Method, device and medium for generating fluid structured grid of radial impeller machinery

Abstract

The present disclosure provides a method, device and medium for generating a fluid structured grid of a radial impeller machine; the generating method comprises: dividing the radial impeller machine into a plurality of radial blade rows by constructing quasi-orthogonal lines in the fluid domain of the meridian view of the radial impeller machine; obtaining a coordinate transformation relationship between each radial blade row and a corresponding axial blade row to transform each radial blade row into a corresponding axial blade row; determining a spanwise grid division parameter of each axial blade row, and obtaining multiple layers of spanwise grids according to the spanwise grid division parameters; converting the three-dimensional rotational surface corresponding to each layer of spanwise grid into a two-dimensional plane in a reference coordinate system, performing two-dimensional grid division, and stacking to form a three-dimensional grid.

Description

Technical Field

[0001] The present disclosure relates to the technical field of impeller machinery, and in particular to a method, device and medium for generating a fluid structured grid of a radial impeller machinery. Background Art

[0002] Rotating machinery has been widely used in aviation, electricity, machinery, chemical industry and other industrial fields. As the core component of rotating machinery, the performance of turbomachinery under high speed and high load conditions directly affects the performance and working efficiency of the entire rotating machinery. In order to accurately evaluate the performance of turbomachinery, finite element simulation analysis technology has become a commonly used technology. In the process of finite element simulation analysis, the mesh quality of turbomachinery has a decisive influence on the accuracy of finite element simulation results.

[0003] However, in the related art, the blade radius of the radial impeller machine changes significantly along the axis of rotation, resulting in a large absolute value of its flow curvature. When the three-dimensional rotational surface (also called three-dimensional B2B surface) in the impeller machine is projected onto a two-dimensional plane, the blade shape will be severely distorted. The greater the flow curvature of the three-dimensional rotational surface, the more severe the distortion of the blade shape, which not only affects the quality of mesh generation, but also affects the accuracy of simulation analysis.

[0004] Therefore, providing a method that can effectively improve the mesh generation quality of radial impeller machinery is a technical problem that urgently needs to be solved. Summary of the invention

[0005] The present disclosure provides a method, device and medium for generating a fluid structured grid of a radial impeller machine; the method can reduce the distortion of the blade shape in the process of projecting a three-dimensional rotational surface onto a two-dimensional plane, thereby effectively improving the grid generation quality of the radial impeller machine and ensuring the accuracy of the finite element simulation results of the radial impeller machine.

[0006] The technical solution of the present disclosure is achieved as follows:

[0007] In a first aspect, the present disclosure provides a method for generating a fluid structured grid of a radial impeller machine, the generating method comprising:

[0008] Dividing the radial impeller machine into a plurality of radial blade rows by constructing quasi-orthogonal lines in a fluid domain of a meridional view of the radial impeller machine;

[0009] Obtaining a coordinate transformation relationship between each radial flow blade row and a corresponding axial flow blade row to transform each radial flow blade row into a corresponding axial flow blade row;

[0010] Determining spanwise meshing parameters of each axial flow blade row, and obtaining multi-layer spanwise meshes according to the spanwise meshing parameters;

[0011] In the reference coordinate system, the three-dimensional rotation surface corresponding to each layer of the span-wise grid is converted into a two-dimensional plane, and then two-dimensional grid division is performed, and the three-dimensional grid is stacked to form a three-dimensional grid; wherein the abscissa of the reference coordinate system is the meridian coordinate in the meridian coordinate system, and the ordinate is the sum of the product of the radius and the angle in the cylindrical coordinate system and the preset adjustment amount.

[0012] In some examples, the step of dividing the radial impeller machine into a plurality of radial blade rows by constructing quasi-orthogonal lines in a fluid domain of a meridional view of the radial impeller machine comprises:

[0013] constructing quasi-orthogonal lines in the fluid domain based on a meridian view of the radial turbomachinery;

[0014] The radial impeller machine is divided into a plurality of radial blade rows by using the quasi-orthogonal lines located at the middle position of the bladeless section between two adjacent stages of impellers in the radial impeller machine.

[0015] In some examples, the quasi-orthogonal lines include:

[0016] A plurality of first quasi-orthogonal lines are constructed at the blade inlet, the leading edge and the trailing edge of each blade cascade, and the blade outlet in the radial impeller machine; wherein two end points of the first quasi-orthogonal lines are fixed; and

[0017] A plurality of second quasi-orthogonal lines are constructed between two adjacent first quasi-orthogonal lines; wherein the plurality of second quasi-orthogonal lines divide the wheel cover line and the disk line of the radial impeller machinery between the two adjacent first quasi-orthogonal lines evenly; or, two endpoints of the plurality of second quasi-orthogonal lines can move respectively along the wheel cover line and the disk line.

[0018] In some examples, obtaining a coordinate transformation relationship between each radial flow blade row and a corresponding axial flow blade row to transform each radial flow blade row into a corresponding axial flow blade row includes:

[0019] Determine the first coordinates of the four vertices of the quadrilateral region where the target conversion point on each quasi-orthogonal line in each radial flow blade row is located in the radial flow coordinate system and the second coordinates in the index coordinate system; wherein the abscissa of the radial flow coordinate system is the circumferential length of the rotating shaft in the cylindrical coordinate system, and the ordinate is the radius in the cylindrical coordinate system; the abscissa of the index coordinate system is the number of the quasi-orthogonal line in each radial flow blade row, and the ordinate is the blade height percentage corresponding to the target conversion point;

[0020] Based on the first coordinate and the second coordinate, a first coordinate conversion relationship between a third coordinate of the target conversion point in the runoff coordinate system and a fourth coordinate in the subscript coordinate system is obtained by bilinear interpolation;

[0021] Based on the length of the streamline at the mean diameter in each radial blade row, a second coordinate conversion relationship between the fourth coordinate of the target conversion point in the subscript coordinate system and the fifth coordinate in the axial flow coordinate system is obtained; wherein the abscissa of the axial flow coordinate system is the meridian coordinate, and the ordinate is the blade height coordinate corresponding to the target conversion point;

[0022] Based on the first coordinate transformation relationship and the second coordinate transformation relationship, each radial flow blade row is transformed into the corresponding axial flow blade row.

[0023] In some examples, determining span-wise meshing parameters of each axial flow blade row includes:

[0024] Based on the trailing edge height and the leading edge height corresponding to each quasi-orthogonal line in each radial blade row, obtaining the flow channel height corresponding to each quasi-orthogonal line;

[0025] Based on a set double exponential distribution function, the flow channel height corresponding to each quasi-orthogonal line, the height of the first layer of spanwise grids in the spanwise grid division parameters, and the number of spanwise grid points in the spanwise grid division parameters, the leaf height percentage of each spanwise grid point on each quasi-orthogonal line is obtained; wherein the double exponential distribution function is obtained according to a distribution parameter used to characterize the steepness of the spanwise grid distribution;

[0026] Based on the leaf height percentage of each spanwise grid point on each quasi-orthogonal line, the leaf height coordinates of each spanwise grid layer on each quasi-orthogonal line are obtained.

[0027] In some examples, the obtaining of the leaf height percentage of each spanwise grid point on each quasi-orthogonal line based on a set double exponential distribution function, a flow channel height corresponding to each quasi-orthogonal line, a height of a first spanwise grid in the spanwise grid division parameters, and a spanwise grid point number in the spanwise grid division parameters includes:

[0028] For a spanwise mesh with no gaps:

[0029] Obtaining the distribution parameter based on the double exponential distribution function, the number of spanwise grid points, the flow channel height corresponding to each quasi-orthogonal line, and the height of the first spanwise grid layer;

[0030] Based on the distribution parameter, the number of spanwise grid points, the flow channel height corresponding to each quasi-orthogonal line, and the height of the first spanwise grid layer, obtaining the blade height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the gapless spanwise grid;

[0031] For spanwise meshes with wheel cover gap type or spanwise meshes with wheel disk gap type:

[0032] Based on the double exponential distribution function, the number of spanwise grid points, the flow channel height and the gap height corresponding to each quasi-orthogonal line, and the height of the first spanwise grid layer, the distribution parameter and the number of gap grids corresponding to the blade segments in each radial blade row are obtained;

[0033] Based on the distribution parameters, the number of gap grids corresponding to the blade rows in each radial blade row, the number of spanwise grid points, the flow channel height and gap height corresponding to each quasi-orthogonal line, and the height of the first layer of spanwise grids, a blade height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid with a wheel cover gap type or the spanwise grid with a wheel disc gap type is obtained;

[0034] For spanwise mesh transitioning from wheel cover gap type to no gap type or from no gap type to wheel cover gap type:

[0035] According to the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the gapless type and the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the wheel cover gap type, obtain the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the wheel cover gap type that transitions from the gapless type to the wheel cover gap type;

[0036] For spanwise mesh transitioning from a gapped to a non-gap type or from a non-gap type to a gapped mesh:

[0037] According to the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the gapless type and the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the disk gap type, the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the disk gap type transitioning to the gapless type or the spanwise grid of the gapless type transitioning to the disk gap type is obtained.

[0038] In some examples, the ordinate of the reference coordinate system is obtained according to the radius at the meridian coordinate, the angle in the cylindrical coordinate system, and the angle of the camber line in the blade at the meridian coordinate.

[0039] In a second aspect, the present disclosure provides a device for generating a fluid structured grid of a radial impeller machine, the generating device comprising: a first dividing unit, a conversion unit, a determination unit, and a second dividing unit; wherein,

[0040] The first dividing section is configured to divide the radial impeller machine into a plurality of radial blade rows by constructing quasi-orthogonal lines in a fluid domain of a meridian view of the radial impeller machine;

[0041] The conversion unit is configured to obtain a coordinate conversion relationship between each radial flow blade row and a corresponding axial flow blade row, so as to convert each radial flow blade row into a corresponding axial flow blade row;

[0042] The determining unit is configured to determine span-wise meshing parameters of each axial flow blade row, and obtain multiple span-wise meshes according to the span-wise meshing parameters;

[0043] The second division unit is configured to convert the three-dimensional rotation surface corresponding to each layer of the span-wise grid into a two-dimensional plane in a reference coordinate system, perform two-dimensional grid division, and stack them to form a three-dimensional grid; wherein the horizontal coordinate of the reference coordinate system is the meridian coordinate in the meridian coordinate system, and the vertical coordinate is the product of the radius and angle in the cylindrical coordinate system and the sum of a preset adjustment amount.

[0044] In a third aspect, the present disclosure provides a computing device, the computing device comprising: a communication interface, a memory and a processor; each component is coupled together via a bus system; wherein,

[0045] The communication interface is used to receive and send signals during the process of sending and receiving information with other external network elements;

[0046] The memory is used to store a computer program that can be run on the processor;

[0047] The processor is used to execute the steps of the method for generating a fluid structured grid of a radial impeller machine according to the first aspect when running the computer program.

[0048] In a fourth aspect, the present disclosure provides a computer storage medium storing a program for generating a fluid structured grid of a radial impeller machinery. When the program for generating a fluid structured grid of a radial impeller machinery is executed by at least one processor, the steps of the method for generating a fluid structured grid of a radial impeller machinery described in the first aspect are implemented.

[0049] The present disclosure provides a method, device and medium for generating a fluid structured grid of a radial impeller machine; by constructing quasi-orthogonal lines in the fluid domain of the meridian view of the radial impeller machine so as to divide the radial impeller machine into a plurality of radial blade rows; and then by obtaining a coordinate transformation relationship to transform each radial blade row into a corresponding axial blade row; determining the spanwise grid division parameters of each axial blade row, and obtaining multiple layers of spanwise grids according to the spanwise grid division parameters; in a reference coordinate system, converting the three-dimensional rotational surface corresponding to each layer of spanwise grid into a two-dimensional plane, performing two-dimensional grid division, and stacking to form a three-dimensional grid, which can reduce the distortion of the blade shape in the process of projecting the three-dimensional rotational surface onto the two-dimensional plane, effectively improve the grid generation quality of the radial impeller machine, and thereby improve the accuracy of the finite element simulation results of the radial impeller machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A schematic flow chart of a method for generating a fluid structured grid for a radial impeller machine provided in the present disclosure.

[0051] Figure 2 It is a schematic diagram of the structure of a radial impeller machine in the related technology.

[0052] Figure 3 for Figure 2 Meridian view of a radial turbomachinery machine shown.

[0053] Figure 4 Schematic diagram of quasi-orthogonal lines constructed in a fluid domain for the present disclosure.

[0054] Figure 5 A schematic diagram of the fluid domain after the quasi-orthogonal lines provided in the present disclosure are constructed.

[0055] Figure 6 A schematic diagram of dividing a radial impeller machine into a plurality of radial blade rows is provided for the present disclosure.

[0056] Figure 7 A schematic diagram of a radial flow blade row provided for the present disclosure.

[0057] Figure 8 for Figure 7 Schematic diagram of the axial flow blade row obtained by converting the radial flow blade row in FIG.

[0058] Fig. 9 A schematic diagram of a double exponential distribution function corresponding to the gapless spanwise grid provided in the present invention.

[0059] Fig.10 A schematic diagram of a double exponential distribution function corresponding to a spanwise grid with a wheel cover gap type provided in the present invention.

[0060] Fig.11 A schematic diagram of a spanwise grid transitioning from a no-gap type to a wheel cover gap type provided in the present disclosure.

[0061] Fig.12 The single flow channel in the radial blade row provided by the present disclosure is in the coordinate system The geometric shape below.

[0062] Fig.13 The single flow channel in the radial blade row provided by the present disclosure is in the coordinate system The geometric shape below.

[0063] Fig.14 The single flow channel in the radial blade row provided by the present disclosure is in the coordinate system The geometric shape below.

[0064] Fig.15 The single flow channel in the radial blade row provided by the present disclosure is in the coordinate system The geometric shape below.

[0065] Fig.16 Schematic diagram of the topology C block provided for the present disclosure.

[0066] Fig.17 Schematic diagram of the topology O block provided for the present disclosure.

[0067] Fig.18 A schematic diagram of the blade topology after being divided into blocks provided by the present disclosure.

[0068] Fig.19 A schematic diagram of the composition of a device for generating a fluid structured grid of a radial impeller machine provided in the present invention.

[0069] Fig. 20 A block diagram of a computing device provided for the present disclosure. DETAILED DESCRIPTION

[0070] The technical solutions in the present disclosure will be described clearly and completely below in conjunction with the accompanying drawings in the present disclosure.

[0071] It should be noted that, for the sake of clarity, not all features of a specific implementation are described and shown in the specification and drawings. Furthermore, in order to avoid unnecessary details that obscure the technical solution that the present disclosure focuses on, only the equipment structure closely related to the technical solution of the present disclosure is described and shown in the specification and drawings, while other details that are not closely related to the technical content of the present disclosure and are known to those skilled in the art are omitted.

[0072] As mentioned above, the radius of the blades of radial impeller machinery varies greatly along the axis of rotation. In the Gaussian curvature formula, the curvature of the three-dimensional rotating surface is equal to the product of the circumferential curvature and the flow curvature. Since the circumferential curvature of the three-dimensional rotating surface is the inverse of its radius, and the flow curvature is equal to the rate of change of the slope of its radius along the flow direction. Therefore, when the radius of the three-dimensional rotating surface changes greatly, the absolute value of its flow curvature will also be large.

[0073] In Riemannian geometry: the sum of the interior angles of a convex triangle is greater than 180 degrees, the sum of the interior angles of a concave triangle is less than 180 degrees, and the sum of the interior angles of a plane triangle is equal to 180 degrees. In other words, when projecting from a convex or concave surface to a two-dimensional plane, the shape of the triangle will be deformed, and the greater the curvature of the surface, the more severe the distortion of the shape after projection. Similarly, in a radial impeller machine, when a three-dimensional rotating surface is projected onto a two-dimensional plane, the shape of the blade will inevitably be distorted, and the greater the curvature of the three-dimensional rotating surface, the more severe the distortion of the shape of the projected blade. Although the distortion of the blades in a radial impeller machine when projected onto a two-dimensional plane is reversible, it also brings difficulties to the mesh generation of the three-dimensional rotating surface. This is mainly because the mesh shape of the two-dimensional plane is significantly different from the mesh shape of the three-dimensional rotating surface, which leads to the inability to control the quality of the 3D mesh well when the two-dimensional mesh (hereinafter referred to as 2D mesh) is stacked to form a three-dimensional mesh (hereinafter referred to as 3D mesh).

[0074] Based on the above description, the inventors hope to reduce the distortion of the blade shape when the three-dimensional surface of revolution is projected onto the two-dimensional plane by defining different coordinate systems of the two-dimensional plane. Figure 1 As shown, the present disclosure provides a method for generating a fluid structured grid of a radial impeller machine, and the generating method specifically includes the following steps.

[0075] In step S101 , the radial impeller machine is divided into a plurality of radial blade rows by constructing quasi-orthogonal lines in a fluid domain of a meridian view of the radial impeller machine.

[0076] See also Figure 2 , which shows a radial impeller machine 1 in the related art. The radial impeller machine 1 specifically includes the following components: a first-stage impeller 10, a second-stage impeller 20, a wheel disc 30, a wheel cover 40, a return channel 50, a cascade diffuser 60, and a volute 70. Among them, the remaining components except the volute 70 are meshed using structured meshes. In some examples, the volute 70 can be meshed using unstructured meshes or hybrid meshes.

[0077] It should be noted that Figure 2The technical solution of the present disclosure is described in detail by taking the radial impeller machine 1 including the first-stage impeller 10 and the second-stage impeller 20 as an example. However, in the specific implementation process, the radial impeller machine 1 may include one or more stages of impellers, and the present disclosure does not specifically limit this.

[0078] also, Figure 2 The space area occupied by each component in the solid domain is a solid domain. In the specific implementation process, the solid domain is subjected to a Boolean inverse operation to obtain the fluid domain in the radial impeller machine 1. The Boolean inverse operation refers to inverting the geometric shape of the solid domain to obtain the geometric shape of the fluid domain. Specifically, the space area between the impeller 30 and the impeller cover 40 needs to be cut in a meridian view to determine the fluid domain. Figure 3 , which shows Figure 2 The meridian view of the radial impeller machine 1 shown in the figure is Figure 3 The geometry of the fluid domain can be obtained by subtracting the space area occupied by the blades from the space area between the wheel disk 30 and the wheel cover 40 in the meridian view shown.

[0079] In step S102, a coordinate transformation relationship between each radial flow blade row and the corresponding axial flow blade row is obtained to transform each radial flow blade row into the corresponding axial flow blade row.

[0080] In the present disclosure, it is expected to utilize the coordinate transformation relationship between each radial flow blade row and the axial flow blade row to transform each radial flow blade row into the corresponding axial flow blade row, and then utilize the simpler geometric relationship in the axial flow coordinate system to generate a mesh. It is understandable that it is easier to generate a high-quality mesh for an axial flow blade row.

[0081] In step S103, spanwise meshing parameters of each axial flow blade row are determined, and multiple layers of spanwise meshes are obtained according to the spanwise meshing parameters.

[0082] In step S104, the three-dimensional rotational surface corresponding to each layer of the span-wise grid is converted into a two-dimensional plane in the reference coordinate system, and then two-dimensional grid division is performed and stacked to form a three-dimensional grid; wherein the abscissa of the reference coordinate system is the meridian coordinate in the meridian coordinate system, and the ordinate is the sum of the product of the radius and the angle in the cylindrical coordinate system and the preset adjustment amount.

[0083] It should be noted that the three-dimensional surface of revolution corresponding to each spanwise grid layer is obtained by surrounding the rotation axis of the radial impeller machine 1 with the corresponding blade section. In the specific implementation process, the three-dimensional surface of revolution includes a line in the cylindrical coordinate system Next The three-dimensional spiral surface composed of curves, and two The pressure surface and suction surface of the main blade are composed of curves, where the cylindrical coordinate system In z Indicates the axial length of the shaft, represents the radius, The above cylindrical coordinate system z The axis is the rotation axis of the radial impeller machine 1 , and the origin of the cylindrical coordinate system is located on the rotation axis of the radial impeller machine 1 .

[0084] In addition, the common two-dimensional plane coordinate systems in the related art include the coordinate system , coordinate system And the coordinate system ,in m represents the meridian coordinate in the meridian coordinate system, which is also the coordinate along the fluid path passing through the blade; Represents the cylindrical coordinate system The radius below; represents the angle of the cylindrical coordinate system. However, the coordinate system The horizontal axis in In the specific implementation process, the length is compressed. Although the length on the ordinate is not deformed, it will also cause the overall angle to be deformed when the three-dimensional rotational surface is projected onto the two-dimensional plane, with the acute angle decreasing and the obtuse angle increasing. In the actual implementation process, although the length does not deform, the overall angle will still deform sharply. Although the shape of the blade can be kept as constant as possible, the vertical coordinate The geometric shape is constructed by integrating from the leading edge of the blade, which requires a lot of calculations and affects the efficiency of mesh generation. It consists of two parts: the horizontal axis m is the meridian coordinate, the ordinate Cylindrical coordinate system The product of the radius and angle under the reference coordinate system plus the preset adjustment amount. The vertical coordinate Considering the use of preset adjustment amount To correct the deformation of the blade shape, so that the reference coordinate system It can more accurately adapt to the projection of the above three-dimensional rotational surface onto the two-dimensional plane.

[0085] for Figure 1The technical solution shown constructs quasi-orthogonal lines in the fluid domain of the meridian view of the radial impeller machinery so as to divide the radial impeller machinery into multiple radial blade rows; then converts each radial blade row into a corresponding axial blade row by obtaining a coordinate transformation relationship; determines the spanwise meshing parameters of each axial blade row, and obtains multiple layers of spanwise meshes according to the spanwise meshing parameters; converts the three-dimensional rotational surface corresponding to each layer of spanwise mesh into a two-dimensional plane in a reference coordinate system, performs two-dimensional meshing, and stacks to form a three-dimensional mesh, which can reduce the distortion of the blade shape in the process of projecting the three-dimensional rotational surface onto the two-dimensional plane, effectively improve the mesh generation quality of the radial impeller machinery, and thus improve the accuracy of the finite element simulation results of the radial impeller machinery.

[0086] for Figure 1 The technical solution shown, in some possible implementations, divides the radial impeller machine into a plurality of radial blade rows by constructing quasi-orthogonal lines in the fluid domain of the meridian view of the radial impeller machine, including:

[0087] Based on the meridian view of radial turbomachinery, quasi-orthogonal lines are constructed in the fluid domain;

[0088] The radial impeller machine is divided into a plurality of radial blade rows by using a quasi-orthogonal line located at a middle position of a bladeless section between two adjacent stages of impellers in the radial impeller machine.

[0089] For the above implementations, in some examples, the quasi-orthogonal lines include:

[0090] A plurality of first quasi-orthogonal lines are constructed at the blade inlet, the leading edge and the trailing edge of each blade cascade, and the blade outlet in the radial impeller machine; wherein two end points of the first quasi-orthogonal lines are fixed; and

[0091] A plurality of second quasi-orthogonal lines are constructed between two adjacent first quasi-orthogonal lines; wherein the plurality of second quasi-orthogonal lines divide the wheel cover line and the disk line of the radial impeller machinery between the two adjacent first quasi-orthogonal lines evenly; or, the two endpoints of the plurality of second quasi-orthogonal lines can move along the wheel cover line and the disk line respectively.

[0092] The quasi-orthogonal lines constructed in the fluid domain are as follows: Figure 4 and 5 As shown. The inlet 80 of the blade, the leading edge and the trailing edge of each cascade, and the outlet 90 of the blade all form a first quasi-orthogonal line, and the two end points of the first quasi-orthogonal line are fixed during the specific implementation process. Figure 4One endpoint of the first quasi-orthogonal line is shown as a black solid circle, and the other endpoint is shown as a black solid square. A plurality of second quasi-orthogonal lines are set between two adjacent first quasi-orthogonal lines. In some examples, the two endpoints of the second quasi-orthogonal line are evenly distributed along the length of the wheel cover line and the length of the roulette line, respectively. In this case, the second quasi-orthogonal line can be simply referred to as an evenly distributed second quasi-orthogonal line, and one of the endpoints is shown as a hollow circle, and the other endpoint is shown as a hollow square. In other examples, the two endpoints of the second quasi-orthogonal line can also be moved along the wheel cover line and the roulette line, respectively. In this case, the second quasi-orthogonal line can be simply referred to as a second quasi-orthogonal line with movable endpoints, such as Figure 4 It should be noted that, in a specific implementation process, the second quasi-orthogonal lines that are evenly distributed and the second quasi-orthogonal lines whose endpoints can be moved can be switched according to actual conditions.

[0093] In addition, the quasi-orthogonal lines constructed during the specific implementation process need to be as perpendicular to the flow channel geometry as possible. In addition, when the length difference between the wheel cover line and the wheel disc line is large and the flow channel is greatly twisted, such as the return channel 50, when constructing the second quasi-orthogonal line, the latter second quasi-orthogonal line may cross the previous second quasi-orthogonal line. At this time, it is necessary to avoid this situation by controlling the second quasi-orthogonal line with movable endpoints. It should be noted that the second quasi-orthogonal line with movable endpoints is usually used as the dividing line between the arc segment and the straight line segment in the shape of the fluid domain. Among them, Figure 5 A schematic diagram of the fluid domain after the quasi-orthogonal lines are constructed is shown.

[0094] In this disclosure, Figure 4 As shown, from the trailing edge of the first stage impeller 10 to the leading edge of the second stage impeller 20, that is, Figure 4 The leafless section from the quasi-orthogonal line i to the quasi-orthogonal line x in the leafless section is obtained by using the quasi-orthogonal line v in the middle of the leafless section ( Figure 4 The bladeless segment is divided into a first part I and a second part II as indicated by the dotted arrow in FIG. 1 , wherein the first part I and the second part II belong to the first-stage impeller 10 and the second-stage impeller 20, respectively. According to the above method, Figure 6 As shown, the radial impeller machine 1 is divided into four radial blade rows. It can be understood that each blade row 100 after division includes an inlet bladeless section 101, a blade section 102, and an outlet bladeless section 103. Subsequently, each radial blade row 100 is meshed separately, and then spliced ​​to obtain the whole machine mesh of the radial impeller machine 1.

[0095] for Figure 1In some possible implementations of the technical solution shown, obtaining a coordinate transformation relationship between each radial flow blade row and a corresponding axial flow blade row to transform each radial flow blade row into a corresponding axial flow blade row includes:

[0096] Determine the first coordinates of the four vertices of the quadrilateral region where the target conversion point on each quasi-orthogonal line in each radial blade row is located in the radial coordinate system and the second coordinates in the index coordinate system; wherein the abscissa of the radial coordinate system is the axial length in the cylindrical coordinate system, and the ordinate is the radius in the cylindrical coordinate system; the abscissa of the index coordinate system is the number of the quasi-orthogonal line in each radial blade row, and the ordinate is the percentage of the blade height corresponding to the target conversion point;

[0097] Based on the first coordinate and the second coordinate, a first coordinate conversion relationship between a third coordinate of the target conversion point in the runoff coordinate system and a fourth coordinate in the subscript coordinate system is obtained by bilinear interpolation;

[0098] Based on the length of the streamline at the mean diameter in each radial blade row, a second coordinate conversion relationship between the fourth coordinate of the target conversion point in the subscript coordinate system and the fifth coordinate in the axial flow coordinate system is obtained; wherein the abscissa of the axial flow coordinate system is the meridian coordinate, and the ordinate is the blade height coordinate corresponding to the target conversion point;

[0099] Based on the first coordinate transformation relationship and the second coordinate transformation relationship, each radial flow blade row is transformed into a corresponding axial flow blade row.

[0100] Specifically, if Figure 7 As shown, for a radial blade row 100, the streamline at the mean diameter can be obtained by connecting the midpoints of all quasi-orthogonal lines ( Figure 7 After coordinate transformation, the streamline at the mean diameter can be transformed from a curve into a straight line, as shown in Figure 8 As shown, the first quasi-orthogonal line and the second quasi-orthogonal line in the radial blade row 100 are both perpendicular to the streamline at the mean diameter.

[0101] The specific process of obtaining the first coordinate transformation relationship and the second coordinate transformation relationship is as follows:

[0102] First, three coordinate systems are established: runoff coordinate system , subscript coordinate system , axial flow coordinate system The runoff coordinate system is The horizontal axis is the axial length in the cylindrical coordinate system, the ordinate is the radius in the cylindrical coordinate system. The horizontal axis is the number of the quasi-orthogonal line in each radial blade row, and the ordinate is the percentage of blade height corresponding to the target conversion point in each radial blade row. Axial flow coordinate system The horizontal axis is the meridian coordinate, the ordinate is the blade height coordinate corresponding to the target transformation point in each radial blade row.

[0103] Secondly, Figure 7 The radial blade row 100 includes For example, the quasi-orthogonal lines The runoff coordinates of the intersection of the quasi-orthogonal lines and the wheel 30 are ,in, , the corresponding leaf height percentage ; The runoff coordinates of the intersection of the quasi-orthogonal lines and the wheel cover 40 are , corresponding to the percentage of leaf height , we can get the The runoff coordinates of the midpoint of the quasi-orthogonal line are for:

[0104]

[0105]

[0106] And the corresponding leaf height percentage .

[0107] Understandably, if Figure 7 As shown above The quasi-orthogonal lines and the streamlines at the mean diameter divide the meridian plane of the corresponding radial blade row into quadrilateral area. The runoff coordinates of the target conversion point on the quasi-orthogonal lines , determine where it falls on the subscript coordinates , subscript coordinates , subscript coordinates And the subscript coordinates In the enclosed quadrilateral area, the above-mentioned first coordinate transformation relationship can be obtained through bilinear interpolation as follows:

[0108] ;

[0109] ;

[0110] in, ; ;and Indicates Quasi-orthogonal lines in The horizontal coordinate in the coordinate system; represents the blade height percentage corresponding to the target conversion point. When the target conversion point is located on the wheel cover 40, is 1, when the target conversion point is on the wheel 30, is 0, when the target conversion point is located on the streamline at the mean diameter, is 0.5; Indicated in the subscript coordinates The axial length at Indicated in the subscript coordinates The radius at .

[0111] It is understandable that in the specific implementation process, if it is known that The leaf height percentage of the target conversion point on the quasi-orthogonal lines , that is, we can calculate the The runoff coordinates of the target conversion point on the quasi-orthogonal lines Conversely, if we know The runoff coordinates of the target conversion point on the quasi-orthogonal lines , we can calculate the The leaf height percentage of the target conversion point on the quasi-orthogonal lines .

[0112] Secondly, calculate the length of the streamline along the mean diameter, and obtain the second coordinate transformation relationship as shown below:

[0113]

[0114]

[0115] in, Indicates Meridian coordinates of the target transformation point corresponding to the intersection of the quasi-orthogonal lines and the streamline at the mean diameter; Indicates The intersection of the quasi-orthogonal lines and the streamline at the mean diameter and the percentage of leaf height is The leaf height coordinates of the target transformation point; Indicates the starting meridian coordinate.

[0116] Understandably, if we know The leaf height percentage of the target conversion point on the quasi-orthogonal lines , we can calculate the The axial flow coordinates of the target transformation point on the quasi-orthogonal lines Conversely, if we know The axial flow coordinates of the target transformation point on the quasi-orthogonal lines , we can solve the first The leaf height percentage of the target conversion point on the quasi-orthogonal lines .

[0117] In the present disclosure, each radial flow blade row can be converted into a corresponding axial flow blade row according to the first coordinate transformation relationship and the second coordinate transformation relationship mentioned above.

[0118] for Figure 1 In some possible implementations of the technical solution shown, determining the spanwise meshing parameters of each axial flow blade row includes:

[0119] Based on the trailing edge height and the leading edge height corresponding to each quasi-orthogonal line in each axial flow blade row, the flow channel height corresponding to each quasi-orthogonal line is obtained;

[0120] Based on the set double exponential distribution function, the flow channel height corresponding to each quasi-orthogonal line, the height of the first layer of spanwise grid in the spanwise grid division parameters, and the number of spanwise grid points in the spanwise grid division parameters, the leaf height percentage of each spanwise grid point on each quasi-orthogonal line is obtained; wherein the double exponential distribution function is obtained according to the distribution parameter used to characterize the steepness of the spanwise grid distribution;

[0121] Based on the leaf height percentage of each spanwise grid point on each quasi-orthogonal line, the leaf height coordinates of each spanwise grid layer on each quasi-orthogonal line are obtained.

[0122] For the above implementation, in some examples, based on the set double exponential distribution function, the flow channel height corresponding to each quasi-orthogonal line, the height of the first layer of spanwise grid in the spanwise grid division parameters, and the number of spanwise grid points in the spanwise grid division parameters, the leaf height percentage of each spanwise grid point on each quasi-orthogonal line is obtained, including:

[0123] For a spanwise mesh with no gaps:

[0124] The distribution parameters are obtained based on the double exponential distribution function, the number of spanwise grid points, the flow channel height corresponding to each quasi-orthogonal line, and the height of the first spanwise grid layer;

[0125] Based on the distribution parameters, the number of spanwise grid points, the flow channel height corresponding to each quasi-orthogonal line and the height of the first spanwise grid layer, the blade height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the gapless spanwise grid is obtained;

[0126] For spanwise meshes with wheel cover gap type or spanwise meshes with wheel disk gap type:

[0127] Based on the double exponential distribution function, the number of spanwise grid points, the flow channel height and gap height corresponding to each quasi-orthogonal line, and the height of the first spanwise grid layer, the distribution parameters and the number of gap grids corresponding to the blade segments in each radial blade row are obtained;

[0128] Based on the distribution parameters, the number of gap grids corresponding to the blade segments in each radial blade row, the number of spanwise grid points, the flow channel height and gap height corresponding to each quasi-orthogonal line, and the height of the first spanwise grid layer, the blade height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid with a wheel cover gap type or the spanwise grid with a wheel disk gap type is obtained;

[0129] For spanwise mesh transitioning from wheel cover gap type to no gap type or from no gap type to wheel cover gap type:

[0130] According to the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the gapless type and the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the wheel cover gap type, the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the wheel cover gap type is obtained;

[0131] For spanwise mesh transitioning from a gapped to a non-gap type or from a non-gap type to a gapped mesh:

[0132] According to the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the gapless type and the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the disk gap type, the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the disk gap type transitioning to the gapless type or from the gapless type to the disk gap type is obtained.

[0133] In some examples, the spanwise grid is divided into three types, namely, a spanwise grid without gaps, a spanwise grid with gaps, and a spanwise grid of transition type, wherein the spanwise grid with gaps is further divided into a spanwise grid with wheel cover gaps and a spanwise grid with wheel disc gaps. The transitional spanwise grid is further divided into a spanwise grid transitioning from a spanwise grid without gaps to a spanwise grid with gaps and a spanwise grid transitioning from a spanwise grid with gaps to a spanwise grid without gaps.

[0134] In the specific implementation process, if the radial impeller machine is a gapless type, the radial blade row adopts a spanwise grid of the gapless type; if the radial impeller machine has a wheel cover gap, the inlet bladeless section of the radial blade row uses a spanwise grid that transitions from the gapless type to the wheel cover gap type, the blade section uses the spanwise grid of the wheel cover gap type, and the outlet bladeless section uses the spanwise grid that transitions from the wheel cover gap type to the gapless type; if the radial impeller machine has a disk gap, the inlet bladeless section of the radial blade row uses a spanwise grid that transitions from the gapless type to the disk gap type, the blade section uses the spanwise grid of the disk gap type, and the outlet bladeless section uses the spanwise grid that transitions from the disk gap type to the gapless type.

[0135] Specifically, if Fig. 9 As shown in the figure, for the spanwise grid without gaps, The flow channel height corresponding to the quasi-orthogonal lines is: , in the specific implementation process, the specific form of the double exponential distribution function is as follows:

[0136]

[0137] in, Indicates the spanwise grid number; Indicates the number of spanwise grid points; d Represents the distribution parameter used to characterize the steepness of the span-wise mesh distribution.

[0138] By solving Get the distribution parameters ,and ;in, Indicates the height of the first layer of grid.

[0139] Therefore, the The first quasi-orthogonal line Solo Exhibition Towards Grid Point Leaf height percentage for:

[0140]

[0141] like Fig.10 As shown, for the spanwise grid with wheel cover gap, by solving get and ,and , is a positive real number; Indicates the spanwise grid with wheel cover gap type The distribution parameters corresponding to the quasi-orthogonal lines; Indicates the spanwise grid number of the blade tip; Indicatesu The gap height on the quasi-orthogonal lines. Fig.10 The solid arrows in illustrative figures indicate the positions of the blade segments, and the dashed arrows in illustrative figures indicate the positions of the gap segments on the wheel cover 40 .

[0142] It should be noted that since each quasi-orthogonal line can be solved to obtain the corresponding number of gap grids, that is, the number of the spanwise grid of the blade tip mentioned above Therefore, by taking the arithmetic mean of all the gap grid numbers corresponding to the blade segments in each radial blade row and rounding it off, the gap grid number corresponding to the blade segment of each radial blade row can be obtained. , and then by solving get , ,and , ;in, Indicates u The distribution parameters corresponding to the quasi-orthogonal lines The distribution parameters of the span-wise grid of the gap segment obtained after correction; Indicates u The distribution parameters corresponding to the quasi-orthogonal lines The distribution parameters of the span-wise grid of the blade segment obtained after correction.

[0143] Therefore, the On the quasi-orthogonal line Solo Exhibition Towards Grid Point Leaf height percentage for:

[0144]

[0145] For the spanwise grid with disc gap, the positions of the gap segment and blade segment are interchanged compared with the spanwise grid with wheel cover gap. By the same token, we can get: On the quasi-orthogonal line Solo Exhibition Towards Grid Point Leaf height percentage for:

[0146]

[0147] For the spanwise meshes transitioning from the wheel cover gap type to the gapless type, from the gapless type to the wheel cover gap type, from the gapless type to the wheel disc gap type, and from the wheel disc gap type to the gapless type, a linear transition method is used, such as Fig.11The schematic diagram of the spanwise grid transitioning from the no-gap type to the wheel cover gap type along the direction from the trailing edge of the previous blade to the leading edge of the current blade (indicated by the solid arrow in the figure), wherein the dotted arrow in the figure indicates the position of the gap section on the wheel cover 40, and thus the first On the quasi-orthogonal line Solo Exhibition Towards Grid Point Leaf height percentage for:

[0148]

[0149] in, represents the meridian coordinate of the trailing edge of the blade where A is located; Represents the meridian coordinate of the leading edge of the blade where B is located; when A is a span-wise grid with a wheel cover gap or a span-wise grid with a wheel disc gap, B is a span-wise grid without a gap; when A is a span-wise grid without a gap, B is a span-wise grid with a wheel cover gap or a span-wise grid with a wheel disc gap.

[0150] It can be understood that after obtaining the blade height percentage of each spanwise grid point on each quasi-orthogonal line in each axial flow blade row, the blade height coordinates at each quasi-orthogonal line in the axial flow blade row can be obtained according to the second coordinate transformation relationship in the aforementioned technical solution. .

[0151] for Figure 1 In the technical solution shown, in some possible implementations, the ordinate of the reference coordinate system is obtained according to the radius at the meridian coordinate, the angle in the cylindrical coordinate system, and the angle of the arc in the blade at the meridian coordinate.

[0152] It can be understood that after each layer of span-wise grid is determined, its corresponding three-dimensional rotational surface can be obtained. In the specific implementation process, each three-dimensional rotational surface needs to generate a 2D grid respectively, and then stacked to form a 3D grid.

[0153] It should be noted that if there are splitter blades in the radial impeller machine, every two The curve can form a set of shunt blades. In addition, in the process of converting radial flow blade rows into axial flow blade rows, the three-dimensional surface of revolution is used Curve composition, blade use Curve composition.

[0154] In addition, when there is a radial impeller machine When there are 3 main blades, for a 360-degree three-dimensional rotating surface, we only need to calculate The flow channel of the degree is sufficient, and the remaining flow channel parts can be obtained through symmetric operations. If there are splitter blades in the radial impeller machine, each splitter blade and main blade needs to generate a flow channel separately, and then generate a flow channel grid.

[0155] In the present disclosure, after generating a three-dimensional surface of revolution, in the reference coordinate system The 3D surface of revolution is converted into a 2D plane, and then a 2D mesh is generated. The vertical coordinate in Set as Function , then the function The expression is as follows:

[0156]

[0157] in, Indicates the corresponding angle of the blade's mid-arc in the cylindrical coordinate system; Indicates the radius corresponding to the meridian coordinate in the cylindrical coordinate system.

[0158] It should be noted that since the bladeless segment has no mid-camber line, is the corresponding angle of the blade leading edge in the cylindrical coordinate system; for the bladeless outlet is the corresponding angle of the blade trailing edge in the cylindrical coordinate system.

[0159] See also Figures 12 to 15 , which respectively show the coordinate system of a single flow channel in a radial blade row , coordinate system , coordinate system And the coordinate system The geometric shape below. Figures 12 to 15 It can be seen that using the reference coordinate system provided in this disclosure When the three-dimensional rotational surface is projected onto a two-dimensional plane, the lengths represented by the horizontal and vertical coordinates and the mid-arc line of the blade will not be deformed, and the deformations at other positions are also minimal, thereby improving the quality of the final generated mesh.

[0160] It should be noted that the arc line of the blade extends upward and downward respectively. The periodic boundary of a single flow channel can be obtained.

[0161] In the specific implementation process, the trailing edge of the blade in the radial blade row is a shear surface, not an elliptical surface. In the meshing process, if the trailing edge of the blade is a shear surface, a topological C block is used, such as Fig.16 If the trailing edge of the blade is an elliptical surface, use the topological O block, such as Fig.17 Specifically, the thickness of the topological O block or C block for:

[0162]

[0163] in, The radius representing the leading edge of the blade; Indicates the input parameters of the setting.

[0164] In the specific implementation process, the topological O block or C block thickness is extended outward along the entire blade , as the boundary of the topological O block or the topological C block, and four H blocks are divided from it, namely H 1 Block, H 2 Block, H 3 Block and H 4 Block, such as Fig.18 As shown. Then along the annular direction and normal direction of the topological C block or the topological O block, the opening of the topological C block, H 1 Block flow direction, H 2 The circumference of the block, H 3 The flow direction of the block and H 4 The number of circumferential grids and the growth factor are set for the circumferential direction of the block. Specifically, the number of circumferential grids can be calculated according to the following formula:

[0165]

[0166] The symbol [ ] indicates rounding to the nearest integer. represents the spanwise grid number, represents the average geometric height in span direction, It represents the average geometric width of the circumferential grid block in the corresponding direction, for example, H 1 Block flow is the distance from the blade inlet to the leading edge of the blade, the annular It is the length of one rotation around the blade surface.

[0167] It is understandable that in order to ensure the stability of the subsequent simulation analysis process, it is also necessary to ensure that the sizes of adjacent grids at the interfaces of different blocks are basically the same. Therefore, the grid settings of the two-dimensional grid need to be consistent, so that the number of grids in the two-dimensional grid is consistent. Finally, the grids corresponding to the same block number corresponding to different three-dimensional rotational surfaces are connected to form a 3D grid.

[0168] Finally, the above 3D grid is smoothed to further optimize the grid quality, which is not elaborated in detail in the present disclosure.

[0169] Based on the same inventive concept as the above technical solution, see Fig.19, which shows a device 190 for generating a fluid structured grid of a radial impeller machine provided by an embodiment of the present disclosure, the device 190 for generating a fluid structured grid of a radial impeller machine comprises: a first dividing unit 1901, a conversion unit 1902, a determination unit 1903 and a second dividing unit 1904; wherein,

[0170] A first dividing unit 1901 is configured to divide the radial impeller machine into a plurality of radial blade rows by constructing quasi-orthogonal lines in a fluid domain of a meridional view of the radial impeller machine;

[0171] A conversion unit 1902 is configured to obtain a coordinate conversion relationship between each radial flow blade row and a corresponding axial flow blade row, so as to convert each radial flow blade row into a corresponding axial flow blade row;

[0172] The determination unit 1903 is configured to determine the span-wise meshing parameters of each axial flow blade row, and obtain multiple span-wise meshes according to the span-wise meshing parameters;

[0173] The second division unit 1904 is configured to convert the three-dimensional rotation surface corresponding to each layer of the span-wise grid into a two-dimensional plane in the reference coordinate system, perform two-dimensional grid division, and stack them to form a three-dimensional grid; wherein the horizontal coordinate of the reference coordinate system is the meridian coordinate in the meridian coordinate system, and the vertical coordinate is the product of the radius and angle in the cylindrical coordinate system and the sum of a preset adjustment amount.

[0174] It should be noted that for the specific implementation methods or implementation examples of the functions configured by the above-mentioned components, please refer to the corresponding steps, implementation methods and examples of the aforementioned technical solutions, and this disclosure will not elaborate on them here.

[0175] The components in this embodiment may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of software function modules.

[0176] If the above integrated unit is implemented in the form of a software function module and is not sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment is essentially or the part that contributes to the prior art or the whole or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) or a processor to perform all or part of the steps of the above method of this embodiment. The aforementioned storage medium includes: U disk, mobile hard disk, read only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store program codes.

[0177] Therefore, an embodiment of the present disclosure provides a computer storage medium, which stores a program for generating a fluid structured grid of a radial impeller machinery. When the program for generating a fluid structured grid of a radial impeller machinery is executed by at least one processor, the steps of the method for generating a fluid structured grid of a radial impeller machinery are implemented.

[0178] According to the above-mentioned fluid structured grid generating device 190 and computer storage medium of radial impeller machinery, see Fig. 20 , which shows the specific hardware structure of a computing device 200 provided by an embodiment of the present disclosure, which is capable of implementing the above-mentioned radial impeller machinery fluid structured grid generation device 190. The computing device 200 may be a wireless device, a mobile or cellular phone (including a so-called smart phone), a personal digital assistant (PDA), a video game console (including a video display, a mobile video game device, a mobile video conferencing unit), a laptop computer, a desktop computer, a TV set-top box, a tablet computing device, an e-book reader, a fixed or mobile media player, etc. The computing device 200 includes: a communication interface 2001, a memory 2002 and a processor 2003; the various components are coupled together through a bus system 2004. It can be understood that the bus system 2004 is used to realize the connection and communication between these components. In addition to the data bus, the bus system 2004 also includes a power bus, a control bus and a status signal bus. However, for the sake of clarity, in Fig. 20 In the figure, various buses are labeled as bus system 2004. Among them,

[0179] The communication interface 2001 is used to receive and send signals during the process of sending and receiving information with other external network elements;

[0180] The memory 2002 is used to store a computer program that can be run on the processor 2003;

[0181] The processor 2003 is configured to perform the following steps when running the computer program:

[0182] The radial impeller machine is divided into a plurality of radial blade rows by constructing quasi-orthogonal lines in the fluid domain of the meridional view of the radial impeller machine;

[0183] Obtaining a coordinate transformation relationship between each radial flow blade row and a corresponding axial flow blade row to transform each radial flow blade row into a corresponding axial flow blade row;

[0184] Determine the spanwise meshing parameters of each axial flow blade row, and obtain multi-layer spanwise meshes according to the spanwise meshing parameters;

[0185] In the reference coordinate system, the three-dimensional rotation surface corresponding to each layer of the span-wise grid is converted into a two-dimensional plane, and then two-dimensional grid division is performed and stacked to form a three-dimensional grid; wherein the abscissa of the reference coordinate system is the meridian coordinate in the meridian coordinate system, and the ordinate is the sum of the product of the radius and the angle in the cylindrical coordinate system and the preset adjustment amount.

[0186] It can be understood that the memory 2002 in the embodiment of the present disclosure can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate synchronous DRAM (DDRSDRAM), enhanced synchronous DRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct RAM bus DRAM (DRRAM). The memory 2002 of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0187] The processor 2003 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit or software instructions in the processor 2003. The above processor 2003 may be a general processor, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The disclosed methods, steps and logic block diagrams in the embodiments of the present disclosure can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in conjunction with the embodiments of the present disclosure can be directly embodied as a hardware decoding processor to execute, or can be executed by a combination of hardware and software modules in the decoding processor. The software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 2002, and the processor 2003 reads the information in the memory 2002 and completes the steps of the above method in combination with its hardware.

[0188] It is understood that the embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit may be implemented in one or more application specific integrated circuits (ASIC), digital signal processors (DSP), digital signal processing devices (DSPD), programmable logic devices (PLD), field programmable gate arrays (FPGA), general purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the above functions of the present application, or a combination thereof.

[0189] For software implementation, the techniques described above in this article can be implemented by modules (such as procedures, functions, etc.) that perform the functions described above in this article. The software code can be stored in a memory and executed by a processor. The memory can be implemented in the processor or outside the processor.

[0190] Specifically, the processor 2003 is further configured to execute the steps of the method for generating the fluid structured grid of the radial impeller machinery in the aforementioned technical solution when running the aforementioned computer program, which will not be described in detail here.

[0191] It should be noted that the technical solutions described in the present disclosure can be combined arbitrarily without conflict.

[0192] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for generating a fluid structured grid for a radial impeller machine, characterized in that: The generation method comprises: Dividing the radial impeller machine into a plurality of radial blade rows by constructing quasi-orthogonal lines in a fluid domain of a meridional view of the radial impeller machine; Obtaining a coordinate transformation relationship between each radial flow blade row and a corresponding axial flow blade row to transform each radial flow blade row into a corresponding axial flow blade row; Determining spanwise meshing parameters of each axial flow blade row, and obtaining multi-layer spanwise meshes according to the spanwise meshing parameters; In a reference coordinate system, the three-dimensional surface of revolution corresponding to each layer of span-wise grid is converted into a two-dimensional plane, and then two-dimensional grid division is performed, and the three-dimensional grid is stacked to form a three-dimensional grid; wherein the abscissa of the reference coordinate system is the meridian coordinate in the meridian coordinate system, and the ordinate is the sum of the product of the radius and the angle in the cylindrical coordinate system and the preset adjustment amount; Wherein, determining the spanwise meshing parameters of each axial flow blade row includes: Based on the trailing edge height and the leading edge height corresponding to each quasi-orthogonal line in each radial blade row, obtaining the flow channel height corresponding to each quasi-orthogonal line; Based on a set double exponential distribution function, the flow channel height corresponding to each quasi-orthogonal line, the height of the first layer of spanwise grids in the spanwise grid division parameters, and the number of spanwise grid points in the spanwise grid division parameters, the leaf height percentage of each spanwise grid point on each quasi-orthogonal line is obtained; wherein the double exponential distribution function is obtained according to a distribution parameter used to characterize the steepness of the spanwise grid distribution; Based on the leaf height percentage of each spanwise grid point on each quasi-orthogonal line, obtaining the leaf height coordinates of each spanwise grid layer on each quasi-orthogonal line; Wherein, based on the set double exponential distribution function, the flow channel height corresponding to each quasi-orthogonal line, the height of the first layer of spanwise grid in the spanwise grid division parameters, and the number of spanwise grid points in the spanwise grid division parameters, obtaining the leaf height percentage of each spanwise grid point on each quasi-orthogonal line includes: For a spanwise mesh with no gaps: Obtaining the distribution parameter based on the double exponential distribution function, the number of spanwise grid points, the flow channel height corresponding to each quasi-orthogonal line, and the height of the first spanwise grid layer; Based on the distribution parameter, the number of spanwise grid points, the flow channel height corresponding to each quasi-orthogonal line, and the height of the first spanwise grid layer, obtaining the blade height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the gapless spanwise grid; For spanwise meshes with wheel cover gap type or spanwise meshes with wheel disk gap type: Based on the double exponential distribution function, the number of spanwise grid points, the flow channel height and the gap height corresponding to each quasi-orthogonal line, and the height of the first spanwise grid layer, the distribution parameter and the number of gap grids corresponding to the blade segments in each radial blade row are obtained; Based on the distribution parameters, the number of gap grids corresponding to the blade segments in each radial blade row, the number of spanwise grid points, the flow channel height and gap height corresponding to each quasi-orthogonal line, and the height of the first layer of spanwise grids, a blade height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to a spanwise grid with a wheel cover gap type or a spanwise grid with a wheel disc gap type is obtained; For spanwise mesh transitioning from wheel cover gap type to no gap type or from no gap type to wheel cover gap type: According to the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the gapless type and the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the wheel cover gap type, obtain the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the wheel cover gap type that transitions from the gapless type to the wheel cover gap type; For spanwise mesh transitioning from a gapped to a non-gap type or from a non-gap type to a gapped mesh: According to the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the gapless type and the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the disk gap type, the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the disk gap type transitioning to the gapless type or the spanwise grid of the gapless type transitioning to the disk gap type is obtained.

2. The generation method according to claim 1, characterized in that: The method divides the radial impeller machine into a plurality of radial blade rows by constructing quasi-orthogonal lines in the fluid domain of the meridian view of the radial impeller machine, comprising: constructing quasi-orthogonal lines in the fluid domain based on a meridian view of the radial turbomachinery; The radial impeller machine is divided into a plurality of radial blade rows by using the quasi-orthogonal lines located at the middle position of the bladeless section between two adjacent stages of impellers in the radial impeller machine.

3. The generation method according to claim 2, characterized in that The quasi-orthogonal lines include: A plurality of first quasi-orthogonal lines are constructed at the blade inlet, the leading edge and the trailing edge of each blade cascade, and the blade outlet in the radial impeller machine; wherein two end points of the first quasi-orthogonal lines are fixed; and A plurality of second quasi-orthogonal lines are constructed between two adjacent first quasi-orthogonal lines; wherein the plurality of second quasi-orthogonal lines divide the wheel cover line and the disk line of the radial impeller machinery between the two adjacent first quasi-orthogonal lines evenly; or, two endpoints of the plurality of second quasi-orthogonal lines can move respectively along the wheel cover line and the disk line.

4. The generation method according to claim 1, characterized in that: The step of obtaining a coordinate transformation relationship between each radial flow blade row and a corresponding axial flow blade row to transform each radial flow blade row into a corresponding axial flow blade row includes: Determine the first coordinates of the four vertices of the quadrilateral region where the target conversion point on each quasi-orthogonal line in each radial blade row is located in the radial coordinate system and the second coordinates in the index coordinate system; wherein the abscissa of the radial coordinate system is the axial length in the cylindrical coordinate system, and the ordinate is the radius in the cylindrical coordinate system; the abscissa of the index coordinate system is the number of the quasi-orthogonal line in each radial blade row, and the ordinate is the percentage of the blade height corresponding to the target conversion point; Based on the first coordinate and the second coordinate, a first coordinate conversion relationship between a third coordinate of the target conversion point in the runoff coordinate system and a fourth coordinate in the subscript coordinate system is obtained by bilinear interpolation; Based on the length of the streamline at the mean diameter in each radial blade row, a second coordinate conversion relationship between the fourth coordinate of the target conversion point in the subscript coordinate system and the fifth coordinate in the axial flow coordinate system is obtained; wherein the abscissa of the axial flow coordinate system is the meridian coordinate, and the ordinate is the blade height coordinate corresponding to the target conversion point; Based on the first coordinate transformation relationship and the second coordinate transformation relationship, each radial flow blade row is transformed into the corresponding axial flow blade row.

5. The generation method according to claim 1, characterized in that: The ordinate of the reference coordinate system is obtained according to the radius at the meridian coordinate, the angle in the cylindrical coordinate system, and the angle of the arc line in the blade at the meridian coordinate.

6. A device for generating a fluid structured grid for a radial impeller machine, characterized in that: The generating device comprises: a first dividing unit, a converting unit, a determining unit and a second dividing unit; wherein, The first dividing section is configured to divide the radial impeller machine into a plurality of radial blade rows by constructing quasi-orthogonal lines in a fluid domain of a meridian view of the radial impeller machine; The conversion unit is configured to obtain a coordinate conversion relationship between each radial flow blade row and a corresponding axial flow blade row, so as to convert each radial flow blade row into a corresponding axial flow blade row; The determining unit is configured to determine span-wise meshing parameters of each axial flow blade row, and obtain multiple span-wise meshes according to the span-wise meshing parameters; The second division unit is configured to convert the three-dimensional rotational surface corresponding to each layer of the span-wise grid into a two-dimensional plane in the reference coordinate system, and then perform two-dimensional grid division, and stack to form a three-dimensional grid; wherein the abscissa of the reference coordinate system is the meridian coordinate in the meridian coordinate system, and the ordinate is the sum of the product of the radius and the angle in the cylindrical coordinate system and the preset adjustment amount; Wherein, the determining unit is configured as follows: Based on the trailing edge height and the leading edge height corresponding to each quasi-orthogonal line in each radial blade row, obtaining the flow channel height corresponding to each quasi-orthogonal line; Based on a set double exponential distribution function, the flow channel height corresponding to each quasi-orthogonal line, the height of the first layer of spanwise grids in the spanwise grid division parameters, and the number of spanwise grid points in the spanwise grid division parameters, the leaf height percentage of each spanwise grid point on each quasi-orthogonal line is obtained; wherein the double exponential distribution function is obtained according to a distribution parameter used to characterize the steepness of the spanwise grid distribution; Based on the leaf height percentage of each spanwise grid point on each quasi-orthogonal line, obtaining the leaf height coordinates of each spanwise grid layer on each quasi-orthogonal line; The determining unit is further configured as: For a spanwise mesh with no gaps: Obtaining the distribution parameter based on the double exponential distribution function, the number of spanwise grid points, the flow channel height corresponding to each quasi-orthogonal line, and the height of the first spanwise grid layer; Based on the distribution parameter, the number of spanwise grid points, the flow channel height corresponding to each quasi-orthogonal line, and the height of the first spanwise grid layer, obtaining the blade height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the gapless spanwise grid; For spanwise meshes with wheel cover gap type or spanwise meshes with wheel disk gap type: Based on the double exponential distribution function, the number of spanwise grid points, the flow channel height and the gap height corresponding to each quasi-orthogonal line, and the height of the first spanwise grid layer, the distribution parameter and the number of gap grids corresponding to the blade segments in each radial blade row are obtained; Based on the distribution parameters, the number of gap grids corresponding to the blade segments in each radial blade row, the number of spanwise grid points, the flow channel height and gap height corresponding to each quasi-orthogonal line, and the height of the first layer of spanwise grids, a blade height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to a spanwise grid with a wheel cover gap type or a spanwise grid with a wheel disc gap type is obtained; For spanwise mesh transitioning from wheel cover gap type to no gap type or from no gap type to wheel cover gap type: According to the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the gapless type and the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the wheel cover gap type, obtain the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the wheel cover gap type that transitions from the gapless type to the wheel cover gap type; For spanwise mesh transitioning from a gapped to a non-gap type or from a non-gap type to a gapped mesh: According to the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the gapless type and the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the disk gap type, the leaf height percentage of each spanwise grid point on each quasi-orthogonal line corresponding to the spanwise grid of the disk gap type transitioning to the gapless type or the spanwise grid of the gapless type transitioning to the disk gap type is obtained.

7. A computing device, characterized in that The computing device includes: a communication interface, a memory and a processor; each component is coupled together through a bus system; wherein, The communication interface is used to receive and send signals during the process of sending and receiving information with other external network elements; The memory is used to store a computer program that can be run on the processor; The processor is used to execute the steps of the method for generating a fluid structured grid for a radial impeller machine as claimed in any one of claims 1 to 5 when running the computer program.

8. A computer storage medium, characterized in that: The computer storage medium stores a program for generating a fluid structured grid for a radial impeller machine, and when the program for generating a fluid structured grid for a radial impeller machine is executed by at least one processor, the steps of the method for generating a fluid structured grid for a radial impeller machine described in any one of claims 1 to 5 are implemented.

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