Provided are a design method for reverse thrust of an open rotor engine, a computer-readable medium, a computer program product, an open rotor engine, and a fan blade

Abstract

The present application relates to 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. Among them, the design method includes: for a plurality of fan blades circumferentially distributed in any stage, configuring the installation angle of each fan blade to be variable, each fan blade rotates around a rotating shaft extending radially, and the rotating shaft corresponding to each fan blade is within the range of 40% to 60% of the chord length of the root profile of the fan blade, and the change range of the installation angle is from 100° to 150°, forming a first structure of the fan blades in any stage; for this first structure, configuring the structure of the fan blades such that when the circumferentially adjacent fan blades rotate around their respective corresponding rotating shafts until they contact, a second structure of the fan blades in any stage is formed, and the contact position at the time of contact is defined as the reference point.

Description

Technical Field

[0001] The present application relates to 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. Background Art

[0002] The progress of aircraft power systems is a necessary guarantee for further improving fuel utilization efficiency and reducing emissions. The thermal propulsion efficiency determines the engine performance, and the thermal propulsion efficiency can be achieved by increasing the propulsion efficiency and the thermal efficiency. The propulsion efficiency is mainly achieved by increasing the bypass ratio. However, for traditional configuration engines, an increase in the bypass ratio means an increase in the nacelle diameter, and its aerodynamic drag and weight also increase continuously, and the engine installation loss increases. When the increase in installation loss offsets the fuel-saving benefit of the increased propulsion efficiency, the critical point is reached.

[0003] The technical ways to improve the thermal efficiency are mainly to increase the overall pressure ratio of the engine, the turbine inlet temperature, and the component efficiency. However, with the development of aeroengine technology, these three elements are currently at a relatively high level, and improving the engine thermal efficiency poses great challenges to aerodynamic design technology and material technology. Since the open rotor engine is not restricted by the nacelle installation effect, it can achieve an ultra-high bypass ratio (30 - 90), which can greatly improve the propulsion efficiency and significantly reduce the fuel consumption rate (it is expected to exceed 20% or more).

[0004] However, since the open rotor engine has no nacelle, the reverse thrust scheme used for traditional engine configurations such as turbofan engines cannot be applied to the open rotor engine. Therefore, there is a need in the art for 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 can provide a reverse thrust scheme for the open rotor engine and has a relatively high reverse thrust efficiency. Summary of the Invention

[0005] In view of the problems existing in the background art, 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 rotation axis is within the range of 40% chord length to 60% chord length of the root profile of the fan blade, the change range of the installation angle is 100° to 150°, and by rotating the blade to obtain a reference point and based on the reference point, according to the requirements of the maximum reverse thrust and the minimum reverse thrust, the maximum reverse thrust position, speed, and the minimum reverse thrust position, speed are obtained, which realizes providing a reverse thrust scheme for the open rotor engine and has a relatively high reverse thrust efficiency.

[0006] The purpose of the present 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, a design method for providing reverse thrust of 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, configure the installation angle of each fan blade to be variable, each fan blade rotates around a radial axis, and the axis corresponding to each fan blade is located within the range of 40% to 60% of the chord length of the root profile of the fan blade, the change range of the installation angle is 100° to 150°, to form a first structure of the fan blades of any stage; for this first structure, configure the structure of the fan blades such that when the circumferentially adjacent fan blades rotate around their respective corresponding axes until they contact, a second structure of the fan blades of any stage is formed, and the contact position at the time of contact is defined as a reference point; for this second structure, based on this reference point, rotate each fan blade around its respective corresponding axis so that there is a gap between the reference points of the adjacent fan blades, to form the maximum reverse thrust position of the fan blades of any stage, and according to the maximum reverse thrust, obtain the maximum reverse thrust speed of the engine corresponding to the maximum reverse thrust position; on the basis of the maximum reverse thrust position, according to the minimum reverse thrust, rotate each fan blade around its respective corresponding axis to adjust the installation angle, and / or adjust the speed of the engine, 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 at 15% to 35% of the blade height of the fan blade.

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

[0014] In one or more embodiments of the design method, configure the blade pitch of the plurality of fan blades of the same stage to be 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 one-stage rotor blades, or two-stage rotor blades, or one-stage rotor and one-stage stator blades.

[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 as 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, and when the computer program is executed by a processor, it implements the design method as described in the first aspect.

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

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

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

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

[0022] In a fifth aspect, a fan blade according to the present application is used for the open rotor engine as 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 within the range of 40% chord length to 60% chord length of the root profile of the fan blade, the change range of the installation angle is from 100° to 150°, and for a plurality of fan blades in the same stage, the contact position when the circumferentially adjacent fan blades rotate around their respective corresponding rotating shafts until they contact is defined as a reference point, and the reference point is located at 15% blade height to 35% blade height of the fan blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above-mentioned and other features, properties, and advantages of the present application will become more apparent from the following description in conjunction with the drawings and embodiments. In the drawings, the same reference numerals always represent the same features. It should be noted that these drawings are only examples and are not drawn under the condition of equal proportion, and should not be used to limit the actual scope of protection required by the present application, where:

[0024] Figure 1 FIG. [FIGURE NUMBER] is a schematic flow chart of a design method for providing reverse thrust of an open rotor engine according to an embodiment.

[0025] Figure 2 FIG. [FIGURE NUMBER] is a schematic structural diagram of an open rotor engine according to an embodiment.

[0026] Figure 3 FIG. [FIGURE NUMBER] is a schematic diagram of multiple fan blades of the same stage of an open rotor engine according to an embodiment.

[0027] Figure 4 FIG. [FIGURE NUMBER] is a schematic diagram of a fan blade of an open rotor engine rotating about a rotation axis according to an embodiment.

[0028] Figure 5 FIG. [FIGURE NUMBER] is a schematic diagram of the range of change in the installation angle of an open rotor engine according to an embodiment.

[0029] Reference Numerals:

[0030] 100 - Open rotor engine

[0031] 1 - Fan blade

[0032] 10 - Rotation axis

[0033] 11 - Rotor blade

[0034] 12 - Stator blade

[0035] 20 - Reference point

[0036] L - Chord length

[0037] H - Span height. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] Now, reference will be made in detail to the various embodiments of the present application. Examples of these embodiments are shown in the drawings and described as follows. Although the present application will be described in conjunction with exemplary embodiments, it should be understood that this specification is not intended to limit the present application to those exemplary embodiments. On the contrary, the present application is intended to cover not only these exemplary embodiments, but also various alternative forms, modifications, equivalent forms, and other embodiments that may be included within the spirit and scope of the present application as defined by the appended claims. Please note that the "FIGURE NUMBER" in the translation needs to be filled with the actual figure number corresponding to each description in the original text.

[0039] In the following description, the orientation or positional relationship indicated by "upstream", "downstream" or other orientation terms is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of 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 direction from "intake" to "outlet" of the engine turbine.

[0040] At the same time, the present application uses specific terms to describe the embodiments of the present application. For example, "one embodiment" and / or "an embodiment" mean a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that the "an embodiment" or "one embodiment" mentioned twice or more at 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 combined appropriately.

[0041] Flowcharts are used in the present application to illustrate the operations performed by the systems according to the embodiments of the present application. It should be understood that the operations before or below are not necessarily executed precisely in sequence. Other operations can also be added to these processes, or one or several steps of operations can be removed from these processes.

[0042] First, the object of the present application is an open rotor engine 100, and the main component that generates reverse thrust is the fan component. The fan blade 1 can also be referred to as a propfan blade, a propeller blade, etc. It can be understood that, as Figure 2 shown, the distribution of the fan blades of the open rotor engine 100 includes at least one stage of fan blades 1. It can be only one stage of rotor blades 11, or two stages of rotor blades 11 rotating in opposite directions, which can be called a double-row counter-rotating rotor, or as Figure 2 shown, one row of rotor blades 11 and one row of stator blades 12. Generally, rotor blades are arranged upstream and stator blades are arranged downstream. The design method to be introduced in detail in the following embodiments can be applied to all of them.

[0043] Referring to Figure 1 shown, in some embodiments, the design method for providing reverse thrust for the open rotor engine 100 may include the following steps:

[0044] S100. For multiple fan blades 1 distributed circumferentially at any level, the installation angle of each fan blade 1 is configured to be variable. Each fan blade 1 rotates around a rotating shaft 10 extending radially. The rotating shaft 10 corresponding to each fan blade 1 is located within the range of 40% to 60% of the chord length of the root profile of the fan blade 1. The variation range of the installation angle is from 100° to 150°, forming the first structure of the fan blades at any level.

[0045] Specifically, as Figure 4 and Figure 5 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 as a structure that can rotate around the rotating shaft 10. The position of the rotating shaft 10 needs to be within the region of 40% to 60% of the chord length L of the root profile of the blade. The variation range of the installation angle of the fan blade needs to be in the interval of 100° to 150° to ensure that the blade has sufficient rotation space, which is also beneficial for generating reverse thrust. Specifically, as Figure 4 shown, the position of the rotating shaft 10 needs to be within the region of 40% - 60% of the chord length of the root profile of the blade. Within this range, the bending moment and torque borne by the blade rotating shaft are smaller, which is beneficial for 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. And as Figure 5 shown, the variation range of the installation angle of the fan blade 1 is in the interval of 100° - 150°. The variation range of the installation angle 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 respective 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°, and it is not limited to this. Within the above range, it is beneficial for the engine reverse thrust scheme design, 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 a decrease in 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, an extension of the angle adjustment response time, and 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, which is the angle between the rotary plane at the blade radius r and the chord length of the blade interface.

[0046] In addition, the structure for realizing the above installation angle change and the rotation of the fan blade 1 can be that the installation angle change is achieved by connecting an adjustment mechanism to the position of the rotating shaft 10. This adjustment mechanism is connected to the rotating shaft 10 through linkages 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 those skilled in the art and will not be elaborated here.

[0047] S200. For the first structure, the structure of the fan blade 1 is configured such that when the circumferentially adjacent fan blades 1 rotate around their respective corresponding rotating shafts 10 until they come into contact to form the second structure of any stage of the fan blades, the contact position at the time of contact is defined as the reference point 20.

[0048] As Figure 3 shown, it can be understood that the reference point 20 is a hypothetical position in the actual structure, and the actual adjacent fan blades 1 are not in contact. The introduction of the reference point 20 here only represents an intermediate state in the execution steps of the design method. The distance between the actual adjacent fan blades 1 will be introduced in the following description.

[0049] In some embodiments, to ensure normal driving efficiency, the number of fan blades 1 is relatively large, and it is difficult to limit the blade pitch to less than 1. When the blade installation angle changes, it will be restricted, and adjacent two blades will touch when rotating to a certain angle. Specifically, generally, the pitch at the blade tip is smaller and the pitch at the root is larger, and the root will touch first. At this time, the design scheme of the blade can be adjusted so that the point where adjacent two blades touch first is controlled in the region of 15% - 35% of the blade height H, and the blade pitch is controlled within 1.2 to give sufficient rotation space for the blades.

[0050] S300. For the second structure, based on the reference point 20, each fan blade 1 is rotated around its respective 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 any stage of the fan blades. According to the maximum reverse thrust, the maximum engine reverse thrust speed corresponding to the maximum reverse thrust position is obtained.

[0051] Specifically, it can be to find the point where adjacent two fan blades 1 touch first by rotating the position of the fan blade 1. Taking this point as the reference, the distance between the reference points 20 of the actual adjacent two blades is controlled within 15 mm - 30 mm. This position is defined as the maximum reverse thrust position. Combining the maximum reverse thrust design requirements, the rotational speed at this position is determined, and this state is the maximum reverse thrust state. As Figure 3As shown, the blade reference point 20 refers to the contact point when adjacent blades rotate towards the angle closing direction (the direction in which the included angle between the blade chord line and the engine axis increases) until they come into contact. This 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, rotate the blade in the angle opening direction (the direction in which the included angle between the blade chord line and the engine axis decreases) to increase this distance. Since adjacent blades are not allowed to contact during the actual operation of the engine, contact may cause blade damage. In some embodiments, it is recommended to set the distance between the blade reference points to 15 mm to 30 mm, and the angle opening is recommended to be set to 5° - 20° to ensure the safe operation of the engine.

[0052] S400. Based on the maximum reverse thrust position, according to the minimum reverse thrust, rotate each fan blade 1 around its corresponding rotating 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 minimum reverse thrust engine speed.

[0053] The reverse thrust design requirements are usually put forward by the aircraft design party, and the engine party needs to meet these design requirements. The maximum reverse thrust position of the design scheme needs to generate a reverse thrust value not less than the design requirements.

[0054] According to the minimum reverse thrust design requirements, rotate the blade within the range not exceeding the maximum reverse thrust position, and vary the speed 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.

[0055] The reverse thrust of the engine design scheme increases with the increase of speed and decreases with the blade installation angle moving away from the maximum reverse thrust position. Then, different combinations of speed and blade installation angle will form different minimum reverse thrust schemes.

[0056] According to the minimum reverse thrust design requirements, rotate the blade within the range not exceeding the maximum reverse thrust position, and vary the speed 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. After obtaining the maximum and minimum reverse thrust states, the intermediate reverse thrust state points are obtained by linear interpolation. Through the above steps, the reverse thrust scheme of the open rotor engine can be obtained, and the reverse thrust scheme obtained by this method has higher efficiency.

[0057] The following uses specific numerical values to more intuitively illustrate the structure of the open rotor engine 100 obtained by the above design method.

[0058] For the fan component of a certain open rotor engine 100, such as Figure 1As shown, its fan component consists of a row of rotor blades 11 and a row of stator blades 12, and the reverse thrust scheme design is carried out.

[0059] At the position of the rotating shaft 10 of the fan blades of both the rotor blades 11 and the stator blades 12, it is at 50% chord length L of the blade root profile. The variation range of the installation angle of the fan blades of the rotor blades 11 is 120°. The variation range of the installation angle of the fan blades of the stator blades 12 is 100°.

[0060] The maximum blade pitch of the fan blades of the rotor blades 11 is 1.18, and the maximum blade pitch of the fan blades of the stator blades 12 is 1.05. The reference point 20 of the fan blades of the rotor blades 11 is at 20% of the blade height H, and the reference point 20 of the fan blades of the stator blades 12 is at 25% of the blade height H. The distance between the adjacent reference points 20 of the fan blades of the rotor blades 11 in the maximum reverse thrust state is 20 mm, and the distance between the adjacent reference points 20 of the fan blades of the stator blades 12 is 20 mm, achieving a reverse thrust efficiency of more than 90% under the condition of meeting the thrust.

[0061] Another aspect of the present application also provides a computer-readable storage medium storing a computer program, which when executed by a processor implements the steps of the design method described in the above embodiments. For details, please refer to the above description and will not be elaborated here.

[0062] In addition, it can be understood that the above computer-readable storage medium can also be in the form of a system, that is, including multiple computer-readable storage sub-media to jointly implement the steps of the design method described above through multiple computer-readable storage media.

[0063] In addition, another aspect of the present application also 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 embodiments. For details, please refer to the above description and will not be elaborated here.

[0064] In some embodiments, as described above, the present application further provides an open rotor engine 100, including at least one stage 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 radial axis 10, and the axis 10 corresponding to each fan blade 1 is located within the range of 40% to 60% of the chord length of the root profile of the fan blade 1, and the change range of the installation angle is 100° to 150°; for a plurality of fan blades 1 of the same stage, the contact position when the circumferentially adjacent fan blades 1 rotate around their respective corresponding axes 10 until they contact is defined as a reference point 20, and for a plurality of fan blades 1 of the same stage, the distance between the reference points 20 of the circumferentially adjacent fan blades 1 is 15 mm to 30 mm. The method of obtaining the above open rotor engine 100 can be the design method described above, but is not limited thereto.

[0065] In some embodiments, the reference point 20 is located at 15% to 35% of the blade height of the fan blade 1.

[0066] In some embodiments, the blade solidity of a plurality of fan blades 1 of the same stage is 1.0 to 1.2.

[0067] In some embodiments, one aspect of the present application further provides a fan blade 1 for the open rotor engine 100 as described in the above embodiments. The installation angle of the fan blade 1 is variable, each fan blade 1 rotates around a radial axis 10, and the axis 10 corresponding to each fan blade 1 is located within the range of 40% to 60% of the chord length of the root profile of the fan blade 1, and the change range of the installation angle is 100° to 150°. For a plurality of fan blades 1 of the same stage, the contact position when the circumferentially adjacent fan blades 1 rotate around their respective corresponding axes 10 until they contact is defined as a reference point 20, and the reference point 20 is located at 15% to 35% of the blade height of the fan blade 1.

[0068] 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 described in the above embodiments include but are not limited to: by setting the installation angle of the fan blade to be variable, and the axis is located within the range of 40% to 60% of the chord length of the root profile of the fan blade, the change range of the installation angle is 100° to 150°, and by rotating the blade to obtain the reference point and based on the reference point, according to the maximum reverse thrust and minimum reverse thrust requirements, the maximum reverse thrust position, speed, and minimum reverse thrust position, speed are obtained, realizing a reverse thrust scheme for the open rotor engine and having a relatively high reverse thrust efficiency.

[0069] The various illustrative logical modules and circuits described in connection with the embodiments disclosed herein can be implemented or performed 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 the 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, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0070] The steps of a method or algorithm described in connection with the embodiments disclosed herein can be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, 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 the processor such that the processor can read from, and write to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.

[0071] In one or more exemplary embodiments, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functions may be stored on or transmitted via a computer-readable medium as one or more instructions or code. The computer-readable medium includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. The storage media may be any available media that can be accessed by a computer. By way of example and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a web site, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc where disks typically 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.

[0072] Although the present application is disclosed above in preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present application. Therefore, all modifications, equivalent changes, and embellishments made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application 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, The open rotor engine (100) includes fan blades (1) of at least one stage, and the design method includes the following steps: 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 rotating shaft (10), and the rotating shaft (10) corresponding to each fan blade (1) is located within the range of 40% to 60% of the chord length of the root profile of the fan blade (1), and the change range of the installation angle is 100° to 150°, forming the first structure of the fan blades of any stage; For this first structure, configure the structure of the fan blades (1) such that when the circumferentially adjacent fan blades (1) rotate around their respective corresponding rotating shafts (10) until they contact, the second structure of the fan blades of any stage is formed, and the contact position during contact is defined as the reference point (20); For this second structure, based on the reference point (20), rotate each fan blade (1) around its respective corresponding rotating shaft (10) such that there is a gap between the reference points (20) of the adjacent fan blades (1), forming the maximum reverse thrust position of the fan blades of any stage, and according to the maximum reverse thrust, obtain the maximum reverse thrust speed of the engine corresponding to the maximum reverse thrust position; Based on the maximum reverse thrust position, according to the minimum reverse thrust, rotate each fan blade (1) around its respective corresponding rotating shaft (10) to adjust the installation angle, and / or adjust the speed of the engine, to obtain the installation angle corresponding to the minimum reverse thrust and the minimum reverse thrust speed of the engine.

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

3. The design method according to claim 1, characterized in that, Rotate each fan blade (1) around its respective corresponding rotating shaft (10) by 5° to 20° such that the distance between the reference points (20) of the adjacent fan blades (1) is 15 mm to 30 mm.

4. The design method according to claim 1, characterized in that, Configure the blade pitch of the plurality of fan blades (1) of the same stage to be 1.0 to 1.

2.

5. The design method according to claim 1, characterized in that, The fan blades (1) of at least one stage of the open rotor engine (100) include one stage of rotor blades, or two stages of rotor blades, or one stage of rotor blades (11) and one stage of stator blades (12).

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

7. A computer program product, comprising a computer program, characterized in that, When this computer program is executed by a processor, it implements the design method according to any one of claims 1-5.

8. An open rotor engine (100), characterized in that, Comprising: At least one stage 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 rotating shaft (10), and the rotating shaft (10) corresponding to each fan blade (1) is located within the range of 40% to 60% of the chord length of the root profile of the fan blade (1), and the change range of the installation angle is 100° to 150°; For multiple fan blades (1) at the same stage, 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). For multiple fan blades (1) at the same stage, the distance between the reference points (20) of the circumferentially adjacent fan blades (1) is 15 mm to 30 mm; each of the fan blades (1) is rotated around its respective corresponding rotating shaft (10) by 5° to 20°.

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 blade height of the fan blade (1).

10. The open rotor engine (100) according to claim 8, characterized in that, The blade solidity of the multiple fan blades (1) at 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) includes one stage of rotor blades, or two stages of rotor blades, or one stage of rotor and one stage of stator blades.

12. A fan blade (1), characterized in that, For the open rotor engine (100) according to any one of claims 8 - 11, the installation angle of the fan blade (1) is variable. Each of the fan blades (1) rotates around a radially extending rotating shaft (10). The rotating shaft (10) corresponding to each of the fan blades (1) is within the range of 40% to 60% of the chord length of the root profile of the fan blade (1). The variation range of the installation angle is 100° to 150°. For multiple fan blades (1) at the same stage, 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). The reference point (20) is located at 15% to 35% of the blade height of the fan blade (1).

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