Lightweight noise reduction blade and blade lightweight noise reduction design method

Abstract

The invention provides a blade lightweight noise reduction design method which comprises the following steps: classifying a circle of blades distributed in the circumferential direction according to the bearing capacity, dividing the blades into at least three stages of bearing blades according to the bearing capacity from large to small, defining the first stage of bearing blade as the blade with the maximum bearing capacity, and defining the second stage of bearing blade as the blade with the maximum bearing capacity; the third-stage bearing blade is defined as a blade with the minimum bearing capacity, and the second-stage bearing blade is defined as a blade with the bearing capacity between the first-stage bearing blade and the third-stage bearing blade; noise reduction design is not adopted for the first-stage bearing blade, and a local hollow structure is adopted for the second-stage bearing blade. According to the method, the lightweight noise reduction design can be realized on the premise of ensuring the safety of the blade. The invention further provides the lightweight noise reduction blade.

Description

Technical Field

[0001] The present invention relates to the field of aeroengines, and in particular to the field of blade design. Background Art

[0002] Existing fan designs often use a fusion design of fan OGV and support plates. The fusion-designed OGV support plates and blades not only play the role of transferring load bearing, but also serve as the outlet diversion function. With the further development of aero-engine material technology, basic research, and design technology, various companies have launched more advanced new-generation aero-engine research and development, among which weight and noise are two important indicators of the leading edge of aero-engines. At the same thrust level, lighter weight often means more competitiveness and higher commercial potential; and lower noise often means a better flight experience and a more comfortable flying environment for air passengers.

[0003] However, safety and lightweight design are often contradictory. Therefore, it is necessary to complete the lightweight and noise reduction design of the blade while ensuring safety. Summary of the invention

[0004] An object of the present invention is to provide a blade lightweight and noise reduction design method.

[0005] Another object of the present invention is to provide a lightweight, noise-reducing blade.

[0006] A blade lightweight noise reduction design method for achieving the above-mentioned purpose includes the following steps: S1. Classifying a circle of blades distributed circumferentially according to the load-bearing weight, and dividing them into at least three levels of load-bearing blades from large to small load-bearing weights, defining the first-level load-bearing blades as the blades with the largest load-bearing weight, defining the third-level load-bearing blades as the blades with the least load-bearing weight, and defining the second-level load-bearing blades as the blades with a load-bearing weight between the first-level load-bearing blades and the third-level load-bearing blades; S2. Not adopting noise reduction design for the first-level load-bearing blades, and making the second-level load-bearing blades adopt a partially hollow structure.

[0007] In order to achieve the above-mentioned purpose, a lightweight noise reduction blade adopts the above-mentioned method to obtain a second-stage load-bearing blade, wherein the second-stage load-bearing blade includes a blade body, a cover plate and a honeycomb structure, the blade body includes reinforcing ribs and a plurality of grooves divided by the reinforcing ribs, the grooves include leading edge grooves and trailing edge grooves, both of which are arranged to be recessed toward the suction surface of the blade; the cover is used to close the groove; and the honeycomb structure is arranged in the groove.

[0008] In one or more embodiments, the blade includes a silencer plate for closing the leading edge groove to form a first chamber, the silencer plate and the cover plate form a second chamber, and the honeycomb structure is provided in both the first chamber and the second chamber.

[0009] In one or more embodiments, both the muffler plate and the cover plate are provided with muffler holes.

[0010] In one or more embodiments, the silencer hole on the cover plate on the suction side of the blade is a conical hole with a cone angle of 45°.

[0011] In one or more embodiments, the honeycomb structure includes a plurality of honeycomb units, each of the honeycomb units includes a central honeycomb and a plurality of annular honeycombs surrounding the central honeycomb.

[0012] In one or more embodiments, the honeycomb unit includes a sound-absorbing hole provided on the cover plate and connected to the central honeycomb, and a sound-transmitting hole connecting the central honeycomb and the annular honeycomb.

[0013] In one or more embodiments, the honeycomb structure is configured to be bonded to the groove by an adhesive film.

[0014] In one or more embodiments, the cover plate is configured to be bonded to the blade body and the honeycomb structure by means of an adhesive film.

[0015] In one or more embodiments, the second stage blade further includes an axial flange mounting edge located at the blade edge plate and a radial connecting hole located at the blade tip.

[0016] The above-mentioned blade lightweight and noise reduction design method conducts detailed classification of blades and adopts a partial hollow design for blades with certain load-bearing performance. It not only realizes the load transfer function, but also realizes the lightweight and noise reduction function of the blade through the partial hollow design and honeycomb structure, thus solving the current design difficulties. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0018] Figure 1 is a schematic diagram of the leaves after classification;

[0019] Figure 2 This is a component breakdown diagram of the lightweight noise reduction blade;

[0020] Figure 3 is a schematic diagram of the leading edge groove, the muffler plate and the leading edge honeycomb;

[0021] Figure 4 is a schematic diagram of the trailing edge groove and the trailing edge honeycomb;

[0022] Figure 5A-5B It is a schematic diagram of the connection structure of the second-level bearer;

[0023] Figure 6It is a cross-sectional view of a lightweight noise-reducing blade;

[0024] Figure 7 is a schematic diagram of a honeycomb unit;

[0025] Figure 8 It is a flow chart of the blade lightweight and noise reduction design method. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0027] It should be noted that these and other subsequent drawings are only examples and are not drawn to scale, and should not be used to limit the actual scope of protection required by the present invention.

[0028] The blade is usually lightened by optimizing the structure and reducing its weight. The blade noise is usually reduced by aerodynamic blade design, structural design, material application and other methods. The blade as a whole is usually required to bear a sufficient amount of load-bearing tasks, such as Figure 1 The outlet guide vane (OGV) of the fan shown is generally used as a stator component at the last stage of the flow channel. Its main function is to change the outflow angle of the fluid in the flow channel and needs to play a role in load transfer.

[0029] In lightweight design, the use of lighter materials and structural features often means problems such as insufficient structural rigidity and insufficient strength margin. Features such as adding new noise-absorbing materials to the blades in noise reduction design will also pose challenges to the overall safety of the blades.

[0030] Therefore, the blade lightweight noise reduction design method disclosed in the present invention can carry out certain lightweight noise reduction designs under the premise of meeting safety requirements, and specifically includes the following steps: S1. Classify a circle of blades distributed circumferentially according to the load-bearing weight, and divide them into at least three levels of blades according to the load-bearing weight from most to least, and define the first-level blades as the blades with the largest load-bearing weight, the third-level blades as the blades with the least load-bearing weight, and the second-level blades as the blades with a load-bearing weight between the first-level blades and the third-level blades; S2. Do not adopt noise reduction design for the first-level blades, and make the second-level blades adopt a partial hollow structure.

[0031] For example, Figure 1 The classification in step S1 is performed by taking the outlet guide vane of the fan as an example.

[0032] There are 48 blades in a circumference of the fan OGV blades, and the 48 fan OGV blades are divided into four levels according to the load-bearing load.

[0033] The first-level load A is the two blades at 12 o'clock and 6 o'clock or the closest to 12 o'clock and 6 o'clock positions, which serve as the main fan OGV and provide the main rigidity and load, and the preferred material is TC4 titanium alloy. The second-level load B is the two blades located at 12 o'clock or the closest to 12 o'clock of the first-level load, which are adjacent to the circumferential blades, and provide auxiliary rigidity and load for the first-level load, and the preferred material is TC4 titanium alloy.

[0034] The blades of the fourth-stage load C and the third-stage load D are arranged alternately in the circumferential direction, and the blades close to the second-stage load are the blades of the fourth-stage load, and the blades close to the 6 o'clock position of the first-stage load or the closest to the 6 o'clock position are the blades of the third-stage load. In this way, the third-stage load includes 24 fans OGV arranged at intervals, preferably made of aluminum alloy; the fourth-stage load includes 22 fans OGV arranged at intervals, preferably made of aluminum alloy.

[0035] In this way, the load-bearing types of fan OGV are carefully classified, and according to the rigidity and load-bearing capacity of different types, material selection or structural design are used to make it meet the function of load transfer.

[0036] For example, in some embodiments, the second-stage load-bearing blade is structurally designed to include an axial flange mounting edge 10 located at the blade edge plate and a radial connection hole 20 located at the blade tip. Each axial flange mounting edge 10 has two bolt connection holes for axially connecting with the outer ring of the intermediate inner casing; each radial connection hole 20 is used to radially connect with the outer ring of the intermediate casing through bolts, such as Figure 5A and 5B Such a design enables the blades carrying the second stage to transmit various types of loads such as aerodynamic force, maneuvering force, FBO load, etc., thus playing the role of load transmission.

[0037] Since the second-stage OGV blade needs to bear aerodynamic force, mechanical force and FBO load, the blade needs to have a certain rigidity. Therefore, the second-stage blade adopts a partially hollow structure, such as Figures 2 to 7 As shown, the blade body 30 , the cover plate 40 and the honeycomb structure 50 are included.

[0038] The blade body 30 includes a reinforcing rib 31 and a plurality of grooves 32 divided by the reinforcing rib 31. The grooves 32 include a leading edge groove 328 and a trailing edge groove 329, both of which are arranged to be recessed toward the suction surface of the blade. Figure 6 shown.

[0039] The blade basin body is designed with the above-mentioned cross-shaped reinforcement rib structure, which not only enhances the bending rigidity of the blade, but also improves the torsional rigidity of the blade, and cooperates with the supporting honeycomb and cover plate to ensure that the blade has sufficient rigidity.

[0040] Those skilled in the art will appreciate that the number of grooves and the shape of the reinforcement ribs may be changed according to specific blade load requirements and are not limited to the above-mentioned four grooves and cross-shaped reinforcement rib structure.

[0041] The cover plate 40 is used to close the groove 32 to form a blade basin pressure surface. The honeycomb structure 50 is arranged in the groove 32 , the honeycomb structure located in the leading edge groove 328 is the leading edge honeycomb 51 , and the honeycomb structure located in the trailing edge groove 329 is the trailing edge honeycomb 52 .

[0042] Considering that the leading edge of the OGV blade has a better noise reduction effect, under the premise of meeting the rigidity requirements, a high noise reduction double-cavity design is adopted for the leading edge honeycomb 51 located in the leading edge groove 328. For example, in some embodiments, the blade further includes a muffler plate 60 for closing the leading edge groove 328 to form a first cavity 321. The muffler plate 60 and the cover plate 40 further form a second cavity 322. The honeycomb structure 50 is provided in both the first cavity 321 and the second cavity 322. In this way, the leading edge honeycomb 51 includes four groups of honeycomb structures.

[0043] The sound-absorbing plate 60 is preferably made of a resin-based composite material, including but not limited to aramid, polyimide, S2 glass fiber, etc.

[0044] Taking into account that the blade trailing edge profile is relatively thin, a single-cavity noise reduction design is carried out for the trailing edge honeycomb 52 while meeting the rigidity requirements. A honeycomb structure is filled in the corresponding area between the cover plate 40 and the trailing edge groove 329 to form a layer of trailing edge honeycomb 52, and a silencer hole 45 is opened in the cover plate 40 corresponding to the trailing edge honeycomb 52.

[0045] Preferably, the silencer hole on the cover plate located on the pressure side of the blade, that is, the back side of the blade, is a conical hole with a cone angle of approximately 45° to absorb sound waves and reduce the back-transmitted noise of the fan.

[0046] The honeycomb structure 50 includes a plurality of honeycomb units 500, each of which includes a central honeycomb 510 and a plurality of annular honeycombs 520 surrounding the central honeycomb 510. Figure 7 In the illustrated embodiment, the central honeycomb 510 and the annular honeycomb 520 are both hexagonal honeycombs, and every seven honeycombs form a silencer group.

[0047] The honeycomb unit 500 includes a sound-absorbing hole 45 disposed on the cover plate 40 and connected to the central honeycomb, and a sound-transmitting hole 46 connecting the central honeycomb and the annular honeycomb. In this way, the honeycomb unit 500 adopts a "one-through-six-through" sound-absorbing design. The sound-absorbing hole on the cover plate corresponds to the middle honeycomb lattice, and the six door-shaped sound-transmitting holes at the bottom are connected to the six honeycombs next door. Through the honeycomb lattice and the sound-absorbing plate, the incoming sound wave energy can be dissipated as much as possible and as quickly as possible, thereby achieving an improved noise reduction effect.

[0048] The honeycomb structure 50 is configured to be bonded to the groove 32 and the muffler plate 60 by means of adhesive film, and the cover plate 40 is configured to be bonded to the blade body 30 and the honeycomb structure 50 by means of adhesive film. After bonding, the cover plate 40 enters the autoclave for curing and molding.

[0049] Therefore, the above-mentioned blade lightweight noise reduction design method carefully classifies the circumferential blades, carries out lightweight noise reduction design of each blade according to the load-bearing characteristics, carries out lightweight noise reduction design while taking rigidity into consideration, and adopts a local hollow structure, which not only realizes the load transfer, but also meets the design requirements of lightweight noise reduction.

[0050] The present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or multiple times in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0051] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0052] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A blade lightweight noise reduction design method, characterized in that: The steps include: S1. Classify a circle of blades distributed in the circumferential direction according to the load-bearing weight, and divide them into at least three levels of load-bearing blades according to the load-bearing weight from large to small, define the first-level load-bearing blade as the blade with the largest load-bearing weight, define the third-level load-bearing blade as the blade with the least load-bearing weight, and define the second-level load-bearing blade as the blade with a load-bearing weight between the first-level load-bearing blade and the third-level load-bearing blade; S2. No noise reduction design is adopted for the first-stage load-bearing blades, and the second-stage load-bearing blades adopt a partially hollow structure.

2. A lightweight noise reduction blade, characterized in that: The second-stage load-bearing blade is obtained by the method according to claim 1, wherein the second-stage load-bearing blade comprises: The blade body includes a reinforcing rib and a plurality of grooves divided by the reinforcing rib, wherein the grooves include a leading edge groove and a trailing edge groove, and are both arranged to be recessed toward the suction surface of the blade; A cover plate, used for closing the groove; The honeycomb structure is arranged in the groove.

3. The lightweight noise reduction blade according to claim 2, characterized in that: The blade comprises a muffler plate for closing the leading edge groove to form a first chamber. The muffler plate and the cover plate form a second chamber. The honeycomb structure is provided in both the first chamber and the second chamber.

4. The lightweight noise reduction blade according to claim 3, characterized in that: The muffler plate and the cover plate are both provided with muffler holes.

5. The lightweight noise reduction blade according to claim 3, characterized in that: The silencer hole on the cover plate on the suction side of the blade is a conical hole with a cone angle of 45°.

6. The lightweight noise reduction blade according to claim 3, characterized in that: The honeycomb structure includes a plurality of honeycomb units, each of which includes a central honeycomb and a plurality of annular honeycombs surrounding the central honeycomb.

7. The lightweight noise reduction blade according to claim 6, characterized in that: The honeycomb unit includes a sound-absorbing hole provided on the cover plate and communicating with the central honeycomb, and a sound-transmitting hole connecting the central honeycomb and the annular honeycomb.

8. The lightweight noise reduction blade according to claim 2, characterized in that: The honeycomb structure is configured to be bonded to the groove via an adhesive film.

9. The lightweight noise reduction blade according to claim 2, characterized in that: The cover plate is configured to be bonded to the blade body and the honeycomb structure through an adhesive film.

10. The lightweight noise reduction blade according to claim 2, characterized in that: The second-stage blade further comprises an axial flange mounting edge located at the blade edge plate and a radial connecting hole located at the blade tip.

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