Blade made of composite material comprising a leading edge shield and turbine engine comprising the blade
By designing an optimized titanium-based alloy shield on the composite blade, the problem of aerodynamic performance degradation caused by shield detachment was solved, and the blade's impact resistance and aerodynamic stability were enhanced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SAFRAN AIRCRAFT ENGINES SAS
- Filing Date
- 2021-10-05
- Publication Date
- 2026-06-23
Smart Images
Figure CN116368287B_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to a leading edge shield for a turbine engine blade, specifically a leading edge shield made of a composite material. Background Technology
[0002] Leading-edge shrouds are typically designed to protect the leading edge of rotating blades or guide vanes from impacts and erosion. In this paper, the term "blade" refers to fan blades and aircraft propeller blades. To limit their weight, these blades are often made of organic-based composite materials, such as fiber-reinforced polymers. While these materials generally possess very favorable mechanical properties, especially for their weight, they are somewhat sensitive to point impacts. Therefore, shrouds, typically made of highly resistant metallic materials such as titanium alloys, are often mounted on the leading edge of such blades to protect them from these impacts. For example, these impacts could result from a bird being sucked into the engine. These shrouds typically take the form of thin pressure-side fins and thin suction-side fins connected by a thicker section bridging the leading edge, conforming to the shape of the blade's leading edge and the adjacent sections of the lower and upper fins. The lower and suction-side fins extend on these sections of the blade's lower and upper fins, respectively, primarily to ensure the shroud's positioning and attachment on the leading edge.
[0003] FR2906320 discloses a leading edge shield that reduces damage to composite blades in the event of an impact from a foreign object.
[0004] To improve the aerodynamic performance of blades, their leading edges have increasingly complex shapes, which makes it complicated to manufacture shields that must fit these shapes and to attach the shields to the blades.
[0005] Furthermore, in cases where the blade is subjected to impact, such as when a bird is inhaled, the shield may detach at least partially from the leading edge of the composite blade, and the resulting changes in the blade's aerodynamic performance associated with aerodynamic degradation may be significant.
[0006] Furthermore, if a portion of the shroud is torn, the leading edge of the blade is no longer protected along its entire height, and the composite material on the exposed leading edge of the blade becomes vulnerable to damage from the external environment. The resulting profile is typically uneven, which also leads to a loss of aerodynamics.
[0007] In addition to the shroud detaching from the blade tip, blade damage, also known as the "hinge effect," may be observed. This damage is also caused by the force exerted on the blade by the fins during the rotational movement of the shroud relative to the blade.
[0008] After such damage, the blades usually need to be repaired and / or replaced.
[0009] Invention Patent Content
[0010] This disclosure is intended to at least partially remedy these shortcomings.
[0011] Therefore, this disclosure relates to a blade comprising: a blade body made of fiber-reinforced organic matrix composite material and a leading-edge shroud, the leading-edge shroud being made of a material having better resistance to point impacts than the composite material of the blade body; the leading-edge shroud being assembled onto the blade body and comprising pressure-side fins and suction-side fins connected by a thicker central portion; the blade comprising an aerodynamic airfoil height and a chord length; and the suction-side fins having:
[0012] The first length projected onto the chord is between 10% and 18% of the chord length, and is set between 70% and 80% of the aerodynamic airfoil height.
[0013] The second length projected onto the chord is between 18% and 26% of the chord length, and is set between 85% and 95% of the aerodynamic airfoil height.
[0014] The third length projected onto the wing chord is between the first and second lengths, and is set at 100% of the aerodynamic airfoil height.
[0015] Due to this geometry of the leading-edge shroud, separation of the suction-side fins during point impacts, such as when a small bird is sucked into the engine, can be reduced. Specifically, the first length allows for reduced separation of the suction-side fins at the blade tip, while the second length allows the fins to provide protection in areas typically subjected to high stress during bird inhalation, where the blade body is relatively thicker. The third length is a compromise between the first and second lengths. Therefore, even during partial separation of the suction-side fins, the aerodynamic performance degradation of blade 16 is reduced compared to prior art blades. The risk of shell degradation can also be reduced by optimizing separation degradation.
[0016] In some embodiments, the first length may be equal to 14% of the chord length.
[0017] In some embodiments, the second length may be equal to 22% of the chord length.
[0018] In some embodiments, the first length may be set at 75% of the aerodynamic airfoil height.
[0019] In some embodiments, the second length may be set at 90% of the aerodynamic airfoil height.
[0020] In some embodiments, the blade body may include a meridional and a latitudinal direction, and the suction-side fin may include a free edge, a first point being disposed at a height on the free edge equal to a first length, and a second point being disposed on the free edge at a height greater than or equal to the first length plus 5% of the aerodynamic airfoil height and less than or equal to 85% of the aerodynamic airfoil height; the first point and the second point define a first vector, and the first vector and the meridional direction at the first point define a first angle, the first angle being greater than or equal to 15°.
[0021] When the first angle is greater than or equal to 15°, the free edge of the shield intersects with multiple meridional strands of the blade body, and these meridional strands are subjected to stress during the impact on the blade.
[0022] In some embodiments, the blade body may include a meridional and a latitudinal direction, and the suction-side fin may include a free edge, a third point is set at 100% of the aerodynamic airfoil height on the free edge, and a fourth point is set at a height on the free edge greater than the second length and less than or equal to 95% of the aerodynamic airfoil height; the third and fourth points define a second vector, and the second vector and the meridional direction at the third point define a second angle, the second angle being greater than or equal to 15°.
[0023] When the second angle is greater than or equal to 15°, the free edge of the shield intersects with multiple meridians of the blade body, and these multiple meridians are subjected to stress during the impact on the blade.
[0024] In some embodiments, the blade body may include a meridional and a latitudinal direction, the suction-side fin includes a free edge, a first point is disposed at a height on the free edge equal to a first length, a second point is disposed on the free edge at a height greater than or equal to the first length plus 5% of the aerodynamic airfoil height, and less than or equal to 85% of the aerodynamic airfoil height; the first and second points define a first vector, the first vector and the meridional direction at the first point define a first angle, the first angle being greater than or equal to 15°; a third point is disposed at 100% of the aerodynamic airfoil height on the free edge, and a fourth point is disposed on the free edge at a height greater than the second length and less than or equal to 95% of the aerodynamic airfoil height; the third and fourth points define a second vector, the second vector and the meridional direction at the third point define a second angle, the second angle being greater than or equal to 15°.
[0025] This disclosure also relates to a turbine engine comprising blades as defined above. Attached Figure Description
[0026] Other features and advantages of the subject matter of this disclosure will become apparent from the following description of embodiments given by way of non-limiting example with reference to the accompanying drawings.
[0027] Figure 1This is a schematic 3D diagram of a bypass turbine engine.
[0028] Figure 2 yes Figure 1 A partial schematic perspective view of the rotating blades of a turbojet engine fan, showing the latitudinal and longitudinal strands according to a blade embodiment.
[0029] Figure 3 According to an embodiment of the blade Figure 1 A schematic perspective view of the rotating blades of a turbojet engine fan.
[0030] Figure 4 This is a partial schematic 3D view of a blade from existing technology.
[0031] Figure 5 It means Figure 4 A curve showing the length of the leading edge of the protective shield.
[0032] Figure 6 yes Figure 3 A partial schematic 3D view of the blade.
[0033] Figure 7 It means Figure 6 A curve showing the length of the leading edge of the protective shield.
[0034] In all figures, the same elements are represented by the same reference numerals. Detailed Implementation
[0035] Figure 1 A bypass turbojet engine 10 is shown, which is a non-limiting example of a turbojet engine, including a gas generator unit 12 and a fan 14. The fan 14 includes a plurality of rotating blades 16 arranged radially about a central axis X, and the aerodynamic design of its profile is such that it propels air by rotating.
[0036] Therefore, as Figure 3 As shown, each blade 16 includes a blade body 18, the blade body 18 having a leading edge 24 ( Figure 3 (dashed line in the diagram), trailing edge 22, blade root 26, and blade tip 28. Between the tips of the blade root 26 and blade tip 28, the blade 16 typically includes an airfoil whose aerodynamic design allows it to propel air in the airflow path that is in direct contact with the airfoil. The “height” on the blade, specifically the “height” on its airfoil, will be considered along the stacking axis Z, which the leading edge 24 specifically follows.
[0037] Under normal operating conditions, the relative wind direction is generally oriented towards the leading edge 24 of each blade. Therefore, the leading edge 24 is particularly vulnerable to impact. Especially when the blade body 18 is made of composite materials, particularly fiber-reinforced polymer matrix materials, it is recommended to protect the leading edge 24 with a leading edge shield 20 integrated into each blade.
[0038] exist Figure 3 In one embodiment, the shroud 20 has pressure-side fins 32, suction-side fins 30, and a thicker central portion 34 designed to span the leading edge 24 of the blade body 18 and connect the suction-side fins 32 and the pressure-side fins 30. The pressure-side fins 32 and the suction-side fins 30 provide positioning of the shroud 20 on the blade body 18. The thicker central portion 34 is also referred to as the nose of the leading edge shroud 20.
[0039] The shield 20 also includes a radially inner end disposed on the side of the blade root 26 and a radially outer end disposed at the blade tip 28.
[0040] Opposite to the nose 34, the pressure-side fin 32 and the suction-side fin 30 each include a free edge 42.
[0041] The leading-edge shroud 20 is made of a composite material with greater stiffness than the blade body. The leading-edge shroud 20 is also made of a material with better resistance to point impacts than the composite material of the blade body. The leading-edge shroud 20 is primarily metallic, more specifically made of titanium-based alloys such as TA6V (Ti-6Al-4V). The leading-edge shroud 20 can also be made of steel or iron alloys, chromium alloys, and nickel alloys (commonly known as Inconel). TM Made using the trademark of [the company / organization]. For the remainder of this article, the term Inconel will be used to refer to this iron-based, chromium-based, and nickel-based alloy.
[0042] Figure 3 The aerodynamic airfoil height H of blade 16 is also shown. 0% is located on one side of the blade root 26, and 100% is located at the blade tip 28. The airfoil is typically connected to the blade root 26 via a shank 26A.
[0043] Figure 2 The weft direction T and warp direction C of the blade body 16 are shown. Vector and vector These represent latitude and longitude, respectively.
[0044] Figure 4 and 5 The blades of existing technology are shown. For example... Figure 4 As shown, in the event of an impact to blade 16, a portion 20A of the shroud 20 may detach from the blade body 18. This portion 20A could lead to a decrease in the aerodynamic performance of blade 16, potentially resulting in a thrust loss of close to 25%. Figure 5As shown, the length of the suction-side fins is displayed on the X-axis, and the aerodynamic airfoil height is displayed on the Y-axis. Therefore, Figure 5 This shows the variation of the suction-side fin length along the aerodynamic airfoil height. The aerodynamic airfoil height H is expressed as a percentage, and at a given aerodynamic airfoil height, the fin length is expressed as a percentage of the chord length. Therefore, the airfoil has an airfoil height H along the stacking axis Z between its lower boundary, at its intersection with shank 26A, and at the tip of its blade 28. The predetermined aerodynamic airfoil height H is considered with reference to the lower boundary 18A of the airfoil (which is also the upper boundary of shank 26A).
[0045] The chord is an imaginary line from the leading edge 24 to the trailing edge 22 of blade 16. The fin length is measured by the projection of the fin onto the chord.
[0046] Figure 6 and Figure 7 and Figure 4 and Figure 5 similar.
[0047] Figure 6 An embodiment of blade 16 is shown and Figure 7 The length of the suction-side fin 30 varies along the aerodynamic airfoil. The height of the aerodynamic airfoil is expressed as a percentage, and at a given aerodynamic airfoil height, the fin length is expressed as a percentage of the chord length.
[0048] As a non-limiting example, the first length is equal to 14% of the chord length and is set at 75% of the aerodynamic airfoil height, the second length is equal to 22% of the chord length and is set at 90% of the aerodynamic airfoil height, and the third length is equal to 18% of the chord length.
[0049] exist Figure 7 In the example, the first point D is on the free edge 42 of the shield 20, at 75% of the aerodynamic airfoil height.
[0050] Furthermore, the second point E is set on the free edge 42 and can be set between 80% and 85% of the aerodynamic airfoil height, where 80% of the aerodynamic airfoil height is equal to the height of the first length 36 plus 5% of the aerodynamic airfoil height.
[0051] As a non-limiting example, the second point E is set at 81% of the aerodynamic airfoil height.
[0052] The first point D and the second point E define the first vector.
[0053] The meridional direction C forms a first angle α with the first vector, which is greater than or equal to 15°.
[0054] The third point G is set on the free edge 42 and at 100% of the aerodynamic airfoil height.
[0055] As a non-limiting example, the second length 38 is at 90% of the aerodynamic airfoil height, and the fourth point F is set on the free edge 42 and can be set between 90% and 95% of the aerodynamic airfoil height.
[0056] As a non-limiting example, point F is set at 95% of the aerodynamic airfoil height on the free edge.
[0057] The third point G and the fourth point F define the second vector.
[0058] The meridional C and the second vector form a second angle β greater than or equal to 15°.
[0059] like Figure 4 and 6 As shown, it can be seen that... Figure 4 In comparison, part of the shield 20A is in Figure 6 The likelihood of the blade detaching from the blade body 18 is reduced. Therefore, during partial detachment of the suction-side skin, the aerodynamic characteristics of the blade 16 deteriorate less compared to blades of the prior art.
[0060] Although this disclosure has been described with reference to specific exemplary embodiments, it will be apparent that various modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the claims. Furthermore, individual features of the different embodiments described may be combined in additional embodiments. Therefore, the specification and drawings should be considered illustrative rather than restrictive.
Claims
1. A leaf (16), comprising: The blade body (18) and leading edge shroud (20) are made of fiber-reinforced organic matrix composite material. The leading edge shroud (20) has better point impact resistance than the composite material of the blade body. The leading edge shroud (20) is assembled onto the blade body (18) and includes a pressure-side fin (32) and a suction-side fin (30) connected by a thicker central portion (34). The blade (16) includes an aerodynamic airfoil height and chord length. The suction-side fin (30) has: The first length (36) projected onto the chord is between 10% and 18% of the chord length, and the first length (36) is set between 70% and 80% of the aerodynamic airfoil height. The second length (38) projected onto the chord, the second length (38) being between 18% and 26% of the chord length, the second length (38) being set between 85% and 95% of the aerodynamic airfoil height, and A third length (40) projected onto the chord, the third length (40) being between the first length (36) and the second length (38), the third length (40) being set at 100% of the aerodynamic airfoil height.
2. The blade (16) according to claim 1, wherein, The first length (36) is equal to 14% of the chord length.
3. The blade (16) according to claim 1, wherein, The second length (38) is equal to 22% of the chord length.
4. The blade (16) according to claim 1, wherein, The first length (36) is set at 75% of the height of the aerodynamic airfoil.
5. The blade (16) according to claim 1, wherein, The second length (38) is set at 90% of the height of the aerodynamic airfoil.
6. The blade (16) according to claim 1, wherein, The blade body (18) includes a meridional (C) and a latitudinal (T) direction. The suction-side fin (30) includes a free edge (42). A first point (D) is located on the free edge (42) at the same height as the first length (36). A second point (E) is located on the free edge (42) at a height greater than or equal to the first length (36) plus 5% of the aerodynamic airfoil height and less than or equal to 85% of the aerodynamic airfoil height. The first point (D) and the second point (E) define a first vector. The first vector and the meridional (C) direction at the first point (D) define a first angle (α). The first angle (α) is greater than or equal to 15°.
7. The blade (16) according to claim 1, wherein, The blade body (18) includes a meridional (C) and a zonal (T) direction. The suction-side fin (30) includes a free edge (42). A third point (G) is located at 100% of the aerodynamic airfoil height on the free edge (42). A fourth point (F) is located at a height greater than the second length (38) and less than or equal to 95% of the aerodynamic airfoil height on the free edge (42). The third point (G) and the fourth point (F) define a second vector. The second vector and the meridional (C) direction at the third point (G) define a second angle (β). The second angle (β) is greater than or equal to 15°.
8. The blade (16) according to any one of claims 1 to 5, wherein, The blade body (18) includes a meridional (C) and a latitudinal (T) axis. The suction-side fin (30) includes a free edge (42). A first point (D) is located on the free edge (42) at the same height as the first length (36). A second point (E) is located on the free edge (42) at a height greater than or equal to the sum of the first length (36) and 5% of the aerodynamic airfoil height, and less than or equal to 85% of the aerodynamic airfoil height. The first point (D) and the second point (E) define a first vector, and the first vector and the first point (D) The meridional direction (C) at the point defines a first angle (α), which is greater than or equal to 15°; the third point (G) is set at 100% of the aerodynamic airfoil height on the free edge (42), and the fourth point (F) is set at a height greater than the second length (38) and less than or equal to 95% of the aerodynamic airfoil height on the free edge (42). The third point (G) and the fourth point (F) define a second vector, and the second vector and the meridional direction (C) at the third point (G) define a second angle (β), which is greater than or equal to 15°.
9. A turbine engine comprising blades according to any one of claims 1 to 8.