Static turbine blade for an aircraft turbomachine
By using a partially imprisoned insert to form the attack edge of the blade in aircraft turbomachine rectifier dawns, the design optimizes mechanical resistance, thermal conductivity, and lightness, addressing the environmental challenges faced by these components.
Patent Information
- Application Number
- FR2023010787
- Authority / Receiving Office
- FR · FR
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-10-09
- Publication Date
- 2025-04-11
AI Technical Summary
Aircraft turbomachine rectifier dawns face challenges due to severe environmental conditions, including mechanical shocks and ice accumulation, which require materials with high mechanical resistance, thermal conductivity, and low mass, but such materials are difficult to find.
The design incorporates a blade with an internal and external plate, featuring a partially imprisoned insert that forms the attack edge and part of the intrados and extrados, allowing for the use of different materials for the insert and body to optimize mechanical resistance, thermal conductivity, and lightness.
This configuration enhances the mechanical robustness and thermal performance of the dawn while minimizing its mass, effectively addressing the environmental challenges faced by aircraft turbomachine rectifier dawns.
Smart Images
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Abstract
Description
Title of the invention: Stator blade for an aircraft turbomachine Technical field
[0001] The present invention relates to the field of aeronautics. It relates more particularly to a rectifier blade for an aircraft turbomachine, and in particular to a compressor rectifier blade, for example a low-pressure compressor. State of the art
[0002] The turbomachines used for aircraft propulsion comprise a gas generator. The gas generator comprises in particular, from upstream to downstream in relation to the direction of gas circulation, a rectifier, a low-pressure compressor and a high-pressure compressor.
[0003] The rectifier and the compressors comprise blades which are required to operate in a harsh environment, and which are in particular subject to mechanical shocks, linked for example to the ingestion of foreign bodies by the turbomachine (for example in the case of ingestion of a bird or hailstones). The blades are also subject to the accumulation of ice, this accumulation being able to become problematic if a piece of ice breaks off and is propelled downstream of the turbomachine, which generally involves a limitation of the gas flow in the turbomachine, or even damage within the turbomachine.
[0004] Due to the thermal and mechanical constraints set out above, the choice of materials when designing a blade is delicate, because this ideally requires a material having both significant mechanical strength, high thermal conductivity (in order to facilitate the action, if necessary, of the de-icing and anti-icing system), and also making it possible to produce a blade with the lowest possible mass. It is therefore difficult to find a material having excellent properties both in terms of mechanical strength and thermal conductivity and lightness. For example, titanium alloys which are often used in the aeronautical field have a very good compromise between mechanical strength and lightness, but are relatively poor thermal conductors.
[0005] The objective of the present invention is to propose a turbomachine rectifier blade which makes it possible to overcome the drawbacks of the state of the art, and in particular those set out above. Statement of the invention
[0006] To this end, the invention relates to a rectifier blade for an aircraft turbomachine, the blade comprising a blade, the blade being secured, at a first end, of an internal plate, and, at a second end opposite the first end, of an external plate, the blade comprising a leading edge and a trailing edge each extending between the internal plate and the external plate, the blade comprising a lower surface and an upper surface extending from the leading edge to the trailing edge; the blade comprising a body and an insert partially trapped in the body, a central part of the insert forming a part of the blade comprising at least the leading edge, the insert comprising a first and a second end part between which the central part of the insert extends, each end part being trapped respectively in a first and a second end part of the body, a central part of the body extending between the two end parts to form the remainder of the blade.
[0007] Thus, by providing a blade comprising an insert forming the leading edge of the blade blade (and a more or less significant part of the extrados and intrados), the remainder of the blade being formed by the body in which the insert is partially trapped, it is easy to design the insert and the body in different materials. It is therefore possible to favor the properties of mechanical resistance and thermal conductivity for the choice of the material constituting the leading edge, and to favor the properties of mechanical resistance and lightness for the choice of the material constituting the body, the latter being able to represent a very large part of the entire blade.By providing that the insert is partially trapped in the body, we ensure the robustness of the link between the body and the insert when the materials constituting them are different, and in particular when they present significant differences in terms of thermal expansion.
[0008] The blade according to the invention may comprise one or more of the following optional characteristics considered alone or in all possible combinations.
[0009] According to one feature, the internal platform is formed by the first end portion of the body and by the first end portion of the insert, and wherein the external platform is formed by the second end portion of the body and by the second end portion of the insert.
[0010] According to one characteristic, the blade is of the variable pitch type and comprises an internal pivot secured to the internal platform and an external pivot secured to the external platform.
[0011] According to one characteristic, the first end portion of the insert and / or the second end portion of the insert have a general annular shape with an axis parallel to the axis of rotation defined by the pivots.
[0012] According to one characteristic, the blade is a hollow blade, the blade comprising an internal cavity delimited partly by the central part of the body and partly by the central part of the insert.
[0013] According to one characteristic, the central part of the insert comprises a lower surface part forming a part of the lower surface of the blade, and an upper surface part forming a part of the upper surface of the blade.
[0014] According to one characteristic, the intrados portion and / or the extrados portion extend from the leading edge over a length less than or equal to 20% of the chord length of the blade, and for example between 5% and 10% of the chord length.
[0015] According to one characteristic, the intrados portion and / or the extrados portion extend from the leading edge over a length greater than or equal to 10% of the chord length of the blade, and for example between 10% and 25% of the chord length.
[0016] According to one characteristic, the blade is a solid blade, in which the intrados part and / or the extrados part comprises a hooking element, the hooking element having a shape facilitating mutual retention between the insert and the body, for example a hooking element having a dovetail shape.
[0017] According to one characteristic, the insert is made of a first material, the body being made of a second material different from the first material.
[0018] According to one characteristic, the insert is made from steel.
[0019] According to one characteristic, the body is made from a titanium-based alloy or an aluminum-based alloy.
[0020] According to one characteristic, the blade is obtained by overmolding the body onto the insert.
[0021] The invention also relates to a turbomachine for aircraft, comprising at least one blade conforming to that defined above. Brief description of the drawings
[0022] [Fig-1] [Fig.l] is a schematic sectional view of an aircraft turbomachine in accordance with the invention.
[0023] [Fig.2] [Fig.2] is a schematic side view of a blade according to the invention.
[0024] [Fig.3] [Fig.3] is a perspective view of the blade of [Fig.2].
[0025] [Fig.4] [Fig.4] is a view similar to [Fig.2], the insert being visible through transparency.
[0026] [Fig.5] [Fig.5] is a section of the blade of [Fig.2] according to plane AA.
[0027] [Fig.6] [Fig.6] is a perspective view of a first example of embodiment of the insert.
[0028] [Fig.7] [Fig.7] is a section of the blade of [Fig.2] along plane BB.
[0029] [Fig.8] [Fig.8] is a perspective view of an insert according to a second mode of realization.
[0030] [Fig.9] [Fig.9] is a view similar to that of [Fig.7], showing the dawn of the [Fig.2] including the insert of [Fig.8].
[0031] [Fig. 10] [Fig. 10] is a view similar to [Fig.5] showing a second example of the embodiment of the blade of the vane.
[0032] [Fig. 11] [Fig. 11] is a view similar to [Fig.5], showing a third example of the embodiment of the blade of the vane. Detailed description
[0033] [Fig. 1] represents an aircraft turbomachine 1 according to the invention, in the example a bypass turbojet (represented without the normally associated nacelle). The turbomachine 1 comprises an air inlet 2 through which a gas flow enters the turbomachine. The gas flow is accelerated by a fan 3. Downstream of the fan 3, the gas flow is separated into a primary flow flowing in an internal annular vein 4, or primary vein 4, and a secondary flow flowing in an external annular vein 5 surrounding the internal annular vein 4, or secondary vein 5. In the primary vein 4, the primary flow successively passes through an inlet rectifier 6 and a gas generator.In the example, the gas generator comprises, from upstream to downstream (with respect to the direction of gas circulation), a low-pressure compressor 7, a high-pressure compressor 8, a combustion chamber 9, a high-pressure turbine 10 and a low-pressure turbine 11, and a gas exhaust casing 12 to which an exhaust nozzle (not shown) is connected. The secondary stream 5 is defined in part by a fan casing 13 surrounding the fan 3 and by a nacelle surrounding the turbomachine (not shown).
[0034] The inlet rectifier 6 comprises inlet guide vanes (commonly referred to as IGV, an acronym corresponding to the English term “inlet guide vanes”). The low-pressure compressor and the high-pressure compressor also comprise stator vanes, or rectifier vanes. The rectifier vanes are fixed vanes, generally variable-pitch vanes (commonly referred to as VSV, an acronym corresponding to the English term “variable stator vanes”).
[0035] Figures 2 to 4 show a blade 20 according to the invention, which can be used as a rectifier blade, for example within the inlet rectifier 6, or within one of the compressors 7, 8.
[0036] In the example of the figures, the blade 20 is a variable-pitch blade. The variable-pitch blades can be maneuvered during operation of the turbomachine so that the blades pivot about a radial axis of rotation relative to the main axis XX of the engine. This pivoting makes it possible to modify the angle of incidence (or pitch angle) of the blades relative to the gas flow coming from upstream of the turbomachine, in particular to adapt this angle to the different flight phases of the aircraft.
[0037] Figures 2 and 3 show the blade 20, respectively seen from the side and in perspective. The blade 20 comprises a blade 22, comprising a first radially internal end 220, or blade root 220, and a second radially external end 222, or blade head 222. The blade 22 is extended, at its first end 220, successively by an internal plate 26 and by an internal pivot 28, and, at its second end 222, successively by an external plate 30 and by an external pivot 32. The terms “external” and “internal” are used in the present application to designate a radially external, respectively radially internal, element of the blade 20, relative to the main axis XX of the turbomachine and with reference to the normal position of use of the blade in the turbomachine.
[0038] The blade 20 is configured to pivot about an axis of rotation YY coinciding with the central axes of the internal pivot 28 and the external pivot 32, the rotation being ensured by a control member not visible in the figures.
[0039] The pivots 28, 32 each have a straight cylindrical shape with a circular base. The plates 26, 30 have a straight cylindrical shape, in the example with a circular base.
[0040] The blade 22 has a leading edge 224 and a trailing edge 226. The leading edge 224 and the trailing edge 226 each extend from the inner plate 26 to the outer plate 30. The blade 22 further comprises a lower surface 230 and an upper surface 232 each extending between the leading edge 224 and the trailing edge 226 (see [Fig.5]).
[0041] According to the invention, the blade 20 comprises a body 34 and an insert 36. The insert 36 comprises a central part 360 forming the leading edge 224 of the blade 22, as well as a part of the intrados 230 and a part of the extrados 232.
[0042] The body 34 comprises a central portion 340 partially forming the blade 22. The central portion 340 of the body 34 forms a majority portion of the blade 22, and, more precisely, forms the entire blade with the exception of the portion of the blade formed by the central portion of the insert 36, that is to say with the exception at least of the leading edge 224. The external shape of the central portion 340 thus corresponds to the external shape of the blade 22 reduced by the external shape of the insert. The body 34 comprises a first end portion 342, or internal end portion, forming a majority portion of the internal platform 26, and a second end portion 344, or external end portion, forming a majority portion of the external platform 30 of the blade. The body 34 also forms the pivots 28, 32 of the blade 20.
[0043] As can be seen in [Fig. 4], which allows the entire insert 36 to be seen through transparency, and in [Fig. 6] which shows the insert 36 alone in perspective, the insert 36 comprises a first end portion 362, or internal end portion, and a second end portion 364, or external end portion. The first end portion 362 and the second end portion 365 are each secured to a opposite end of the central portion 360 of the insert 36.
[0044] As visible in [Fig. 4], each end portion 362, 364 of the insert 36 is trapped in the corresponding end portion 342, 344 of the body 34. Thus, the insert 36 is partially trapped in the body 34, the central portion of the insert 36 forming the leading edge 224 of the blade not being trapped in the body 34.
[0045] The configuration of the blade 20 described above makes it possible to design the insert 36 in a material different from the material in which the body 34 is designed. In particular, it is possible to favor the properties of mechanical strength and thermal conductivity for the choice of the material constituting the insert 36 (and therefore the leading edge), and to favor the properties of mechanical strength and lightness for the choice of the material constituting the body 34, the latter being able to represent a very large part of the entire blade. By providing that the insert 36 is partially trapped in the body 34, the robustness of the connection between the body and the insert is ensured when the materials constituting them are different, and in particular when they have significant differences in terms of thermal expansion.
[0046] The insert 36 may for example be made from a steel, and in particular a steel having a thermal conductivity greater than or equal to 10W / m / K. The body 34 may for example be made from a titanium alloy or an aluminum alloy.
[0047] In one embodiment, the blade 20 is a hollow blade. Thus, as visible in [Fig. 5], which illustrates a section of the blade 20 of [Fig. 2] along the plane AA, the blade 22 of the blade 20 comprises an internal cavity 228. In the example, the internal cavity 228 is delimited in part by the central part 340 of the body 34 and in part by the central part 360 of the insert 36. The central part of the insert 36 thus has a hollowed-out shape in section, limiting the mass thereof and thus promoting deicing of the leading edge of the blade 22.
[0048] As visible in [Fig. 6], the first and / or second end portion 362, 364 of the insert 36 may have a generally annular shape, defining a central cavity 362a, 364a. Such a configuration limits the mass of the insert 36 and further promotes retention of the insert within the body 34.
[0049] [Fig. 7] is a cross-sectional view along the axis BB of [Fig. 2] of the blade 20, which therefore includes the insert of [Fig. 6]. It can be seen that the outer end portion 364 of the insert 36 is trapped in the outer end portion 344 of the body 34.
[0050] As visible in Figures 8 and 9, which are views similar to those of Figures 6 and 7, one and / or the other of the end parts 362, 364 of the insert 36 may not have a generally annular shape, but have an open shape, in the example a generally arcuate shape.
[0051] As can be seen in [Fig. 10], which represents a sectional view of the blade 22 similar to the view in [Fig. 5], whether the blade 20 is hollow or solid, the central portion 360 of the insert 36 can be shaped so that a lower surface portion 366 of the central portion 360, which forms a portion of the lower surface of the blade 22, is of a length different from the length of a higher surface portion 368 of the central portion 360, which forms a portion of the upper surface of the blade 22. In the example in [Fig. 10], the lower surface portion is longer than the upper surface portion.
[0052] In order to limit the mass of the insert 36, the length of the intrados portion 366 and / or the length of the extrados portion 368 is less than 20% of the chord length of the blade 22, and for example between 5% and 10% of this chord length.
[0053] As seen in [Fig. 11], which shows a sectional view of a blade 22 similar to the view in [Fig. 10], the blade 22 may be solid. Furthermore, the central portion of the insert 36 may be configured such that a portion thereof, in the example the intrados portion 366, extends over at least 10% of the chord length of the blade. In the example of [Fig. 11], the intrados portion 366 extends over at least about 25% of the chord length. Furthermore, as visible in [Fig. 1 1], the intrados portion 366 or the extrados portion 368 may comprise a hooking element 370, having a shape facilitating mutual retention between the insert 36 and the body 34. In the example, the intrados portion 366 comprises a hooking element 370 having a dovetail shape.
[0054] The main steps in manufacturing a blade according to the invention are described below, when the blade is produced by molding.
[0055] The method comprises a first step of manufacturing the insert 36, for example by molding and / or by forming and / or by machining. The insert is made of a material having a mechanical strength suitable for enabling the blade to withstand various mechanical stresses, and in particular impacts due to foreign bodies. As described previously, the insert 36 is for example made from a steel, and in particular from a steel having a conductivity greater than or equal to 10 W / m / K.
[0056] The method then comprises a step of overmolding the body 34 onto the insert 36. During the overmolding step, the insert 36 is first placed in a mold comprising an imprint making it possible to mold the body 34. Then, the body 34 is overmolded onto the insert 36, so as to obtain a blade 20 conforming to that described in the present description. In particular, as already described, the overmolding step makes it possible to ensure that the end portions of the insert 36 are trapped in the body 34. As described previously, the body 34 is made of a material having a good compromise between lightness and mechanical strength, such as for example a titanium-based alloy, or an aluminum-based alloy.
[0057] In order to be able to produce the blade 22 by overmolding the insert 36, the insert 36 is made of a material having a melting point higher than that in which the body 34 is molded.
Claims
Claims
1. Vane (20) for a rectifier for an aircraft turbomachine (1), the vane (20) comprising a blade (22), the blade (22) being secured, at a first end (222), to an internal plate (26), and, at a second end (224) opposite the first end (222), to an external plate (30), the blade (22) comprising a leading edge (224) and a trailing edge (226) each extending between the internal plate (26) and the external plate (30), the blade (22) comprising a lower surface (230) and an upper surface (232) extending from the leading edge (224) to the trailing edge (226); the blade (20) comprising a body (34) and an insert (36) partially trapped in the body (34), a central part (360) of the insert (36) forming a part of the blade (22) comprising at least the leading edge (224), the insert (36) comprising a first and a second end part (362;364) between which the central portion (360) of the insert (36) extends, each end portion (362, 364) being trapped respectively in a first and a second end portion (342; 344) of the body (34), a central portion (340) of the body (34) extending between the two end portions (342, 344) to form the remainder of the blade (22).;
2. A rectifier vane (20) according to the preceding claim, wherein the inner platform (26) is formed by the first end portion (342) of the body (34) and by the first end portion (362) of the insert (36), and wherein the outer platform (30) is formed by the second end portion (344) of the body (34) and by the second end portion (364) of the insert (36).
3. A rectifier vane (20) according to claim 1 or 2, the vane being of the variable pitch type and comprising an internal pivot (28) secured to the internal platform (26) and an external pivot (32) secured to the external platform (30).
4. Vane (20) of a rectifier according to the preceding claim, in which the first end portion (362) of the insert (36) and / or the second end portion (364) of the insert (36) have a generally annular shape with an axis parallel to the axis of rotation (YY) defined by the pivots (28, 32).
5. A rectifier blade (20) according to any preceding claim, wherein the blade (20) is a hollow blade, the vane (22) comprising an internal cavity (228) delimited in part by the central portion (340). of the body (34) and partly by the central part (360) of the insert (36).
6. A rectifier vane (20) according to one of the preceding claims, in which the central portion (360) of the insert (36) comprises a lower surface portion (366) forming a portion of the lower surface (230) of the blade (22), and an upper surface portion (368) forming a portion of the upper surface (232) of the blade (22).
7. Vane (20) of a rectifier according to the preceding claim, in which the intrados portion (366) and / or the extrados portion (368) extend from the leading edge (224) over a length less than or equal to 20% of the chord length of the blade (22), and for example between 5% and 10% of the chord length.
8. A rectifier blade (20) according to claim 6 or 7, wherein the intrados portion (366) and / or the extrados portion (368) extend from the leading edge (224) over a length greater than or equal to 10% of the chord length of the blade (22), and for example between 10% and 25% of the chord length.
9. Vane (20) of a rectifier according to the preceding claim, the vane (20) being a solid vane, in which the intrados portion (366) and / or the extrados portion (368) comprises a hooking element (370), the hooking element (370) having a shape facilitating mutual retention between the insert (36) and the body (34), for example a hooking element (370) having a dovetail shape.
10. A rectifier vane (20) according to one of the preceding claims, in which the insert (36) is made of a first material, the body (34) being made of a second material different from the first material.
11. A rectifier vane (20) according to the preceding claim, wherein the insert (36) is made from steel.
12. A rectifier vane (20) according to claim 10 or 11, wherein the body (34) is made from a titanium-based alloy or an aluminum-based alloy.
13. Blade (20) according to one of the preceding claims, the blade (20) being obtained by overmolding the body (34) onto the insert (36).
14. Turbomachine (1) for aircraft, comprising at least one blade (20) according to one of the preceding claims.
Citation Information
Patent Citations
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