Dimension reduction conversion method for complex radial three-dimensional blade to meridian flow surface

Abstract

The invention discloses a dimensionality reduction conversion method for a complex radial three-dimensional blade to a meridian flow surface. The method comprises the following steps: firstly, decomposing a complex radial three-dimensional blade with the blade height of H into a plurality of basic radial flow surface two-dimensional blade molded lines according to different relative blade heights h / H, and selecting one blade molded line for discretization to obtain discrete coordinates (X, Y); and carrying out dimensionless processing on the coordinates by utilizing the characteristic parameters to obtain dimensionless coordinates (X1, Y1). Transforming the relational expression through coordinates; ; ; and converting the dimensionless coordinates to the meridian flow surface to obtain corresponding dimensionless coordinates (X2, Y2). And performing proportional adjustment on (X2, Y2) to obtain coordinates of discrete points of the two-dimensional blade profile of the meridian flow surface. And repeating the process, and performing dimensionality reduction on the two-dimensional molded lines of all the sections to convert the two-dimensional molded lines of the meridian flow surface into two-dimensional molded lines of the meridian The method ensures that the flow channel area change rule and the pressure distribution characteristic are not changed before and after conversion.

Description

Technical Field

[0001] This invention relates to the field of turbine blade design, specifically a method for reducing the dimension of a complex radial three-dimensional blade to a meridional flow surface. Background Technology

[0002] Turbine machinery is a highly efficient rotating device that converts energy in a fluid medium into mechanical work, and it is widely used in various fields such as power generation and aerospace.

[0003] With the increasing national requirements for energy conservation and emission reduction, improving turbine efficiency in various industries is becoming increasingly urgent.

[0004] As a core component of turbine energy conversion, the internal losses of the flow path blades directly determine the unit's operating efficiency. Because the flow within the flow path blades presents multi-factor, cross-dimensional, and strongly coupled challenges, capturing and studying these losses is a prerequisite and key to improving efficiency. For a long time, renowned research institutions both domestically and internationally have invested significant human and material resources in numerical simulation and experimental research on these losses.

[0005] For most axial-flow turbines, the flow direction of the fluid inside the turbine can generally be decomposed into axial (or at a slight angle to the axial direction) and tangential. However, in some fields, the mainstream flow direction within the turbine stage is not so straightforward. For example, the purely radial blades used in the first stage of large steam turbines and the guide vanes of centripetal turbines require decomposition into radial and tangential flow directions. For such complex three-dimensional radial blades, in order to study the influencing factors and variation patterns of various losses (shape loss, secondary flow loss, etc.) separately, dimensionality reduction and simplification are necessary.

[0006] Currently, the numerical analysis methods and planar blade cascade experiments commonly used in the industry to study the characteristics of blade loss are all based on blade cascades flowing in the meridional plane.

[0007] However, radial airfoils exhibit radius changes during flow, and the area variation between adjacent blades is not solely determined by the airfoil itself but is also influenced by radius changes, which is entirely different from the flow characteristics within a meridional flow surface. Therefore, to maintain the flow channel area variation and surface pressure distribution characteristics, two-dimensional airfoils of each radial blade cross-section cannot be directly used for performance analysis or planar blade cascade experimental research. Currently, the industry lacks a dimensionality reduction transformation method that can accurately preserve these aerodynamic characteristics. A method is needed to transform the radially flowing airfoil to a meridional flow surface, maintaining its cross-sectional aerodynamic characteristics. Based on this, subsequent planar blade cascade experiments, flow field numerical simulations, and other related research can be conducted to obtain the load characteristics and surface loss data of each airfoil cross-section, providing data support for performance optimization. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for the dimensionality reduction transformation of complex radial three-dimensional blades into meridional flow surfaces. This method can realize the transformation of radial flow surface two-dimensional blade profiles into meridional flow surface two-dimensional blade profiles, while ensuring that the flow channel area change law and flow surface pressure distribution characteristics of the blade profiles remain unchanged before and after the transformation.

[0009] The technical objective of this invention is achieved through the following technical solution: A method for dimensionality reduction transformation of complex radial three-dimensional blades into meridional flow surfaces, characterized by the following steps: S1: Select a complex radial three-dimensional blade, the blade height of which is H; decompose the complex radial three-dimensional blade into several basic radial flow surface two-dimensional blade profiles corresponding to different relative blade heights h / H; S2: Describe one of the basic radial flow surface two-dimensional blade profiles in step S1 using the coordinates (X,Y) of several discrete points; S3: Dimensionless processing is performed on the discrete point coordinates (X, Y) obtained in step S2 using characteristic parameters to obtain dimensionless discrete coordinate points (X1, Y1); the characteristic parameters include one or more of the following: chord length b, installation angle γ, pitch s, throat width o, section height h, relative blade height h / H, and relative grating pitch s / b; S4: The dimensionless discrete coordinate points (X1, Y1) obtained in step S3 are transformed into dimensionless discrete coordinate points (X2, Y2) of the two-dimensional blade profile on the meridional flow surface using the following coordinate transformation relationship: ; ; S5: The dimensionless discrete coordinates (X2, Y2) of the two-dimensional blade profile on the meridional surface obtained in step S4 are proportionally adjusted, and the two-dimensional blade profile of the basic radial flow surface corresponding in step S1 is finally transformed into the discrete coordinates of the two-dimensional blade profile of the meridional flow surface. S6: Repeat steps S2 to S5 to reduce the dimensionality of all the basic radial flow surface two-dimensional blade profiles in step S1 to meridional flow surface two-dimensional profiles.

[0010] Preferably, in step S1, the basic radial flow surface two-dimensional blade profile is composed of a curve formed by four closed connections: the leading edge, the pressure surface, the trailing edge, and the suction surface.

[0011] Preferably, in step S3, the dimensionless processing is achieved by simultaneously dividing the coordinates (X, Y) of the discrete point by the characteristic parameter.

[0012] Preferably, in step S5, the scaling adjustment is to restore the converted meridional flow surface two-dimensional blade profile to a physical size suitable for planar blade cascade tests or numerical simulation analysis.

[0013] Preferably, the two-dimensional blade profile of the meridional flow surface transformed by the method is used for planar blade cascade tests and / or flow field numerical simulation analysis to obtain the load characteristics and surface loss data of the blade profile.

[0014] A turbomachinery component, wherein the basic airfoil of the turbomachinery component is a three-dimensional blade formed by stacking and / or twisting a two-dimensional profile of a meridional flow surface obtained by the aforementioned method of dimensional reduction transformation of complex radial three-dimensional blades into meridional flow surfaces; the turbomachinery component is a centripetal turbine blade, a radial stage blade of an axial turbine, or a stationary blade cascade of a centrifugal compressor.

[0015] A turbomachinery comprising the turbomachinery components described above, wherein the working medium of the turbomachinery is air, water vapor, or carbon dioxide.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention provides a method for the dimensionality reduction transformation of complex radial three-dimensional blades into meridional flow surfaces. This method can realize the transformation of radial flow surface two-dimensional blade profiles into meridional flow surface two-dimensional blade profiles, while ensuring that the flow channel area change law and flow surface pressure distribution characteristics of the blade profiles remain unchanged before and after the transformation. 2. Based on the transformation method proposed in this invention, complex radial three-dimensional blades can be reduced in dimension, and planar blade cascade test studies or flow field numerical simulation analysis studies can be carried out on several two-dimensional blade profiles from the root to the top after transformation to obtain load characteristics and surface loss data of each cross-section blade profile, providing data support for performance optimization.

[0017] 3. The impeller machinery components (such as radial turbine blades, radial stage blades of axial turbines, and stator blades of centrifugal compressors) designed and manufactured by the method of this invention are suitable for different working media (such as air, water vapor, carbon dioxide, etc.). This method has strong versatility, the designed products have excellent performance, and it is easy to implement in engineering. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a radial three-dimensional blade, where H is the total height of the blade body and h is the distance between a certain cross section and the root of the blade. Figure 2 This is a schematic diagram of the two-dimensional blade profile; Figure 3 This is a flowchart of the method of the present invention; In the diagram, the markings are: 1-blade leading edge; 2-blade pressure surface; 3-blade trailing edge; 4-blade suction surface; o-throat width; b-chord length; s-pitch; γ-installation angle. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0021] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] Example 1 like Figures 1-3 As shown, a method for dimensionality reduction transformation of complex radial three-dimensional blades into meridional flow surfaces is characterized by the following steps: S1: Select a complex radial three-dimensional blade with a blade height of H; decompose the complex radial three-dimensional blade into several basic radial flow surface two-dimensional blade profiles corresponding to different relative blade heights h / H.

[0023] In this embodiment, the blade height of the complex radial three-dimensional blade is H. The blade is formed by stacking and twisting several basic radial flow surface two-dimensional blade profiles (the two-dimensional blade profiles are positioned relative to the blade height as h / H) according to a certain pattern. The complex radial three-dimensional blade is decomposed into several basic radial flow surface two-dimensional blade profiles corresponding to different relative blade heights h / H.

[0024] The basic radial flow surface two-dimensional airfoil section is a closed curve formed by connecting four spline curves in sequence: the leading edge 1, the pressure surface 2, the trailing edge 3, and the suction surface 4.

[0025] The basic two-dimensional airfoil has characteristic parameters: chord length b, installation angle γ, pitch s, throat width o, basic two-dimensional airfoil section height h, relative blade height h / H, and relative kerf pitch s / b.

[0026] S2: Describe one of the basic radial flow surface two-dimensional blade profiles in step S1 using the coordinates (X,Y) of several discrete points; In this embodiment, one example is a two-dimensional blade profile of a basic radial flow surface. The two-dimensional blade profile of one of the basic radial flow surfaces in step S1 can be described by the discrete point coordinates (X,Y) of a two-dimensional blade profile of a certain blade height section of the basic radial flow surface, as shown in Table 1.

[0027] Table 1. Coordinates of discrete points of a two-dimensional airfoil at a certain blade height section on the basic radial flow surface.

[0028] S3: Dimensionless processing is performed on the discrete point coordinates (X, Y) obtained in step S2 using characteristic parameters to obtain dimensionless discrete coordinate points (X1, Y1); the characteristic parameters include chord length b, installation angle γ, pitch s, throat width o, cross section height h, relative blade height h / H, and relative gate pitch s / b. In specific implementation, in step S3, the dimensionless processing is achieved by dividing the coordinates (X, Y) of the discrete point by the characteristic parameter.

[0029] Specifically, the two-dimensional blade profiles of the radial flow surface at each relative blade height section position are dimensionless, and the horizontal and vertical planes are used as reference planes to make the two-dimensional blade profiles of the radial flow surface in step S2 dimensionless as a whole.

[0030] In this embodiment, the coordinates (X, Y) of the discrete points in Table 1 above are simultaneously divided by the characteristic parameters to achieve dimensionless representation, thereby obtaining the discrete reference points of the two-dimensional blade profile for each cross-section radial flow surface. The dimensionless discrete point coordinates of a certain blade height section of the basic radial flow surface are described in Table 2.

[0031] Table 2. Dimensionless discrete point coordinates of a two-dimensional airfoil with a certain blade height section on the basic radial flow surface.

[0032] S4: Convert the dimensionless discrete coordinate point (X1, Y1) obtained in step S3 into a dimensionless coordinate point (X2, Y2) on the meridional flow surface through the following coordinate transformation relationship.

[0033] In this embodiment, the dimensionless discrete coordinate points (X1, Y1) of the two-dimensional blade profiles on each radial flow surface based on step S3 are transformed to dimensionless coordinate points (X2, Y2) on the meridional flow surface of the blade at the same streamline position according to the following relationship. Table 3 describes the coordinates of the dimensionless discrete points of the two-dimensional blade profiles on the meridional flow surface.

[0034]

[0035] In this embodiment, X1,Y1 are the dimensionless discrete point coordinates of a two-dimensional blade profile at a certain cross-section of the basic radial flow surface, and X2,Y2 are the dimensionless discrete point coordinates of a two-dimensional blade profile on the meridional flow surface.

[0036] Table 3. Dimensionless discrete point coordinates of two-dimensional blade profiles on the meridional surface. .

[0037] S5: The dimensionless discrete coordinates (X2, Y2) of the two-dimensional blade profile on the meridional surface obtained in step S4 are scaled up, and finally the two-dimensional blade profile of the basic radial flow surface corresponding in step S1 is transformed into the discrete coordinates of the two-dimensional blade profile of the meridional flow surface.

[0038] In step S5, the scaling adjustment is to restore the converted meridional flow surface two-dimensional blade profile to a physical size suitable for planar blade cascade tests or numerical simulation analysis.

[0039] S6: Repeat steps S2 to S5 to reduce the dimensionality of all the basic radial flow surface two-dimensional blade profiles in step S1 to meridional flow surface two-dimensional profiles.

[0040] This method can realize the transformation from radial flow surface two-dimensional airfoil to meridional flow surface two-dimensional airfoil, while ensuring that the flow channel area change law and flow surface pressure distribution characteristics of the airfoil remain unchanged before and after the transformation.

[0041] The two-dimensional blade profile of the meridional flow surface transformed by the method in this embodiment is used for planar blade cascade experiments and / or flow field numerical simulation analysis to obtain the load characteristics and surface loss data of the blade profile. This technique enables the dimensionality reduction of complex radial three-dimensional blades, obtaining the load characteristics and surface loss data of each cross-section of the blade profile, providing data support for performance optimization.

[0042] Example 2 An impeller mechanical component, wherein the basic blade profile of the impeller mechanical component is a three-dimensional blade formed by stacking and / or twisting a two-dimensional profile of a meridional flow surface obtained by the dimensionality reduction transformation method of the complex radial three-dimensional blade in Example 1; the impeller mechanical component is a radial turbine blade, a radial stage blade of an axial turbine, or a stationary blade of a centrifugal compressor.

[0043] A turbomachinery comprising the turbomachinery components described above, wherein the working medium of the turbomachinery is air, water vapor, or carbon dioxide.

[0044] The impeller machinery components (such as radial turbine blades, radial stage blades of axial turbines, and stator blades of centrifugal compressors) designed and manufactured based on the method of Example 1 are suitable for different working media (such as air, water vapor, carbon dioxide, etc.). This method is highly versatile, the designed products have excellent performance, and are easy to implement in engineering.

[0045] The technical solutions provided by the embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the embodiments of the present invention. The descriptions of the embodiments above are only for helping to understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the embodiments of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for reducing the dimensionality of a complex radial three-dimensional blade-to-meridian surface, characterized by, The method comprises the following steps: S1: selecting a complex radial three-dimensional blade, the height of the blade being H; and decomposing the complex radial three-dimensional blade into a plurality of basic radial flow surface two-dimensional blade profiles corresponding to different relative blade height h / H positions; S2: describing one of the basic radial flow surface two-dimensional blade profiles obtained in step S1 by using the coordinates (X, Y) of a plurality of discrete points; S3: performing dimensionless processing on the discrete point coordinates (X, Y) obtained in step S2 by using characteristic parameters, to obtain dimensionless discrete coordinate points (X1, Y1); the characteristic parameters include one or more of chord length b, installation angle γ, pitch s, throat width o, section height h, relative blade height h / H, and relative pitch s / b; S4: converting the dimensionless discrete coordinate points (X1, Y1) obtained in step S3 into dimensionless discrete coordinate points (X2, Y2) of a two-dimensional blade profile on a meridional flow surface through the following coordinate transformation relationship: ； ； S5: performing proportional adjustment on the dimensionless discrete coordinate points (X2, Y2) of the two-dimensional blade profile on the meridional flow surface obtained in step S4, to finally convert the corresponding basic radial flow surface two-dimensional blade profile in step S1 into a two-dimensional blade profile discrete point coordinate on a meridional flow surface; S6: repeating steps S2 to S5 to reduce the dimensionality of all the basic radial flow surface two-dimensional blade profiles in step S1 to convert them into meridional flow surface two-dimensional profiles.

2. The method of dimensional reduction of complex radial three-dimensional blade-to-meridian surfaces according to claim 1, wherein, In step S1, the basic radial flow surface two-dimensional blade profile is composed of a curve formed by the closed connection of a leading edge, a pressure surface, a trailing edge, and a suction surface.

3. The method of dimensional reduction of complex radial three-dimensional blade-to-meridian surfaces according to claim 1, wherein, In step S3, the dimensionless processing is achieved by simultaneously dividing the coordinates (X, Y) of the discrete points by the characteristic parameters.

4. The method of dimensional reduction of complex radial three-dimensional blade-to-meridian surfaces according to claim 1, wherein, In step S5, the proportional adjustment is to restore the converted meridional flow surface two-dimensional blade profile to a physical size suitable for planar cascade testing or numerical simulation analysis.

5. The method of dimensional reduction of complex radial three-dimensional blade-to-meridian surfaces according to claim 1, wherein, The meridional flow surface two-dimensional blade profile converted by the method is used for planar cascade testing and / or flow field numerical simulation analysis, to obtain load characteristics and profile loss data of the blade profile.

6. A component of a turbomachinery, characterized in that, The basic blade profile of the turbomachinery component is a three-dimensional blade formed by stacking and / or twisting the meridional flow surface two-dimensional profile obtained by the meridional flow surface dimensionality reduction method of the complex radial three-dimensional blade in any one of claims 1 to 5; The turbomachinery component is a radial turbine blade, an axial turbine radial stage blade, or a centrifugal compressor static blade cascade.

7. A turbomachinery characterized by, The turbomachinery component as claimed in claim 6, wherein the working medium of the turbomachinery is air, water vapor, or carbon dioxide.

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