side (21) and a concave side (22),

(9) a first inflatable element (3) suitable for being filled with air,

(10) the first inflatable element (3) being in contact with at least part of the concave side (22), thus reinforcing the leading plate (2).

(11) The first inflatable element (3) serves as a structural reinforcement for the leading plate (2). This makes unnecessary the use of stringers or ribs for this purpose, thus saving weight and avoiding inspections of these composite parts.

(12) This leading edge (1) also comprises strings (7). Each one of these strings is attached to two different points of the first inflatable element (3), thus establishing the maximum distance between such points. The arrangement of several strings (7) in the first inflatable element (3) allows the inflatable element (3) to keep a predetermined shape.

(13) FIG. 2 shows a side view of a second embodiment of a leading edge according to the invention. In this embodiment, the leading edge (1) also comprises a leading plate (2) and a first inflatable element (3) as in the embodiment of FIG. 1. In this embodiment, the leading edge (1) further comprises an outer coverage (5) which covers the leading plate (2). This outer coverage (5) is suitable for further covering a torsion box of the airfoil where the leading edge (1) is intended to be installed. In these embodiments, the attachment of the outer coverage to the torsion box is made by attaching one end of the outer coverage to some attaching means located in the rear spar of the torsion box.

(14) This leading edge (1) is suitable for being installed in an airfoil which comprises a torsion box. In this case, this leading edge (1) has the advantage of providing a continuous outer surface, given by the outer coverage (5), which makes it easier for the airflow to remain in a laminar flow, thus reducing the drag around the airfoil where the leading edge (1) is to be installed.

(15) This leading edge (1) further comprises an inflation valve (8) suitable for controlling the pressure inside the first inflatable element (3). This inflation valve (8) is easily accessible for a maintenance check or to modify the pressure of the first inflatable element (3).

(16) FIG. 3 shows a side view of a third embodiment of a leading edge according to the invention. In this embodiment, the leading edge (1) also comprises a leading plate (2) and a first inflatable element (3) as in the embodiment of FIG. 1. In this embodiment, the leading edge (1) further comprises

(17) a second inflatable element (4) suitable for being filled with air, the second inflatable element (4) being in contact with at least part of the convex side (21) of the leading plate (2), and

(18) an outer coverage (5) covering the second inflatable element (4) and the leading plate (2), suitable for further covering the torsion box.

(19) This embodiment differs from the embodiment of FIG. 2 in that it also comprises a second inflatable element (4) which is arranged between the leading plate (2) and the outer coverage (5).

(20) In different embodiments, both first and second inflatable elements (3, 4) are made of a material comprising fibers made of aramids, nylon or ultra-high-molecular-weight polyethylene and a matrix. In more specific embodiments, the matrix comprises silicone, chlorosulfonated polyethylene or thermoplastic polyurethane.

(21) FIG. 4 shows an airfoil (10) comprising a leading edge (1) according to any of preceding figures. In this particular figure, the leading edge (1) is configured according to FIG. 2, but an airfoil (10) comprising any other leading edge (1) according to the invention is also part of the invention.

(22) While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, the terms a or one do not exclude a plural number, and the term or means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.