Guide vane and turbofan engine comprising it

Abstract

The application discloses a guide stator blade and a turbofan engine comprising the same. The outer surface of the guide stator blade is in an arc structure, and a plurality of first perforations are arranged on the outer surface of the guide stator blade. When the guide stator blade is applied to the turbofan engine, the wake shed by the rotation of the upstream fan rotor hits the outer channel guide stator blade, and due to the arc structure of the stator blade surface, the airflow can move downstream along the surface, the noise can enter the first perforations of the arc surface, the first perforations increase the air damping to attenuate the noise, thus the smoothing airflow and noise reduction problems can be solved, and the first layer of noise reduction effect is realized. Compared with the prior art, the scheme has the advantages of simple structure and better noise reduction effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of turbofan engines, in particular to a guide vane and a turbofan engine comprising the same. BACKGROUND

[0002] The main noise sources of civil aircraft include engine noise, airframe noise, and interference noise between power system and airframe. Among them, engine noise includes fan noise, jet noise, turbine noise and core noise. Airframe noise includes noise of high-lift devices, noise of landing gear and interference noise between power system and airframe.

[0003] For modern high-bypass-ratio turbofan engines, fan noise is the main noise source, which radiates forward through the inlet duct and radiates backward through the outer bypass duct. The noise produced by the fan can be mainly divided into three parts:

[0004] (1) Pure tone, which is composed of blade passing frequency (BPF) tone and its harmonics. Pure tone has two generation mechanisms: rotor-generated noise and rotor-stator interaction-generated noise. In rotor tone, noise generation is related to blade load and thickness. The acoustic field generated by the rotor rotates at the same speed as the fan. In rotor-stator interaction, noise is generated by the interaction between the trailing vortex of the rotor blade and the downstream stator blade;

[0005] (2) Shaft order tone, i.e. sawtooth noise occurring at the shaft rotation frequency, also known as multiple tones. Sawtooth noise is essentially a shock noise, which is only generated when the blade tip reaches supersonic speed. At supersonic fan tip speed, due to the difference in blade installation angle between the blade and the blade, sawtooth tone is generated at the shaft rotation frequency.

[0006] (3) Broadband noise, which is mainly generated by random turbulent disturbances interacting with the fan surface.

[0007] Among them, fan noise is the main noise source of modern aircraft engine overflight and approach phase. For aircraft engine fan noise, the main noise components include rotor-stator interference tone, multiple tone shock noise and broadband noise. Among them, as one of the main components of fan noise, fan rotor-stator interference tone is a discrete noise generated by the mutual interference of fan rotor and stator.

[0008] Rotor / stator interference noise in high-bypass-ratio turbofan engines mainly includes fan and outlet guide vane interference noise. The physical mechanism of fan / compressor discrete tone noise can be summarized as follows: monopole noise generated by blade volume displacement, dipole noise generated by the steady force of the blade acting on the fluid, and dipole noise generated by the unsteady force of the blade acting on the fluid

[0009] In the prior art, in order to reduce the fan noise, the tip part is offset in the rotation direction of the fan rotor blade on the basis of the position of the outer channel exit stator guide vane, that is, the circumferential positive rake angle of the outer channel exit stator guide vane is increased, so as to optimize the outer channel exit stator guide vane, reduce the noise generated by the fan rotor blade wake sweeping the outer channel exit stator guide vane, and at the same time, the root position of the outer channel exit stator guide vane is fixed, only the root part is inclined in the opposite direction of the rotation direction of the fan rotor blade, so as to ensure that the aerodynamic performance of the fan is not deteriorated. The shape of the outer channel exit stator guide vane in the vertical view of the outer channel axis is generally C-shaped. However, the noise reduction effect in the prior art is relatively limited, and the noise reduction effect is low. SUMMARY

[0010] The technical problem to be solved by the present application is to overcome the above-mentioned defects in the prior art, and to provide a guide stator vane and a turbofan engine comprising the same.

[0011] The present application solves the above technical problems by the following technical solutions:

[0012] A guide stator vane, wherein the outer surface of the guide stator vane is arc-shaped, and a plurality of first perforations are arranged on the outer surface of the guide stator vane.

[0013] In the present application, when the guide stator vane is applied to a turbofan engine, the wake shed by the upstream fan rotor hits the outer channel guide stator vane. Since the surface of the stator vane is arc-shaped, the airflow can move downstream along the surface, and the noise can enter the first perforations of the arc-shaped surface. The first perforations increase air damping to attenuate noise, thus solving the problems of smoothing airflow and noise reduction, and achieving the first layer of noise reduction effect. Compared with the prior art, the present application has a simple structure and better noise reduction effect.

[0014] Preferably, the guide stator vane is internally provided with a plurality of noise reduction devices. Along the span direction, each noise reduction device comprises a plurality of honeycomb assemblies, and each honeycomb assembly comprises a plurality of honeycomb structures arranged at intervals along an extension direction different from the span direction.

[0015] In the present application, when the noise enters the honeycomb cavity, it will be frictioned and attenuated in the honeycomb cavity, thus achieving the second layer of noise reduction effect. The distribution of the honeycomb assemblies divides the interior of the stator guide vane into a plurality of regions, which is conducive to improving the noise reduction effect.

[0016] Preferably, for any one of the honeycomb assemblies, the gap between the adjacent two honeycomb structures is filled with a porous material.

[0017] And / or, the internal pores of at least one of the honeycomb structures are filled with a porous material.

[0018] In the scheme, the porous material has the advantage of sound absorption frequency band width, the gap between the honeycomb structures or the porous material filled in the pores of the honeycomb structures can increase the effective noise reduction bandwidth, and the third layer of noise reduction effect is realized.

[0019] Preferably, the porous material is a foamed metal.

[0020] Preferably, at least one downstream of the honeycomb assembly is provided with a noise reduction plate, and the noise reduction plate is provided with a plurality of second perforations.

[0021] In the scheme, the second perforations on the noise reduction plate have the effect of increasing air damping and attenuating noise. The rear side of the honeycomb structure is designed with a noise reduction plate with perforations, the second perforations continue to attenuate noise and provide a lower channel for noise, and the fourth layer of noise reduction effect is realized.

[0022] Preferably, the noise reduction plate is located between two adjacent honeycomb assemblies.

[0023] Preferably, the noise reduction plate extends in a direction parallel to the extension direction.

[0024] Preferably, the downstream of any one of the honeycomb assemblies is provided with the noise reduction plate.

[0025] Preferably, each noise reduction plate extends from the first layer of the noise reduction device to the last layer of the noise reduction device.

[0026] In the scheme, each noise reduction plate is shared by multiple layers of noise reduction devices, the guide vane blade is easy to form, and the overall stability of the guide vane blade is improved.

[0027] Preferably, the tail of the guide vane blade is provided with a sawtooth structure.

[0028] In the scheme, the sawtooth structure can weaken the tail edge vortex structure, reduce the tail edge noise, and realize the fifth layer of noise reduction effect.

[0029] The application also provides a turbofan engine comprising the guide vane blade.

[0030] On the basis of conforming to the common sense in the art, the above-mentioned preferred conditions can be combined at will, that is, the preferred examples of the application are obtained.

[0031] The positive progress effect of the application is that:

[0032] In this guide stator blade, when applied to a turbofan engine, the wake of the upstream fan rotor hitting the outer bypass guide stator blade allows airflow to move downstream along its curved surface. Noise can enter the first perforation on the curved surface, increasing air damping and attenuating noise. Therefore, this solves the problems of smooth airflow and noise reduction, achieving the first layer of noise reduction. Compared to existing technologies, this solution has a simpler structure and better noise reduction effect. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of a preferred embodiment of the present invention, showing the application of a guide stator blade to a turbofan engine.

[0034] Figure 2 This is a schematic diagram of the internal structure of a guide stator blade according to a preferred embodiment of the present invention.

[0035] Figure 3 This is a three-dimensional structural diagram of a guide stator blade according to a preferred embodiment of the present invention.

[0036] Explanation of reference numerals in the attached figures:

[0037] 10 guide stator blades

[0038] 20 fan rotor blades

[0039] 30 curved panel

[0040] 301 First Perforation

[0041] 40 honeycomb structure

[0042] 50 porous materials

[0043] 60 noise reduction panels

[0044] 70 serrated structure Detailed Implementation

[0045] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments.

[0046] like Figures 1-3 As shown, this embodiment discloses a flow guide stator blade 10. The outer surface of the flow guide stator blade 10 has an arc-shaped structure, and a plurality of first perforations 301 are provided on the outer surface of the flow guide stator blade 10.

[0047] In the embodiment, when the guide vane 10 is applied to a turbofan engine, the rotating wake shed by the upstream fan rotor blade 20 hits the outer bypass guide vane 10, and the airflow can move downstream along the arc-shaped surface of the guide vane 10, the noise can enter the first perforations 301 on the arc-shaped surface, the first perforations 301 increase the air damping to attenuate the noise, thus solving the problems of smoothing the airflow and reducing the noise, and achieving the first layer of noise reduction effect. Compared with the prior art, the scheme has the advantages of simple structure and good noise reduction effect.

[0048] It should be noted that, as shown in Figures 2-3 , the first perforations 301 are schematically and randomly distributed in the circumferential direction.

[0049] As shown in Figures 2-3 , along the spanwise direction, the guide vane 10 is internally provided with a plurality of honeycomb assemblies, and each honeycomb assembly includes a plurality of honeycomb structures 40 arranged in an extension direction different from the spanwise direction.

[0050] Wherein, after the noise enters the honeycomb cavity, it will be attenuated by friction and in the honeycomb cavity, and the second layer of noise reduction effect can be achieved. The distribution of the honeycomb assembly divides the interior of the guide vane into multiple regions, which is conducive to improving the noise reduction effect.

[0051] As shown in Figures 2-3 , for any honeycomb assembly, the gap between the adjacent two honeycomb structures 40 is filled with a porous material 50, and the internal pores of at least one honeycomb structure 40 are filled with a porous material 50.

[0052] Wherein, the porous material 50 has the advantage of wide sound absorption frequency band, and filling the gap between the honeycomb structures 40 or the pores of the honeycomb structure with the porous material 50 can increase the effective noise reduction bandwidth, and achieve the third layer of noise reduction effect.

[0053] It should be noted that, in alternative embodiments, the gap between the adjacent two honeycomb structures 40 can be filled with a porous material only, and the internal pores of at least one honeycomb structure 40 can be filled with a porous material only. In addition, it should be noted that, in the present embodiment, the porous material filled in the gap between the adjacent two honeycomb structures 40 and the porous material filled in the internal pores of at least one honeycomb structure 40 can be the same or different materials.

[0054] Specifically, as an illustrative embodiment, in the present embodiment, the filled porous material 50 is all foamed metal.

[0055] As shown in Figures 2-3 , the downstream of at least one of the honeycomb assemblies is provided with a noise reduction plate 60, and the noise reduction plate is provided with a plurality of second perforations.

[0056] The second perforation on the noise reduction plate 60 increases air damping and attenuates noise. The rear side of the honeycomb structure 40 is designed with a perforated noise reduction plate 60, which utilizes the second perforation to further attenuate noise and provide a lower-level channel for noise, thus achieving a fourth layer of noise reduction.

[0057] Furthermore, the noise reduction plate 60 is located between two adjacent cell modules. The noise reduction plate extends in a direction parallel to the aforementioned extension direction. As an illustrative embodiment, the noise reduction plate 60 is provided downstream of any cell module.

[0058] In a preferred embodiment, each noise reduction plate 60 extends from the first noise reduction device in the multi-layer noise reduction device to the last noise reduction device.

[0059] Each noise reduction plate 60 is shared by multiple noise reduction devices, making the flow guide stator blade 10 easy to form and improving the overall stability of the flow guide stator blade 10.

[0060] It should be noted that, Figure 2 and Figure 3 The diagram schematically illustrates a cellular component, wherein a cellular structure 40 of multiple cellular components at the same height along the aforementioned extending direction can be formed as a single integral structure or as multiple discrete cellular structures. Furthermore, it should be noted that... Figure 2 and Figure 3 The two honeycomb structures 40 are only schematically indicated by the reference numeral 40 in the attached drawing. In reality, Figure 2 and Figure 3 The short and medium-sized tubular structures are all honeycomb structures 40. Similarly, the noise reduction plate 60 and the porous material 50 are only schematically shown with reference numerals 60 and 50, respectively.

[0061] It should be noted that, in addition to the second perforation, the noise reduction plate 60 also has connection holes for connecting to the honeycomb structure 40 or through holes for the honeycomb structure 40 to pass through (not shown in the figure). Specifically, if the multiple honeycomb structures 40 along the blade span direction are a single unit, the noise reduction plate 60 has through holes for the single structural member composed of multiple honeycomb structures 40 to pass through; if the multiple honeycomb structures along the blade span direction are separate structures, the noise reduction plate 60 also has connection holes for connecting to the honeycomb structure 40.

[0062] In addition, such as Figures 2-3 As shown, the tail of the guide stator blade 10 is provided with a serrated structure 70.

[0063] Among them, the sawtooth structure 70 can weaken the trailing edge vortex structure, reduce trailing edge noise, and achieve the fifth layer of noise reduction.

[0064] The embodiment also provides a turbofan engine, which comprises the above-mentioned guide vane 10.

[0065] In the turbofan engine, the first to fifth layers of the stator guide vanes 10 are matched to reduce noise, so that a better noise reduction effect can be achieved without affecting the fan aerodynamic, structural and weight performance.

[0066] Although the specific embodiments of the present application are described above, those skilled in the art should understand that this is only an example, and the protection scope of the present application is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present application, and these changes and modifications all fall within the protection scope of the present application.

Claims

1. A guide vane for a flow guide stator, characterized in that An outer surface of the guide vane is arc-shaped, and the outer surface of the guide vane is provided with a plurality of first perforations; The guide vane is internally provided with a plurality of layers of noise reduction devices, along a blade span direction, each layer of the noise reduction devices comprises a plurality of honeycomb assemblies, and each honeycomb assembly comprises a plurality of honeycomb structures which are spaced apart along an extension direction different from the blade span direction; At least one of the honeycomb assemblies is downstream provided with a noise reduction plate, and the noise reduction plate is provided with a plurality of second perforations.

2. The guide vane of claim 1, wherein For any one of the honeycomb assemblies, a gap between two adjacent honeycomb structures is filled with a porous material. And / or, an internal pore of at least one of the honeycomb structures is filled with a porous material.

3. The guide vane of claim 2, wherein The porous material is a foam metal.

4. The guide vane of claim 1, wherein The noise reduction plate is located between two adjacent honeycomb assemblies.

5. The guide vane of claim 1 wherein, The noise reduction plate extends along a direction parallel to the extension direction.

6. The guide vane of claim 1, wherein Any one of the honeycomb assemblies is downstream provided with the noise reduction plate.

7. The guide vane of claim 1 wherein, Each noise reduction plate extends from a first layer of the noise reduction devices to a last layer of the noise reduction devices in the plurality of layers of the noise reduction devices.

8. The guide vane of any one of claims 1-7, wherein, A tail portion of the guide vane is provided with a sawtooth structure.

9. A turbofan engine characterized by, The guide vane comprises the guide vane according to any one of claims 1-8.

Images