A method for matrixing geometry division of blade cooling holes

Abstract

The application discloses a kind of blade cooling hole matrixing geometric division methods, including reading finite element geometric model data, utilize geometric model identification function to be automatically divided into several block by geometric model, and obtain "line pair", "face" and "face pair" data, utilize "face pair" data to track, obtain all "line group" data of model, then obtain the corresponding "line group" group in region, the division region of cooling hole is matrixed by setting two parameters M, N, finally generate new geometric model data, the present application makes up the defect that geometric model cannot be automatically divided cooling hole region in finite element pre-processing software, algorithm efficiency is high, reduces a large amount of manual operation, greatly improves overall work efficiency.

Description

Technical fields:

[0001] This invention belongs to the field of finite element preprocessing and geometric model recognition technology, and particularly relates to a matrix-based geometric partitioning method for blade cooling holes. Background technology:

[0002] Existing finite element processing software cannot automatically divide the cooling hole area into geometric models, and the algorithm is inefficient, requiring a lot of manual operation, resulting in low overall work efficiency.

[0003] The purpose of this invention is to provide a matrix-based geometric partitioning method for the finite element geometric model of the external flow field of the blade, based on the requirement of adding cooling holes to the blade. Summary of the Invention:

[0004] To address the above problems, the technical problem to be solved by the present invention is to provide a method for matrixing the geometry of blade cooling holes, comprising the following steps:

[0005] (1) Read the finite element geometric model data;

[0006] (2) Using the geometric model recognition function, the geometric model is automatically divided into several blocks, and “line pairs”, “faces” and “faces” data are obtained;

[0007] (3) Use “face” data for tracking to obtain all “line group” data of the model: Define the opposite edge line data of a face as having the same characteristics and belonging to the same “line group”. Since each “face” is indexed by the number of the line data of the intersection of two faces and records the number of the line data at both ends, a “line group” can be formed by tracking. That is, take any “face” data, record the current index, map it to the corresponding “face” data according to the number of the line data at both ends, and record the current “face” data index. At the same time, each “face” data cannot be tracked repeatedly during this process. By analogy, the next “line group” can be recorded. Then, take any “face” data that has not been tracked and repeat the above process until all “faces” are tracked, and all “line group” data of the model can be obtained.

[0008] (4) Select the area where cooling holes need to be divided and obtain the corresponding "line group" group for that area;

[0009] (5) Set two parameters M and N to matrix the division area of ​​the cooling hole. The division area of ​​the cooling hole is generally a quadrilateral surface. The sides of this quadrilateral are connected by several line data. The parameters M and N are the number of segments for two pairs of sides of the quadrilateral respectively. Finally, the quadrilateral is divided into MXN small quadrilateral blocks. The number of segments is first allocated according to the length ratio of the line data itself. Then, the division point position of each line data is allocated proportionally. In this division method, new geometric model data is generated.

[0010] Preferably, the finite element geometric model data in step (1) refers to all the line data contained in the geometric model.

[0011] Preferably, the new geometric model data generated in step (5) can retain all the vertices of the original geometric model and maintain the basic framework of the geometric model.

[0012] The beneficial effects of this invention are as follows: The partitioning method provided by this invention makes up for the defect in finite element preprocessing software that cannot automatically partition the cooling hole area of ​​the geometric model. Moreover, the algorithm is highly efficient, reduces a lot of manual operation, and greatly improves the overall work efficiency. Attached image description:

[0013] Figure 1 A schematic diagram of the various data structures involved in the automatic block partitioning algorithm for finite element geometric models;

[0014] Figure 2 A schematic diagram of the external flow field geometry model of an aero-engine blade provided by the present invention;

[0015] Figure 3 A schematic diagram of the block model of the external flow field of an aero-engine blade provided by the present invention;

[0016] Figure 4 This is a schematic diagram of the geometric wireframe of the external flow field of an aero-engine blade and the block model of the cooling hole division region provided by the present invention;

[0017] Figure 5 A schematic diagram of the cooling hole division area of ​​an aero-engine blade on the XY plane provided by the present invention;

[0018] Figure 6 A schematic diagram of the geometric wireframe of the external flow field of the aero-engine blade after the cooling hole region is divided, and the block model of the cooling hole region provided by the present invention;

[0019] Figure 7 This is a schematic diagram of the block model of the external flow field of an aero-engine blade after the cooling hole region is divided according to the present invention. Detailed implementation method:

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments and accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0021] like Figure 1-7 As shown, the method for matrixing the cooling holes of the blades according to the present invention includes the following steps:

[0022] (1) Read the finite element geometric model data, that is, all the line data contained in the geometric model;

[0023] (2) Using the geometric model recognition function, the geometric model is automatically divided into several blocks, and “line pairs”, “faces” and “faces” data are obtained;

[0024] (3) Use “face” data for tracking to obtain all “line group” data of the model: Define the opposite edge line data of a face to have the same characteristics (the number of nodes must be the same when meshing) and belong to the same “line group”. Since each “face” is indexed by the number of the line data of the intersection of two faces and records the number of the line data at both ends, a “line group” can be formed by tracking. That is, take any “face” data, record the current index (line data number), map it to the corresponding “face” data according to the number of the line data at both ends, and record the current “face” data index. At the same time, each “face” data cannot be tracked repeatedly during this process. By analogy, the next “line group” can be recorded. Then, take any “face” data that has not been tracked and repeat the above process until all “faces” are tracked, and all “line group” data of the model can be obtained.

[0025] (4) Select the area where cooling holes need to be divided and obtain the corresponding "line group" group for that area;

[0026] (5) Set two parameters M and N to matrix the division area of ​​the cooling hole. The division area of ​​the cooling hole is generally a quadrilateral surface. The sides of this quadrilateral are connected by several line data. The parameters M and N are the number of segments for two pairs of sides of the quadrilateral respectively. Finally, the quadrilateral is divided into MXN small quadrilateral blocks. The number of segments is first allocated according to the length ratio of the line data itself. Then, the division point position of each line data is allocated proportionally. With this division method, the generated new geometric model data can retain all the vertices of the original geometric model and maintain the basic framework of the geometric model.

[0027] like Figure 1As shown, nodes of various data structures are highlighted in the form of spheres. In order to show the composition of the data structure, gray spheres represent common nodes and thick lines represent collinear data.

[0028] Example: The process of geometrically partitioning the cooling holes of aero-engine blades into a matrix includes the following steps:

[0029] (1) Read the finite element geometric model data of the external flow field of the aero-engine blade, such as Figure 2 As shown, all line data for the geometric model is obtained, totaling 499 lines. All line data will be uniformly sorted and numbered in the program.

[0030] (2) Using the geometric model recognition function, the geometric model was automatically divided into 117 blocks, and 2086 “line pairs”, 415 “faces” and 2068 “faces” were obtained.

[0031] (3) Using “face-to-face” data to track and obtain 17 “line groups”.

[0032] (4) Figure 4 The image shows a block area surrounding the blade surface. The inner surface of these blocks is the target area defined by the cooling holes. The "line groups" contained in this area are obtained.

[0033] (5) Figure 4 The displayed cooling hole division area can be viewed as a special case of a quadrilateral surface where one pair of opposite sides are closed. Figure 5 An example cross-section of the curved surface in the XY plane is given, dividing the cooling hole area into four parts: pressure side (PS), suction side (SS), leading edge (LE), and trailing edge (TE). From the geometric model's structure, the pressure side and suction side, as well as the leading edge and trailing edge, share the same "line groups." Therefore, the matrix parameter M can be considered as the number of segments in the Z direction of the entire area, and the parameter N can be considered as two parts, representing the number of segments in the X and Y directions, denoted as N_X and N_Y, respectively. Here, we take M=10, N_X =10, N_Y = 3, i.e., N = N_X + N_Y = 13. The number of segments in each direction is assigned to the corresponding "line groups," and these "line groups" are then divided proportionally, such as... Figure 6 This generates a new geometric model after the division, and the cooling hole division area is also divided into MX N blocks. Figure 7 It is the block model diagram of the overall model after reading the divided geometric model data. Based on the characteristics of the "line group", the whole model has been divided.

[0034] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method of matrixing geometry partitioning of a blade cooling hole, characterized by: The method comprises the following steps: (1) reading finite element geometric model data; (2) using geometric model identification function, the geometric model is automatically divided into several blocks, and "line pair", "surface" and "surface pair" data are obtained; (3) using "surface pair" data for tracking, all "line group" data of the model are obtained: defining that the data of opposite sides of a surface have the same characteristics and belong to the same "line group", since each "surface pair" is indexed by the data of lines intersecting two surfaces and records the data of the two end lines, a "line group" can be connected in the form of tracking, that is, taking any "surface pair" data, recording the current index, mapping the data of the two end lines to the corresponding "surface pair" data according to the index, recording the index of the current "surface pair" data, and in the process, each "surface pair" data cannot be tracked repeatedly, so as to record the next "line group", then taking any "surface pair" data which has not been tracked and repeating the above process until all "surface pairs" are tracked, and all "line group" data of the model are obtained; (4) selecting an area needing to be divided into cooling holes, and obtaining the corresponding "line group" group of the area; (5) setting two parameters M and N to matrix the division area of the cooling hole, the division area of the cooling hole is generally a quadrilateral curved surface, the edges of the quadrilateral are connected by a plurality of line data, and the parameters M and N are the division numbers of two pairs of edges of the quadrilateral, respectively, and finally the quadrilateral is divided into M × N small quadrilateral blocks, the division number is allocated according to the length proportion of the plurality of line data, and then the division point positions of each line data are allocated according to equal proportion, so that the new geometric model data is generated in the above division manner.

2. The method according to claim 1, wherein: The finite element geometric model data are all line data contained in the geometric model.

3. The method according to claim 1, wherein: The generated new geometric model data can retain all vertices of the original geometric model and maintain the basic framework of the geometric model.

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