Open type rotor engine

Abstract

The open rotor engine according to the present invention comprises: a plurality of stator blades mounted on the outside of the open rotor engine; the rotor blades are installed on the outer side of the open type rotor engine and located on the front side of the stator blades, and the rotor blades are fixed to an engine rotating shaft and rotate along with rotation of the engine rotating shaft. A concave-convex model is arranged on the top face of the rotor blade and close to the area of the rear edge side of the rotor blade, and a concave-convex model is arranged on the pressure face or the suction face of the rotor blade and close to the blade root area of the rear edge side of the rotor blade. A concave-convex shape is arranged on the pressure face or the suction face of the rotor blade and is close to the blade top area of the rear edge side of the rotor blade.

Description

Technical Field

[0001] This application relates to an open rotor engine. Background Art

[0002] Aircraft engines usually use ducted turbofan engines. However, in 2021, GE and Safran jointly released a RISE open fan concept. Compared with the conventional ducted turbofan engines, the open rotor engine with this open fan has lower fuel consumption at the same flight speed, so it has become the development direction of future aircraft engines. An open rotor engine is a gas turbine engine that drives a propeller fan to generate thrust through the power turbine output shaft power. It is a new type of engine between turboprop and turbofan, also known as a propeller fan engine or a ducted fanless engine. It can be regarded as an ultra-high bypass ratio turbofan engine without an outer duct, or as a propeller fan engine equipped with high-performance propellers. An open rotor engine mainly consists of a gas generator, a power turbine, a transmission device, and a contra-rotating propeller fan composed of multiple wide-chord, swept, and thin blades. According to the different positions of the propeller fan in the engine, it can be divided into a tractor type and a pusher type. According to the drive method, it can be divided into two categories: gear drive and direct drive.

[0003] The open fan in an open rotor engine is an impeller mechanical system used to generate thrust (or pull) without an outer casing. It is a rotating component between a propeller and a fan, also known as a propeller fan or a ducted fanless. The open fan is the propeller of the open rotor engine. Compared with a propeller, it has a larger cruise Mach number and a higher power per unit area of the propeller disk. It has more blades with smaller diameters than a propeller. The blades are of a swept design and have a reduced thickness, and their appearance is closer to that of a fan. According to the blade row configuration, it can be divided into three typical structures: single-row rotor, double-row contra-rotating, and rotor-stator. The open fan inherits the design characteristics of the front row blades of the open rotor and the principle of energy recovery and efficiency improvement of the rear row blades. The difference is that the rear row blades are no longer designed as rotors but as stator blades, called swirl recovery stator blades. This rotor-stator configuration is called an open fan. In an open rotor engine, the rotor-stator open fan has a row of rotating blades plus a row of swirl recovery stators (rear stator blades). The two rows of blades jointly generate forward thrust, and under high-subsonic cruise conditions, it is equivalent in efficiency to the relative contra-rotating open fan. Moreover, the single-row rotor configuration is more concise and compact, and the rear stator has the potential to reduce interference noise and eliminate stator load noise.

[0004] In recent years, with the further improvement of the requirements for engine economy and the environmental protection requirements of the International Civil Aviation Organization (ICAO), as well as the introduction of more stringent airworthiness regulations, green environmental protection has become the theme of the times. As a kind of propeller between the propeller and the fan, the open rotor engine has experienced great development in the aviation field. The open rotor engine can save 20% - 30% fuel compared with the conventional turbofan engine, showing great potential in energy conservation and becoming one of the potential power options for the next generation of civil aircraft.

[0005] The airworthiness noise requirements put forward by the International Civil Aviation Organization increase year by year. Whether a civil aircraft can meet the strict airworthiness noise requirements has become one of the decisive factors for the product to be put on the market. Therefore, in addition to focusing on high aerodynamic performance, the research on the noise level of the propeller fan has also become very popular.

[0006] Although the open rotor engine has great fuel-saving potential, due to the lack of nacelle shielding outside the propeller fan, its noise is significantly increased compared with the turbofan engine. Whether it can achieve a significant reduction in noise and meet the increasingly stringent airworthiness requirements has become the biggest challenge faced by the open rotor engine. The noise sources of the open rotor engine are very complex. Its maximum noise mainly comes from the counter-rotating propeller fan blades. Although there is a certain broadband noise, the maximum noise generated by the open rotor is mainly tonal noise, including: tip vortex interference tone, viscous wake interference tone, interference tone of the front and rear potential fields, tone of a single rotor, tone of the air inlet angle, and steady-state distortion tone.

[0007] Regarding the noise reduction of the open rotor, a large amount of research work has been done at home and abroad, and a series of measures for optimizing the design to reduce noise have been developed. For example, appropriately reducing the tip speed, optimizing the design of the wide-chord swept thin airfoil, appropriately increasing the number of blades, reasonably selecting parameters such as the number ratio, diameter ratio, and axial distance of the front and rear rows of blades, as well as measures such as blowing the pylon wake, installing acoustic liners on the acoustic reflection surface of the fuselage, and using the acoustic shielding of the fuselage and tail wing can effectively reduce the noise of the open rotor. Summary of the Invention

[0008] Technical Problem to be Solved by the Invention

[0009] Figure 1 The blade structure of the existing open rotor engine is shown. After the front row of rotor blades rotate at high speed, a hub vortex will be formed in the root region and a tip vortex will be formed at the tip. In order to reduce the interference noise between the rotating and stationary blades, the common practice is to (1) increase the spacing between the front row of rotor blades and the rear row of stator blades; (2) reduce the diameter of the stator blades to reduce the contact area between the airflow and the stator blades, thereby reducing the rotor wake acting on the stator blades.

[0010] However, affected by the spatial structure, it is usually very difficult to adjust the spacing between the front-row rotor blades and the rear-row stator blades. Therefore, the conventional method of increasing the distance between the rotor blades and the stator blades cannot be adopted. In addition, if the contact area between the air flow and the stator blades is reduced by reducing the diameter of the stator blades, it is possible that the aerodynamic performance of the open fan cannot meet the flight requirements. Therefore, it is often very difficult to reduce the noise generated on the stator blades while meeting the aerodynamic performance requirements of the blades of the open rotor engine. In order to reduce the noise while minimizing the impact on the fan aerodynamic performance, it is necessary to redesign the front-row rotor blades and the rear-row stator blades.

[0011] The present invention is completed in view of the above problems, and its purpose is to provide an open rotor engine that can fully reduce the noise of the open rotor fan without affecting the thrust and efficiency of the open rotor engine and meet the aerodynamic performance requirements.

[0012] Technical means for solving technical problems

[0013] According to an exemplary embodiment of the present invention, there is provided an open rotor engine, comprising:

[0014] A plurality of stator blades, which are installed on the outer side of the open rotor engine;

[0015] A plurality of rotor blades, which are installed on the outer side of the open rotor engine and are located on the front side of the stator blades. The plurality of rotor blades are fixed on the engine rotating shaft and rotate with the rotation of the engine rotating shaft.

[0016] An uneven shape is provided in a region on the top surface of the rotor blade and near the trailing edge side of the rotor blade.

[0017] An uneven shape is provided in the root region of the pressure surface or the suction surface of the rotor blade and near the trailing edge side of the rotor blade.

[0018] An uneven shape is provided in the tip region of the pressure surface or the suction surface of the rotor blade and near the trailing edge side of the rotor blade.

[0019] Preferably, in the open rotor engine of the above exemplary embodiment,

[0020] The uneven shape on the pressure surface or the suction surface of the rotor blade is provided within a range from the center of the rotor blade to the trailing edge of the rotor blade.

[0021] Preferably, in the open rotor engine of the above exemplary embodiment,

[0022] The uneven shape is provided in a range on the top surface of the rotor blade and at a distance of 30% or less of the rotor blade chord length from the trailing edge of the rotor blade.

[0023] Preferably, in the open rotor engine of the above exemplary embodiment,

[0024] The tip region of the rotor blade is a region on the pressure surface or the suction surface of the rotor blade, from the center of the rotor blade in the air flow direction to the trailing edge of the rotor blade, and at a distance of 10% or less of the rotor blade height from the top surface of the rotor blade.

[0025] Preferably, in the open rotor engine of the above exemplary embodiment,

[0026] The root region of the rotor blade is a region on the pressure surface or the suction surface of the rotor blade, from the center of the rotor blade in the air flow direction to the trailing edge of the rotor blade, and at a distance of 8% or less of the rotor blade height from the bottom surface of the rotor blade.

[0027] Preferably, in the open rotor engine of the above exemplary embodiment,

[0028] An uneven shape is provided in a region on the top surface of the stator blade and near the leading edge side of the stator blade.

[0029] An uneven shape is provided in the root region on the pressure surface or the suction surface of the stator blade and near the leading edge side of the stator blade.

[0030] An uneven shape is provided in the tip region on the pressure surface or the suction surface of the stator blade and near the leading edge side of the stator blade.

[0031] Preferably, in the open rotor engine of the above exemplary embodiment,

[0032] The uneven shape on the pressure surface or the suction surface of the stator blade is provided in a range from the center of the stator blade to the leading edge of the stator blade.

[0033] Preferably, in the open rotor engine of the above exemplary embodiment,

[0034] The uneven shape is provided in a range on the top surface of the stator blade and at a distance of 30% or less of the stator blade chord length from the leading edge of the stator blade.

[0035] Preferably, in the open rotor engine of the above exemplary embodiment,

[0036] The tip region of the stator vane is on the pressure surface or the suction surface of the stator vane, from the center of the stator vane in the air flow direction to the leading edge of the stator vane, and the distance to the top surface of the stator vane is a region below 10% of the stator vane height.

[0037] Preferably, in the open rotor engine of the above exemplary embodiment,

[0038] The root region of the stator vane is on the pressure surface or the suction surface of the stator vane, from the center of the stator vane in the air flow direction to the leading edge of the stator vane, and the distance to the bottom surface of the stator vane is a region below 8% of the stator vane height.

[0039] Preferably, in the open rotor engine of the above exemplary embodiment,

[0040] The concave-convex shape is a sphere protruding outward on the blade surface.

[0041] Preferably, in the open rotor engine of the above exemplary embodiment,

[0042] The spherical arc length of the sphere is an integer multiple of a quarter wavelength of the harmonic frequency noise generated on the stator vane.

[0043] Preferably, in the open rotor engine of the above exemplary embodiment,

[0044] The diameter of the concave-convex shape is in the range of 2 mm to 10 mm, and the distance between the concave-convex shapes is in the range of 4 mm to 8 mm.

[0045] Preferably, in the open rotor engine of the above exemplary embodiment,

[0046] The concave-convex shape is a wake controller composed of two protrusions on the blade surface with an airfoil streamline shape, and a channel that gradually widens from the side near the leading edge of the rotor blade to the side near the trailing edge of the stator vane is formed in the wake controller.

[0047] Preferably, in the open rotor engine of the above exemplary embodiment,

[0048] The width of the narrowest part of the channel is 50% of the chord length of the wake controller, and the width of the widest part of the channel is 150% of the chord length of the wake controller.

[0049] Preferably, in the open rotor engine of the above exemplary embodiment,

[0050] The height of the wake controller ranges from 5 mm to 9 mm, the length along the airflow direction ranges from 8 mm to 12 mm, and the chord length of the wake controller ranges from 6 mm to 12 mm.

[0051] Advantages of the Invention

[0052] According to the present invention, an open rotor engine can be provided, which can sufficiently reduce the noise of the open rotor fan without affecting the thrust and efficiency of the open rotor engine and meet the aerodynamic performance requirements.

[0053] Specifically,

[0054] 1. The present invention solves the problem of how to effectively control the blade noise sources. By providing concave-convex shapes on the top surface, tip region, and root region of the front row blades, the present invention promotes the airflow exchange and mixing between the pressure surface and the suction surface, suppresses the formation of trailing edge shedding vortices and tip vortices of the front row blades, and can effectively control these two blade noise sources.

[0055] 2. The present invention solves the problem of how to reduce the interference effect between the front and rear row blades. After the shedding vortices and tip vortices are weakened by the concave-convex shapes of the front row blades, some of the shedding vortices and tip vortices will impact the surface of the rear row blades. By providing concave-convex shapes on the top surface, pressure surface, and suction surface near the leading edge of the rear row blades, the intensity of the shedding vortices or wakes from the front row blades impacting the surface of the rear row blades can be further reduced, achieving a secondary noise reduction effect.

[0056] Other features and aspects will become clear through the following detailed description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The present invention can be better understood by describing exemplary embodiments of the present invention in conjunction with the accompanying drawings, in which:

[0058] Figure 1 Shows a schematic structural diagram of the blades of an existing open rotor engine.

[0059] Figure 2 Shows a schematic structural diagram of the rotor blades and stator blades of the open rotor engine according to Embodiment 1 of the present invention.

[0060] Figure 3 Shows a schematic diagram of the concave-convex shapes of the open rotor engine according to Embodiment 1 of the present invention.

[0061] Figure 4 Shows a schematic structural diagram of the blades of the open rotor engine according to Embodiment 1 of the present invention.

[0062] Figure 5Shows a schematic diagram of the wake controller of the open rotor engine involved in Embodiment 1 of the present invention. Detailed implementation manners

[0063] The following will describe the detailed implementation manners of the present invention. It should be noted that in the specific description process of these implementation manners, for the sake of concise description, this specification cannot describe all features of the actual implementation manners in detail. It should be understood that in the actual implementation process of any implementation manner, just as in the process of any engineering project or design project, in order to achieve the specific goals of the developer and to meet system-related or business-related restrictions, various specific decisions are often made, and these will also change from one implementation manner to another. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for those of ordinary skill in the art related to the content disclosed in the present invention, some design, manufacturing or production changes based on the technical content disclosed in this disclosure are just conventional technical means and should not be understood as the content of this disclosure being insufficient.

[0064] Unless otherwise defined, the technical terms or scientific terms used in the claims and the specification should have the ordinary meaning understood by those of ordinary skill in the technical field to which the present invention belongs. The "first", "second" and similar terms used in the specification and claims of this patent application do not indicate any order, quantity or importance, but are only used to distinguish different components. The terms such as "a" or "an" do not indicate a quantity limitation, but indicate that there is at least one. The terms such as "comprising" or "including" mean that the elements or objects appearing before "comprising" or "including" cover the elements or objects listed after "comprising" or "including" and their equivalent elements, and do not exclude other elements or objects. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, nor are they limited to direct or indirect connections.

[0065] Embodiment 1

[0066] Figure 2 Shows a schematic diagram of the structure of the rotor blades and stator blades of the open rotor engine involved in Embodiment 1 of the present invention. Figure 3 Shows a schematic diagram of the concave-convex shape of the open rotor engine involved in Embodiment 1 of the present invention.

[0067] As Figure 2As shown in the figure, the open rotor engine of this embodiment successively includes, from upstream to downstream, along the direction of gas flow inside the open rotor engine (the air flow direction is indicated by arrow A in the figure): a housing 3, a compressor (not shown), an annular combustion chamber (not shown), a high-pressure turbine (not shown), a low-pressure turbine (not shown), an engine rotating shaft, a rotor device, and a stator device. Among them, the rotation of the low-pressure turbine drives the rotation of the rotor blades 1, and the combustion gas discharged from the low-pressure turbine is released from the tail of the engine to increase the engine thrust.

[0068] The rotor device is an assembly that rotates at a high speed and does work on the air flow. The rotor device has a plurality of stator blade bases and a plurality of rotor blades 1. Each rotor blade 1 is circumferentially installed on the engine rotating shaft along the engine rotating shaft through the corresponding rotor blade base, and will rotate with the rotation of the engine rotating shaft. The plurality of rotor blades 1 are located outside the housing of the open rotor engine.

[0069] Each rotor blade 1 has: a top surface, a pressure surface ( Figure 2 the front side in Figure 2 ), and a suction surface ( the back side in ). On the pressure surface or the suction surface of the rotor blade 1, there are respectively: a tip region 12 near the top surface of the rotor blade 1 and near the trailing edge side (downstream side in the air flow direction) of the rotor blade 1, and a root region 13 near the bottom surface of the rotor blade 1 and near the trailing edge side of the rotor blade 1. Among them, the top surface of the rotor blade 1 is divided into the first half 10 of the top surface and the second half 11 of the top surface in the air flow direction. Among them, the first half 10 of the top surface of the rotor blade 1 is the region on the top surface of the rotor blade 1 and the distance to the leading edge of the rotor blade 1 is below 70% of the rotor blade chord length (that is, the distance range from the leading edge is 0% - 70% of the chord length). The second half 11 of the top surface of the rotor blade 1 is the region on the top surface of the rotor blade 1 and the distance to the trailing edge of the rotor blade 1 is below 30% of the rotor blade chord length (that is, the distance range from the leading edge is 70% - 100% of the chord length).

[0070] Concave-convex patterns are respectively provided in the tip region 12, the root region 13 of each rotor blade 1, and the second half 11 of the top surface of each rotor blade 1. The concave-convex pattern is a plurality of hemispheres protruding outward on the blade surface as shown in Figure 3 . The diameter of the sphere is 4 mm, and the distance between the protruding hemispheres is 4 mm.

[0071] The tip region 12 of the rotor blade 1 is on the pressure surface or the suction surface of the rotor blade 1, from the center of the rotor blade 1 in the air flow direction A to the trailing edge of the rotor blade 1, and the distance to the top surface of the rotor blade 1 is below 10% of the rotor blade height. (That is, the distance range from the bottom surface of the blade is 90% - 100% of the span).

[0072] The root region 13 of the rotor blade 1 is a region on the pressure surface or the suction surface of the rotor blade 1, starting from the center of the rotor blade 1 in the air flow direction A to the trailing edge of the rotor blade 1, and the distance to the bottom surface of the rotor blade 1 is below 8% of the rotor blade height. (That is, the distance to the bottom surface of the blade is in the range of 0% - 8% of the span).

[0073] The stator device includes: a plurality of stator blade bases and a plurality of stator blades 2. Each stator blade 2 is coaxially fixed to the housing 2 of the open rotor engine 1 along the circumferential direction of the engine rotating shaft through the corresponding stator blade base. The plurality of stator blades 2 are located downstream of the rotor blade 1, that is, on the rear side of the rotor blade 1, and are located outside the housing of the open rotor engine.

[0074] Each stator blade 2 has: a top surface, a pressure surface, and a suction surface. On the pressure surface and the suction surface, there are respectively a tip region 21 close to the top surface of the stator blade 2 and close to the leading edge side (the upstream side in the air flow direction) of the stator blade 2, and a root region 22 close to the bottom surface of the stator blade 2 and close to the leading edge side of the stator blade 2.

[0075] The tip region 21 of the stator blade 2 is a region on the pressure surface or the suction surface of the stator blade 2, starting from the center of the stator blade 2 in the air flow direction to the leading edge of the stator blade 2, and the distance to the top surface of the stator blade 2 is below 10% of the stator blade height (that is, the distance to the bottom surface of the blade is in the range of 90% - 100% of the span).

[0076] The root region 22 of the stator blade 2 is a region on the pressure surface or the suction surface of the stator blade 2, starting from the center of the stator blade 2 in the air flow direction to the leading edge of the stator blade 2, and the distance to the bottom surface of the stator blade 2 is below 8% of the stator blade height (that is, the distance to the bottom surface of the blade is in the range of 0% - 8% of the span).

[0077] On the top surface of the stator blade, the tip region 21, and the root region 22 of each stator blade 2, there are respectively provided concave - convex patterns. The concave - convex pattern is Figure 3 a plurality of hemispheres protruding outward on the blade surface as shown. The diameter of the sphere is 4 mm, and the distance between the protruding hemispheres is 4 mm.

[0078] By designing the rear half - section 11 of the top surface of the front - row rotor blade 1 into an arc - shaped serrated section, that is, a hemispherical concave - convex pattern, and designing the upper half - section of the trailing edge, that is, the tip region 12, into an arc - shaped serrated section, that is, a hemispherical concave - convex pattern, the tip vortex can be broken, the tip vortex can be broken into small vortices, and the intensity of the tip vortex and the wake can be reduced. Thus, the noise source of the blade can be effectively controlled and the noise can be reduced.

[0079] By providing concave-convex patterns in the root region (within 8% of the span) and tip region (90%-100% of the span) near the trailing edge on the rear half of the top surface, pressure surface, and suction surface of the rotor blade, and the concave-convex patterns are composed of hemispheres and planes. When the hub vortex and tip vortex flow through the concave-convex patterns, it can promote the exchange between the pressure surface and suction surface at the trailing edge, strengthen the mixing of the flow fields on the two surfaces, break the hub vortex and tip vortex into small vortices, inhibit the formation of the tip vortex, trailing edge separation vortex (i.e., hub vortex), and wake on the rotor blade 1, reduce the intensity of the hub vortex and tip vortex, and thus can effectively control the blade noise source and reduce noise.

[0080] After the shedding vortex or wake of the front-row rotor blade 1 is weakened by the concave-convex pattern, part of it will impact the surface of the rear-row stator blade 2. By providing concave-convex patterns on the top surface, pressure surface, and suction surface near the leading edge of the rear-row stator blade 2, it can further reduce the intensity of the shedding vortex (i.e., hub vortex), wake, and tip vortex impacting the surface of the rear-row stator blade 2, further reduce the interference effect between the front-row and rear-row blades, have a secondary noise reduction effect, and thus reduce noise.

[0081] By providing concave-convex patterns only in the rear half 10 of the top surface of the front-row rotor blade 1 and designing the front half 10 of the top surface of the front-row rotor blade 1 into a flat shape, the impact on aerodynamic performance can be reduced.

[0082] The arc-shaped sawtooth section is related to the blade harmonic frequency. Specifically, by setting the arc length of the spherical surface of the sphere to an integer multiple of one-quarter wavelength of the harmonic frequency noise generated on the stator blade 2, such as 2-5 times, the phase of the tip vortex can be controlled, and thus the probability of the shedding vortex of the front-row blade impacting the rear-row stator blade can be reduced.

[0083] The present invention only provides concave-convex patterns in local areas on the surfaces of the front and rear blades respectively. On the premise of having a small impact on aerodynamic performance, it can effectively reduce the interference noise between the front-row and rear-row blades.

[0084] In summary, in order to reduce the impact on the fan aerodynamic performance, the present invention redesigns the front-row rotor blade and the rear-row stator blade.

[0085] The specific effects in Example 1 are as follows:

[0086] (1) By providing hemispherical concave-convex patterns in the root region (0%-8% of the span) near the trailing edge of the front-row rotor blade, it can strengthen the airflow exchange and airflow mixing between the pressure surface and suction surface at the root trailing edge, and inhibit the formation of the hub vortex. When the observation angle is 90 degrees to 100 degrees and the noise is predicted by the numerical prediction method, it can reduce the probability of the hub vortex impacting the rear-row stator blade by 10%-15%, achieve a noise reduction of 2-3 dB, and the thrust change is within 5%, and the aerodynamic performance does not decrease significantly, which can meet the flight requirements.

[0087] (2) By respectively arranging hemispherical concave-convex shapes at the rear half (70%-100% chord length range) of the top surface of the front row rotor blades, in the tip region near the trailing edge, i.e., the trailing edge top (90%-100% span), and without arranging concave-convex shapes in the front half (0%-70% chord length range) of the top surface of the rotor blades, the shedding of the tip vortex and the trailing edge vortex can be reduced, that is, the sound source of the shedding vortex of the rotor blades can be suppressed, and the influence on the aerodynamic performance can be reduced. When the observation angle is 90 degrees to 100 degrees and the noise is predicted by the numerical prediction method, the probability of the tip shedding vortex hitting the rear row stator blades can be reduced by 10% to 15%, the noise reduction amount can reach 3 to 4 dB, and the thrust change is within 5%, and the aerodynamic performance does not decrease significantly, which can meet the flight requirements.

[0088] (3) By arranging hemispherical concave-convex shapes in the tip region and the root region of the front row rotor blades, the air flow exchange and mixing between the pressure surface and the suction surface of the rotor blades can be promoted, the trailing edge vortex shedding and the wing tip vortex can be suppressed, and the formation of the hub vortex can be suppressed, the blade noise source can be effectively controlled, the noise source of the front row blades and the interference effect between the front and rear row blades can be controlled, and the open rotor noise can be effectively reduced. When the observation angle is 90 degrees to 100 degrees and the noise is predicted by the numerical prediction method, the probability of the tip shedding vortex and the hub vortex hitting the rear row stator blades can be reduced by 10% to 15%, the noise reduction amount can reach 3 to 4 dB, and the thrust change is within 5%, and the aerodynamic performance does not decrease significantly, which can meet the flight requirements.

[0089] (4) By arranging hemispherical concave-convex shapes in the rear half of the top surface, the tip region, and the root region of the front row rotor blades, and designing the front half of the top surface of the front row rotor blades into a flat shape, the tip vortex can be broken, making it break into small tip vortices, reducing the probability of the shedding vortex of the front row blades hitting the rear row, further effectively controlling the blade noise source, controlling the noise source of the front row blades and the interference effect between the front and rear row blades, effectively reducing the open rotor noise, and reducing the influence on the aerodynamic performance. When the observation angle is 90 degrees to 100 degrees and the noise is predicted by the numerical prediction method, the probability of the tip shedding vortex and the hub vortex hitting the rear row stator blades can be reduced by 10% to 15%, the noise reduction amount can reach 5 to 6 dB, and the thrust change is within 5%, and the aerodynamic performance does not decrease significantly, which can meet the flight requirements.

[0090] (5) After the shedding vortices or wakes of the front-row rotor blades are weakened by the concave-convex profiles, some of the shedding vortices or wakes will still impact the surface of the rear-row stator blades. Therefore, by respectively arranging hemispherical concave-convex profiles in the area on the top surface of the stator blades and near the leading-edge side of the stator blades, in the tip regions near the leading edge on the pressure surface and suction surface of the rear-row stator blades, and in the root regions, the intensity of the shedding vortices or wakes of the front-row rotor blades impacting the surface of the rear-row stator blades can be further reduced, the interference effect between the front-row and rear-row blades can be attenuated, and a secondary noise reduction effect is achieved. When the observation angle is 90 degrees to 100 degrees and the noise is predicted by the numerical prediction method, the probability of the tip shedding vortices and hub vortices impacting the rear-row stator blades can be reduced by 10% to 15%, the noise reduction amount can reach 2 to 3 dB, and the thrust change is within 5%, and the aerodynamic performance does not decrease significantly, which can meet the flight requirements.

[0091] (6) By arranging concave-convex profiles in the rear half of the top surface of the front-row rotor blades, in the tip regions near the trailing edge on the pressure surface and suction surface of the rotor blades, in the root regions, in the area on the top surface of the stator blades and near the leading-edge side of the stator blades, and in the tip regions near the leading edge on the pressure surface and suction surface of the stator blades, and in the root regions, the tip vortices can be broken, making them break into small tip vortices, reducing the probability of the shedding vortices of the front-row blades impacting the rear row, further effectively controlling the blade noise source, controlling the front-row blade noise source and the interference effect between the front-row and rear-row blades, effectively reducing the open-rotor noise, and reducing the impact on the aerodynamic performance. The intensity of the shedding vortices or wakes of the front-row rotor blades impacting the surface of the rear-row stator blades can be further reduced, the interference effect between the front-row and rear-row blades can be attenuated, and a secondary noise reduction effect is achieved. When the observation angle is 90 degrees to 100 degrees and the noise is predicted by the numerical prediction method, the probability of the tip shedding vortices and hub vortices impacting the rear-row stator blades can be reduced by 10% to 15%, the noise reduction amount can reach 5 to 6 dB, and the thrust change is within 5%, and the aerodynamic performance does not decrease significantly, which can meet the flight requirements.

[0092] The numerical values given above are only one example. In addition, the distance between the concave-convex profiles can be in the range of 4 mm to 8 mm. The diameter of the concave-convex profiles can be in the range of 2 mm to 10 mm, for example.

[0093] Embodiment 2

[0094] Figure 4 The structural schematic diagram of the blades of the open-rotor engine involved in Embodiment 1 of the present invention is shown. Figure 5 The schematic diagram of the wake controller of the open-rotor engine involved in Embodiment 1 of the present invention is shown.

[0095] The difference between Embodiment 2 and the above-mentioned Embodiment 1 is that in Embodiment 2, the wake controller 32 is used to replace the hemispherical concave-convex profiles.

[0096] As shown Figure 4 in the figure, a row of miniature wake controllers 32 are respectively arranged in the rear half section 11 of the top surface of the rotor blade 1, the tip region 12 and the root region 13 near the trailing edge of the rotor blade 1, the tip region 21 and the root region 22 near the leading edge of the stator blade 2. The miniature wake controller 32 is composed of two protrusions located on the blade surface and having an airfoil streamline shape. The height of the protrusion is about 5 mm, the length along the air flow direction A is about 8 mm, the chord length is 10 mm, and it is designed with an airfoil streamline shape, which can smooth the air flow at the blade wake. A channel that gradually widens from the side near the leading edge of the rotor blade 1 to the side near the trailing edge of the stator blade 2, that is, a channel that is narrow at the front and wide at the rear, is formed between the two opposite protrusions of each wake controller 32 as a flow channel. The width of the narrowest part of the channel is 50% of the chord length of the wake controller, that is, 5 mm, and the width of the widest part of the channel is 150% of the chord length of the wake controller, that is, 15 mm. The wake controller 32 can smooth the air flow at the blade wake, slow down the air flow after the wake air flow passes through the wake controller 32, can control the hub vortex and the tip vortex, and reduce the intensity of the front row blade wake hitting the rear row blade, thereby reducing the noise. By respectively arranging a row of miniature wake controllers in the root region and the tip region of the rotor blade and the stator blade, the local flow fields of the root and the tip can be effectively adjusted. After smoothing the flow field, the degree of disorder of the flow field at this place can be reduced, thereby suppressing the formation of the hub vortex and the tip vortex.

[0097] In Embodiment 2, by arranging wake controllers in the rear half section of the top surface of the rotor blade, the tip region near the trailing edge and the root region, the local flow fields of the root and the tip can be effectively adjusted, the flow field can be smoothed, the wake flow velocity can be reduced, the degree of disorder of the flow field at this place can be reduced, thereby suppressing the formation of the hub vortex and the tip vortex, and reducing the sound source intensity, that is, reducing the intensity of the shed vortex of the front row blade hitting the rear row blade. By respectively arranging a row of miniature wake controllers in the tip region and the root region near the leading edge of the stator blade, the interference effect between the front and rear row blades is further reduced, and secondary noise reduction is achieved. When the observation angle is 90 degrees to 100 degrees and the noise is predicted by the numerical prediction method, the probability of the tip shed vortex and the hub vortex hitting the rear row stator blade can be reduced by 10% to 15%, the noise reduction amount reaches 3 dB, and the thrust change is within 5%, and the aerodynamic performance does not decrease significantly, which can meet the flight requirements.

[0098] The height of the wake controller can be in the range of 5 mm to 9 mm. The length of the wake controller along the air flow direction can be in the range of 8 mm to 12 mm, and the chord length of the wake controller can be in the range of 6 mm to 12 mm.

[0099] The structure of the present invention is not limited to Figures 2 to 5For the mechanical structures shown, those skilled in the art can conceive of various mechanical structures based on the inventive concept of the present invention.

[0100] In Embodiments 1 to 2, the diameters of the rotor blades and the stator blades are 3 meters to 4 meters.

[0101] The above describes the open rotor engine of the representative embodiments of the present invention.

[0102] Note that Figures 2 to 5 only examples according to the design concept of the present invention are depicted, and it is not intended to limit the scope of the present invention.

[0103] Thus, the present invention can effectively reduce noise on the premise of reducing the influence on aerodynamic performance.

[0104] For engines with ducts, there is also the problem of interference noise between rotor blades and stator blades. Therefore, in addition to the above embodiments, the concave-convex shapes on the rotor blades and stator blades involved in Embodiments 1 and 2 of the present invention can be provided on a ducted turbofan engine, so as to reduce the interference noise between the rotor blades and the stator blades.

[0105] It should be understood that the above description is illustrative rather than restrictive. For example, the above embodiments (and / or aspects thereof) can be used in combination with each other. In addition, many modifications can be made without departing from the scope of the present invention to adapt a specific situation or material to the teachings of the various embodiments of the present invention. Although the dimensions and types of the materials described herein are used to define the parameters of the various embodiments of the present invention, each embodiment is not meant to be restrictive, but rather an exemplary embodiment. Many other embodiments will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the various embodiments of the present invention should be determined with reference to the appended claims and the full scope of the equivalent forms claimed thereby.

[0106] Industrial applicability

[0107] The stator device of the present invention can be widely applied to aircraft engines such as open rotor engines and ducted turbofan engines that require noise reduction while ensuring aerodynamic performance.

[0108] Reference numeral description

[0109] 1 Rotor blade

[0110] 2 Stator blade

[0111] 3 Housing

[0112] 10 The first half of the top surface

[0113] 11 The second half of the top surface

[0114] 12 blade tip region

[0115] 13 blade root region

[0116] 21 blade tip region

[0117] 22 blade root region

[0118] 31 hemispherical concave-convex shape

[0119] 32 wake controller

Claims

1. An open rotor engine, characterized in that, comprising: a plurality of stator blades, which are installed on the outer side of the open rotor engine; a plurality of rotor blades, which are installed on the outer side of the open rotor engine and are located on the front side of the stator blades, and the plurality of rotor blades are fixed on the engine rotating shaft and rotate with the rotation of the engine rotating shaft, a concavo-convex pattern is provided in the area on the top surface of the rotor blade and close to the trailing edge side of the rotor blade, a concavo-convex pattern is provided in the root area on the pressure surface or suction surface of the rotor blade and close to the trailing edge side of the rotor blade, a concavo-convex pattern is provided in the tip area on the pressure surface or suction surface of the rotor blade and close to the trailing edge side of the rotor blade.

2. The open rotor engine according to claim 1, characterized in that, the concavo-convex pattern on the pressure surface or suction surface of the rotor blade is provided within the range from the center of the rotor blade to the trailing edge of the rotor blade.

3. The open rotor engine according to claim 1, characterized in that, the concavo-convex pattern is provided on the top surface of the rotor blade within the range where the distance to the trailing edge of the rotor blade is 30% or less of the rotor blade chord length.

4. The open rotor engine according to claim 1, characterized in that, the tip area of the rotor blade is the area on the pressure surface or suction surface of the rotor blade, from the center of the rotor blade in the air flow direction to the trailing edge of the rotor blade, and the distance to the top surface of the rotor blade is 10% or less of the rotor blade height.

5. The open rotor engine according to claim 1, characterized in that, the root area of the rotor blade is the area on the pressure surface or suction surface of the rotor blade, from the center of the rotor blade in the air flow direction to the trailing edge of the rotor blade, and the distance to the bottom surface of the rotor blade is 8% or less of the rotor blade height.

6. The open rotor engine according to claim 1, characterized in that, a concavo-convex pattern is provided in the area on the top surface of the stator blade and close to the leading edge side of the stator blade, a concavo-convex pattern is provided in the root area on the pressure surface or suction surface of the stator blade and close to the leading edge side of the stator blade, a concavo-convex pattern is provided in the tip area on the pressure surface or suction surface of the stator blade and close to the leading edge side of the stator blade.

7. The open rotor engine according to claim 6, characterized in that, the concavo-convex pattern on the pressure surface or suction surface of the stator blade is provided within the range from the center of the stator blade to the leading edge of the stator blade.

8. The open rotor engine according to claim 6, characterized in that, the concavo-convex pattern is provided on the top surface of the stator blade within the range where the distance to the leading edge of the stator blade is 30% or less of the stator blade chord length.

9. The open rotor engine according to claim 6, characterized in that, The tip region of the stator blade is a region on the pressure surface or suction surface of the stator blade, starting from the center of the stator blade in the air flow direction to the leading edge of the stator blade, and the distance to the top surface of the stator blade is below 10% of the stator blade height.

10. The open rotor engine according to claim 6, wherein, The root region of the stator blade is a region on the pressure surface or suction surface of the stator blade, starting from the center of the stator blade in the air flow direction to the leading edge of the stator blade, and the distance to the bottom surface of the stator blade is below 8% of the stator blade height.

11. The open rotor engine according to any one of claims 1 to 10, wherein, The concave-convex shape is a sphere protruding outward on the blade surface.

12. The open rotor engine according to claim 11, wherein, The spherical arc length of the sphere is an integer multiple of a quarter wavelength of the harmonic frequency noise generated on the stator blade.

13. The open rotor engine according to claim 11, wherein, The diameter of the concave-convex shape is in the range of 2 mm to 10 mm, and the distance between the concave-convex shapes is in the range of 4 mm to 8 mm.

14. The open rotor engine according to any one of claims 1 to 10, wherein, The concave-convex shape is a wake controller composed of two protrusions located on the blade surface and having an airfoil streamline shape, and a channel gradually widening from the side close to the leading edge of the rotor blade to the side close to the trailing edge of the stator blade is formed in the wake controller.

15. The open rotor engine according to claim 14, wherein, The width of the narrowest part of the channel is 50% of the chord length of the wake controller, and the width of the widest part of the channel is 150% of the chord length of the wake controller.

16. The open rotor engine according to claim 15, wherein, The height of the wake controller is in the range of 5 mm to 9 mm, the length along the air flow direction is in the range of 8 mm to 12 mm, and the chord length of the wake controller is in the range of 6 mm to 12 mm.

Images