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EP-4739888-A1 - BLADE MADE OF COMPOSITE MATERIAL FOR A TURBINE ENGINE, AIRCRAFT TURBINE ENGINE AND METHOD FOR MANUFACTURING A BLADE MADE OF COMPOSITE MATERIAL FOR A TURBINE ENGINE, IN PARTICULAR OF AN AIRCRAFT

EP4739888A1EP 4739888 A1EP4739888 A1EP 4739888A1EP-4739888-A1

Abstract

The invention relates to a blade (7) made of composite material for a turbine engine (10), in particular of an aircraft, the blade (7) comprising an airfoil (70) formed by a fibrous preform embedded in a resin and extending along an axis (A) of elongation, the airfoil (70) comprising a leading edge (73), a trailing edge (74), a pressure side (71) and a suction side (72) connected to the pressure side (71) by the leading edge (73) and the trailing edge (74), the airfoil (70) further comprising at least one serrated element (9) formed by a plurality of teeth (92) and covering at least part of the leading edge (73) and/or the trailing edge (74), wherein the at least one serrated element (9) is made of a thermosetting or thermoplastic material.

Inventors

  • PERLIN, MATTHIEU PATRICK JEAN ROGER
  • BEDLE, Alexandre René Roger
  • GARCIA, Grégory

Assignees

  • SAFRAN AIRCRAFT ENGINES

Dates

Publication Date
20260513
Application Date
20240701

Claims (15)

  1. 1. A composite material blade (7) for a turbomachine (10), in particular an aircraft, said blade (7) comprising a blade (70) formed by a fiber preform embedded in a resin and extending along an elongation axis (A), said blade (70) comprising a leading edge (73), a trailing edge (74), a lower surface (71) and an upper surface (72) connected to the lower surface (71) by the leading edge (73) and the trailing edge (74), the blade (70) further comprising at least one serration element (9) formed by several teeth (92) and covering at least part of the leading edge (73) and/or the trailing edge (74), characterized in that said at least one serration element (9) is made of a thermosetting or thermoplastic material.
  2. 2. Composite material blade according to claim 1, characterized in that said at least one clamping element (9) is fixed along the leading edge (73) and/or the trailing edge (74) by a layer of glue (C).
  3. 3. Blade made of material according to claim 1 or 2, characterized in that said at least one serration element (9) extends from the leading edge (73) and/or the trailing edge (74) to a part of the intrados (71) and/or the extrados (72).
  4. 4. Composite material blade according to claim 2 or 3, characterized in that it comprises at least one sacrificial layer (S) comprising for example glass fibers, and interposed between the glue layer (C) and the leading edge (73) and/or the trailing edge (74).
  5. 5. Blade made of composite material according to any one of the preceding claims, characterized in that it comprises a protective sheath (8) at least partly covering the leading edge (73), said at least one clamping element (9) at least partly covering this protective sheath (8).
  6. 6. Composite material blade according to any one of the preceding claims, characterized in that said at least one clamping element (9) has a length (Lg) measured along a longitudinal axis (B) perpendicular to the elongation axis (A), which represents between 20 and 100% of a length (L?) of the blade chord (70) measured in the same plane (PL).
  7. 7. Composite material blade according to any one of the preceding claims, characterized in that said at least one serration element (9) has a height (Hg) measured along the elongation axis (A), which represents between 30 and 100% of a total height (H?) of the blade (70) measured in the same plane PH.
  8. 8. Composite material blade according to any one of the preceding claims, characterized in that the fiber preform is produced by weaving fibers in three dimensions or by superimposing several layers of fibers.
  9. 9. A composite material blade according to any preceding claim, characterized in that the thermosetting material comprises an epoxy resin pre-impregnated with carbon fibers or glass fibers, or the thermoplastic material comprises a polyether-ether-ketone, poly-aryl-ether-ketone, poly-ether-imide or epoxy resin.
  10. 10. Blade made of composite material according to any one of claims 2 to 9, characterized in that the adhesive layer (C) has a thickness (Ec) of between 50 and 400 pm, preferably between 100 and 350 pm, the thickness (Ec) being measured along a cross section to the axis of elongation (A).
  11. 11. Aircraft turbomachine (10) comprising at least one blade (7) made of composite material according to any one of the preceding claims.
  12. 12. Method for manufacturing a blade (7) made of composite material according to any one of claims 1 to 10, for a turbomachine (10), in particular an aircraft, the method comprising the following steps: (a) providing the blade (7) comprising the blade (70) formed from the fibrous preform embedded in resin, the blade (70) comprising the leading edge (73), the trailing edge (74), the intrados (71) and the extrados (72) connected to the intrados (71) by the leading edge (73) and the trailing edge (74), (b) producing said at least one clamping element (9) from thermosetting or thermoplastic material, (c) mounting and fixing said at least one clamping element (9) so as to cover at least part of the leading edge (73) and/or the trailing edge (74).
  13. 13. Manufacturing method according to the preceding claim, characterized in that step (c) comprises gluing (C2) said at least one clamping element (9) on at least one part of the leading edge (73) and/or the trailing edge (74).
  14. 14. Manufacturing method according to the preceding claim, characterized in that the bonding (C2) is carried out in an autoclave under a vacuum cover, for example at a pressure of between 2 and 10 bars and at a temperature of between 100 and 200°C.
  15. 15. Manufacturing method according to claim 13 or 14, characterized in that before the bonding (C2), step (c) comprises a deposition (ci) of a sacrificial layer (S) on at least part of the leading edge (73) and/or the trailing edge (74), so as to place this sacrificial layer (S) between the layer of glue (C) and the leading edge (73) and/or the trailing edge (74).

Description

DESCRIPTION TITLE : BLADE MADE OF COMPOSITE MATERIAL FOR A TURBOMACHINE, AIRCRAFT TURBOMACHINE AND METHOD FOR MANUFACTURING A BLADE MADE OF COMPOSITE MATERIAL FOR A TURBOMACHINE, IN PARTICULAR AN AIRCRAFT TURBOMACHINE Technical field The invention relates to the field of turbomachines, in particular aircraft turbomachines, and in particular to the propulsive propellers of these turbomachines which comprise blades. More particularly, the invention relates to composite material blades for such turbomachines, and more precisely to improving the noise reduction of these blades in operation, as well as a method for manufacturing such blades. Technical background The state of the art includes in particular documents FR-A1 -3073018, FRAI -3073019, US-A1 -2017/226865 and US-A1 -2013/156592. A propulsive propeller for a turbomachine, particularly an aircraft, can be shrouded (figure 1) as is the case for a fan for example, or can be unshrouded (figure 2) as is the case for an “open-rotor” type architecture for example. A propeller comprises a plurality of blades rotating about a longitudinal axis of the turbomachine. Each blade comprises a blade having a leading edge, a trailing edge, a lower surface and an upper surface connected to the lower surface by the leading edge and the trailing edge. Currently, more and more blades are made of composite material to reduce the mass while having good mechanical properties. For example, blades made of composite material are made by injecting a resin, for example by liquid resin injection molding (RTM, acronym for the English expression "Resin Transfer Molding") into a fiber preform, formed for example of fibers woven in three dimensions (3D). Regardless of the composite or metallic material of the blades, it is known to modify the geometry of these blades to control and/or reduce noise of aerodynamic origin. For this, the geometry of the leading edge and/or the trailing edge of the blade is modified by adding a serration element (known as "wavy leading/trailing edge", "serrated leading/trailing edge" or "leading/trailing edge serration"). The principle of reducing noise emissions generated by blades is based on spatially shifting the noise sources distributed along the leading edge or the trailing edge by means of serrations (or otherwise known as undulations or teeth), which may or may not be identical. For this principle to apply, the dimensions (height, length, thickness, etc.) of the serrations must be adapted to the incident aerodynamic field (such as the air flow passing through the blades with more or less turbulence) which varies according to the engine speed of the turbomachine. Furthermore, the clamping element must be both easily repairable (since it is visible to passengers) and resistant to HCF (High-Cycle Fatigue) type damage that can generate cracks in the clamping element (and therefore in the blade) during operation. In addition, several other constraints must be taken into account for the production of composite blades comprising such a clamping element, such as: - the clamping element has a complex geometry, in particular with teeth having variations in dimensions (such as its thickness, length, shape, etc.) which can alter and form a misalignment with the composite material (in particular the woven fibers) during shaping in an RTM injection molding manufacturing mold, - the placement of the clamping element on the leading edge or the trailing edge can be complex, particularly for complex geometries (dimensions and shape) of the aerodynamic profile blades, - the teeth of the clamping element have low thicknesses (of the order of 2.5 mm minimum) which can be damaged during handling, - the clamping element, typically made of metal (such as titanium), must be compatible with the composite material of the blade (in particular of the woven type in three dimensions), and - the clamping element, particularly made of metal, can weigh down and encumber the blade. In this context, it is interesting to propose a solution to overcome at least one of the aforementioned drawbacks, in particular by optimizing and simplifying the integration of a clamping element in a blade made of composite material, while facilitating the maintenance of this clamping element. Summary of the invention The present invention provides a simple, effective and economical solution to the aforementioned drawbacks of the prior art. For this purpose, the invention relates to a composite material blade for a turbomachine, in particular an aircraft, said blade comprising a blade formed by a fiber preform embedded in a resin and extending along an elongation axis A, said blade comprising a leading edge, a trailing edge, a lower surface and an upper surface connected to the lower surface by the leading edge and the trailing edge, said blade further comprising at least one serration element formed by several teeth and covering at least part of the leading edge and/or the trailing edge. According to t