Guide vane assembly and turbofan engine comprising it

Abstract

The application discloses a guide stator vane assembly and a turbofan engine comprising the same. The guide stator vane assembly comprises a guide stator vane and an air guide device arranged upstream of the guide stator vane. The guide stator vane is internally provided with a plurality of exhaust ducts. The air guide device is in communication with the plurality of exhaust ducts. The leading edge of the guide stator vane is provided with a plurality of perforations in communication with the exhaust ducts. When the guide stator vane assembly is applied to the turbofan engine, the air guide device can realize air guiding. Under the action of the air guide device, when the wake shed by the upstream fan rotor rotation approaches the guide stator vane, the airflow from the air guide device can blow the wake apart or scatter the wake, so as to reduce the intensity of the wake impacting the stator, thereby reducing the interference noise of the rotor and the stator. The airflow compression device can pressurize the airflow, which is conducive to forming the leading edge of the guide stator vane into a micro jet with high intensity, and further reducing the interference noise of the rotor and the stator.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of turbofan engines, in particular to a guide vane assembly 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 sound field generated by the rotor will rotate 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, which is the 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 and blade installation angle, 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 interaction tone, multiple tone shock noise and broadband noise. Among them, as one of the main components of fan noise, fan rotor-stator interaction tone is a discrete noise generated by the interaction of fan rotor and stator.

[0008] Rotor / stator interaction noise in high-bypass-ratio turbofan engines mainly includes fan and outlet guide vane interaction 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 outlet stator guide vane, that is, the circumferential positive rake angle of the outer channel outlet stator guide vane is increased to optimize the outer channel outlet stator guide vane, reduce the noise generated by the fan rotor blade wake sweeping the outer channel outlet stator guide vane, and at the same time, the root position of the outer channel outlet stator guide vane is fixed, only the blade 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 outlet 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 flow guide stator vane assembly and a turbofan engine comprising the same.

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

[0012] A flow guide stator vane assembly, comprising a flow guide stator vane and an air induction device, the air induction device is arranged upstream of the flow guide stator vane, the flow guide stator vane is internally provided with a plurality of exhaust pipes, the air induction device is in communication with the plurality of exhaust pipes, and the leading edge of the flow guide stator vane is provided with a plurality of perforations, the perforations are in communication with the exhaust pipes.

[0013] In the present application, when the flow guide stator vane assembly is applied to a turbofan engine, the air induction device can realize air induction. Under the action of the air induction device, when the wake shed by the upstream fan rotor rotation approaches the flow guide stator vane, the airflow from the air induction device will blow away or scatter the wake, which can reduce the intensity of the wake impacting the stator, thereby reducing the rotor and stator interference noise.

[0014] Preferably, the flow guide stator assembly further comprises an airflow compression device for compressing the airflow, and the airflow compression device is located between the air induction device and the exhaust pipe in the flow direction of the airflow.

[0015] In the present application, the airflow compression device can pressurize the airflow, which is conducive to forming a high-intensity microjet at the leading edge of the flow guide stator vane, and is more conducive to scattering the wake of the fan rotor, dispersing large-scale vortices into small-scale vortices, and further reducing the intensity of the wake impacting the stator, thereby further reducing the rotor and stator interference noise.

[0016] Preferably, the airflow compression device is arranged at the end of the air induction device, or the airflow compression device is arranged adjacent to the end of the air induction device.

[0017] In the scheme, the air flow compression device is close to the bleed air device, so that the air flow from the bleed air device can be compressed quickly and reliably, which is beneficial to ensure the noise reduction effect.

[0018] Preferably, the bleed air device comprises a bleed air pipe, which has a first end and a second end along the flow direction of the air flow, and the air flow compression device is connected to the second end of the bleed air pipe.

[0019] Alternatively, the air flow compression device is arranged in the bleed air pipe and close to the second end of the bleed air pipe.

[0020] In the scheme, the structure of the bleed air device is simple, which is beneficial to simplify the overall structure of the guide vane blade assembly and reduce the cost of noise reduction.

[0021] Preferably, the cross-sectional size of the second end of the bleed air pipe is smaller than the cross-sectional size of the first end of the bleed air pipe.

[0022] In the scheme, the air flow is compressed to a certain extent during the process of being guided by the bleed air pipe, which is beneficial to the strength of the air flow ejected from the outlet of the bleed air pipe, and further beneficial to reliably blow away the wake of the fan rotor.

[0023] Preferably, the bleed air pipe is a bent structure and has a first connecting pipe and a second connecting pipe connected in series, the first connecting pipe corresponds to the first end of the bleed air pipe, and the second connecting pipe corresponds to the second end of the bleed air pipe.

[0024] In the scheme, on the one hand, it is convenient to guide the air flow; on the other hand, a larger air flow flow path can be realized on the basis of occupying less space, which is further beneficial to ensure the strength of the air flow ejected from the outlet of the bleed air device.

[0025] Preferably, the cross-sectional size of the second connecting pipe gradually decreases along the flow direction of the air flow.

[0026] Preferably, the air flow compression device comprises a micro vortex compressor.

[0027] In the scheme, the micro scroll compressor is a compressor with a fixed involute scroll rotating disc and an involute moving scroll disc rotating eccentrically and presenting a compression volume. The scroll compressor is novel and precise in structure, and has the advantages of small volume, low noise, light weight, small vibration, small energy consumption, long service life, continuous and smooth gas transmission, reliable operation, clean gas source and the like. The working principle of the scroll compressor is that the scroll compressor is formed by the mutual engagement of two double-function equation type lines of dynamic and static vortex discs. The gas is sucked into the periphery of the static disc through the air filter, and with the rotation of the eccentric shaft, the gas is gradually compressed in the compression cavity, and then continuously discharged through the axial hole of the central part of the static disc.

[0028] Preferably, the inside of the guide vane is provided with multiple layers of the exhaust pipe, each layer of the exhaust pipe comprises multiple exhaust pipes, and the multiple exhaust pipes of each layer are distributed on a sector surface.

[0029] In the scheme, multiple layers of exhaust pipes are provided, and each layer of exhaust pipes also has multiple exhaust pipes. The arrangement of these exhaust pipes is conducive to the flow of air flow and conducive to improving the noise reduction effect.

[0030] Preferably, the bottom of each layer of the multiple exhaust pipes is provided with a support plate.

[0031] In the scheme, the support plate mainly supports the multiple exhaust pipes located thereon, which is conducive to ensuring the stability of the exhaust pipes, thereby improving the reliability of noise reduction.

[0032] Preferably, the inside of the guide vane is provided with a main pipe, the first end of each layer of the multiple exhaust pipes is connected and communicated with the main pipe, and the tail end extends towards the inner wall of the guide vane. The main pipe is communicated with the air guide device.

[0033] In the scheme, the air flow from the air guide device flows into the main pipe, and then flows into the corresponding multiple exhaust pipes of each layer from the main pipe, and then flows out through the perforations of the leading edge of the guide vane.

[0034] Preferably, the tail end of each exhaust pipe extends to the arc-shaped edge of the guide vane at most;

[0035] Or, the length of the exhaust pipe extending out of the arc-shaped edge is not greater than 5mm.

[0036] In the scheme, if the length of the exhaust pipe extending out of the arc-shaped edge is too long, it will easily affect the flow of the surrounding air flow, and will generate larger noise, affecting the noise reduction effect.

[0037] Preferably, the trailing edge of the guide vane is provided with a noise reduction structure made of a porous medium.

[0038] In the scheme, the fan rotor wake and large-scale vortex are blown by the leading edge blowing effect, the wake continues to act on the trailing edge along the chord direction of the blade, is absorbed and dissipated by the porous medium material, and noise reduction can be further performed.

[0039] The application further provides a turbofan engine comprising a fan and the above-mentioned guide vane assembly, the guide vane assembly being located downstream of the fan, the air bleeding device being located between the fan and the guide vane assembly, and the air bleeding device extending into the outer channel near one end of the fan.

[0040] On the basis of common sense in the art, the above-mentioned preferred conditions can be combined arbitrarily, that is, each preferred example of the application is obtained.

[0041] The positive progress effect of the application is that:

[0042] In the guide vane assembly, when the guide vane assembly is applied to a turbofan engine, the air bleeding device can bleed air, under the action of the air bleeding device, the wake shed by the upstream fan rotor when approaching the guide vane will be blown away or scattered by the airflow from the air bleeding device, the large-scale vortex will be scattered into small-scale vortex, the intensity of the wake hitting the stator can be reduced, and thus the interference noise of the rotor and the stator can be reduced. Compared with the prior art, the scheme has simple structure and better noise reduction effect.

[0043] The airflow compression device can pressurize the airflow, which is conducive to forming the leading edge part of the guide vane with high-intensity microjet, and is more conducive to blowing away the wake of the fan rotor, scattering the large-scale vortex into small-scale vortex, and further reducing the intensity of the wake hitting the stator, so as to further reduce the interference noise of the rotor and the stator.

[0044] The fan rotor wake and large-scale vortex are blown by the leading edge blowing effect, the wake continues to act on the trailing edge along the chord direction of the blade, is absorbed and dissipated by the porous medium material, and noise reduction can be further performed. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 The structure schematic view of the guide vane applied to the turbofan engine of the preferred embodiment of the application.

[0046] Figure 2 The internal structure schematic view of the guide vane of the preferred embodiment of the application.

[0047] Figure 3 The another internal structure schematic view of the guide vane of the preferred embodiment of the application.

[0048] Figure 4 The three-dimensional structure schematic view of the guide vane of the preferred embodiment of the application.

[0049] Reference signs:

[0050] 10 guide vane

[0051] 101 perforation

[0052] 102 noise reduction structure

[0053] 20 fan rotor blade

[0054] 30 bleed air device

[0055] 301 first connecting pipe

[0056] 302 second connecting pipe

[0057] 40 air flow compression device

[0058] 50 air discharge pipe

[0059] 60 large scale vortex

[0060] 70 small scale vortex

[0061] 80 main pipe DETAILED DESCRIPTION

[0062] The present application will be further described by way of example with reference to the accompanying drawings.

[0063] As shown in the drawings, Figures 1-4 the present embodiment discloses a guide vane assembly, which comprises a guide vane 10 and a bleed air device 30 arranged upstream of the guide vane 10, the guide vane 10 is internally provided with a plurality of air discharge pipes 50, the bleed air device 30 is in communication with the plurality of air discharge pipes 50, the leading edge of the guide vane 10 is provided with a plurality of perforations 101, and the perforations 101 are in communication with the air discharge pipes 50.

[0064] In the present embodiment, when the guide vane assembly is applied to a turbofan engine, the bleed air device 30 can realize bleed air, under the action of the bleed air device 30, when the wake shed by the upstream fan rotor rotating approaches the guide vane 10, the air flow from the bleed air device 30 can blow open or scatter the wake, which can reduce the intensity of the wake impacting the stator, thereby reducing the interference noise of the rotor and the stator.

[0065] In a preferred embodiment, the guide vane assembly further comprises an air flow compression device 40 for compressing air flow, and the air flow compression device 40 is located between the bleed air device 30 and the air discharge pipe 50 along the flow direction of the air flow.

[0066] The airflow compression device 40 can pressurize the airflow, which is conducive to forming a high-intensity microjet at the leading edge of the guide vane 10, and is more conducive to dispersing the wake of the fan rotor and breaking up the large-scale vortex 60 into small-scale vortexes 70, thereby further reducing the intensity of the wake hitting the stator, so as to further reduce the interference noise of the rotor and the stator.

[0067] In another preferred embodiment, the airflow compression device 40 is arranged at the end of the bleed air device 30, or the airflow compression device 40 is arranged adjacent to the end of the bleed air device 30.

[0068] The airflow compression device 40 is close to the bleed air device 30, which can quickly and reliably compress the airflow from the bleed air device 30, and is conducive to ensuring the noise reduction effect.

[0069] As shown in Figure 1 The bleed air device 30 includes a bleed air pipe, which has a first end and a second end along the flow direction of the airflow, and the airflow compression device 40 is connected to the second end of the bleed air pipe.

[0070] Alternatively, the airflow compression device 40 is arranged in the bleed air pipe and close to the second end of the bleed air pipe.

[0071] The structure of the bleed air device 30 is relatively simple, which is conducive to simplifying the overall structure of the guide vane assembly and reducing the noise reduction cost.

[0072] As a preferred embodiment, the cross-sectional size of the second end of the bleed air pipe is smaller than the cross-sectional size of the first end of the bleed air pipe.

[0073] The airflow is compressed to a certain extent during the process of being guided by the bleed air pipe, which is conducive to the strength of the airflow sprayed from the outlet of the bleed air pipe, and further conducive to reliably dispersing the wake of the fan rotor.

[0074] As shown in Figure 1 The bleed air pipe is a bent structure and has a first connecting pipe 301 and a second connecting pipe 302 connected in series, the first connecting pipe 301 corresponds to the first end of the bleed air pipe, and the second connecting pipe 302 corresponds to the second end of the bleed air pipe. On the one hand, the above structure is conducive to guiding the airflow; on the other hand, a large airflow flow path can be realized on the basis of occupying less space, which is conducive to ensuring the strength of the airflow sprayed from the outlet of the bleed air device 30.

[0075] As another preferred embodiment, the cross-sectional size of the second connecting pipe 302 gradually decreases along the flow direction of the airflow.

[0076] In this embodiment, the airflow compression device 40 includes a micro-vortex compressor.

[0077] The micro scroll compressor is a compressor with a fixed involute scroll orbiting disk and an involute moving scroll disk that rotates eccentrically and has a compressible volume. The scroll compressor has the advantages of novel and precise structure, small size, low noise, light weight, small vibration, small energy consumption, long service life, continuous and stable gas transmission, reliable operation, clean gas source, etc. The working principle of the scroll compressor is that the scroll compressor is formed by the mutual engagement of two double-function equation type dynamic and static scroll disks. The gas is sucked into the periphery of the static disk through the air filter, and with the rotation of the eccentric shaft, the gas is gradually compressed in the compression chamber, and then continuously discharged through the axial hole of the central part of the static disk.

[0078] It should be noted that the micro scroll compressor in this embodiment is only a schematic air flow compression device 40. In other alternative embodiments, any air flow compression device 40 applicable to this purpose can also be used.

[0079] As shown in Figure 3 and Figure 4 , the inner part of the guide stator blade 10 is provided with multiple layers of exhaust ducts 50, each layer of exhaust ducts 50 includes multiple exhaust ducts 50, and the multiple exhaust ducts 50 of each layer are distributed on a sector surface. Figure 2 One layer of exhaust ducts 50 is schematically shown in Figures 2-4 As shown in , for this layer of exhaust ducts 50, the exhaust ducts 50 located in the middle are relatively long, and the exhaust ducts 50 located on both sides are relatively short.

[0080] Figure 3 and Figure 4 schematically show that each layer of exhaust ducts 50 has 5 exhaust ducts 50. In the top view of the guide stator blade 10, the multiple layers of exhaust ducts 50 overlap. In other alternative embodiments, the number of exhaust ducts 50 in each layer of exhaust ducts 50 can be set to other numbers according to actual design needs.

[0081] In which multiple layers of exhaust ducts 50 are provided, and each layer of exhaust ducts 50 also has multiple exhaust ducts 50. The arrangement of these exhaust ducts is beneficial to the flow of air flow and helps to improve the noise reduction effect.

[0082] In another preferred embodiment, the bottom of each layer of multiple exhaust ducts 50 is provided with a support plate (not shown in the figure). Preferably, the two adjacent layers of exhaust ducts 50 are connected to the top and bottom of the corresponding support plate, respectively.

[0083] The support plate mainly supports the multiple exhaust pipes 50 located thereon, which is beneficial to ensure the stability of the exhaust pipes 50, thereby improving the reliability of noise reduction. The two adjacent layers of exhaust pipes 50 are connected to the top and bottom of the support plate, respectively, which is beneficial to improve the overall stability of the multiple layers of exhaust pipes 50.

[0084] As shown in Figure 3 and Figure 4 The inner part of the guide stator blade is also provided with a main pipe 80. The leading end of the multiple exhaust pipes 50 of each layer is connected and communicated with the main pipe 80, and the trailing end extends towards the inner wall of the guide stator blade 10. The main pipe 80 is in communication with the bleed air device 30.

[0085] In this scheme, the air flow from the bleed air device 30 flows into the main pipe 80, and then flows into the corresponding multiple exhaust pipes 50 of each layer from the main pipe 80, and then flows out through the perforations 101 of the leading edge of the guide stator blade 10.

[0086] In another preferred embodiment, the trailing end of each exhaust pipe 50 extends to the arc-shaped edge of the guide stator blade 10 at most. Or, the length of the exhaust pipe 50 extending out of the arc-shaped edge is not greater than 5 mm.

[0087] If the length of the exhaust pipe 50 extending out of the arc-shaped edge is too long, it will easily affect the flow of the surrounding air flow, and will generate more noise, affecting the noise reduction effect.

[0088] In another preferred embodiment, the trailing edge of the guide stator blade 10 is provided with a noise reduction structure 102 made of porous medium. After the fan rotor wake and large-scale vortex 60 are blown by the leading edge, the wake continues to act on the trailing edge along the chord direction of the blade, and is absorbed and dissipated by the porous medium material, which can further reduce noise. The porous medium can be, but is not limited to, porous foam metal.

[0089] It should be noted that the wider the coverage of the above-mentioned noise reduction structure 102, the better the noise reduction effect, that is, according to the actual noise reduction demand, the noise reduction structure 102 can be filled as much as possible in the inner part of the guide stator blade 10 without affecting the normal use of other structures (such as the exhaust pipe 50).

[0090] The embodiment also provides a turbofan engine, which comprises a fan and the above-mentioned guide stator blade assembly. The guide stator blade assembly is located downstream of the fan. The bleed air device 30 is located between the fan and the guide stator blade 10, and the end of the bleed air device 30 close to the fan extends into the outer channel.

[0091] Although the specific embodiments of the present application have been described above, it is understood by those skilled in the art that the present application is only illustrated by way of example, and the scope of protection of the present application is defined by the appended claims. Those skilled in the art can make various changes or modifications to the embodiments without departing from the principles and essence of the present application, and such changes and modifications fall within the scope of protection of the present application.

Claims

1. A flow guide stator vane assembly, characterized by, The guide vane assembly comprises a guide vane and a bleed air device, the bleed air device is arranged upstream of the guide vane between the fan rotor and the guide vane, the bleed air device comprises a bleed air pipe, along the flow direction of the airflow, the bleed air pipe has a first end and a second end, the first end is located downstream of the fan rotor; The guide vane is internally provided with a plurality of exhaust pipes, the plurality of exhaust pipes of each layer is distributed on a sector surface, the second end of the bleed air pipe of the bleed air device is in communication with the plurality of exhaust pipes, the leading edge of the guide vane is provided with a plurality of perforations, and the perforations are in communication with the exhaust pipes; The trailing edge of the guide vane is provided with a noise reduction structure made of porous medium.

2. The guide vane assembly of claim 1, wherein, The guide vane assembly further comprises an airflow compression device for compressing the airflow, along the flow direction of the airflow, the airflow compression device is located between the bleed air device and the exhaust pipes.

3. The guide vane assembly of claim 2, wherein, The airflow compression device is arranged at the end of the bleed air device, or the airflow compression device is arranged adjacent to the end of the bleed air device.

4. The guide vane assembly of claim 2, wherein, The airflow compression device is connected to the second end of the bleed air pipe. Or, the airflow compression device is arranged in the bleed air pipe and close to the second end of the bleed air pipe.

5. The guide vane assembly of claim 4, wherein, The cross-sectional size of the second end of the bleed air pipe is smaller than the cross-sectional size of the first end of the bleed air pipe.

6. The guide vane assembly of claim 5, wherein, The bleed air pipe is a bent structure and has a first connecting pipe and a second connecting pipe connected in series, the first connecting pipe corresponds to the first end of the bleed air pipe, and the second connecting pipe corresponds to the second end of the bleed air pipe.

7. The guide vane assembly of claim 6, wherein, Along the flow direction of the airflow, the cross-sectional size of the second connecting pipe gradually decreases.

8. The guide vane assembly of claim 2, wherein, The airflow compression device comprises a micro-vortex compressor.

9. The guide vane assembly of claim 1, wherein, The bottom of each layer of the plurality of exhaust pipes is provided with a support plate.

10. The guide vane assembly of claim 1, wherein, The interior of the guide vane is further provided with a main pipe, the leading end of each layer of the plurality of exhaust pipes is connected to and communicated with the main pipe, and the trailing end extends towards the inner wall of the guide vane, and the main pipe is in communication with the bleed air device.

11. The guide vane assembly of claim 10, wherein, The trailing end of each exhaust pipe extends to the arc-shaped edge of the guide vane at most; Or, the exhaust pipe extends out of the arc-shaped edge by a length of not more than 5 mm.

12. A turbofan engine characterized by, It comprises a fan and the guide vane assembly according to any one of claims 1-11, the guide vane assembly is located downstream of the fan, the bleed air device is located between the fan and the guide vane, and the bleed air device extends into the outer channel at one end close to the fan.

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