Aerodynamic or hydrodynamic blade made of layered material

Abstract

A blade made of layered material, such as composite material, configured for exposure to a fluid flow, comprises skins (1, 2) defined between a leading edge (3) and a trailing edge (4) which skins in cross-section form a flow profile. The layered material may consist of several layers of fiber material (5, 5′, . . . ) impregnated with a matrix material, wherein layers of fiber material each comprise a respective body portion (6, 6′, . . . , 13) between and transverse to the skins and each at least a respective skin portion (7, 7′, . . . ; 8, 8′, . . . ) that forms part of the skins. The said skin portions all extend from the related body portion in the direction of the trailing edge. Of said skin portions at least two consecutive skin portions of the one skin overlap and/or two consecutive skin portions of the other skin overlap each other.

Claims

1. A blade made of layered material, the blade being configured to be exposed to a fluid flow, and comprising skins defined between a leading edge and a trailing edge of the blade, said skins including a first skin and a second skin and forming a flow profile in cross-section, wherein the layered material comprises several layers of material, the layers of material each comprising a respective body portion between and transverse to the skins and each has at least a respective skin portion that forms part of the skins, wherein said skin portions all extend from the related body portion in a direction of the trailing edge, and wherein of said skin portions at least two consecutive skin portions of the first skin or of the second skin overlap each other, and further wherein at least a skin portion of the first skin or of the second skin has an end that is free at the exterior of the first skin or of the second skin.

2. The blade according to claim 1, wherein one or more layers of fiber material of the layered material each comprise a respective body portion and each on either side of the body portion in each case a respective skin portion that forms part of the first skin and a respective skin portion that forms part of the second skin, while forming layers of material that are U-shaped and nested in each other.

3. The blade according to claim 1, wherein skin portions that form part of the first skin or the second skin, in cross-section have a dimension that is smaller than a chord or a camber line of the flow profile.

4. The blade according to claim 1, wherein skin portions that form part of the first skin or of the second skin at the most partially overlap each other, viewed in cross-section.

5. The blade according to claim 4, wherein, when considered in cross-section, a first skin portion that forms part of the first skin or the second skin, respectively, covering a second skin portion that forms part of the first skin or the second skin, respectively, ends at greater distance from the trailing edge than the second skin portion does.

6. The blade according to claim 1, wherein a filler of a foam material is situated between the skins and the bodies.

7. The blade according to claim 1, wherein at least one spar is provided, the at least one spar comprising at least the respective body portion of a layer of material which body portion extends between and transverse to the skins and at least a skin portion that forms part of the first skin or of the second skin.

8. The blade according to claim 7, further comprising a supporting layer of material that is enclosed between two body portions of a respective layer of material.

9. The blade according to claim 7, wherein at least two spaced apart spars are provided, the spars and an area of the skins extending in between them defining a torsion box.

10. The blade according to claim 1, wherein a number of skin portions in a central area of the first skin or the second skin, respectively, which central area is situated spaced apart from the leading edge and the trailing edge, is higher than a number of skin portions in an edge area of the first skin or the second skin, respectively, which edge area is adjacent to the leading edge or the trailing edge.

11. The blade according to claim 1, wherein between the two overlapping skin portions of the layers of material comprising a body portion between the skins and at least a skin portion that forms part of the first skin or of the second skin, an additional skin portion is situated that exclusively extends within the first skin or exclusively within the second skin.

12. The blade according to claim 1, wherein of at least three consecutive layers of material that each comprise a body portion between and transverse to the skins as well as at least a skin portion that forms part of the first skin or of the second skin, the skin portions having respective consecutive ends that are spaced apart from each other in the first skin or the second skin, respectively.

13. The blade according to claim 1, wherein, of layers of material that comprise a body portion between and transverse to the skins as well as at least a skin portion that forms part of the first skin or of the second skin, at least the first skin portion has an end that is free at an exterior of the first skin or the exterior of the second skin, respectively.

14. The blade according to claim 1, wherein layers of material extend continuously between the trailing edge and the leading edge, which continuous layers of material cover the skin portions of the layers of material that comprise a body portion between the skins and at least a skin portion that forms part of the first skin or a skin portion that forms part of the second skin.

15. The blade according to claim 1, wherein layers of material comprise layers of fiber material impregnated with a matrix material, wherein a fiber direction of a layer of fiber material is oriented parallel with, at ±45° relative to, or at 90° relative to the cross-section defining the flow profile.

16. The blade according to claim 1, configured as an aerodynamic blade for exposure to an air flow or gas flow, wherein the first skin forms an underpressure skin and the second skin forms an overpressure skin, and wherein a camber line of the flow profile is curved.

17. The blade according to claim 16, configured as one of: a vane for a wind turbine, an airfoil for an airplane, a steering surface for an airplane, a flap/aileron for an airplane, a winglet for an airplane, or a propeller blade for an airscrew.

18. The blade according to claim 1, wherein the flow profile at the leading edge has a curvature with a first radius of curvature that is larger than a second radius of curvature at the trailing edge.

19. The blade according to claim 1, wherein the leading edge and the trailing edge extend between two opposite blade ends, at least one body portion at one of the blade ends being provided with coupling means for coupling the blade to a support structure.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) The invention will further be described on the basis of the exemplary embodiment shown in the figure.

(2) FIG. 1 shows an exploded view in cross-section of the profile of a blade.

(3) FIG. 2 shows a top view of the blade.

DESCRIPTION OF THE EMBODIMENTS

(4) FIG. 1 shows a slightly exploded view of the profile of an aerodynamic blade. The blade has an underpressure skin 1 and an overpressure skin 2 extending between the leading edge 3 and the trailing edge 4. The blade is built up from layers of fiber material 5, 5′, . . . that each consist of a body portion 6, 6′, . . . , a skin portion 7, 7′, . . . that forms part of the underpressure skin 1 as well as a skin portion 8, 8′, . . . that forms part of the overpressure skin 2. The layers of fiber material 5, 5′, . . . all have a U-shape, wherein the legs of the U-shape are oriented towards the trailing edge 4. This is advantageous in terms of aerodynamics.

(5) The skin portions 7, 7′, . . . of the underpressure skin 1 overlap each other partially, and in the exemplary embodiment shown each have an end 9, 9′, . . . that is free at the exterior of the underpressure skin. Likewise, the skin portions 8, 8′, . . . of the overpressure skin 2 overlap each other, wherein they have a free end 10, 10′, . . . that is free at the exterior of the overpressure skin.

(6) Between the body portions 5, 5′, . . . there are in each case fillers in the form of foam blocks 11, 11′, . . . . The body portions 5, 5″ are each adhered to a surface of a supporting foam layer 12, 12′. A body portion 13, 13′ is also adhered to the other surface of the supporting foam layer 12. In that way the spars 14, 14′ are formed. Two of such spars are spaced apart from each other and together with the parts of the underpressure skin 1 and the overpressure skin 2 situated in between, form a torsion box. The body portions 13, 13′ at the other surface of the supporting foam layer 12, 12′ also form part of U-shaped layers of fiber material.

(7) Between the skin portions 7, 7′, . . . ; 8, 8′, . . . of the layers of fiber material 5, 5′, . . . that have a body portion 6, 6′, . . . , further layers of fiber material 15, 15′, . . . are provided that serve to reinforce the skins locally. Said further layers of fiber material 15 exclusively extend into those skins 1, 2, and are not provided with a body portion.

(8) The top view of FIG. 2 shows that the blade extends between the free end 17 and the opposite end 18 that has to be attached to for instance the hub of a wind turbine or the body of an airplane. For that purpose, some body portions 6, 6′, 6″, . . . are provided with coupling means 16, 16′, 16″, . . . . In particular the spars 14, 14′, of which the body portions 6, 6″ are part, are provided with such coupling means 16, 16″. This may for instance regard fittings that can be attached to associated counterparts of a wind turbine hub, or an airplane body and the like.

(9) Although in the above there is question of fiber material, another material can also be used for U-shaped layers with skin portions and body portions, such as a metal for instance aluminum. Instead of foam material other suitable fillers are also possible

LIST OF REFERENCE NUMBERS

(10) 1. Underpressure skin 2. Overpressure skin 3. Leading edge 4. Trailing edge 5, 5′, . . . Layer of fiber material 6, 6′, . . . Body portion 7, 7′, . . . Skin portion 8, 8′, . . . Skin portion 9, 9′, . . . Free end skin portion 10, 10′, . . . Free end skin portion 11, 11′, . . . Foam material filler 12, 12′, . . . Layer of supporting foam material 13, 13′, . . . Body portion 14, 14′ Spar 15, 15′, . . . Layer of fiber material 16, 16′, . . . Coupling means