Noise reduction stationary blade and open type rotor engine

Abstract

The noise reduction stationary blade comprises a blade body shell and a cavity, and further comprises a first through hole, a perforated plate and a first-class resonant cavity layer, and the first through hole is formed in the blade body shell; the perforated plate is arranged in the cavity, and a plurality of second through holes are formed in the perforated plate; the first-class resonant cavity layer is arranged between the blade body shell and the perforated plate and comprises a plurality of first-class resonant cavities, and each first-class resonant cavity communicates with a first through hole in the blade body shell and a second through hole in the perforated plate. The noise reduction stationary blade has a multi-layer noise elimination effect on the premise that the aerodynamic performance is not affected, and noise can be effectively reduced. The invention further provides an open rotor engine.

Description

Technical Field

[0001] The present invention relates to the field of blades, and in particular to the field of blade noise reduction. Background Art

[0002] An open rotor engine is a gas turbine engine that generates thrust by driving a propeller fan through the output shaft power of a power turbine. It is between a turboprop and a turbofan, and is also called a propfan engine or an unducted fan engine. It mainly includes four major components: a gas generator, a power turbine, a transmission device, and a propfan. According to the different positions of the propfan in the engine, it can be divided into traction type and propulsion type; according to the drive mode, it can be divided into gear drive and direct drive. Compared with traditional turboprop engines, due to its ultra-high bypass ratio, it has higher propulsion efficiency and lower fuel consumption rate, and has low operating costs and high cycle efficiency.

[0003] Although open rotor engines have great potential for fuel saving, the noise problem is prominent because there is no nacelle shielding and containment outside the propeller fan. Common noise reduction methods include modifying parameters such as the ratio of the number of front and rear rows of blades, the diameter ratio and the axial distance, or setting a specific blade structure to reduce noise. However, these noise reduction methods will also affect the aerodynamic parameters of the blades, thereby affecting the overall performance of the open rotor. Summary of the invention

[0004] An object of the present invention is to provide a noise reducing stator.

[0005] To achieve the above-mentioned purpose, the noise reduction stator includes a blade body shell and a cavity, and also includes a first through hole, a porous plate, and a first type of resonance cavity layer, wherein the first through hole is arranged on the blade body shell; the porous plate is arranged in the cavity, and a plurality of second through holes are arranged on it; the first type of resonance cavity layer is arranged between the blade body shell and the porous plate, and includes a plurality of first type of resonance cavities, and each of the first type of resonance cavities is respectively connected to a first through hole on the blade body shell and a second through hole on the porous plate.

[0006] In one or more embodiments, the noise reduction stator includes a plurality of porous plates, and also includes one or more second-type resonance cavity layers, wherein the second-type resonance cavity layers are arranged between adjacent porous plates, and include a plurality of second-type resonance cavities, and the second-type resonance cavities are respectively connected to the second through holes on two adjacent porous plates.

[0007] In one or more embodiments, at least some of the layers of the porous plates are arranged with unequal spacing.

[0008] In one or more embodiments, the noise reduction vane further includes a radial support rod located in the cavity.

[0009] In one or more embodiments, the noise reduction stator further includes a porous medium, which is disposed in the innermost porous plate and surrounds the radial support rod.

[0010] In one or more embodiments, the first type of resonant cavity and / or the second type of resonant cavity is a hexagonal or / and quadrilateral or / and circular resonant cavity.

[0011] In one or more embodiments, the blade airfoil shell includes a pressure surface and a suction surface, and the first through hole is arranged on the pressure surface and the suction surface.

[0012] In one or more embodiments, a diameter of the first through hole ranges from 1 to 2 mm.

[0013] In one or more embodiments, the porous plate is an airfoil-shaped porous plate.

[0014] Another object of the present invention is to provide an open rotor engine comprising the above-mentioned noise reduction stator blades.

[0015] The above-mentioned noise reduction stator blades do not modify the shape or blade profile of the blades. Instead, a resonance cavity is set inside the blades, which is equivalent to forming a multi-layer airfoil perforated plate acoustic liner inside the blades, thereby absorbing noise of different frequencies inside the stator blades. Therefore, the noise can be significantly reduced without almost affecting the aerodynamic performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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:

[0017] Figure 1 It is an external schematic diagram of an open rotor stator;

[0018] Figure 2 is a schematic diagram of the opening position of the first through hole;

[0019] Figure 3 is a cross-sectional schematic diagram of an embodiment of a noise reduction stator blade;

[0020] Figure 4 is a cross-sectional schematic diagram of another embodiment of a noise reduction stator;

[0021] Figure 5 is a schematic diagram of the structure of the resonant cavity layer;

[0022] Figure 6 yes Figure 3 A partial enlarged view of the leading edge A of the middle blade.

[0023] Symbols and Markings

[0024] 10 Noise reduction stator blades

[0025] 11 Blade shell

[0026] 12 Cavity

[0027] 13 First through hole

[0028] 14 Multiwell Plate

[0029] 15. The first type of resonant cavity layer

[0030] 17 The second type of resonant cavity layer

[0031] 18 Radial support rod

[0032] 19 Porous Media

[0033] 115 Pressure surface

[0034] 116 Suction surface

[0035] 140 Second through hole

[0036] 150 First-class resonant cavity

[0037] 170 The second type of resonant cavity DETAILED DESCRIPTION

[0038] 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.

[0039] 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.

[0040] The open rotor engine is also called the unducted propfan engine. The open rotor engine has a relatively large duct and a low jet velocity. Its maximum noise mainly comes from the open fan blades. According to its source, the open fan noise can be divided into the blade's own noise and the interference noise between the rotating and stationary blades. According to the nature of the sound source, the open fan noise includes single-tone noise and broadband noise. Among them, single-tone noise is mainly generated by the periodic interaction between the blade and the incoming flow, which is usually related to the blade passing frequency and its harmonics. Broadband noise is mainly caused by the blade pulsation force with random characteristics such as the turbulent boundary layer developed along the blade surface, the vortex shedding on the surface of the object, and the interference between the blade and the incoming flow turbulence. The sources of open rotor single-tone noise mainly include the interference single tone of the blade tip vortex, the interference single tone of the viscous wake, the interference single tone of the front and rear potential fields, and the single tone noise of a single rotor.

[0041] For rotor-stator open rotor engines, there is usually a row of rotor blades with a row of swirl recovery stators, also known as swirl recovery stator blades, and the two rows of blades together generate forward thrust. The single-row rotor configuration is relatively simple and compact, and the rear row of stators has the potential to reduce interference noise and eliminate stator load noise.

[0042] At present, noise reduction measures mainly rely on the reasonable selection of aerodynamic design parameters to suppress noise, that is, the reasonable selection of parameters such as the ratio of the number of front and rear blades, the diameter ratio and the axial distance to reduce noise. Bionic noise reduction technology also has a certain noise reduction effect academically and theoretically, but this noise reduction method often changes the shape of the blade and affects the aerodynamic performance of the blade.

[0043] The noise reduction vanes disclosed in the present disclosure can achieve effective noise attenuation without substantially affecting aerodynamic performance. Figures 2 to 5 As shown, the noise reduction stator blade 10 includes a blade body shell 11 and a cavity 12 , and also includes a first through hole 13 , a porous plate 14 and a first type of resonance cavity layer 15 .

[0044] The first through hole 13 is arranged on the blade airfoil shell 11 . The blade airfoil shell 11 includes a pressure surface 115 and a suction surface 116 . The first through hole 13 is arranged on the pressure surface 115 and the suction surface 116 , and serves as a microchannel for noise to enter the interior of the blade.

[0045] Preferably, the first through hole 13 is a micro hole with a relatively small diameter, ranging from 1 mm to 2 mm, and can attenuate noise by utilizing the viscosity of the micro hole.

[0046] The porous plate 14 is disposed in the cavity 12, and is preferably an airfoil structure, on which a plurality of second through holes 140 are disposed. The first type resonance cavity layer 15 is disposed between the airfoil shell 11 and the porous plate 14, and includes a plurality of first type resonance cavities 150, each of which is respectively connected to a first through hole 13 on the airfoil shell 11 and a second through hole 140 on the porous plate 14. It can be understood that the circumferential direction of the first type resonance cavity 150 connected to the first through hole 13 is substantially perpendicular to the airfoil shell region where the first through hole 13 is located. Since the airfoil shell 11 is a curved surface, the first type resonance cavity 150 in the first type resonance cavity layer 15 has different extension directions.

[0047] Specific structure such as Figure 5 As shown, a first type of resonant cavity layer 15 is provided between the blade body shell 11 with the first through hole 13 on the upper side and the porous plate 14 in the blade body cavity. When noise enters through the first through hole 13, it is attenuated by these first type of resonant cavities 150. This is because after the noise enters the resonant cavity, it can significantly dissipate energy through up and down resonance in it, thereby achieving the purpose of noise reduction.

[0048] Preferably, the noise reduction stator comprises a multi-layer porous plate 14, such as Figure 4 The three-layer airfoil porous plates 14, 14', 14" shown in the figure further include one or more layers of second-type resonance cavity layers 17 arranged between adjacent porous plates 14. Each layer of second-type resonance cavity layer 17 includes a plurality of second-type resonance cavities 170 distributed in an array, and the second-type resonance cavities 170 are respectively connected to the second through holes 140 on two adjacent porous plates 14.

[0049] That is, multiple layers of airfoil curved acoustic lining are arranged inside the blade, and one or more layers of second type resonance cavity layer 17 are designed behind the first type resonance cavity layer 15 to facilitate the entry of noise into the second type resonance cavity 170 and attenuate the entering noise by multiple layers.

[0050] The first type resonant cavity 150 and / or the second type resonant cavity 170 are hexagonal or / and quadrilateral or / and circular resonant cavities.

[0051] Furthermore, in some embodiments, the spacing between at least some layers of the porous plates 14 is set to be unequal, so that the lengths of the second type resonance cavities 170 of different layers are different, so that the multi-layer resonance cavities inside the blade form a series of resonance cavities with different heights. Since the resonance height is related to the sound absorption frequency, the structure can absorb a variety of noise frequencies and has a broadband sound absorption effect.

[0052] Reference Figure 2 and Figure 3 As shown, the noise reduction stator blade also includes a radial support rod 18 located in the cavity 12 to support the entire stator blade. The porous medium 19 is arranged in the innermost porous plate 14 of the cavity and is arranged around the radial support rod 18. The porous medium material is filled around the middle support rod, and when a small amount of noise enters the central area of ​​the stator blade, it can be absorbed by the porous medium 19, further achieving the effect of attenuating noise.

[0053] Therefore, the above-mentioned noise reduction stators solve the problem of single sound absorption measures in traditional noise reduction schemes, and provide multiple noise attenuation paths of internal multi-layer airfoil curved surface sound lining and internal porous medium. The internal multi-layer airfoil curved surface sound lining and internal porous medium can absorb noise of different frequencies respectively, further widening the sound absorption frequency band, thereby maximizing the purpose of multiple noise attenuation.

[0054] Specifically, the above-mentioned blade structure achieves sound absorption in three ways: first, the viscosity of the small holes on the surface of the stator blade shell can directly attenuate part of the noise; second, the resonance cavity contained in the internal multi-layer airfoil perforated plate sound lining can further absorb noise of different frequencies; third, when a small amount of noise enters the central area of ​​the stator blade, it is absorbed by the internal porous medium material, thereby utilizing the three structures to maximize the effect of multiple noise attenuation.

[0055] In addition, this design does not modify the geometric shape of the rotor and stator blades, but only opens micro holes on the surface of the blade body. Therefore, it can significantly reduce the impact on the aerodynamic performance of the blade while ensuring the noise attenuation effect.

[0056] In combination with the introduction to the above-mentioned noise reduction stator blades, it can also be understood that an open rotor engine including the noise reduction stator blades has a better noise reduction effect.

[0057] It should be noted that the above content uses words such as "first" and "second" to limit components, which is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0058] At the same time, 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 more 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.

[0059] 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 noise reduction stator blade, characterized in that: It includes the blade body shell and the cavity, and also includes: A first through hole is provided on the blade body shell; A porous plate, disposed in the cavity, and having a plurality of second through holes; The first type of resonance cavity layer is arranged between the blade body shell and the porous plate, and includes a plurality of first type of resonance cavities, each of which is connected to a first through hole on the blade body shell and a second through hole on the porous plate.

2. The noise reduction stator according to claim 1, characterized in that: The noise reduction stator includes multiple layers of porous plates and one or more layers of second-type resonance cavity layers. The second-type resonance cavity layers are arranged between adjacent porous plates and include multiple second-type resonance cavities. The second-type resonance cavities are respectively connected to the second through holes on two adjacent porous plates.

3. The noise reduction stator according to claim 1, characterized in that: The spacings between at least some of the porous plates are arranged to be unequal.

4. The noise reduction stator according to claim 2, characterized in that: The noise reduction stator blade also includes a radial support rod located in the cavity.

5. The noise reduction stator according to claim 4, characterized in that: The noise reduction stator also includes a porous medium, which is arranged in the innermost porous plate and surrounds the radial support rod.

6. The noise reduction stator according to claim 2, characterized in that: The first type of resonant cavity and / or the second type of resonant cavity is a hexagonal or / and quadrilateral or / and circular resonant cavity.

7. The noise reduction stator according to claim 1, characterized in that: The blade airfoil shell comprises a pressure surface and a suction surface, and the first through hole is arranged on the pressure surface and the suction surface.

8. The noise reduction stator according to claim 1, characterized in that: The diameter of the first through hole ranges from 1 to 2 mm.

9. The noise reduction stator according to claim 1, characterized in that: The porous plate is an airfoil porous plate.

10. An open rotor engine, characterized in that: Comprising the noise reduction stator blade as described in any one of claims 1-9.

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