Lightweight noise reduction blade and blade lightweight noise reduction design method

Abstract

Provided is a quantified noise reduction design method, comprising the following steps: classifying a circle of blades in a circumferential direction according to load capacity, and obtaining multiple types of blades according to different load capacities; using hollow noise reduction blade design for a type of blades with the least load capacity, and not performing noise reduction design for a type of blades with the most load capacity. Also provided is a light-weight noise reduction blade, comprising a blade body, a pair of cover plates, a sound-absorbing plate and a pair of honeycomb structures, wherein the blade body comprises a frame and a hollow cavity in the frame; the pair of cover plates are arranged on both sides of the blade to close the hollow cavity; the sound-absorbing plate is arranged in the hollow cavity and between the pair of cover plates; and the pair of honeycomb structures are arranged between the cover plates and the sound-absorbing plate. The above method classifies the blades and then performs light-weight noise reduction design on the blades, which not only ensures safety but also achieves the design goal of light-weight noise reduction.

Description

Technical Field

[0001] This invention relates to the field of aero-engines, and more specifically to the field of blade structure design. Background Technology

[0002] With the development of aero-engines, designs integrating the fan outer duct (OGV) with the blades have emerged. The integrated OGV blades and blades serve both to transfer loads and to guide airflow at the outlet. Furthermore, the fan outer duct OGV design also needs to possess adequate noise reduction performance, such as through the use of honeycomb structures or other fillers.

[0003] However, noise reduction design and lightweight design are generally contradictory. Using lighter materials and structural features often means safety issues such as insufficient structural rigidity and insufficient strength margin; while adopting noise-reducing blade design means introducing noise-absorbing materials or features in structural design and material application, which will increase the weight of the blade to some extent, and will also pose greater challenges to overall safety. Summary of the Invention

[0004] One objective of this invention is to provide a lightweight and noise-reducing design method for blades.

[0005] Another objective of this invention is to provide a lightweight, noise-reducing blade.

[0006] The blade lightweighting and noise reduction design method to achieve the above objectives includes the following steps: S1. Classify the circumferentially distributed blades according to their load-bearing capacity, and obtain multiple types of blades according to different load-bearing capacities; S2. Use hollow noise reduction blade design for the type of blade with the least load-bearing capacity, and do not perform noise reduction design for the type of blade with the most load-bearing capacity.

[0007] To achieve the above objectives, a lightweight noise-reducing blade is obtained using the above method, which yields a type of blade with minimal load-bearing capacity. This type of blade includes a blade body, a pair of cover plates, a sound-absorbing plate, and a pair of honeycomb structures. The blade body includes a frame and a hollow cavity located within the frame. The pair of cover plates are respectively disposed on both sides of the blade to enclose the hollow cavity. The sound-absorbing plate is disposed between the pair of cover plates and located within the hollow cavity. The pair of honeycomb structures are respectively disposed between the cover plates and the sound-absorbing plate.

[0008] In one or more embodiments, the cover plate is provided with sound-absorbing holes corresponding to the honeycomb structure.

[0009] In one or more embodiments, the silencing holes on the cover plate on the back side of the blade are tapered holes with a 45° cone angle.

[0010] In one or more embodiments, the cellular structure includes a plurality of cellular cells, each cellular cell including a central cellular cell located in the middle and an annular cellular cell surrounding the central cellular cell.

[0011] In one or more embodiments, each of the cellular units includes a sound-absorbing hole disposed on the cover plate and a sound-transmitting hole disposed on the wall surface of the central cellular unit, the sound-transmitting hole being used to connect the central cellular unit and each of the annular cellular units.

[0012] In one or more embodiments, the cover plate is configured to be bonded to the honeycomb structure and the blade body by an adhesive film, and the honeycomb structure is configured to be bonded to the sound-absorbing plate by an adhesive film.

[0013] In one or more embodiments, the sound-absorbing plate is made of resin composite material.

[0014] In one or more embodiments, the sound-absorbing plate is made of an elastic material.

[0015] In one or more embodiments, the honeycomb structure is made of aluminum alloy honeycomb.

[0016] The aforementioned blade lightweighting and noise reduction design method, based on a detailed blade load-bearing capacity layout, implements different noise reduction and lightweighting designs for different blades according to their load-bearing capacities. Blades with the highest load-bearing capacity are not subject to lightweighting design to ensure their load-bearing capacity and safety. Blades with the lowest load-bearing capacity are designed with a hollow structure to achieve lightweighting. Noise reduction is further achieved through sound-absorbing holes, honeycomb structures, and sound-absorbing plates on the cover plate. In this way, lightweight noise-reducing blade design is efficiently implemented while ensuring safety, resolving the contradictions inherent in traditional designs. Attached Figure Description

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

[0018] Figure 1 This is a schematic diagram of leaf classification;

[0019] Figure 2 This is a component exploded view of one embodiment of a lightweight noise-reducing blade;

[0020] Figure 3 This is a cross-sectional view of one embodiment of a lightweight noise-reducing blade;

[0021] Figures 4A-4B This is a schematic diagram of lightweight, noise-reducing blades;

[0022] Figures 5A-5B This is a schematic diagram of a honeycomb structure;

[0023] Figure 6 This is a design structural diagram of the cover plate's sound-absorbing holes;

[0024] Figure 7 yes Figure 6 Cross-sectional view of the NN position in the middle;

[0025] Figure 8 This is a flowchart of a blade lightweighting and noise reduction design method.

[0026] Symbol marking explanation

[0027] 10. Blade body

[0028] 11. Border

[0029] 12 Hollow Cavity

[0030] 20 Cover plate

[0031] 21. Leaf back cover plate

[0032] 22 Leaf Pot Cover

[0033] 30 Sound-absorbing panels

[0034] 40. Honeycomb structure

[0035] 41 Honeycomb on the underside of the leaf

[0036] 42. Honeycomb on the side of the leaf basin

[0037] 44 silencer holes

[0038] 45 Sound transmission holes

[0039] 400 cellular units

[0040] 401 Cellular

[0041] 410 Central Cell

[0042] 420 Circumferential Cellular Detailed Implementation

[0043] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0044] It should be noted that these and other accompanying drawings are merely examples and are not drawn to scale, and should not be construed as limiting the scope of protection of the present invention.

[0045] The lightweight noise reduction design method for blades described in this disclosure can efficiently carry out the design of lightweight noise reduction blades while meeting safety requirements.

[0046] First, the circumferentially distributed blades are classified according to their load-bearing capacity, resulting in multiple types of blades. Then, the blades with the lowest load-bearing capacity are designed with hollow noise reduction blades, while the blades with the highest load-bearing capacity are not designed with noise reduction.

[0047] Specifically, with Figure 1 Taking the fan's outlet guide vane (OGV) as an example, the fan OGV has a total of 48 blades in one revolution, and the 48 fan OGV blades are divided into four levels according to the load-bearing capacity.

[0048] The first-stage load-bearing component A consists of the two blades at or closest to the 12 o'clock and 6 o'clock positions. As the main fan OGV, it provides the primary rigidity and load-bearing capacity, and is preferably made of TC4 titanium alloy. The second-stage load-bearing component B consists of the two circumferentially adjacent blades located at or closest to the 12 o'clock position of the first-stage load-bearing component. It provides auxiliary rigidity and load-bearing capacity for the first-stage load-bearing component, and is preferably made of TC4 titanium alloy.

[0049] The blades of the fourth-stage carrier C and the third-stage carrier D are arranged alternately in the circumferential direction, with the blades closest to the second-stage carrier being the blades of the fourth-stage carrier, and the blade closest to or from the 6 o'clock position of the first-stage carrier being the blade of the third-stage carrier. Thus, the third-stage carrier comprises 24 spaced-apart fan OGVs, preferably made of aluminum alloy; the fourth-stage carrier comprises 22 spaced-apart fan OGVs, preferably made of aluminum alloy.

[0050] In this way, by classifying the blades according to their load-bearing capacity, and with the load-bearing capacity of each level of blade clearly defined, appropriate materials and structures can be selected based on the rigidity and load-bearing capacity of different levels of blades. This allows for blade noise reduction design while ensuring safety. No noise reduction design is applied to the first-level load-bearing blades, which bear the largest load, as they perform the main load-bearing function. For the fourth-level load-bearing blades, which bear the least load, the weight can be appropriately reduced, and a hollow noise reduction blade design can be adopted.

[0051] Those skilled in the art will understand that blade grading includes, but is not limited to, the use of Figure 1 The classification method shown is determined based on the actual load carried by the blade, and the number of levels is not limited to the four categories mentioned in the above embodiments.

[0052] This type of blade with the lowest load-bearing capacity can be used Figures 2 to 4BThe lightweight noise-reducing blade structure shown includes a blade body 10, a pair of cover plates 20, a sound-absorbing plate 30, and a pair of honeycomb structures 40.

[0053] The blade body 10 includes a frame 11 and a hollow cavity 12 located within the frame 11. A pair of cover plates 20 are respectively disposed on both sides of the blade to close the hollow cavity 12 and form the blade base 13 and the blade back 14. The cover plate located on the blade back 14 side is called the blade back cover plate 21, and the cover plate located on the blade base 13 side is called the blade base cover plate 22, as shown below. Figure 3 As shown, the hollow cavity 12 occupies the main space of the blade, including the leaf root side and the leaf tip side, which will greatly reduce the weight.

[0054] The sound-absorbing plate 30 is disposed between the blade back cover plate 21 and the blade basin cover plate 22, and is located within the hollow cavity 12. The sound-absorbing plate 30 may be made of resin-based composite materials, including but not limited to aramid, polyimide, S2 glass fiber, etc.

[0055] The sound-absorbing plate 30 can also be made of an elastic material with a certain degree of elasticity, which can be squeezed into the hollow cavity 12 in the middle.

[0056] The honeycomb structure 40 is respectively disposed between the cover plate 10 and the sound-absorbing plate 30, forming a honeycomb 41 on the back side of the leaf and a honeycomb 42 on the leaf basin side. The inner sides of the honeycomb 41 on the back side of the leaf and the honeycomb 42 on the leaf basin side are bonded to the middle sound-absorbing plate 30 with adhesive film, and the outer sides are bonded to the cover plate 10 with adhesive film.

[0057] The honeycomb structure preferably uses high bending strength aluminum alloy honeycomb to ensure overall rigidity, but resin-based composite honeycomb can also be used.

[0058] In this way, the blade basin side cover plate, honeycomb, and silencing plate together form the blade basin side silencing cavity, and the blade back side cover plate, honeycomb, and silencing plate together form the blade back side silencing cavity, so that the blades carried by this stage form a double silencing cavity structure on both sides of the blade basin and blade back, minimizing the noise transmitted from the fan to the rear.

[0059] The cellular structure 40 includes a plurality of cellular units 400, and each cellular unit 400 includes a plurality of cells 401. The cellular unit 400 includes a central cell 410 located in the center and a plurality of circumferential cells 420 surrounding the central cell 410.

[0060] Those skilled in the art will understand that the central cell 410 and the circumferential cell 420 include, but are not limited to, Figure 5A The hexagonal honeycomb structure shown.

[0061] Each cellular unit 400 includes a sound-absorbing hole 44 disposed on the cover plate 20, with the sound-absorbing hole 44 on the cover plate directly above the central cellular lattice; it also includes sound-transmitting holes 45 disposed on the wall surface of the central cellular unit 410. That is, it adopts a "one-way-six-connections" sound-absorbing design, with the central cellular unit 410 connected to the outside world through multiple door-shaped sound-transmitting holes 45 connected to multiple adjacent circumferential cellular units 420, such as... Figure 5A and 5B As shown, the honeycomb lattice and sound-absorbing plate can dissipate the energy of incoming sound waves to the maximum and fastest speed, thereby improving the noise reduction effect.

[0062] Both the blade basin cover plate 22 and the blade back cover plate 21 have sound-absorbing holes 44 on their surfaces. The sound-absorbing holes 44 are preferably tapered holes with a 45° cone angle to absorb sound waves and reduce fan back-transmission noise. Each honeycomb cell 400 has a tapered sound-absorbing hole 44 in the middle of its "one-way-six-way" honeycomb lattice.

[0063] Leaf basin cover plate 22 and leaf back cover plate 21 are bonded to the frame 11 of honeycomb structure 40 and leaf body 10 by adhesive film.

[0064] The aforementioned lightweight noise-reducing blades use lightweight honeycomb and composite material sound-absorbing panels instead of aluminum alloy, combined with a hollow cavity, to achieve a weight reduction effect. Thus, for the fourth-stage load-bearing fan OGV blades, which bear the least load, the blade weight is expected to be reduced by 45%, with an overall noise reduction of over 2dB; while no weight reduction design is applied to blades of other load-bearing stages.

[0065] In this way, by classifying blades according to their rigidity and load-bearing capacity, lightweight design of blades is carried out, which not only ensures the overall safety of the blades but also achieves lightweight and noise reduction design. Under the premise of meeting safety requirements, lightweight and noise-reducing blade design is carried out efficiently, resolving the contradictions in traditional design.

[0066] This application uses specific terms to describe embodiments of the application. Terms such as "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the application. Therefore, it should be emphasized and noted that references to "an embodiment," "one embodiment," or "an alternative embodiment" in different locations throughout this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0067] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for lightweighting and reducing noise in blades, characterized in that, The blades are OGV fan blades, and the process includes the following steps: S1. The circumferentially distributed blades are classified according to their load capacity. Based on the different load capacities, the OGV blades of the fan are divided into four levels according to their load capacity. The first level of load capacity provides the main rigidity and load capacity, the second level of load capacity provides auxiliary rigidity and load capacity, and the blades of the fourth level and third level of load capacity are arranged alternately in the circumferential direction, with the blades closer to the second level of load capacity being the blades of the fourth level of load capacity. S2. For the type of blade with the least load-bearing capacity, a hollow noise-reducing blade design is adopted, which is a lightweight noise-reducing blade, including: The blade body includes a frame and a hollow cavity located within the frame; A pair of cover plates are respectively disposed on both sides of the blade to seal the hollow cavity; A sound-absorbing plate is disposed between the pair of cover plates and located within the hollow cavity; and A pair of honeycomb structures are respectively disposed between the cover plate and the sound-absorbing plate; No noise reduction design is applied to the type of blade that bears the most weight.

2. The method as described in claim 1, characterized in that, The cover plate is provided with sound-absorbing holes corresponding to the honeycomb structure.

3. The method as described in claim 1, characterized in that, The sound-absorbing holes on the cover plate on the back side of the blade are tapered holes with a 45° cone angle.

4. The method as described in claim 1, characterized in that, The cellular structure includes multiple cellular units, each of which includes a central cellular unit located in the middle and a ring cellular unit surrounding the central cellular unit.

5. The method as described in claim 4, characterized in that, Each of the cellular units includes a sound-absorbing hole disposed on the cover plate and a sound-transmitting hole disposed on the wall surface of the central cellular unit, the sound-transmitting hole being used to connect the central cellular unit and each of the annular cellular units.

6. The method as described in claim 1, characterized in that, The cover plate is configured to be bonded to the honeycomb structure and the blade body by means of an adhesive film, and the honeycomb structure is configured to be bonded to the sound-absorbing plate by means of an adhesive film.

7. The method as described in claim 1, characterized in that, The sound-absorbing plate is made of resin composite material.

8. The method as described in claim 1, characterized in that, The sound-absorbing plate is made of an elastic material.

9. The method as described in claim 1, characterized in that, The honeycomb structure is made of aluminum alloy honeycomb.

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