Stator vane for an aircraft turbine engine, aircraft turbine engine and method for manufacturing a stator vane

Abstract

The invention relates to a de-icing or ice-prevention solution based on a stator vane (3) for an aircraft turbine engine. The vane is provided with a heating element and comprises an airfoil (1) comprising an airfoil body (100), a leading edge (111), a trailing edge (112), a root (12) and a tip (11). The airfoil further comprises a cavity (18) arranged inside the airfoil body and extending from the tip (11) and a mandrel (23) for supporting the heating element. The mandrel and the heating element are housed inside the cavity in the airfoil. The heating element comprises an electric cable (24) wound around the mandrel. The vane further comprises a support attached to the mandrel to allow positioning thereof in the cavity. The aircraft turbine engine comprises a splitter nose for forming a separation between annular flow channels for a first flow and a second flow from the turbine engine, and a row of stator vanes located upstream of the splitter nose and comprising at least the vane. A method for manufacturing the vane comprises the steps of providing the airfoil body, forming the cavity in the airfoil body, and assembling the vane such that the mandrel and the heating element are housed within the cavity.

Description

AIRSPIN EQUIPPED WITH A HEATING ELEMENT technical field

[0001] The present invention relates to a turbine blade for an aircraft turbomachine. The invention also relates to a method for manufacturing such a turbine blade. Previous art

[0002] De-icing / anti-icing systems for turbomachine blades, particularly stator blades, play a crucial role in maintaining aerodynamic performance and safety. Some prior art systems involve integrating heating elements directly onto the blade surface. One method consists of machining a groove on the blade surface to accommodate an electrical cable. This solution is, for example, discussed in document WO2024 / 110140 A1, which proposes a blade with an electrical conductor housed in a groove and coated with a metallic powder. While functional, this solution has drawbacks such as reduced aerodynamic performance of the blade and higher manufacturing costs. Description of the invention

[0003] An object of the present invention is to provide a blade de-icing / anti-icing solution that is effective, simpler to manufacture and less expensive compared to the prior art.

[0004] To this end, a stator blade for an aircraft turbomachine is proposed, the blade being equipped with a heating element and comprising: - a blade comprising a blade body, a leading edge, a trailing edge, a root and a tip, said blade further comprising a cavity disposed within the blade body and extending from the tip, - a chuck to support the heating element, the chuck and the heating element being housed inside said cavity of the blade, the heating element comprising an electrical cable wound around the chuck, said blade further comprising a support fixed to the mandrel to allow positioning of the latter in the cavity.

[0005] The stator blade (or simply "the blade") according to the invention offers several advantages. First, the blade according to the invention provides an effective defrosting / anti-icing solution. The mandrel serves as a structural support for the heating element, facilitating its installation inside the blade cavity. This configuration allows for precise and stable positioning of the heating element, ensuring homogeneous interaction with the inner wall of the cavity for improved heat distribution. This results in faster and more efficient defrosting, ensuring that all critical areas of the blade receive an adequate amount of heat.

[0006] The blade according to the invention offers simplified manufacturing. The cavity at the blade can be produced with less stringent tolerances and at lower costs compared to prior art solutions. This manufacturing simplification leads to cost reductions, making the invention both economical and efficient.

[0007] Furthermore, the blade according to the invention is particularly robust. The blade preserves the structural integrity of the blade, avoiding the drawbacks associated with prior methods, such as machining surface grooves. The internal cavity design allows the heating element to be placed in an area subjected to minimal mechanical stress, thus reducing stress on the blade and improving its durability. Since the blade surface is primarily subjected to stress, placing the heating element inside the blade body helps to extend its lifespan. Moreover, by integrating the heating element into the blade body, it can be protected from external conditions and mechanical stresses. This reduces the risk of damage to the solution and increases its reliability.

[0008] The heating element comprises an electrical cable wound around the chuck. Advantageously, the chuck serves as a structural support around which the electrical cable is wound. This electrical cable acts as the heat source. When an electric current is applied, the cable heats up due to its Electrical resistance. The heat is thus transferred to the cavity walls and subsequently to the blade body to defrost or prevent frost formation. Regarding the chuck design, the chuck diameter is configured to respect the permissible bend radius of the electrical cable, since a bend radius that is too small can cause excessive mechanical stress on the cable, leading to internal conductor breaks, loss of resistance to partial discharges, or electrical breakdown.

[0009] This advantageously allows for easy modulation of the heating power according to specific operating needs. Adjusting the winding density (winding frequency) allows control of the overall electrical resistance of the heating element.

[0010] The blade also includes a support attached to the chuck to allow for its positioning within the cavity. Advantageously, the support ensures precise alignment of the chuck with the blade cavity, thus reducing the risk of misalignment that could lead to malfunctions. Preferably, the support uses geometric reference points to guarantee that the chuck is correctly positioned within specified tolerances, by shimming its axial position and ensuring its coaxiality with the cavity. This also improves the quality of the assembly.

[0011] The term "stator" in this document refers to the stator. The stator is the stationary part of the turbomachine, as opposed to the rotor, which is the rotating part. As those skilled in the art know, "stator blades" are the blades fixed to the turbomachine casing that do not rotate with the rotor.

[0012] The use, in this document, of the verb "comprendre" (to understand), its variants, and its conjugations, cannot in any way exclude the presence of elements other than those mentioned. Similarly, the use, in this document, of the indefinite article "un" (a), "une" (an), or the definite article "le" (the), "la" (the), or "l'" (I) to introduce an element does not exclude the presence of a plurality of these elements.

[0013] In one embodiment, the chuck is cylindrical. Advantageously, this provides a uniform surface for winding the electrical cable. This facilitates the manufacture of the blade and the installation of the electrical cable, because the cylindrical shape allows for regular windings.

[0014] In one embodiment, the support includes a platform that bears against the head. Advantageously, the platform serves as a support base for the chuck, stabilizing its position within the blade cavity. This helps maintain optimal alignment and prevents movement that could cause damage during turbomachine operation. Furthermore, the platform provides a stable and sufficiently large bearing surface to ensure a solid and precise blade assembly.

[0015] Preferably, the platform and blade head have complementary sections designed to fit together. As those skilled in the art will understand, complementary sections are sections of corresponding shapes (male and female). Advantageously, this allows for a more secure physical connection between the platform and the blade. This minimizes the relative movement of the mandrel and heating element with respect to the blade, thus reducing the risk of vibration or displacement that could compromise the assembly. This embodiment also allows for simpler assembly and maintenance. The complementary sections facilitate alignment and assembly during installation or replacement, making the process less error-prone and faster. For maintenance, dismantling a nested structure is generally simpler and safer, allowing quick access to the heating element.

[0016] In one embodiment, the support includes a trunnion. Advantageously, the trunnion serves as a connection point between the blade and a part of the turbomachine. In a particular configuration, the support can be formed by the trunnion to ensure precise positioning of the mandrel within the cavity. This guarantees a more compact blade assembly.

[0017] Preferably, the cavity is blind. Advantageously, this avoids opening onto the aerodynamic part of the blade. Indeed, an opening in the cavity onto this surface would imply additional work to seal or rebuild the aerodynamic surface of the blade, which could compromising its performance. Thus, by keeping the cavity closed at one end, the structural and aerodynamic integrity of the blade is preserved while efficiently integrating the heating element.

[0018] In one embodiment, the cavity is located in an area having a thickness between 90% and 100% of a maximum thickness of the blade body.

[0019] In one embodiment, the cavity has a depth between 30% and 80% of the distance measured between the head and the foot.

[0020] In one embodiment, the cavity is located at a distance from the leading edge less than or equal to 1 / 3 of the distance measured between the leading edge and the trailing edge.

[0021] The invention further proposes an aircraft turbomachine comprising a separation nozzle to form a separation between annular flow channels of a first flow and a second flow from the turbomachine, and a row of stator blades located upstream of the separation nozzle and comprising at least one blade according to any one of the aforementioned embodiments.

[0022] In this turbomachine configuration, the blade extends over a greater height, corresponding to the height of the flow passing through it, and therefore has a greater thickness compared to other types of turbomachine blades. This characteristic is particularly advantageous in the context of the invention. Indeed, thanks to its greater thickness, the blade is particularly well-suited to accommodate internal cavities without compromising its structural strength. This allows for the integration of heating elements while maintaining the blade's robustness and efficiency within the aerodynamic flow. All the preferred embodiments and all the advantages of the blade according to the invention are transposed mutatis mutandis to the present turbomachine.

[0023] The invention further proposes a method for manufacturing a blade according to any of the aforementioned embodiments and comprising the following steps: a. provide a blade body, b. make a cavity in the blade body, c. assemble the blade so that the mandrel and the heating element are housed inside the cavity.

[0024] The advantages presented for the auger according to the invention apply to the process, mutatis mutandis.

[0025] Preferably, step b of the process includes a cavity drilling step. The cavity in the blade body is thus created by drilling. Advantageously, drilling allows for precise control over the size and shape of the cavity for housing the heating element. Drilling machines, such as CNC machines, offer high repeatability, ensuring that each cavity conforms to predefined tolerances. These tolerances remain relatively less stringent compared to prior art manufacturing methods. Drilling is often faster than other cavity manufacturing methods.

[0026] Preferably, step c of the process includes an assembly step selected from welding, bonding, face, riveting, or shrink fitting.

[0027] Preferably, step c of the process includes an assembly step by interlocking. Brief description of the figures

[0028] Other features and advantages of the present invention will become apparent from the detailed description that follows, for understanding of which reference should be made to the accompanying figures, among which: - Figure 1 illustrates a perspective view of a (disassembled) turbine blade, according to one embodiment of the invention, - Figure 2 illustrates a perspective view of a blade (assembled), according to one embodiment of the invention, - Figure 3 illustrates a longitudinal section of a blade, according to one embodiment, - Figure 4 illustrates a longitudinal section of a blade, according to another embodiment.

[0029] The drawings in the figures are not to scale. Similar features are generally denoted by similar reference numerals in the figures. Within the scope of this document, identical or analogous features may bear the same reference numerals. Furthermore, the presence of reference numerals or letters in the drawings shall not be considered limiting, even when such numerals or letters are specified in the claims. Detailed description of certain embodiments of the invention

[0030] This section provides a detailed description of certain embodiments of the present invention. The invention is described with specific embodiments and references to figures, but the invention is not limited by them. In particular, the drawings and figures described below are schematic only and are not limiting.

[0031] Figure 1 illustrates a perspective view of a blade in a disassembled version, according to an embodiment of the invention. The blade 3 comprises a blade 1, the blade comprising a blade body 100, a leading edge 111, a trailing edge 112, a foot 12 and a tip 11, the blade 1 further comprising a cavity 18 disposed inside the blade body 100 and extending from the tip 11.

[0032] The blade 3 includes a mandrel 23 for holding a heating element in position. This heating element is preferably an electrical cable 24 wound around the mandrel 23 and designed to generate the heat necessary to defrost or prevent frost formation on a surface of the blade 1. Preferably, the blade 3 includes a frame 28 attached to the mandrel 23. The frame 28 is preferably adapted to integrate the power supply and / or control components for the electrical cable 24.

[0033] Inside the blade body 100, a cavity 18 extends from the tip 11. This cavity 18 is integrated into the structure of the blade 1 to house the mandrel 23. Preferably, the cavity 18 is a diameter bore. For example, the cavity 18 is located in a more massive area of ​​the blade 1. Advantageously, the Thicker regions offer more material to absorb the stress induced by the presence of a cavity, thus reducing the risk of fatigue or breakage under mechanical and thermal stresses. For example, cavity 18 is located in an area where the thickness 13 of the blade body 100 is between 90% and 100% of its maximum thickness. Preferably, cavity 18 is located in an area where the thickness 13 of the blade body 100 is at its maximum.

[0034] Preferably, the cavity 18 is made by drilling. Preferably, the diameter of the drilling is calculated so as to retain at least 1 mm of material from the body 100 on each side of the cavity 18. Advantageously, sufficient remaining material around the drilling helps to prevent cracks or breaks that may occur due to mechanical stresses and vibrations during normal operation of the turbomachine.

[0035] Preferably, the mandrel 23 is fully housed within the cavity 18 when the blade 3 is assembled. As illustrated in Figure 1, the heating element comprises an electrical cable 24 wound around the mandrel 23. When an electric current is applied, the resistance of the electrical cable 24 converts the electrical energy into heat. The wound configuration increases the contact area of ​​the electrical cable 24 with the air confined between the mandrel 23 and the wall of the cavity 18, allowing heat dissipation through the blade body 100.

[0036] The chuck 23 is preferably elongated and cylindrical. The diameter 70 of the chuck 23 is selected based on the size of the cavity 18 in the blade 1 and the amount of electrical cable 24 required to produce the desired amount of heat. Preferably, the length of the chuck 23 essentially corresponds to the depth 19 of the cavity 18 in the blade 1 to maximize the winding space for the electrical cable 24. Figure 2 illustrates a perspective view of a blade 3 in an assembled version, according to the same embodiment. In this configuration, the stator blade 1 is assembled, forming a compact system ready for use, for example, in a turbomachine. The frame 28 is thus designed so that its edges are perfectly aligned with the leading edge 111 and the trailing edge 112 of the blade 1. This avoids introducing any offset and, consequently, disturbances in the airflow around blade 3. This helps to preserve the optimal aerodynamic characteristics of blade 3, thus contributing to better overall turbomachine efficiency.

[0037] Figure 3 illustrates a longitudinal section of a blade 3, according to one embodiment. The blade 3 comprises a blade 1. The blade 1 comprises a body 100 and an internal cavity 18 disposed inside the body 100 and extending from the head 11. The cavity 18 is preferably a diameter bore.

[0038] The blade further includes a mandrel 23 for holding a heating element in position. The heating element is an electrical cable 24 wound around the mandrel 23 with a winding pitch 60. Preferably, the mandrel 23 is arranged with some play in the cavity 18. The mandrel 23 is preferably cylindrical. Alternatively, the mandrel may be slightly conical and / or curved. Thus, the cavity 18 has a shape corresponding to that of the mandrel 23.

[0039] The heating power of the heating element 20 is modulated according to the pitch 60 of the winding of the electric cable 24 around the mandrel 23. By increasing the winding frequency (inversely proportional to the pitch 60 of winding), the total resistance of the electric cable 24 increases, which makes it possible to increase the amount of heat generated.

[0040] The blade further includes a support fixed to the mandrel 23 to allow positioning of the latter in the cavity 18. Preferably, the support includes a platform 22 bearing against the head 11.

[0041] For example, the platform 22 has a cylindrical shape. Preferably, the support further includes a trunnion 25. Preferably, the trunnion 25 has a cylindrical shape. The trunnion 25 (or pivot) can mechanically cooperate with a turbomachine housing. It can provide a pivot connection with it. Preferably, the trunnion 25 is a hollow cylinder. The trunnion 25 includes power supply wires 26 and can incorporate components connected to the power cable 24. Preferably, the trunnion 25 is aligned with an axis of the cavity 18.

[0042] Preferably, the platform 22 and the blade head 11 of blade 1 each have complementary portions (17, 27) so as to fit together in the other. For example, the head 11 may have a cylindrical (male) extension 17 that fits into a corresponding cylindrical (female) cavity 27 in the platform 22, as illustrated in Figure 3. This ensures a stable and centered connection. Other portion shapes known to those skilled in the art may be used and may consist, for example, of notches and protrusions, interlocking conical shapes, dovetail shapes, etc. The examples just described are given by way of illustration and are not intended to be limiting; those skilled in the art could easily implement other portion shapes without departing from the scope of the invention.

[0043] As illustrated in Figure 3, the cavity 18 is, for example, located midway between the leading edge 111 and the trailing edge 112. Preferably, the cavity 18 is located laterally in an interval between the leading edge 111 and 1 / 3 of the width 16 measured between the leading edge 111 and the trailing edge 112. Even more preferably, the cavity 18 is located in an interval between the leading edge 111 and 1 / 4 of the width 16.

[0044] Advantageously, this maximizes defrosting efficiency in areas where frost formation is most critical. This position concentrates the heat generated by the heating element 20 in the areas forward of the vane 3, where the airflow is most likely to cause frost buildup.

[0045] Preferably, the cavity 18 at the blade body 100 follows a path of the leading edge 111. This means that the cavity 18 can be curved or profiled to follow the aerodynamic shape of the leading edge 111. Thus, the path of the cavity 18 can be configured to match the natural curvature of the leading edge 111, allowing for better heat distribution where it is most needed to prevent ice buildup. For example, the cavity 18 has a depth 19 of between 30% and 80% of the blade height 1, measured between the tip 11 and the root 12. Preferably, the cavity 18 has a depth 19 of between 60% and 80% of the height.

[0046] Figure 4 illustrates a longitudinal section of blade 3, according to another embodiment. Figure 4 illustrates a longitudinal section similar to that of the figure 3. Unlike figure 3, where the chuck 23 is fixed to the platform 22, figure 4 illustrates a configuration where the chuck 23 can be fixed only to the trunnion 25, as a support to allow precise positioning in the cavity 18.

[0047] This configuration simplifies the structure by eliminating the mounting platform 22, which can offer advantages in terms of compactness and weight reduction. Preferably, the blade head 11 is equipped with a plate 7 serving as an assembly point with the trunnion 25. The plate 7 is preferably annular in shape, with its axis aligned with the opening of the cavity 18.

[0048] For example, a recess 72 corresponding to the shape of the trunnion 25 is provided in the plate 7 to receive it. This prevents friction and contact wear. Preferably, the recess 72 includes a shoulder 71 acting as a physical stop, preventing movement of the trunnion 25 once it is positioned in the recess 72. This ensures that the chuck 23 fixed to the trunnion 25 remains at a predetermined depth within the cavity 18 in the blade 3.

[0049] In the illustrated embodiments, several techniques can be used to secure the assembly in position once it has been assembled. These techniques include welding, bonding, screwing, riveting, and shrink fitting. Each method has its own advantages, allowing adaptation to different operational environments and levels of mechanical stress.

[0050] In summary, the invention proposes a defrosting / anti-icing solution based on a blade 3 equipped with a heating element, offering increased efficiency, simplified manufacturing, and reduced cost compared to existing solutions. The blade 3 comprises a blade 1 with a cavity 18 and a mandrel 23 with a heating element housed inside this cavity 18, thus ensuring efficient heat distribution.

Claims

Demands 1. Stator blade (3) for an aircraft turbomachine, said blade (3) being equipped with a heating element and comprising: - a blade (1) comprising a blade body (100), a leading edge (111), a trailing edge (112), a root (12) and a tip (11), said blade (1) further comprising a cavity (18) disposed inside the blade body (100) and extending from the tip (11), - a mandrel (23) for supporting the heating element, the mandrel (23) and the heating element being housed inside said cavity (18) of the blade (1), the heating element comprising an electrical cable (24) wound around the mandrel (23), said blade (3) further comprising a support fixed to the mandrel (23) to allow positioning of the latter in the cavity (18).

2. Blade (3) according to the preceding claim, characterized in that the support comprises a platform (22) bearing against said head (11).

3. Blade (3) according to the preceding claim, characterized in that said platform (22) and said head (11) respectively comprise complementary portions (17,27) so as to fit together.

4. Blade (3) according to any one of the preceding claims, characterized in that the support comprises a trunnion (25).

5. Blade (3) according to any one of the preceding claims, characterized in that the cavity (18) is located in an area having a thickness (13) between 90% and 100% of a maximum thickness of the blade body (100).

6. Blade (3) according to any one of the preceding claims, characterized in that the cavity (18) has a depth (19) between 30% and 80% of a distance measured between the head (11) and the foot (12).

7. Blade (3) according to any one of the preceding claims, characterized in that the cavity (18) is located at a distance from the leading edge (111) less than or equal to 1 / 3 of a distance (16) measured between the leading edge (111) and the trailing edge (112).

8. Aircraft turbomachine comprising: - a separation nozzle to create a separation between annular flow channels of a first and a second flow originating from the turbomachine, and - a row of stator blades located upstream of the separating nozzle and comprising at least one blade (3) according to any one of the preceding claims.

9. Method of manufacturing a blade (3) according to any one of claims 1 to 7, and comprising the following steps: a. providing a blade body (100) (1), b. making a cavity (18) in the blade body (100) (1), and c. assembling the blade (3) so that the mandrel (23) and the heating element are housed inside said cavity (18).

10. Manufacturing method according to the preceding claim, characterized in that step b. comprises a step of drilling said cavity (18). - 14 - 11. Manufacturing method according to any one of claims 9 or 10, characterized in that step c. comprises an assembly step by interlocking.

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