Fan blade and aero-engine

Abstract

The utility model provides a fan blade and aero-engine, the fan blade has a controllable failure structure, the controllable failure structure is formed by combining a plurality of sheet bodies, each sheet body is divided by a groove to form a plurality of areas, and the bottom of the groove is provided with a tip; after the controllable failure structure is impacted, the blade body in the impacted area falls off from the fan blade along the groove. According to the fan blade and the aero-engine, a controllable failure structure formed by combining a plurality of blade bodies is adopted at the position, impacted by the bird body, of the fan blade, so that the fan blade is broken under the bird impact load, the broken area is controllable, and the aerodynamic performance loss of the aero-engine after the bird impact is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of aeroengines, and particularly relates to a fan blade and an aeroengine. Background Art

[0002] The takeoff and landing processes of an aircraft are the stages most prone to bird strikes. Before the appearance of aircraft, there were no high-speed man-made flying vehicles. The flight of birds in the air did not overlap with human activities and would not cause harm. The emergence of aircraft has changed the situation. Due to the high flight speed of aircraft, when colliding with flying birds, it often causes great damage. In serious cases, it will cause the crash of the aircraft. At present, bird strikes are one of the important factors threatening aviation safety. Especially for turbofan engines, flying birds are often sucked into the intake port, resulting in the deformation / failure of the fan blades of the turbofan engine, or jamming the engine, causing the engine to shut down and even catch fire. The damage to the power system of the aircraft is often fatal and will directly lead to the stall and crash of the aircraft. Therefore, there are strict requirements for the design and strength of turbofan engines, and bird strike tests are carried out to ensure safety. The engine should be able to withstand a certain number and mass of bird strikes and still maintain the required performance. In recent years, according to actual needs, more stringent bird strike regulations have been put forward for large civil engines.

[0003] The vast majority of birds have the characteristics of small body size and light mass. Therefore, the damage caused by bird strikes mainly comes from the speed of the flying vehicle rather than the mass of the birds themselves. With the development of aviation technology, the speed of man-made flying vehicles has been continuously increasing. According to the momentum theorem, a 0.45-kg bird colliding with an aircraft flying at a speed of 80 km / h will generate a force of 1500 N, and colliding with an aircraft flying at a speed of 960 km / h will generate a force of 216,000 N. The high-speed movement makes the destructive power of bird strikes reach an astonishing level.

[0004] When a bird collides with an aeroengine in flight, the fan blades of the aeroengine need to be able to resist the damage caused by bird strikes. For the impact of medium-mass birds, it is required that the damage to the fan blades be controlled within an acceptable range (the resulting thrust loss of the aeroengine does not exceed 25%).

[0005] Among them, due to the very high rotational speed of the fan blades of a turbofan engine, the bird impact load they bear is greater. Titanium alloy materials or titanium alloy metal reinforcing edges are usually used to ensure the bird strike resistance of the fan blades. However, with the increasing requirements for engine economy, higher requirements are put forward for reducing the weight of aeroengines. In order to reduce the weight of the fan blades, new fan blade structure designs, materials, and preparation schemes are needed. By adopting an impact-fragile structure form to control the damage degree of the fan blades under bird impact loads, in this type of structure, under the action of bird impact loads, the impact energy is absorbed through the structural failure of the fan blades to ensure the safety of the engine. Therefore, designing and preparing fan blades with a controllable impact failure structure has great application value. Controllable impact failure means that when the fan blades are struck by a bird, through the structural design of the struck part, it fails in a predetermined form under the impact load so as to achieve controllable failure degree.

[0006] However, the existing fan blade designs have the following problems:

[0007] First, for the metal fan blade body or the resin matrix carbon fiber composite fan blade edge trim to reduce the structural weight, whether it is thinning or using lightweight materials, the problem of insufficient resistance to foreign object impacts such as bird strikes needs to be solved.

[0008] Second, the new impact-resistant structure needs to have the strength and stiffness required by the normal working load.

[0009] Third, the new impact-resistant structure needs to have process feasibility.

[0010] In view of this, the inventors of the present application have designed a fan blade and an aeroengine in order to overcome the above technical problems. Utility Model Content

[0011] The technical problem to be solved by the present utility model is to provide a fan blade and an aeroengine in order to overcome the defect of insufficient resistance to foreign object impacts such as bird strikes in the existing fan blades.

[0012] The present utility model solves the above technical problems through the following technical solutions:

[0013] The present utility model provides a fan blade, characterized in that the fan blade has a controllable failure structure, the controllable failure structure is formed by combining a plurality of sheet bodies, and a plurality of regions are formed by dividing the sheet bodies through grooves, and the bottom of the grooves has a tip; after being impacted, the sheet bodies in the impacted area fall off the fan blade along the grooves.

[0014] According to one or more embodiments of the present utility model, the controllable failure structure is arranged at the leading edge of the fan blade.

[0015] According to one or more embodiments of the present utility model, the controllable failure structure is in a turtle shell pattern or a checkerboard pattern.

[0016] According to one or more embodiments of the present utility model, the sheet body has a triangular or combined polygon structure.

[0017] According to one or more embodiments of the present utility model, the groove is an inverted triangle.

[0018] According to one or more embodiments of the present utility model, the groove is filled with packing material, and the surface of the fan blade remains smooth.

[0019] According to one or more embodiments of the present utility model, the controllable failure structure is integrally formed with the fan blade by means of 3D printing technology.

[0020] The present utility model also provides an aeroengine, characterized in that the aeroengine includes the fan blade as described above.

[0021] The positive and progressive effects of the present utility model are as follows:

[0022] The fan blade of the present utility model has at least the following advantages:

[0023] First, by optimizing the groove structure and size between multiple sheet bodies of the fan blade, the fan blade has sufficient impact resistance and can resist bird strikes.

[0024] Second, by adopting a controllable failure structure formed by combining multiple sheet bodies at the part of the fan blade where the bird body impacts, it will break under the bird strike load, and the broken area is controllable, reducing the loss of the aeroengine's aerodynamic performance after a medium bird strike.

[0025] Third, the fan blade of the present utility model can be processed by machining or 3D printing. Description of the Drawings

[0026] The above-mentioned and other features, properties and advantages of the present utility model will become more obvious through the following description with reference to the drawings and embodiments. In the drawings, the same reference numerals always represent the same features, where:

[0027] Figure 1 is a schematic diagram of an aeroengine fan blade and a bird strike.

[0028] Figure 2a is a schematic diagram of a checkerboard pattern controllable failure structure in an embodiment of the fan blade of the present utility model.

[0029] Figure 2b is Figure 2a an enlarged view of part A of

[0030] Figure 3a It is a schematic diagram of the controllable failure structure in the form of a tortoise shell in an embodiment of the fan blade of the present utility model.

[0031] Figure 3b It is a three-dimensional schematic diagram of the controllable failure structure in the form of a tortoise shell in an embodiment of the fan blade of the present utility model.

[0032] Figure 4 It is a schematic diagram of the structure of the groove in an embodiment of the fan blade of the present utility model.

[0033] Figure 5a It is a schematic diagram of the fan blade of the present utility model being impacted by a bird body.

[0034] Figure 5b It is a schematic diagram of the bird strike failure of the fan blade of the present utility model.

[0035]

Reference Signs

[0036] Aeroengine 100

[0037] Fan blade 200

[0038] Controllable failure structure 210

[0039] Blade body 211

[0040] Groove 212

[0041] Tip 213

[0042] Filler 214

[0043] Flying bird 300 Detailed Embodiment

[0044] To make the above objects, features and advantages of the present utility model more obvious and understandable, the following detailed description of the specific embodiments of the present utility model will be given with reference to the accompanying drawings.

[0045] Now, embodiments of the present utility model will be described in detail with reference to the drawings. Now, preferred embodiments of the present utility model will be described in detail, and examples thereof are shown in the drawings. In any possible case, the same reference signs will be used to represent the same or similar parts in all the drawings. In addition, although the terms used in the present utility model are selected from well-known and commonly used terms, some of the terms mentioned in the specification of the present utility model may be selected by the applicant according to his or her judgment, and their detailed meanings are described in the relevant parts of the description herein. In addition, it is required to understand the present utility model not only through the actual terms used, but also through the meaning implied by each term.

[0046] As Figures 1 to 5bAs shown in the figure, the present utility model provides a fan blade 200, which has a controllable failure structure 210. The controllable failure structure 210 is formed by combining a plurality of sheet bodies 211. Each sheet body 211 is divided by a groove 212 to form a plurality of regions, and the bottom of the groove 212 has a tip 213;

[0047] After the controllable failure structure 210 is impacted, the sheet bodies 211 in the impacted area fall off from the fan blade 200 along the groove 212.

[0048] The specific shape and size of the groove 212 can be obtained through structural optimization according to design requirements such as the configuration of the fan blade, the bird strike load specified by the bird ingestion requirements of the aero-engine, etc.

[0049] Under the action of the bird strike load, stress concentration occurs at the tip 213 at the bottom of the groove 212, and cracks are initiated. The cracks extend to the inner layer of the fan blade 200 to generate penetrating cracks, causing the sheet body 211 to collapse and separate from the main body of the fan blade 200.

[0050] The tip 213 at the bottom of the groove 212 can avoid fatigue problems caused by crack propagation under the vibration working load of the aero-engine 100 through structural optimization design.

[0051] Furthermore, by optimizing the structure and size of the groove 212, the fan blade 200 has sufficient impact resistance, so as to be able to resist the impact of small birds.

[0052] Under the effect of improving the anti-bird strike ability of the fan blade 200, the controllable failure structure 210 formed by combining a plurality of sheet bodies 211 can make the blade thinner or use lightweight materials, thereby reducing the weight of the fan blade 200.

[0053] The fan blade 200 of the present utility model adopts a controllable failure structure 210 formed by combining a plurality of sheet bodies 211 at the part where the fan blade 200 is struck by a bird body, so that it fractures under the bird strike load, and the fracture area is controllable, reducing the loss of the engine aerodynamic performance after a medium bird strike.

[0054] As a preferred implementation mode of the fan blade 200 of the present utility model, the controllable failure structure 210 is arranged at the leading edge of the fan blade 200.

[0055] The leading edge of the fan blade 200 is the part that may be struck by a bird body inhaled by the aero-engine 100. Under the bird strike load, the sheet bodies 211 in the impacted area will fall off from the fan blade 200 along the groove 212, so as to control the plastic deformation or failure range of the fan blade 200.

[0056] Such as Figures 2a to 3bAs shown, as a preferred embodiment of the fan blade 200 of the present utility model, the controllable failure structure 210 is in a tortoise shell pattern or a checkerboard pattern.

[0057] As Figure 2a and Figure 2b shown, the fan blade 200 has a checkerboard-patterned controllable failure structure 210; as Figure 3a and Figure 3b shown, the fan blade 200 has a tortoise shell-patterned controllable failure structure 210.

[0058] The tortoise shell pattern and checkerboard pattern controllable failure structures 210 are integral structures, and are divided into multiple small tortoise shell or checkerboard-shaped regions by the grooves 212. Preferably, these regions are distributed at the parts of the leading edge of the fan blade 200 that may be impacted by a bird body sucked into the aeroengine 100.

[0059] Under the bird strike load, the tortoise shell grids or checkerboard grids in the impact area will fall off from the fan blade 200 along the grooves 212, so as to control the plastic deformation or failure range of the fan blade 200.

[0060] The controllable failure structure 210 includes, but is not limited to, Figure 2a and Figure 2b the checkerboard structure forms shown and Figure 3a and Figure 3b the tortoise shell structure forms shown. Figure 2a The remaining structures (such as the blade profile, tenon structure, etc.) of the fan blade 200 shown in

[0061] As a preferred embodiment of the fan blade 200 of the present utility model, the sheet body 211 has a triangular or combined polygon structure.

[0062] Multiple triangular or combined polygon sheet bodies 211 are combined together to form the fan blade 200, and the sheet bodies 211 are divided by the grooves 212.

[0063] By designing the shape and size of the controllable failure structure 210, the plastic deformation or failure range of the fan blade 200 under the bird strike load can be controlled.

[0064] As Figure 3b and Figure 4 shown, as a preferred embodiment of the fan blade 200 of the present utility model, the groove 212 is an inverted triangle.

[0065] Figure 3b and Figure 4 show the details of the groove 212 structure. In Figure 3bTaking the controllable failure structure 210 in the form of a tortoise shell as an example, there are inverted triangular grooves 212 between the sheet bodies 211 in the form of a tortoise shell. When a bird strike load acts on the controllable failure structure 210, stress concentration occurs at the bottom sharp corners of the grooves 212, and cracks extend towards the inner layer of the fan blade 200 to generate penetrating cracks, causing the tortoise shell lattice to collapse and separate. This can not only absorb the impact energy of the bird body but also limit the damage to a local area, thereby preventing the overall plastic deformation or failure of the fan blade 200. In other forms of the controllable failure structure 210 styles or other shapes of the sheet body 211 designs, the setting of the inverted triangular groove 212 is similar to that of the controllable failure structure 210 in the tortoise shell form shown in Figure 3b and will not be elaborated here.

[0066] The groove 212 is not limited to an inverted triangular structure, and its structural feature is that there is a tip 213 at the bottom, so as to generate stress concentration under the bird strike load and cause the sheet body 211 at the impacted part to detach from the fan blade 200.

[0067] According to the airworthiness requirements of aero-engines, the fan blade 200 needs to be able to withstand a bird strike without structural damage. Through bird strike numerical simulation calculation or experimental testing of the present utility model, the size of the tip 213 shown in Figure 3b is designed so that it can withstand a bird strike without being damaged.

[0068] Figure 4 As shown, as a preferred embodiment of the fan blade 200 of the present utility model, the groove 212 is filled with a filler 214, and the surface of the fan blade 200 remains smooth.

[0069] The filler 214 filled inside the groove 212 is preferably made of a lightweight material such as resin, and the surface of the fan blade 200 remains smooth to ensure the aerodynamic efficiency.

[0070] As a preferred embodiment of the fan blade 200 of the present utility model, the controllable failure structure 210 is integrally formed with the fan blade 200 by a 3D printing process.

[0071] Preferably, the groove 212 can be formed by a machining process or can be formed together with the fan blade 200 by a 3D printing process.

[0072] The fan blade 200 of the present utility model can be used as a wide-chord fan blade of a turbofan engine, including but not limited to lightweight alloy fan blades such as aluminum alloy, and resin-based carbon fiber composite fan blades. Among them, the fan blade 200 of the present utility model is impacted by a flying bird 300 flying along the axis during high-speed rotation, and 3-5 blades may be damaged. The traditional fan blade adopts a continuum structure and is prone to overall deformation or failure under the action of bird strike load. Moreover, under different operating conditions such as different rotational speeds of the fan blade 200, different speeds of the bird body, and different impact point positions, the blade damage is uncertain, and all operating conditions cannot be reproduced through tests. Therefore, there is a risk of not meeting the airworthiness requirements of the aeroengine for bird strike resistance.

[0073] The fan blade 200 of the present utility model adopts a fail-safe structure at the position where it may be impacted by a bird body. Under the action of bird strike load, only the impact area is damaged, and the range and degree of bird strike damage are controllable and deterministic.

[0074] As Figure 1 shown, the present utility model also provides an aeroengine 100, and the aeroengine 100 includes the fan blade 200 as described above.

[0075] The aeroengine 100 can be a turbofan engine. Figure 1 Shown is the fan blade 200 of the turbofan engine and the intention of bird strike absorption.

[0076] Among them, the fan blade 200 is impacted by a flying bird 300 flying along the axis during high-speed rotation, and 3-5 blades may be damaged.

[0077] The traditional fan blade 200 adopts a continuum structure and is prone to overall deformation or failure under the action of bird strike load. Moreover, under different operating conditions such as different rotational speeds of the fan blade 200, different speeds of the bird body, and different impact point positions, the blade damage is uncertain, and all operating conditions cannot be reproduced through tests. Therefore, there is a risk of not meeting the airworthiness requirements of the aeroengine for bird strike resistance.

[0078] Since the fan blade 200 of the aeroengine 100 of the utility model adopts a controllable fail-safe structure 210 at the position where it may be impacted by a bird body, only the impact area is damaged under the action of bird strike load, and the range and degree of bird strike damage are controllable and deterministic. Figure 1 The other structures such as the nacelle of the turbofan engine in the figure are for illustration purposes and are not limited thereto.

[0079] Figure 5a and Figure 5b Shown is the failure mode schematic diagram of the fan blade 200 of the present utility model provided with a controllable fail-safe structure 210 after being impacted by a flying bird 300.

[0080] According to the airworthiness requirements of aero-engines, the fan blade 200 needs to be able to withstand bird strikes without suffering structural damage. Through bird strike numerical simulation calculations or experimental tests, the present utility model designs the size of the tip 213 so that it can withstand bird strikes without being damaged. Compared with traditional fan blades, the fan blade 200 of the present utility model will only suffer local damage under medium bird strike loads, and the engine thrust loss does not exceed 25%, fully ensuring the airworthiness requirements of aero-engines.

[0081] In summary, the fan blade and aero-engine of the present utility model have the following many advantages:

[0082] First, by optimizing the groove 212 structure and size between more than 200 blades 211 of the fan blade 200, the fan blade 200 has sufficient impact resistance and can resist bird strikes.

[0083] Second, by adopting a controllable failure structure 210 formed by combining multiple blades 211 at the part of the fan blade 200 that is struck by a bird, it will break up under bird strike loads, and the fragmentation area is controllable, reducing the loss of engine aerodynamic performance after a medium bird strike.

[0084] Third, the fan blade 200 of the present utility model can be machined or processed by 3D printing.

[0085] Although the specific implementation manners of the present utility model have been described above, those skilled in the art should understand that these are only examples. The protection scope of the present utility model is defined by the appended claims. Without departing from the principles and essence of the present utility model, those skilled in the art can make various changes or modifications to these implementation manners, but these changes and modifications all fall within the protection scope of the present utility model.

Claims

1. A fan blade, characterized in that, The fan blade has a controllable failure structure, which is formed by combining a plurality of sheets. Each of the sheets is divided by grooves to form a plurality of regions, and the bottom of the groove has a tip; After being impacted, the sheets in the impacted area of the controllable failure structure fall off from the fan blade along the grooves.

2. The fan blade according to claim 1, characterized in that, The controllable failure structure is arranged at the leading edge of the fan blade.

3. The fan blade according to claim 1, wherein, The controllable failure structure is in a turtle shell pattern or a checkerboard pattern.

4. The fan blade according to claim 1, characterized in that, The sheet is in a triangular or combined polygon structure.

5. The fan blade according to claim 1, wherein, The groove is an inverted triangle.

6. The fan blade according to claim 1, wherein The groove is filled with filler, and the surface of the fan blade remains smooth.

7. The fan blade according to claim 1, wherein, The controllable failure structure is integrally formed with the fan blade by a 3D printing process.

8. An aeroengine, characterized in that, The aeroengine includes the fan blade according to any one of claims 1-7.

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