Design method and device for blade end wall wing knife

Abstract

The invention discloses a design method and device for blade end wall winged knives. The method comprises the steps that the end wall winged knives are arranged on the upper end wall and the lower end wall of a blade channel; a molded line of the winged knife in the length direction is designed into a B spline curve formed by reversely solving control points of a B spline based on points on three molded lines. The device comprises a winged knife arrangement unit and a molded line design unit. According to the method, the wing knife molded line is constructed through the B spline curve modeling, the geometric parameters of the end wall wing knife are determined based on the blade geometric parameters and the blade inlet boundary layer thickness, the flexibility of the wing knife in the design process can be improved so as to adapt to the variable working condition flow field structure of the gas compressor, and therefore secondary flow development in a channel can be better restrained, end wall losses are reduced, and the design efficiency is improved. And the stable working margin of the compressor is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of gas turbines, and particularly relates to a design method and device for a blade end wall winglet. BACKGROUND

[0002] As a core component of an aero-engine and a gas turbine, the aerodynamic performance of a compressor directly determines the efficiency and stability of the entire power device. In the design of modern high-load compressors, in order to pursue higher single-stage pressure ratio and power density, the blade load is continuously increased, and the secondary flow phenomenon in the flow passage is also increasingly severe, which becomes a key bottleneck restricting the further improvement of performance.

[0003] In the compressor passage, especially in the end wall region, there are complex secondary flow structures, mainly including a horseshoe vortex formed by the accumulation of an end wall boundary layer, a passage vortex driven by a transverse pressure gradient, and an angle region separation, etc., as shown in FIG. 1. Figure 1 These strong vortex structure not only brings significant additional flow loss, reduces the efficiency of the compressor, but also causes flow blockage, reduces the stable working margin, and even induces unstable working conditions such as rotating stall, which seriously threatens the safe operation of the engine.

[0004] In order to suppress these secondary flows and widen the stable working boundary, researchers have developed various flow control technologies. Among them, the end wall winglet as a widely studied passive control device shows great engineering application potential due to its simple structure, high reliability and no need for external energy input. The winglet is a thin sheet structure installed on the inner wall and extending into the flow passage along the blade height direction, usually located on the suction side of the blade. Its core idea is to interrupt or weaken the transverse migration of low-energy fluid under the transverse pressure gradient in advance through its physical blocking effect, so as to suppress the formation and development scale of the main secondary flow structure such as the passage vortex.

[0005] The traditional winglet profile shape is generally constructed according to the shape of the blade or the flow passage. When the compressor is in a non-design condition, this configuration is no longer in line with the main flow, and cannot achieve good variable condition performance, and cannot fully exert the potential of the winglet device flow control. In order to overcome the inherent defects of the traditional winglet, a design method for an end wall winglet is proposed, which can effectively suppress secondary flow, reduce end wall region loss, and at the same time, minimize the additional resistance loss caused by the winglet itself, and avoid excessive interference with the main flow. SUMMARY

[0006] The purpose of the present application is to provide a design method and device of blade end wall winglet, which uses B-spline curve modeling to construct winglet profile, and determines the geometric parameters of end wall winglet based on blade geometric parameters and blade inlet boundary layer thickness.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme: A design method of blade end wall winglet, comprising: Arranging the end wall winglet on the upper and lower end walls of the blade passage; Designing the profile of the winglet in the length direction as a B-spline curve formed by the control points of the B-spline inversely calculated based on the points on the three profiles.

[0008] The present application is further improved in that the points on the three profiles are defined as A, B and C points, wherein the A point is the starting point of the profile, the B point is the ending point of the profile, and the C point is the point with the maximum vertical distance from the line connecting the A and B points.

[0009] The present application is further improved in that the axial distance of the A point from the blade leading edge is l ax , the circumferential distance of the A point from the suction surface is l ay , and the value range of l ax is 0~50%b, and the value range of l ay is 10%T~50%T; wherein b is the axial chord length of the blade, and T is the pitch of the blade.

[0010] The present application is further improved in that the axial distance of the B point from the blade leading edge is l bx , the circumferential distance of the B point from the suction surface is l by , and the value range of l bx is 50%b~100%b, and the value range of l by is 10%T~50%T, and l by <l ay .

[0011] The present application is further improved in that the vertical distance of the C point from the line connecting the A and B points is d, and the value range of d is -δ~+δ, d is a positive value, i.e. the winglet is curved towards the pressure surface of the blade, d is a negative value, i.e. the winglet is curved towards the suction surface, and δ is the inlet flow boundary layer thickness of the blade.

[0012] The present application is further improved in that the width of the side near the suction surface of the winglet and the side near the pressure surface of the winglet from the winglet profile is w1 and w2 respectively, and the value range of w1 and w2 is 1%δ~20%δ.

[0013] The further improvement of the present application is that the height of the winglet is h, and h is 5%delta~100%delta.

[0014] The further improvement of the present application is that the meridian surface shape of the winglet is rectangular, triangular or circular arc.

[0015] A design device of a blade end wall winglet, comprising: A winglet arrangement unit arranges the end wall winglet on the upper and lower end walls of the blade passage. A profile design unit designs the profile of the winglet in the length direction as a B-spline curve composed of control points of a B-spline inversely calculated based on three points on the profile.

[0016] A computer readable storage medium stores a computer program, and the computer program realizes the steps of the design method of the blade end wall winglet when executed by a processor.

[0017] Compared with the prior art, the present application has at least the following beneficial technical effects: The traditional winglet design method is often limited by fixed geometric shape or simple curve construction method, and it is difficult to finely adjust according to the specific working conditions and flow field characteristics of different compressors. The present application uses B-spline curve to model the winglet profile, and the B-spline curve has local support and strong shape expression ability, which can accurately shape various complex winglet shapes conforming to the principle of fluid mechanics by adjusting the position and weight of the control points. The geometric parameters of the end wall winglet are determined based on the blade geometric parameters and the blade inlet boundary layer thickness, and this innovative design concept realizes the accurate matching of the winglet parameters with the blade and the key characteristics of the flow field.

[0018] Inside the compressor, due to the presence of the end wall and the interaction of the blade surface boundary layer, complex secondary flow phenomena such as passage vortex, corner vortex, etc. are easily formed in the blade passage. These secondary flows will cause the energy loss of the airflow to increase, reducing the efficiency of the compressor. The blade end wall winglet design method of the present application can intervene and block the secondary flow at the key position by reasonably designing the winglet profile and geometric parameters. The additional resistance generated by the winglet can change the flow trajectory of the airflow, weaken the strength of the secondary flow, and prevent its further development and diffusion, thereby reducing the energy loss caused by the secondary flow, making the airflow pass through the blade passage more smoothly, and improving the aerodynamic performance of the compressor. The end wall is a complex area of internal flow in the compressor, where the airflow is prone to separation and reattachment, resulting in increased flow loss. The winglet design of the present application can improve the flow structure near the end wall, making the airflow more evenly distributed on the end wall surface, reducing the occurrence of flow separation. At the same time, the winglet can also guide the airflow to form a more favorable pressure gradient near the end wall, inhibit the thickening of the boundary layer, and reduce the end wall friction loss. Through these comprehensive effects, the flow loss in the end wall region of the compressor is significantly reduced, and the overall efficiency of the compressor is improved, providing a strong guarantee for the efficient operation of the compressor.

[0019] The stable working margin of the compressor refers to the ability of the compressor to maintain stable operation when deviating from the design working condition. Under variable working conditions, the internal flow field of the compressor is prone to stall, surge and other unstable phenomena, which seriously affects the performance and safety of the compressor. The blade end wall winglet design method of the present application improves the flow stability inside the compressor by effectively suppressing the development of secondary flow and reducing end wall loss. Stall and surge are common dangerous operating conditions of the compressor, which can cause a sharp decline in compressor performance and even cause equipment damage. The winglet design of the present application reduces the separation and backflow of the airflow in the blade passage by optimizing the flow field structure, reducing the likelihood of stall and surge. At the same time, the winglet can also adjust the airflow in time at the initial stage of stall, inhibit the expansion and development of the stall, provide a certain buffer time for the compressor, and enable the control system to take timely measures to avoid the occurrence of surge.

[0020] In summary, the design configuration method of the present application is simple, and increases the flexibility of the winglet in the design process to adapt to the variable working condition flow field structure of the compressor, thereby better suppressing the development of secondary flow in the passage, reducing the end wall loss, and improving the stable working margin of the compressor. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the specific embodiments of the present application or the prior art, the accompanying drawings needed to be used in the specific embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0022] Figure 1 Schematic diagram of vortex system near the wall in the blade passage.

[0023] Figure 2 Schematic diagram of the present application from the top.

[0024] Figure 3 Schematic diagram of the structure of the present application.

[0025] Figure 4 Schematic diagram of the structure of the present application.

[0026] Figure 5 Structure block diagram of a design device of a blade end wall winglet of the present application. DETAILED DESCRIPTION

[0027] In the following, only some exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present application. Therefore, the accompanying drawings and description are considered to be exemplary in nature rather than limiting.

[0028] In the description of the present application, it should be understood that, when used in the specification and the appended claims, the terms "comprise" and "include" indicate the presence of described features, integers, steps, operations, elements, and / or components, but do not exclude one or more other features, integers, steps, operations, elements, components, and / or sets thereof.

[0029] It should also be understood that the terms used in the present application specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the present application specification and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0030] It should be further understood that the term "and / or" used in the present application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0031] Various structural diagrams according to the disclosed embodiments of the present application are shown in the drawings. These diagrams are not drawn to scale, in which certain details are exaggerated for clarity of presentation and may be omitted, the shapes and relative sizes and positions of the various regions, layers, and any other illustrative features shown in the drawings are again for illustration only and may deviate in actual devices from that shown in the drawings, as specified herein or as specifically contemplated, depending on manufacturing processes or technical limitations. One skilled in the art can, however, design additional structures that have different shapes, sizes, and relative positions or arrangements of the regions / layers, as actual needs require.

[0032] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0033] Embodiment 1 As shown in the drawings, Figures 2 to 4 the present application provides a design method of a blade end wall winglet, comprising: arranging the end wall winglet on the upper and lower end walls of the blade passage; designing the profile of the winglet in the length direction as a B-spline curve composed of control points of a B-spline inversely derived based on points on three profiles.

[0034] In this embodiment, the points on the three profiles are defined as A, B, and C points, respectively, wherein the A point is the starting point of the profile, the B point is the ending point of the profile, and the C point is the point with the maximum perpendicular distance from the line connecting the A and B points.

[0035] In this embodiment, the axial distance of the A point from the blade leading edge is l ax , the circumferential distance of the A point from the suction surface is l ay , the value range of l ax is 0~50%b, and the value range of l ay is 10%T~50%T; wherein b is the axial chord length of the blade, and T is the pitch of the blade.

[0036] In this embodiment, the axial distance of the B point from the blade leading edge is l bx , the circumferential distance of the B point from the suction surface is l by , the value range of l bx is 50%b~100%b, and the value range of l by is 10%T~50%T, and l by < l ay .

[0037] In this embodiment, the perpendicular distance of the C point from the line connecting the A and B points is d, and the value range of d is -δ~+δ, d is a positive value, i.e., the winglet is curved towards the pressure surface of the blade, d is a negative value, i.e., the winglet is curved towards the suction surface, and δ is the boundary layer thickness of the incoming flow at the inlet of the blade.

[0038] In the embodiment, the width of the winglet near the suction surface side and the width of the winglet near the pressure surface side from the winglet profile are w1 and w2 respectively, and the value range of w1 and w2 is 1%δ~20%δ.

[0039] In the embodiment, the height of the winglet is h, and h is 5%δ~100%δ.

[0040] In the embodiment, the meridian plane shape of the winglet is rectangular, triangular or circular arc.

[0041] Embodiment 2 As shown in the drawings, the specific embodiment of the application is illustrated by taking a second stage stator blade of a certain compressor as an example. Figures 2 to 4

[0042] The partial design parameters of the compressor rotor are shown in Table 1.

[0043] Table 1 Partial design parameters of a certain compressor second stage stator blade

[0044]

[0045] According to the design method in the content of the application, the following design is carried out: According to the secondary flow in the passage near the stall condition of the blade, the end wall winglet is arranged on the surface of the hub end wall. First, the geometric parameters of points A, B and C on the winglet profile are determined.

[0046] The axial distance lax of the starting point A of the end wall winglet profile from the blade leading edge is 10%b, that is, 6mm; The circumferential distance lay of the starting point A of the end wall winglet profile from the blade suction surface is 40%T, that is, 12.8mm; The axial distance lbx of the terminal point B of the end wall winglet profile from the blade leading edge is 70%b, that is, 42mm; The circumferential distance lby of the terminal point B of the end wall winglet profile from the blade suction surface is 25%T, that is, 8mm; The vertical distance d of point C from the line connecting points A and B is 0.2δ, that is, 3mm; According to the geometric parameters of points A, B and C, the B-spline curve composed of the control points of the B-spline is the end wall winglet profile.

[0047] The width w1 of the winglet near the suction surface side from the winglet profile is 5%δ, that is, 0.75mm; The width w2 of the winglet near the pressure surface side from the winglet profile is 2%δ, that is, 0.3mm; The height h of the winglet is 80%δ, that is, 12mm; The meridian plane shape of the winglet is rectangular. ​

[0048] The end wall winglet designed based on the method adopts a B-spline curve to construct the profile line in the length direction, and the profile line of the winglet can be accurately and freely shaped by flexibly adjusting the control points of the curve. On this basis, the key geometric parameters such as the width, height, circumferential and axial positions of the winglet are reasonably configured, which significantly enhances the adaptability and flexibility of the winglet configuration in the design process. The parameterized design method makes the winglet better adapt to the changes of the flow field structure of the compressor under different working conditions, so as to more accurately and efficiently suppress the generation and development of secondary flow in the passage, effectively reduce the flow loss in the end wall region, and finally achieve the purpose of significantly improving the stable working margin of the compressor.

[0049] Embodiment 3 As shown in the Figure 5 The application provides a design device of a blade end wall winglet, which comprises: The winglet arrangement unit arranges the end wall winglet on the upper and lower end walls of the blade passage. The profile line design unit designs the profile line of the winglet in the length direction as a B-spline curve composed of control points of a B-spline inversely obtained based on three points on the profile line.

[0050] Embodiment 4 The application provides a computer readable storage medium, which stores a computer program, and the computer program realizes the steps of the design method of the blade end wall winglet when executed by a processor.

[0051] Those skilled in the art should understand that the embodiments of the application can be provided as a method, a system, or a computer program product. Therefore, the application can adopt a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the application can adopt a computer program product in the form of being implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program codes.

[0052] The application is described with reference to flowcharts and / or block diagrams of the methods, systems and computer program products according to the embodiments of the application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be realized by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing devices to produce a machine, so that the instructions executed by the computer or other programmable data processing devices produce a device for realizing the functions specified in the flowcharts and / or block diagrams. Figure 1 The system that realizes the functions specified in one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0053] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0054] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0055] Example 5 The present invention also provides an electronic device, comprising: a processor and a memory coupled to the processor, the memory storing a computer program, which, when executed by the processor, implements the steps of the design method for a blade endwall wing fence.

[0056] The electronic device may also include one or more of a multimedia component, an input / output (I / O) interface, and a communication component.

[0057] The processor is configured to control overall operations of the electronic device to complete all or part of the steps in the storage medium sharing method. The memory is configured to store various types of data to support operations of the electronic device, which can include, for example, instructions for any application or method operating on the electronic device, and application-related data, such as contact data, sent and received messages, pictures, audio, video, and the like. The memory can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk, or optical disk. The multimedia component can include a screen and an audio component. The screen can be, for example, a touch screen, and the audio component is configured to output and / or input audio signals. For example, the audio component can include a microphone configured to receive external audio signals. The received audio signals can be further stored in the memory or transmitted through the communication component. The audio component also includes at least one speaker configured to output audio signals. The I / O interface provides an interface between the processor and other interface modules, which can be a keyboard, a mouse, a button, and the like. The buttons can be virtual buttons or physical buttons. The communication component is configured to perform wired or wireless communication between the electronic device and other devices. Wireless communication, such as Wi-Fi, Bluetooth, near field communication (NFC), 2G, 3G, or 4G, or a combination of one or more of them, so the corresponding communication component can include a Wi-Fi module, a Bluetooth module, and an NFC module.

[0058] In an exemplary embodiment, the electronic device can be implemented by one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic elements for performing the storage medium sharing method.

[0059] The above shows and describes the basic principles and main features of the present application and the advantages of the present application. It is obvious for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended to encompass all variations falling within the meaning and scope of the equivalent elements of the claims. Any reference signs in the claims should not be regarded as limiting the claims to which they relate.

[0060] Furthermore, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the present specification is described in this way only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand. The above is only to illustrate the technical idea of the present application, and cannot limit the protection scope of the present application, and any modification made on the basis of the technical solutions according to the technical idea of the present application falls within the protection scope of the claims of the present application.

Claims

1. A method of designing a blade endwall winglet, characterized by, The method comprises: arranging the end wall winglet on the upper and lower end walls of the blade passage; designing the profile of the winglet in the length direction as a B-spline curve composed of control points of a B-spline reversely calculated based on three points on the profile.

2. A method of designing a blade end wall winglet according to claim 1, characterised in that, The three points are defined as A, B and C points, wherein the A point is the starting point of the profile, the B point is the ending point of the profile, and the C point is the point with the maximum vertical distance from the line connecting the A and B points.

3. A method of designing a blade end wall wing according to claim 2, characterised in that, The axial distance of point A from the leading edge of the blade is l ax , the circumferential distance from the suction surface is l ay , the value range of l ax is 0~50%b, the value range of l ay is 10%T~50%T; wherein, b is the axial chord length of the blade, and T is the pitch of the blade.

4. A method of designing a blade end wall wing according to claim 2, characterised in that, The axial distance of point B from the leading edge of the blade is l bx The circumferential distance of point B from the suction surface is l by The value range of l bx is 50%b~100%b, the value range of l by is 10%T~50%T, and l by < l ay .

5. A method of designing a blade end wall wing according to claim 2, characterised in that, The vertical distance of the C point from the line connecting the A and B points is d, and the value range of d is -δ~+δ, d is positive, i.e., the winglet is curved towards the pressure surface of the blade, d is negative, i.e., the winglet is curved towards the suction surface of the blade, and δ is the thickness of the boundary layer of the incoming flow at the inlet of the blade.

6. A method of designing a blade end wall wing according to claim 5, characterised in that, The width of the side close to the suction surface and the side close to the pressure surface of the winglet from the profile of the winglet is w1 and w2 respectively, and the value range of w1 and w2 is 1%δ~20%δ.

7. A method of designing a blade end wall wing according to claim 5, characterised in that, The height of the winglet is h, and h is 5%δ~100%δ.

8. A method of designing a blade end wall winglet according to claim 1, characterized in that, The meridian plane shape of the winglet is rectangular, triangular or circular arc.

9. A design apparatus for a blade end wall winglet, characterized by, The method comprises: arranging the end wall winglet on the upper and lower end walls of the blade passage; designing the profile of the winglet in the length direction as a B-spline curve composed of control points of a B-spline reversely calculated based on three points on the profile.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and the computer program, when executed by the processor, implements the steps of the design method of the blade end wall winglet according to any one of claims 1-8.

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