Design method for providing reverse thrust of open rotor engine, computer readable medium, computer program product, open rotor engine and fan blade

Abstract

The invention relates to a design method for providing reverse thrust of an open rotor engine, a computer readable medium, a computer program product, the open rotor engine and a fan blade. The design method comprises the steps that for a plurality of fan blades distributed in the circumferential direction of any stage, the installation angle of each fan blade is configured to be variable, each fan blade rotates around a rotating shaft extending in the radial direction, and the rotating shaft corresponding to each fan blade is located in the range of 40% chord length to 60% chord length of the root molded surface of the fan blade; the change range of the mounting angle is 100-150 degrees, and a first structure of the fan blade of any stage is formed; for the first structure, the fan blades are configured in the mode that when the fan blades adjacent in the circumferential direction rotate around the corresponding rotating shafts till the fan blades make contact with the corresponding rotating shafts, a second structure of the fan blades of any stage is formed, and the contact position during contact is defined as a reference point.

Description

Technical Field

[0001] The present application relates to a design method for providing reverse thrust of an open rotor engine, a computer-readable medium, a computer program product, an open rotor engine and a fan blade. Background Art

[0002] The progress of aircraft power systems is a necessary guarantee for further improving fuel efficiency and reducing emissions. The performance of an engine is determined by thermal propulsion efficiency, which can be achieved by improving propulsion efficiency and thermal efficiency. Propulsion efficiency is mainly achieved by increasing the bypass ratio, but for engines with traditional configurations, the increase in bypass ratio means an increase in the nacelle diameter, its aerodynamic resistance and weight also continue to increase, and the engine installation loss increases. When the increase in installation loss offsets the fuel saving benefits of improved propulsion efficiency, a critical point is reached.

[0003] The main technical approach to improving thermal efficiency is to increase the engine's total compression ratio, turbine pre-temperature, and component efficiency. However, with the development of aviation engine technology, these three factors are already at a relatively high level. Improving engine thermal efficiency poses a huge challenge to both aerodynamic design technology and material technology. Since open rotor engines are not restricted by the nacelle installation effect, they can achieve a very large bypass ratio (30 to 90), which can greatly improve propulsion efficiency and significantly reduce fuel consumption (expected to exceed 20%).

[0004] However, since the open rotor engine has no nacelle, the reverse thrust scheme used in traditional engine configurations such as turbofan engines cannot be applied to the open rotor engine. Therefore, the art needs a new design method for providing reverse thrust for an open rotor engine, a computer-readable medium, a computer program product, an open rotor engine, and a fan blade, which provide a reverse thrust scheme for the open rotor engine and have a higher reverse thrust efficiency. Summary of the invention

[0005] In view of the problems existing in the background technology, the purpose of the present application is to provide a design method for providing reverse thrust for an open rotor engine, a computer-readable medium, a computer program product, an open rotor engine and a fan blade. By setting the fan blade installation angle to be variable, and the rotating shaft being located in the range of 40% chord length to 60% chord length of the root profile of the fan blade, the installation angle varies from 100° to 150°, and a reference point is obtained by rotating the blade and based on the reference point, according to the maximum reverse thrust and minimum reverse thrust requirements, the maximum reverse thrust position and rotation speed and the minimum reverse thrust position and rotation speed are obtained, thereby providing a reverse thrust solution for the open rotor engine with high reverse thrust efficiency.

[0006] The purpose of this application is to provide a design method for providing reverse thrust for an open rotor engine.

[0007] Another object of the present application is to provide a computer-readable medium.

[0008] Another object of the present application is to provide a computer program product.

[0009] Another object of the present application is to provide an open rotor engine.

[0010] Another object of the present application is to provide a fan blade.

[0011] In a first aspect, according to a design method for providing reverse thrust for an open rotor engine according to the present application, the open rotor engine includes at least one stage of fan blades, and the design method includes the following steps: for a plurality of circumferentially distributed fan blades of any stage, each of the fan blades is configured with a variable installation angle, each of the fan blades rotates around a radially extending rotation axis, the rotation axis corresponding to each of the fan blades is located within a range of 40% chord length to 60% chord length of the root profile of the fan blade, and the installation angle varies in a range of 100° to 150°, thereby forming a first structure of the fan blades of any stage; for the first structure, the fan blades are configured such that when the circumferentially adjacent fan blades rotate around their respective corresponding rotation axes until they contact , forming a second structure of the fan blades of any level, the contact position when in contact is defined as a reference point; for the second structure, based on the reference point, each of the fan blades is rotated around the corresponding rotating shaft, so that there is a gap between the reference points of adjacent fan blades, forming the maximum reverse thrust position of the fan blades of any level, and according to the maximum reverse thrust, the maximum reverse thrust speed of the engine corresponding to the maximum reverse thrust position is obtained; on the basis of the maximum reverse thrust position, according to the minimum reverse thrust, each of the fan blades is rotated around the corresponding rotating shaft to adjust the installation angle, and / or adjust the engine speed, to obtain the installation angle corresponding to the minimum reverse thrust and the minimum reverse thrust speed of the engine.

[0012] In one or more embodiments of the design method, the reference point is located between 15% and 35% of the height of the fan blade.

[0013] In one or more embodiments of the design method, each of the fan blades is rotated 5° to 20° around the corresponding rotation axis, so that the distance between the reference points of adjacent fan blades is 15 mm to 30 mm.

[0014] In one or more embodiments of the design method, the blade consistency of the plurality of fan blades configured in the same stage is 1.0 to 1.2.

[0015] In one or more embodiments of the design method, the fan blades of at least one stage of the open rotor engine include a first-stage rotor blade, or a two-stage rotor blade, or a first-stage rotor and a first-stage stator blade.

[0016] In a second aspect, a computer-readable medium according to the present application has a computer program thereon, and the program is executed by a processor to implement the steps in the design method described in the first aspect that can be implemented by a computer program.

[0017] In a third aspect, a computer program product according to the present application includes a computer program, which implements the design method described in the first aspect when executed by a processor.

[0018] In a fourth aspect, an open rotor engine according to the present application comprises: at least one level of fan blades; wherein, for the circumferentially distributed multiple fan blades of any level, the installation angle of each fan blade is variable, each fan blade rotates around a radially extending rotating shaft, the rotating shaft corresponding to each fan blade is located within the range of 40% chord length to 60% chord length of the root profile of the fan blade, and the installation angle varies within the range of 100° to 150°; for multiple fan blades at the same level, the contact position when the circumferentially adjacent fan blades rotate around their respective corresponding rotating shafts until they come into contact is defined as a reference point, and for multiple fan blades at the same level, the distance between the reference points of circumferentially adjacent fan blades is 15mm to 30mm.

[0019] In one or more embodiments of the open rotor engine, the reference point is located between 15% and 35% of the fan blade's height.

[0020] In one or more embodiments of the open rotor engine, the blade consistency of the plurality of fan blades of the same stage is 1.0 to 1.2.

[0021] In one or more embodiments of the open rotor engine, at least one stage of fan blades of the open rotor engine includes a first-stage rotor blade, or two-stage rotor blades, or a first-stage rotor and a first-stage stator blade.

[0022] In the fifth aspect, according to the fan blade of the present application, it is used in the open rotor engine described in the fourth aspect, the installation angle of the fan blade is variable, each of the fan blades rotates around a radially extending rotating shaft, the rotating shaft corresponding to each of the fan blades is located in the range of 40% chord length to 60% chord length of the root profile of the fan blade, the installation angle varies in the range of 100° to 150°, and for multiple fan blades at the same level, the contact position when the circumferentially adjacent fan blades rotate around their respective corresponding rotating shafts until they come into contact is defined as the reference point, and the reference point is located at 15% to 35% of the extension height of the fan blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and other features, properties and advantages of the present application will become more apparent through the following description in conjunction with the accompanying drawings and embodiments. In the accompanying drawings, the same reference numerals always represent the same features. It should be noted that these drawings are only examples and are not drawn in proportion. They should not be used to limit the actual scope of protection claimed in the present application. Among them: Figure 1 A schematic flow chart of a method for designing reverse thrust of an open rotor engine according to an embodiment of the present invention.

[0024] Figure 2 The figure is a schematic structural diagram of an open rotor engine according to an embodiment.

[0025] Figure 3 A schematic diagram of multiple fan blades of the same stage of an open rotor engine according to one embodiment.

[0026] Figure 4 A schematic diagram of the fan blades of an open rotor engine rotating around a rotation axis according to an embodiment.

[0027] Figure 5 A schematic diagram of the variation range of the installation angle of an open rotor engine according to an embodiment.

[0028] Reference numerals: 100-Open Rotor Engine 1-Fan blade 10-Rotation shaft 11-Rotor blades 12-Stator blades 20-base point L - Chord length H - height. DETAILED DESCRIPTION

[0029] Reference will now be made in detail to the various embodiments of the application, the examples of which are shown in the accompanying drawings and are described below. Although the application will be described in conjunction with the exemplary embodiments, it should be appreciated that this specification is not intended to limit the application to those exemplary embodiments. On the contrary, the application is intended to not only cover these exemplary embodiments, but also to cover various alternative forms, modified forms, equivalent forms and other embodiments that may be included in the spirit and scope of the application defined by the appended claims.

[0030] In the following description, the directions or positional relationships indicated by "upstream", "downstream" or other directional terms are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present application. In addition, in the specification of the present application, "upstream", "downstream", "front" and "rear" are distinguished based on the general flow direction of air during engine operation, that is, during engine operation, air generally flows from "upstream" to "downstream" and from "front" to "rear", and this direction is also roughly the "intake" to "exhaust" direction of the engine turbine.

[0031] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment" and / or "an embodiment" means a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0032] Flowcharts are used in this application to illustrate the operations performed by the system according to the embodiments of the application. It should be understood that the preceding or following operations are not necessarily performed precisely in order. Other operations may also be added to these processes, or one or more operations may be removed from these processes.

[0033] First, the object of the present application is an open rotor engine 100, the main component of which generates reverse thrust is the fan component, and the fan blade 1 can also be called a propeller blade, a propeller blade, etc. It can be understood that, for example, Figure 2 As shown, the fan blades of the open rotor engine 100 include at least one level of fan blades 1, which may be only one level of rotor blades 11, or two levels of rotor blades 11 that rotate in opposite directions, which may be called a double-row counter-rotating rotor, or may be such as Figure 2 As shown, a row of rotor blades 11 and a row of stator blades 12, generally the rotor blades are arranged upstream and the stator blades are arranged downstream, and the design method which will be described in detail in the following embodiments can be applied to both.

[0034] refer to Figure 1 As shown, in some embodiments, a design method for providing reverse thrust of an open rotor engine 100 may include the following steps: S100. For the circumferentially distributed multiple fan blades 1 of any level, the installation angle of each fan blade 1 is configured to be variable, each fan blade 1 rotates around a radially extending rotating shaft 10, the rotating shaft 10 corresponding to each fan blade 1 is located within the range of 40% chord length to 60% chord length of the root profile of the fan blade 1, and the installation angle varies in the range of 100° to 150°, thereby forming the first structure of the fan blades of any level.

[0035] Specifically, if Figure 4 as well as Figure 5 As shown, the key to the fan component generating reverse thrust is to change the installation angle of the fan blade 1. Therefore, the fan blade 1 must be designed to be rotatable around the rotation axis 10. The rotation axis 10 must be located within the 40% to 60% chord length L region of the blade root profile. The fan blade installation angle must vary within the range of 100° to 150° to ensure that the blade has sufficient rotation space, which is also beneficial for generating reverse thrust. Specifically, Figure 4 As shown, the position of the rotating shaft 10 needs to be within the 40% to 60% chord length area of ​​the blade root profile. Within this range, the bending moment and torque borne by the blade rotating shaft are small, which is beneficial to the engine strength design. If it exceeds this range, the bending moment and torque borne by the blade rotating shaft will increase, and there is a risk that the strength design requirements may not be met. Figure 5 As shown, the installation angle of the fan blade 1 varies in the range of 100° to 150°. The installation angle variation range refers to the difference between the maximum installation angle and the minimum installation angle during the operation of the engine. Different engines correspond to their own angle variation ranges. For example, the angle variation range of one engine is 100°, and the angle variation range of another engine can be 120°, which is not limited to this. Being within this range or above is conducive to the design of the engine reverse thrust scheme, and higher reverse thrust and reverse thrust efficiency can be obtained. If the angle range is less than 100°, the rotation range is too small, which will lead to reduced reverse thrust and may not meet the reverse thrust design requirements. If it exceeds 150°, it may lead to difficulties in the design of the adjustment mechanism, and the angle adjustment response time is prolonged, which is not conducive to the engine operation efficiency. The meaning of "installation angle" here is similar to the usual meaning in this field, that is, the blade installation angle β, also called the pitch angle, is the angle between the rotation plane at the blade radius r and the chord length of the blade interface.

[0036] In addition, the structure for realizing the above-mentioned installation angle change and fan blade 1 rotation can be that the installation angle change is realized by connecting the position adjustment mechanism of the rotating shaft 10, and the adjustment mechanism is connected to the rotating shaft 10 through connecting rods such as rocker arms, and a hydraulic rod is used to push the rotating shaft 10 to rotate. This is an adjustment and rotation structure well known to technicians in this field and will not be repeated here.

[0037] S200. For the first structure, the structure of the fan blades 1 is configured such that when the circumferentially adjacent fan blades 1 rotate around their respective corresponding rotating shafts 10 until they contact to form the second structure of the fan blades of any level, the contact position at the time of contact is defined as the reference point 20.

[0038] like Figure 3 As shown, it can be understood that the reference point 20 is an assumed position in the actual structure, and the actual adjacent fan blades 1 are not in contact. The reference point 20 is introduced here only to represent an intermediate state in the execution step of the design method. The actual spacing between adjacent fan blades 1 will be introduced in the following description.

[0039] In some embodiments, in order to ensure normal driving efficiency, the number of fan blades 1 is large, and the blade density is difficult to be limited within 1. The blade installation angle will be limited when changing, and two adjacent blades will touch each other when rotating to a certain angle. Specifically, the density of the tip of the blade is generally smaller, and the density of the root is greater, so the root will touch each other first. At this time, the design of the blade can be adjusted so that the point where two adjacent blades touch each other first is controlled in the area of ​​15%~35% of the height H, and the blade density is controlled within 1.2, giving the blades sufficient rotation space.

[0040] S300. For the second structure, based on the reference point 20, each fan blade 1 is rotated around its corresponding rotating shaft 10 so that there is a gap between the reference points 20 of adjacent fan blades 1, forming the maximum reverse thrust position of the fan blades of any level, and according to the maximum reverse thrust, the maximum reverse thrust speed of the engine corresponding to the maximum reverse thrust position is obtained.

[0041] Specifically, the point where two adjacent fan blades 1 first touch each other can be found by rotating the position of the fan blades 1. Based on this point, the distance between the reference points 20 of the two adjacent blades in practice is controlled to be 15 mm to 30 mm. This position is defined as the maximum reverse thrust position. Combined with the maximum reverse thrust design requirements, the rotation speed of this position is determined, and this state is the maximum reverse thrust state. Figure 3As shown, the blade reference point 20 refers to the contact point when the adjacent blades rotate in the angle closing direction (the direction in which the angle between the blade chord and the engine axis increases) until they come into contact. The contact point 20 is located on two adjacent fan blades 1 and is defined as the blade reference point. Each blade has two adjacent blades, so each blade has two reference points. When the blades are in contact, the distance between the two reference points at the contact position is 0. At this time, the blade is rotated in the angle opening direction (the direction in which the angle between the blade chord and the engine axis decreases) to increase the distance. Since adjacent blades are not allowed to come into contact during actual engine operation, contact may cause damage to the blades. In some embodiments, the distance between the blade reference points is recommended to be set to 15mm to 30mm, and the angle opening is recommended to be set to 5°~20° to ensure safe engine operation.

[0042] S400. Based on the maximum reverse thrust position, according to the minimum reverse thrust, each fan blade 1 is rotated around its corresponding rotation axis 10 to adjust the installation angle, and / or adjust the engine speed to obtain the installation angle corresponding to the minimum reverse thrust and the minimum reverse thrust speed of the engine.

[0043] The reverse thrust design requirements are usually proposed by the aircraft designer, and the engine designer must meet the design requirements. The maximum reverse thrust position of the design solution needs to produce a reverse thrust value not less than the design requirements.

[0044] According to the minimum reverse thrust design requirements, the blades are rotated within a range not exceeding the maximum reverse thrust position, the speed is changed within the available speed range, and the combination of blade position and speed that meets the minimum reverse thrust design requirements is found. This state is the minimum reverse thrust state.

[0045] The reverse thrust of the engine design increases with the increase of the speed, and decreases with the blade installation angle away from the maximum reverse thrust position. Therefore, different combinations of speeds and blade installation angles will form different minimum reverse thrust schemes.

[0046] According to the minimum reverse thrust design requirements, the blades are rotated within the range not exceeding the maximum reverse thrust position, and the speed is changed within the available speed range to find the combination of blade position and speed that meets the minimum reverse thrust design requirements. This state is the minimum reverse thrust state. The maximum and minimum reverse thrust states are obtained, and the intermediate reverse thrust state point is obtained by linear interpolation. The reverse thrust scheme of the open rotor engine can be obtained through the above steps, and the reverse thrust scheme obtained by this method has a higher efficiency.

[0047] The structure of the open rotor engine 100 obtained by the above design method is more intuitively explained below through specific numerical values.

[0048] For a fan component of an open rotor engine 100, such as Figure 1As shown, the fan component is composed of a row of rotor blades 11 and a row of stator blades 12, and a reverse thrust scheme is designed.

[0049] The positions of the rotating shaft 10 of the fan blades of the rotor blade 11 and the stator blade 12 are both at 50% of the chord length L of the blade root profile. The installation angle of the fan blade of the rotor blade 11 varies in a range of 120°. The installation angle of the fan blade of the stator blade 12 varies in a range of 100°.

[0050] The maximum consistency of the fan blades of the rotor blade 11 is 1.18, the maximum consistency of the fan blades of the stator blade 12 is 1.05, the fan blade reference point 20 of the rotor blade 11 is at 20% of the spread height H, the fan blade reference point 20 of the stator blade 12 is at 25% of the spread height H, the distance between the reference points 20 of adjacent fan blades of the rotor blade 11 in the maximum reverse thrust state is 20 mm, the distance between the adjacent fan blade reference points 20 of the stator blade 12 is 20 mm, achieving a reverse thrust efficiency of more than 90% under the thrust condition.

[0051] Another aspect of the present application further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the steps of the design method described in the above embodiment are implemented. Please refer to the above description for details, which will not be repeated here.

[0052] In addition, it can be understood that the above-mentioned computer-readable storage medium can also be in a system form, that is, it includes multiple computer-readable storage sub-media, so as to jointly implement the steps of the design method described above through multiple computer-readable storage media.

[0053] In addition, another aspect of the present application further provides a computer program product, including a computer program, which, when executed by a processor, implements the steps of the design method described in the above embodiment. Please refer to the above description for details, which will not be repeated here.

[0054] In some embodiments, as described above, the present application also provides an open rotor engine 100, including at least one level of fan blades 1; wherein, for the circumferentially distributed multiple fan blades 1 of any level, each fan blade 1 is configured with a variable installation angle, each fan blade 1 rotates around a radially extending shaft 10, the shaft 10 corresponding to each fan blade 1 is located within the range of 40% chord length to 60% chord length of the root profile of the fan blade 1, and the installation angle varies from 100° to 150°; for multiple fan blades 1 at the same level, the contact position when the circumferentially adjacent fan blades 1 rotate around their respective corresponding shafts 10 until they come into contact is defined as the reference point 20, and for multiple fan blades 1 at the same level, the distance between the reference points 20 of the circumferentially adjacent fan blades 1 is 15mm to 30mm. The method for obtaining the above-mentioned open rotor engine 100 may be the design method described above, but is not limited thereto.

[0055] In some embodiments, reference point 20 is located at 15% to 35% of the height of fan blade 1 .

[0056] In some embodiments, the blade consistency of multiple fan blades 1 of the same stage is 1.0 to 1.2.

[0057] In some embodiments, one aspect of the present application further provides a fan blade 1 for an open rotor engine 100 as described in the above embodiments, wherein the installation angle of the fan blade 1 is variable, each fan blade 1 rotates around a radially extending rotating shaft 10, the rotating shaft 10 corresponding to each fan blade 1 is located within the range of 40% chord length to 60% chord length of the root profile of the fan blade 1, the installation angle varies within the range of 100° to 150°, and for multiple fan blades 1 at the same level, the contact position when the circumferentially adjacent fan blades 1 rotate around their respective corresponding rotating shafts 10 until they come into contact is defined as the reference point 20, and the reference point 20 is located between 15% and 35% of the extension height of the fan blade 1.

[0058] In summary, the beneficial effects of the open rotor engine reverse thrust design method, computer-readable medium, computer program product, open rotor engine and fan blade introduced in the above embodiments include but are not limited to: by setting the fan blade installation angle to be variable, and the rotating shaft being located in the range of 40% chord length to 60% chord length of the root profile of the fan blade, the installation angle varies from 100° to 150°, and a reference point is obtained by rotating the blade and based on the reference point, according to the maximum reverse thrust and minimum reverse thrust requirements, the maximum reverse thrust position and rotation speed and the minimum reverse thrust position and rotation speed are obtained, thereby providing a reverse thrust solution for the open rotor engine with high reverse thrust efficiency.

[0059] The various illustrative logic modules and circuits described in conjunction with the embodiments disclosed herein may be implemented or executed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in cooperation with a DSP core, or any other such configuration.

[0060] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor so that the processor can read and write information from / to the storage medium. In an alternative, a storage medium may be integrated into a processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and the storage medium may reside in a user terminal as discrete components.

[0061] In one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented as a computer program product in software, each function may be stored on or transmitted by a computer-readable medium as one or more instructions or codes. Computer-readable media include both computer storage media and communication media, including any media that facilitates the transfer of a computer program from one place to another. Storage media may be any available media that can be accessed by a computer. As an example and not limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of an instruction or data structure and can be accessed by a computer. Any connection is also properly referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwaves, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves are included in the definition of the medium. Disk and disc as used herein include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0062] Although the present application is disclosed as above with preferred implementation modes, it is not intended to limit the present application. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present application. Therefore, any modification, equivalent change and modification made to the above implementation modes according to the technical essence of the present application without departing from the content of the technical solution of the present application shall fall within the protection scope defined by the claims of the present application.

Claims

1. A design method for providing reverse thrust of an open rotor engine, characterized in that: An open rotor engine (100) comprises at least one stage of fan blades (1), and the design method comprises the following steps: For a plurality of circumferentially distributed fan blades (1) of any one stage, the installation angle of each fan blade (1) is configured to be variable, each fan blade (1) rotates around a radially extending rotation axis (10), the rotation axis (10) corresponding to each fan blade (1) is located within a range of 40% to 60% of the chord length of the root profile of the fan blade (1), and the installation angle varies within a range of 100° to 150°, thereby forming a first structure of the fan blades of any one stage; For the first structure, the fan blades (1) are configured such that when the circumferentially adjacent fan blades (1) rotate around their respective corresponding rotation axes (10) until they come into contact, a second structure of the fan blades of any one level is formed, and the contact position when in contact is defined as a reference point (20); For the second structure, based on the reference point (20), each of the fan blades (1) is rotated around the corresponding rotation axis (10) so that there is a gap between the reference points (20) of adjacent fan blades (1), thereby forming a maximum reverse thrust position of the fan blades of any one stage, and obtaining the maximum reverse thrust rotation speed of the engine corresponding to the maximum reverse thrust position according to the maximum reverse thrust; Based on the maximum reverse thrust position and according to the minimum reverse thrust, each of the fan blades (1) is rotated around the corresponding rotation shaft (10) to adjust the installation angle, and / or adjust the engine speed, to obtain the installation angle corresponding to the minimum reverse thrust and the engine minimum reverse thrust speed.

2. The design method according to claim 1, characterized in that: The reference point (20) is located at 15% to 35% of the height of the fan blade (1).

3. The design method according to claim 1, characterized in that: Each of the fan blades (1) is rotated 5° to 20° around the corresponding rotation axis (10), so that the distance between the reference points (20) of adjacent fan blades (1) is 15 mm to 30 mm.

4. The design method according to claim 1, characterized in that: The blade density of the plurality of fan blades (1) configured at the same level is 1.0 to 1.

2.

5. The design method according to claim 1, characterized in that: At least one stage of fan blades (1) of the open rotor engine (100) comprises a first-stage rotor blade, or a two-stage rotor blade, or a first-stage rotor blade (11) and a first-stage stator blade (12).

6. A computer readable medium having a computer program thereon, characterized in that The program is executed by a processor to implement the steps in the design method as described in any one of claims 1 to 5 that can be implemented by a computer program.

7. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the design method as described in any one of claims 1 to 5 is implemented.

8. An open rotor engine (100), characterized in that: include: at least one level of fan blades (1); Wherein, for a plurality of circumferentially distributed fan blades (1) of any stage, the installation angle of each fan blade (1) is configured to be variable, each fan blade (1) rotates around a radially extending rotation axis (10), the rotation axis (10) corresponding to each fan blade (1) is located within a range of 40% to 60% of the chord length of the root profile of the fan blade (1), and the range of variation of the installation angle is 100° to 150°; For multiple fan blades (1) at the same level, the contact position of the circumferentially adjacent fan blades (1) when they rotate around their respective corresponding rotation axes (10) until they come into contact is defined as a reference point (20); for multiple fan blades (1) at the same level, the distance between the circumferentially adjacent reference points (20) of the fan blades (1) is 15 mm to 30 mm.

9. The open rotor engine (100) according to claim 8, characterized in that: The reference point (20) is located at 15% to 35% of the height of the fan blade (1).

10. The open rotor engine (100) according to claim 8, characterized in that: The blade consistency of the plurality of fan blades (1) of the same stage is 1.0 to 1.

2.

11. The open rotor engine (100) according to claim 8, characterized in that: At least one stage of fan blades (1) of the open rotor engine (100) comprises a first-stage rotor blade, or two-stage rotor blades, or a first-stage rotor and a first-stage stator blade.

12. A fan blade (1), characterized in that: For an open rotor engine (100) as described in any one of claims 8 to 11, the installation angle of the fan blade (1) is variable, each of the fan blades (1) rotates around a radially extending rotation axis (10), the rotation axis (10) corresponding to each of the fan blades (1) is located within a range of 40% to 60% of the chord length of the root profile of the fan blade (1), the installation angle varies within a range of 100° to 150°, and for multiple fan blades (1) at the same level, the contact position of the circumferentially adjacent fan blades (1) when they rotate around their respective corresponding rotation axes (10) until they come into contact is defined as a reference point (20), and the reference point (20) is located at 15% to 35% of the extension height of the fan blade (1).

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