Modeling method for integral impeller cycle symmetric solid

Abstract

This invention relates to a modeling method for a cyclic symmetric solid impeller, comprising: acquiring the number of blades and blade profile coordinate data of the integral impeller; obtaining a spline curve based on the blade profile coordinate data; obtaining the blade body based on the spline curve; obtaining a 2D geometric model of the impeller disk based on the spline curve; obtaining the disk body based on the 2D geometric model of the disk; obtaining a preliminary model containing one blade by combining the blade body and the disk body; generating a cutting guide line on the disk body based on the spline curve; and cutting the preliminary model according to the number of blades and the cutting guide line to obtain a cyclic symmetric solid model containing one blade. This invention can reduce the workload of analysis and design, can be automated through software, and can be applied to automated optimization design, thereby improving efficiency.

Description

Technical Field

[0001] This invention relates to the field of impeller modeling technology, and in particular to a modeling method for an integral impeller cyclic symmetrical solid. Background Technology

[0002] An integral impeller refers to a structure in aero-engines or gas turbines, such as an integral fan blade disk, an integral axial flow blade disk, an integral diagonal flow impeller, an integral centrifugal impeller, or an integral turbine blade disk. It is an indispensable part of the compressor or turbine in aero-engines or gas turbines. The integral impeller is a key component in the engine, directly related to the engine's safety, reliability, and durability, and is a component whose strength is a key factor in performance evaluation.

[0003] like Figure 1 The integral impeller shown includes 26 blades and a disk; that is, the integral impeller includes, for example,... Figure 2 The diagram shows 26 identically shaped loop segments, each containing one blade. Strength calculation of the integral impeller is an essential part of the design analysis process. Vibration analysis of the integral impeller facilitates the identification of different modes of structural vibration. However, both strength and vibration analysis of the integral impeller require analysis and design of the entire solid model, which is inefficient. Existing commercial modeling software requires generating the solid model through menus and toolbars on the software interface, involving numerous steps, a cumbersome process, and difficulty in automation. This causes inconvenience in practical engineering applications and hinders its use in automated structural optimization design. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a modeling method for an integral impeller cyclic symmetrical solid, which can reduce the workload of analysis and design, and can be automated by software and applied to automated optimization design, thereby improving efficiency.

[0005] To address the aforementioned technical problems, this invention provides a modeling method for an integral impeller cyclic symmetrical solid, comprising the following steps:

[0006] S1: Obtain the total number of blades of the impeller, obtain the blade shape coordinate data, and obtain the spline curve based on the blade shape coordinate data;

[0007] S2: Obtain the blade body based on the spline curve, combine the spline curve to obtain the 2D geometric model of the overall impeller disk, and obtain the disk body based on the 2D geometric model of the disk;

[0008] S3: Combine the blade body and the disk body to obtain a preliminary model containing one blade;

[0009] S4: Generate a cutting guide line on the wheel body according to the spline curve, and cut the preliminary model according to the number of blades and the cutting guide line to obtain a cyclic symmetric solid model containing one blade.

[0010] Preferably, the acquisition of the leaf shape coordinate data specifically includes:

[0011] The overall impeller coordinate system is established with the axial direction of the overall impeller as the x-axis, the circumferential direction of the overall impeller as the y-axis, and the direction of the blades as the z-axis.

[0012] Multiple cross sections are set on the blade, and the blade coordinate data is obtained by taking the same number and arrangement of blade coordinate points on each cross section.

[0013] Preferably, the spline curve is obtained based on the leaf shape coordinate data, specifically as follows:

[0014] Connect the leaf shape coordinate points on each cross section end to end to obtain a closed curve, and use the closed curve as the spline curve.

[0015] Preferably, the blade body is obtained based on the spline curve, specifically as follows:

[0016] The spline curve that contacts the impeller disk is used as the blade root bottom section spline curve, and the bottom surface of the blade is established according to the shape of the blade root bottom section spline curve.

[0017] The spline curve furthest from the impeller disk is used as the blade tip section spline curve, and the tip surface of the blade is established based on the shape of the blade tip section spline curve.

[0018] Connect all spline curves to form the blade surface, and combine the bottom surface, top surface and blade surface to form the blade body.

[0019] Preferably, a 2D geometric model of the impeller disk is obtained by combining the spline curve, and the disk body is obtained based on the 2D geometric model of the disk, specifically as follows:

[0020] A cross section is set along the axial direction of the overall impeller, and a 2D geometric model of the disk is obtained by combining the spline curve of the blade root bottom section. The 2D geometric model of the disk is rotated with the axial direction of the overall impeller as the rotation axis to obtain the disk body.

[0021] Preferably, a preliminary model containing one blade is obtained by combining the blade body and the disk body. Specifically, the blade body and the disk body are merged by performing a sum operation in Boolean operations, and the merged surface of the blade body and the disk body is the bottom curved surface.

[0022] Preferably, a cutting surface guide line is generated on the wheel body based on the spline curve, specifically as follows:

[0023] The outwardly convex curve on the leaf root bottom section spline curve is taken as the leaf back, and the inwardly concave curve on the leaf root bottom section spline curve is taken as the leaf basin. The leaf back and leaf basin are used as the two ends to form the midline.

[0024] Obtain the minimum axial coordinate value xmin and the maximum axial coordinate value xmax on the 2D geometric model of the roulette wheel.

[0025] The extension line extends along the centerline to both ends of the central axis of the wheel body. The two ends of the extension line turn gently until they reach xmin and xmax and then stop extending. The two ends of the extension line are parallel to the central axis of the wheel body. The extension line at this time and the centerline are connected as the cutting surface guide line.

[0026] Preferably, the method for generating the cutting surface guide line is as follows:

[0027] Taking the central axis of the wheel body as the boundary, n points are taken on both sides of the extension line, with points 1 to n on one side and points n+1 to 2n on the other side; the coordinate value of the first point is less than or equal to xmin, and the coordinate value of the 2nth point is greater than or equal to xmax;

[0028] On one side of the extension line, starting from the first point, take n points towards the central axis of the roulette wheel. On the center line, starting from near the first point, take two points 1' and 2' towards the central axis of the roulette wheel. Let the slope of the central axis of the roulette wheel be k0 = 0. The distance from point 1' to point 1 is divided into n line segments.

[0029] Let the projected coordinates of point 1' in the xy plane be (X1', Y1'); and the projected coordinates of point 2' in the xy plane be (X2', Y2'). Then the slope k1' from point 1' to point 2' is:

[0030] k1' = (Y2'-Y1') / (X2'-X1');

[0031] Calculate the slope increment dk of each line segment between point 1 and point 1':

[0032] dk=(k0-k1') / n,

[0033] Let the slope of n line segments be denoted as ki, and the method for calculating ki (i = 1, 2, ..., n) is as follows:

[0034] ki = k1' + i × dk;

[0035] The formula for calculating the x-coordinate (X1) of point 1 and the coordinates (Xj, Yj) of points 1 to n is as follows:

[0036] Xj=X1'+i×(X1-X1') / n, j=n-i+1;

[0037] Yj = Y1' + ki × (Xj - X1');

[0038] Connect points 1 to 1' to obtain the extension line on one side;

[0039] On the other side of the extension line, starting from the 2nth point, take n points in the direction of the central axis of the roulette wheel. On the center line, starting from the 2nth point, take two points, 1” and 2”, in the direction of the central axis of the roulette wheel. The distance from point 1” to point 2n is divided into n line segments.

[0040] Let the projected coordinates of point 1” on the xy plane be (X1”, Y1”); and the projected coordinates of point 2” on the xy plane be (X2”, Y2”). Then the slope k1” from point 1” to point 2” is:

[0041] k1”=(Y2”-Y1”) / (X2”-X1”);

[0042] The slope increment dk” of each line segment between point 2n and point 1” is calculated as follows:

[0043] dk”=(k0-k1”) / n,

[0044] The slope of n line segments is expressed as ki”, and the calculation method for ki” (i” = n+1, n+2, ..., 2n) is as follows:

[0045] ki”=k1”+i”×dk”;

[0046] The formula for obtaining the x-axis coordinate X(n+1) of point n+1, and the coordinates (Xj”, Yj”) of points n+1 to 2n is as follows:

[0047] Xj”=X1”+i”×(X(n+1)-X1”) / n, j”=2n-i”+1;

[0048] Yj”=Y1”+ki”×(Xj”-X1”);

[0049] Connect points 1” to 2n to obtain the extension line on the other side;

[0050] The cutting surface guide line is obtained by sequentially connecting points 1 to 1', the center line, and points 1” to 2n.

[0051] Preferably, the preliminary model is cut according to the number of blades and the guide line of the cutting surface to obtain a cyclic symmetric solid model containing one blade, specifically:

[0052] An initial cutting surface is obtained along the central axis of one of the blades on the preliminary model, passing through the cutting surface guide line and the central axis of the wheel body.

[0053] The initial cutting surface is rotated counterclockwise by an angle of alf / 2 about the central axis of the wheel body to obtain the first cutting surface; the initial cutting surface is rotated clockwise by an angle of alf / 2 about the central axis of the wheel body to obtain the second cutting surface.

[0054] The preliminary model is cut using the first and second cutting surfaces to obtain the cyclic symmetric solid model.

[0055] Preferably, the alf angle is calculated as follows:

[0056] alf = 360 / nDlade,

[0057] Wherein, nDlade is the number of blades of the overall impeller.

[0058] The technical solution of the present invention has the following advantages compared with the prior art:

[0059] This invention generates a cyclic symmetric solid model. When analyzing and designing the entire impeller, only the individual cyclic symmetric solid model needs to be analyzed and designed, and then extended from the individual cyclic symmetric solid model to the entire impeller. There is no need to analyze and design the overall structure of the entire impeller, which greatly reduces the workload of analysis and design and improves efficiency. At the same time, this invention can be automated through software and applied to automated optimization design, thereby shortening the design cycle and further improving efficiency. Attached Figure Description

[0060] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0061] Figure 1 This is a schematic diagram of the integral impeller structure;

[0062] Figure 2 yes Figure 1 The circumferential section of the integral impeller includes a complete blade;

[0063] Figure 3 This is a flowchart of the present invention;

[0064] Figure 4 This is a schematic diagram of the airfoil coordinate data of an axial flow blade;

[0065] Figure 5 This is a schematic diagram of the airfoil coordinate data of a turbine blade;

[0066] Figure 6 Is Figure 4 The spline curve obtained based on this;

[0067] Figure 7 This is a schematic diagram showing the relationship between the spline curve of the leaf root bottom section and the bottom surface;

[0068] Figure 8 This is a schematic diagram of the bottom curved surface of the three-dimensional blade body;

[0069] Figure 9 It is a schematic diagram showing the relationship between the spline curve and the tip surface of the blade tip section, and the spline curve and the blade surface.

[0070] Figure 10 It is a schematic diagram of the top curved surface and the blade curved surface of the three-dimensional blade body;

[0071] Figure 11 This is a cross-sectional view of the overall impeller in this embodiment;

[0072] Figure 12 yes Figure 11 Enlarged view of the 2D geometric model of the central roulette wheel;

[0073] Figure 13 This is a schematic diagram of a preliminary model containing one blade in this embodiment;

[0074] Figure 14 This is a schematic diagram of the upper centerline of the spline curve at the base of the leaf root;

[0075] Figure 15 This is a schematic diagram of the guide lines for the cutting surface;

[0076] Figure 16 This is a schematic diagram of the process of generating the extension line;

[0077] Figure 17 This is a schematic diagram of the rotating cut surface;

[0078] Figure 18 This is a schematic diagram of the preliminary model for cutting the cutting surface;

[0079] Figure 19 yes Figure 18 The cyclic symmetric solid model obtained by cutting the initial model. Detailed Implementation

[0080] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0081] Reference Figure 3 As shown in the flowchart, this invention discloses a modeling method for an overall impeller-cycle symmetrical solid, including the following steps:

[0082] S1: Obtain the total number of blades of the impeller, obtain the blade shape coordinate data, and obtain the spline curve based on the blade shape coordinate data;

[0083] S1-1: In this embodiment, ... Figure 1 Taking the integral impeller as an example, the number of blades of the integral impeller is nBlade = 26.

[0084] S1-2: Obtain leaf shape coordinate data:

[0085] like Figure 2 As shown, the overall impeller coordinate axes are established by using the axial direction of the overall impeller as the x-axis, the circumferential direction as the y-axis, and the direction along the blade as the z-axis (i.e., along the blade height). Multiple cross-sections are set on the blade, and the blade coordinate data is obtained by taking the same number and arrangement of blade coordinate points on each cross-section. For example, in... Figure 4 The axial flow blade shown has 11 cross-sections along the z-axis. The blade coordinates are obtained by taking points of the same number and arrangement on these 11 interfaces, as shown in the figure. Figure 4 As shown at each point, the airfoil coordinate points on all 11 sections constitute the airfoil coordinate data. For example, in... Figure 5 The turbine blade shown has three cross-sections along the z-axis. The blade profile coordinates are obtained by taking points of the same number and arrangement on these three interfaces, as shown in the figure. Figure 5 As shown in the diagram, the blade coordinate points on all three cross sections are the blade coordinate data.

[0086] S1-3: Obtain the spline curve based on the airfoil coordinate data:

[0087] Connecting the leaf-shaped coordinate points on each cross-section end-to-end yields a closed curve, which is then used as the spline curve, such as... Figure 6 The following is based on Figure 4 The 11 spline curves were obtained from the leaf shape coordinate points.

[0088] S2: Obtain the blade body based on the spline curve, combine the spline curve to obtain the 2D geometric model of the overall impeller disk, and obtain the disk body based on the 2D geometric model of the disk.

[0089] S2-1: Obtain the blade body based on the spline curve:

[0090] S2-1-1: As Figure 7 As shown, the spline curve in contact with the impeller disk is used as the blade root bottom section spline curve, and the bottom surface of the blade is established based on the shape of the blade root bottom section spline curve; a schematic diagram of the bottom surface of the three-dimensional blade body is shown below. Figure 8 As shown.

[0091] S2-1-2: As Figure 9 As shown, the spline curve furthest from the impeller disk is taken as the blade tip section spline curve, and the tip surface of the blade is established according to the shape of the blade tip section spline curve.

[0092] S2-1-3: All spline curves are connected using a sweeping method to form the blade surface. The bottom surface, top surface, and blade surface are then combined to form the blade body. A schematic diagram of the top surface and blade surface on the three-dimensional blade body is shown below. Figure 10 As shown, by piecing together the bottom curved surface, the top curved surface, and the blade curved surface, a closed 3D shape is obtained, which is as follows. Figure 8 or Figure 10 The blade body shown.

[0093] S2-2: Combine the spline curves to obtain the 2D geometric model of the overall impeller disk, and obtain the disk body based on the 2D geometric model of the disk:

[0094] A cross-section is set along the axial direction of the integral impeller, and a 2D geometric model of the disk is obtained by combining the spline curve of the blade root bottom cross-section. The 2D geometric model of the disk is then rotated around the axial direction of the integral impeller as the rotation axis to obtain the disk body. Figure 11 The diagram shown is a cross-sectional view of the overall impeller of the axial flow disk in this embodiment. The diagram illustrates the 2D geometric model of the disk. The 2D geometric model of the disk is enlarged as shown below. Figure 12 As shown, the 2D geometric model of the impeller consists of a portion of the spline curve at the blade root bottom section, straight line segments, and circular arc segments. The impeller body obtained by rotating the 2D geometric model of the impeller 180° around the axis of rotation of the entire impeller is shown below. Figure 13 As shown in the image.

[0095] The geometric elements included in the solid model are:

[0096] 1) Vertex, such as Figure 12 The endpoints of each line segment shown are the vertices of the 2D model.

[0097] 2) An edge is formed by connecting vertices, such as... Figure 12 The curve segments shown (straight lines and arcs) are the edges.

[0098] 3) A ring, which is formed by closed edges, such as... Figure 12 The closed edges shown form a loop.

[0099] 4) Surface, which is composed of rings.

[0100] 5) Solid: "stitching" closed curved surfaces together to form a solid.

[0101] S3: Combining the blade body and the disk body to obtain a preliminary model containing one blade: Performing a Boolean sum operation to merge the blade body and the disk body, the merged surface of the blade body and the disk body is the bottom curved surface. The preliminary model containing one blade formed by merging is as follows: Figure 13 As shown.

[0102] S4: Generate a cutting guide line on the impeller body based on the spline curve. Cut the preliminary model according to the number of blades and the cutting guide line to obtain a cyclic symmetric solid model containing one blade. After obtaining the cyclic symmetric solid model, the overall impeller can be analyzed and further designed.

[0103] S4-1: Generate a cutting surface guide line on the wheel body according to the spline curve:

[0104] S4-1-1: As Figure 14 As shown, the outwardly convex curve on the leaf root bottom section spline curve is taken as the leaf back, and the inwardly concave curve on the leaf root bottom section spline curve is taken as the leaf basin, with the leaf back and leaf basin as the two ends to form the midline.

[0105] S4-1-2: As Figure 12 As shown, the minimum axial coordinate value xmin and the maximum axial coordinate value xmax on the 2D geometric model of the roulette wheel are obtained.

[0106] S4-1-3: As Figure 15 As shown, the extension line extends axially from the centerline towards both ends of the wheel body, gradually turning at both ends until it reaches xmin and xmax and stops extending. The two ends of the extension line are parallel to the central axis of the wheel body. Connecting this extension line with the centerline serves as the cutting surface guide line. This cutting surface guide line encompasses the entire wheel body.

[0107] by Figure 16 For example, the method for generating the cutting surface guide line is as follows:

[0108] S4-1-3-1: Taking the central axis of the wheel body as the boundary, n points are taken on both sides of the extension line, with points 1, 2, ..., n on one side and points n+1, n+2, ..., 2n on the other side; the coordinate value of the first point is less than or equal to xmin, and the coordinate value of the 2nth point is greater than or equal to xmax; in this embodiment, n = 6.

[0109] S4-1-3-1: On one side of the extension line, starting from point 1, take six points from 1 to 6 towards the central axis of the roulette wheel. On the center line, starting from point 1 near point 1, take two points 1' and 2' towards the central axis of the roulette wheel. When extending to the left from points 1' and 2' on the center line, gently rotate towards the axis. Let the slope of the central axis of the roulette wheel be k0 = 0. The distance from point 1' to point 1 is divided into six line segments from ① to ⑥.

[0110] S4-1-3-2: Let the projected coordinates of point 1' in the xy plane be (X1', Y1'); and the projected coordinates of point 2' in the xy plane be (X2', Y2'). Then the slope k1' from point 1' to point 2' is:

[0111] k1' = (Y2'-Y1') / (X2'-X1');

[0112] S4-1-3-3: Calculate the slope increment dk of each line segment between point 1 and point 1':

[0113] dk=(k0-k1') / n,

[0114] Let the slopes of n line segments ① to ⑥ be expressed as ki = k1, k2, ..., k6. Then, the method for calculating ki is as follows:

[0115] ki = k1' + i × dk;

[0116] S4-1-3-4: Obtain the x-axis coordinate X1 of point 1, and the coordinates (Xj, Yj) of points 1 to 6. The formula for calculating j = n - i + 1 is:

[0117] Xj = X1' + i × (X1 - X1') / n,

[0118] Yj = Y1' + ki × (Xj - X1');

[0119] This gives us the coordinates of six points 1 to 6. Connecting points 1 to 1' (1 to 6 and 1') gives us the extension line on one side.

[0120] S4-1-3-5: The extension line on the other side is generated using the same method. On the other side of the extension line, starting from the (n+1)th point, take six points from 2n-5 to 2n towards the central axis of the roulette wheel. On the center line, starting near the 2nth point, take two points, 1” and 2”, towards the central axis of the roulette wheel. When extending to the left from points 1” and 2” on the center line, smoothly turn towards the axis. The section between point 1” and point 1” is divided into six line segments from ①” to ⑥”.

[0121] S4-1-3-6: Let the projected coordinates of point 1” on the xy plane be (X1”, Y1”); and the projected coordinates of point 2” on the xy plane be (X2”, Y2”). Then the slope k1” from point 1” to point 2” is:

[0122] k1”=(Y2”-Y1”) / (X2”-X1”);

[0123] S4-1-3-7: Calculate the slope increment dk” of each line segment between point 2n and point 1” as follows:

[0124] dk”=(k0-k1”) / n,

[0125] Express the slopes of the six line segments ①”~⑥” as ki”=k2n-5”,k2n-4”,…,k2n”, then the method for calculating ki” is as follows:

[0126] ki = k1" + i × dk;

[0127] S4-1-3-8: The formula for calculating the x-axis coordinate X(2n-5) of point 2n-5 to the coordinates (Xj”, Yj”) of points 2n-5 to 2n is as follows:

[0128] Xj”=X1”+i”×(X(n+1)-X1”) / n, j”=2n-i”+1;

[0129] Yj”=Y1”+ki”×(Xj”-X1”);

[0130] This gives us the coordinates of six points from 2n-5 to 2n. Connecting points 1” to 2n (1” and 2n-5 to 2n) gives us the extension line on one side.

[0131] S4-1-3-9: Connect points 1 to 1', the center line, and points 1” to 2n in sequence to obtain the cutting surface guide line.

[0132] S4-2: Based on the number of blades and the guide line of the cutting surface, the preliminary model is cut to obtain a cyclically symmetric solid model containing one blade:

[0133] S4-2-1: As Figure 17 As shown, an initial cutting surface is obtained along the central axis of one of the blades on the preliminary model, passing through the cutting surface guide line and the central axis of the wheel body.

[0134] S4-2-2: The initial cutting surface is rotated counterclockwise by an angle of alf / 2 about the central axis of the wheel body to obtain the first cutting surface, and the initial cutting surface is rotated clockwise by an angle of alf / 2 about the central axis of the wheel body to obtain the second cutting surface.

[0135] The method for calculating the alf angle is as follows:

[0136] alf = 360 / nDlade,

[0137] Wherein, nDlade is the number of blades of the overall impeller.

[0138] S4-2-3: As Figure 18 As shown, the preliminary model is cut using the first and second cutting surfaces to obtain the following... Figure 19 The illustrated cyclic symmetric solid model. When cutting the initial model, the guide line of the cutting surface should be kept as parallel as possible to the central axis of the disk body to avoid sharp corner structures. The cutting surface varies along the shape of the blade and extends to both sides, gradually becoming parallel to the axis, thereby obtaining a high-quality finite element mesh, which is then used to cut and obtain the cyclic symmetric solid model.

[0139] This invention generates a cyclic symmetric solid model. When analyzing and designing the entire impeller, only the individual cyclic symmetric solid model needs to be analyzed and designed, and then extended from the individual cyclic symmetric solid model to the entire impeller. This eliminates the need to analyze and design the overall structure of the entire impeller. For example, when analyzing... Figure 1 When analyzing and designing the integral impeller shown, only 1 / 26 of the structure needs to be analyzed and designed, reducing the computational scale to approximately 1 / 26 of the original. This significantly reduces the workload of analysis and design, improving efficiency. Furthermore, this invention can be automated through software and applied to automated optimization design, thereby shortening the design cycle, further improving efficiency, and contributing to the design of higher-performance engines. The method of this invention can also be used in the structural design of similar integral impellers in other compressors and compression pumps.

[0140] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0141] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1A device that provides the functions specified in one or more boxes.

[0142] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0143] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable apparatus for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0144] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A modeling method for an integral impeller-shaped cyclic symmetrical solid, characterized in that, Includes the following steps: S1: Obtain the total number of blades of the impeller, obtain the blade shape coordinate data, and obtain the spline curve based on the blade shape coordinate data; S2: Obtain the blade body based on the spline curve, combine the spline curve to obtain the 2D geometric model of the overall impeller disk, and obtain the disk body based on the 2D geometric model of the disk; The blade body is obtained based on the spline curves, specifically as follows: the spline curve in contact with the impeller disk is used as the blade root bottom section spline curve, and the bottom surface of the blade is established based on the shape of the blade root bottom section spline curve; the spline curve farthest from the impeller disk is used as the blade tip top section spline curve, and the tip surface of the blade is established based on the shape of the blade tip top section spline curve; all spline curves are connected to form the blade body surface, and the blade body surface, combined with the bottom surface, tip surface, and blade body surface, are used to form the blade body. S3: Combine the blade body and the disk body to obtain a preliminary model containing one blade; S4: Generate a cutting guide line on the wheel body according to the spline curve, and cut the preliminary model according to the number of blades and the cutting guide line to obtain a cyclic symmetric solid model containing one blade; Based on the spline curve, a cutting surface guide line is generated on the wheel body. Specifically, the outwardly convex curve on the spline curve of the leaf root bottom section is taken as the leaf back, and the inwardly concave curve on the spline curve of the leaf root bottom section is taken as the leaf basin. The leaf back and leaf basin are used as the two ends to form the center line. The minimum axial coordinate value xmin and the maximum axial coordinate value xmax on the 2D geometric model of the wheel are obtained. The center line is extended towards both ends of the central axis of the wheel body. The two ends of the extension line turn gently until they reach xmin and xmax and stop extending. The two ends of the extension line are parallel to the central axis of the wheel body. The extension line at this time and the center line are connected to form the cutting surface guide line. The preliminary model is cut according to the number of blades and the cutting guide line to obtain a cyclic symmetric solid model containing one blade. Specifically, an initial cutting surface is obtained by cutting along the central axis of one blade on the preliminary model, passing through the cutting guide line and the central axis of the wheel body. The initial cutting surface is rotated counterclockwise by an angle of alf / 2 about the central axis of the wheel body to obtain a first cutting surface. The initial cutting surface is rotated clockwise by an angle of alf / 2 about the central axis of the wheel body to obtain a second cutting surface. The preliminary model is cut using the first and second cutting surfaces to obtain the cyclic symmetric solid model.

2. The modeling method for an integral impeller cyclic symmetrical solid according to claim 1, characterized in that: The acquisition of leaf shape coordinate data specifically involves: The overall impeller coordinate system is established with the axial direction of the overall impeller as the x-axis, the circumferential direction of the overall impeller as the y-axis, and the direction of the blades as the z-axis. Multiple cross sections are set on the blade, and the blade coordinate data is obtained by taking the same number and arrangement of blade coordinate points on each cross section.

3. The modeling method for an integral impeller cyclic symmetrical solid according to claim 2, characterized in that: The spline curve is obtained based on the aforementioned leaf shape coordinate data, specifically as follows: Connect the leaf shape coordinate points on each cross section end to end to obtain a closed curve, and use the closed curve as the spline curve.

4. The modeling method for an integral impeller cyclic symmetrical solid according to claim 1, characterized in that: The 2D geometric model of the impeller disk is obtained by combining the spline curves. The disk body is then obtained based on this 2D geometric model, specifically as follows: A cross section is set along the axial direction of the overall impeller, and a 2D geometric model of the disk is obtained by combining the spline curve of the blade root bottom section. The 2D geometric model of the disk is rotated with the axial direction of the overall impeller as the rotation axis to obtain the disk body.

5. The modeling method for an integral impeller cyclic symmetrical solid according to claim 1, characterized in that: By combining the blade body and the disk body, a preliminary model containing one blade is obtained. Specifically, the blade body and the disk body are merged by performing a sum operation in Boolean operations, and the merged surface of the blade body and the disk body is the bottom curved surface.

6. The modeling method for an integral impeller cyclic symmetrical solid according to claim 1, characterized in that: The method for generating the cutting surface guide line is as follows: Taking the central axis of the wheel body as the boundary, n points are taken on both sides of the extension line, with points 1 to n on one side and points n+1 to 2n on the other side; the coordinate value of the first point is less than or equal to xmin, and the coordinate value of the 2nth point is greater than or equal to xmax; On one side of the extension line, starting from the first point, take n points towards the central axis of the roulette wheel. On the center line, starting from near the first point, take two points 1' and 2' towards the central axis of the roulette wheel. Let the slope of the central axis of the roulette wheel be k0=0. The distance from point 1' to point 1 is divided into n line segments. Let the projected coordinates of point 1' in the xy plane be (X1', Y1'), and the projected coordinates of point 2' in the xy plane be (X2', Y2'). Then the slope k1' from point 1' to point 2' is: k1'=(Y2'-Y1') / (X2'-X1'); Calculate the slope increment dk of each line segment between point 1 and point 1': dk = (k0 - k1') / n, Let ki represent the slope of n line segments. The method for calculating ki is as follows: ki = k1' + i × dk; Where i = 1, 2, ..., n; The formula for calculating the x-coordinate (X1) of point 1 and the coordinates (Xj, Yj) of points 1 to n is as follows: Xj=X1'+i×(X1-X1') / n, j=n-i+1; Yj = Y1' + ki × (Xj - X1'); Connect points 1 to 1' to obtain the extension line on one side; On the other side of the extension line, starting from the 2nth point, take n points in the direction of the central axis of the roulette wheel. On the center line, starting from the 2nth point, take two points, 1” and 2”, in the direction of the central axis of the roulette wheel. The distance from point 1” to point 2n is divided into n line segments. Let the projected coordinates of point 1” on the xy plane be (X1”, Y1”); and the projected coordinates of point 2” on the xy plane be (X2”, Y2”). Then the slope k1” from point 1” to point 2” is: k1”=(Y2”-Y1”) / (X2”-X1”); The slope increment dk” of each line segment between point 2n and point 1” is calculated as follows: dk”=(k0-k1) / n, The slope of n line segments is denoted as ki”. The method for calculating ki” is as follows: ki”=k1”+i”×dk”; Where, i”=n+1,n+2,…,2n; The formula for obtaining the x-axis coordinate X(n+1) of point n+1 and the coordinates (Xj”, Yj”) of points n+1 to 2n is as follows: Xj”=X1”+i”×(X(n+1)-X1”) / n, j”=2n-i”+1; Yj”=Y1”+ki”×(Xj”-X1”); Connect points 1” to 2n to obtain the extension line on the other side; The cutting surface guide line is obtained by connecting points 1 to 1', the center line, and points 1” to 2n in sequence.

7. The modeling method for an integral impeller cyclic symmetrical solid according to claim 1, characterized in that: The method for calculating the alf angle is as follows: alf=360 / nDlade, Wherein, nDlade is the number of blades of the overall impeller.

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