Mesh generation method, device, equipment and medium for finite element analysis of aircraft airfoil quadrilateral structure

Abstract

The present application discloses a grid generation method, apparatus, equipment and medium for finite element analysis of quadrilateral structures of aircraft airfoils, and relates to the technical field of multi-physics field coupling numerical simulation. The method calculates the curvilinear distance between discrete grid points and the trailing edge points of the upper wing surface of the airfoil; initially segments the airfoil grid to obtain each quadrilateral region, calculates each first control corner point at the leading edge and trailing edge corresponding to the upper wing surface and the lower wing surface, each second control corner point inside the airfoil, each first grid edge around the airfoil contour, each intersecting edge at the leading edge and trailing edge, and the second grid edge inside the airfoil, constructs a computational domain grid, deletes duplicate grid points, updates the grid point list and updates the grid cell list on the computational domain grid; generates a grid for finite element analysis of quadrilateral structures of aircraft airfoils according to the target grid point list and the target grid cell list, and can ensure full quadrilateralization of the grid cells and consistency of the grid cells between different airfoil sections.

Description

Technical Field

[0001] The present invention relates to the technical field of multi-physics field coupling numerical simulation, and in particular to a grid generation method, device, equipment and medium for finite element analysis of an aircraft airfoil quadrilateral structure. Background Art

[0002] Currently, there are two main methods for generating quadrilateral meshes for airfoils: one is to use manual interaction, by dividing the airfoil into multiple sub-regions, and then splicing and splitting each sub-region to generate a quadrilateral mesh; the other is to use the boundary layer propulsion tiling method to arrange grid points on the boundary contour of the airfoil, and then propel them along the direction of the internal normal to generate a quadrilateral mesh. However, the first method can ensure that the generated units are all quadrilaterals, but it requires a lot of manual intervention and is relatively time-consuming; the second method can achieve automatic generation, but in areas where there are conflicts in the propulsion direction, the quadrilateral mesh may degenerate into triangles, and full quadrilateralization cannot be guaranteed. In addition, the meshes of different airfoil sections may face inconsistent numbers of nodes, units, and node connection relationships, making it difficult to connect to form hexahedral units.

[0003] As can be seen from the above, how to ensure the full quadrilateralization of grid cells and the consistency of grid cells between different airfoil sections and realize grid generation for finite element analysis of aircraft airfoil quadrilateral structures is a problem to be solved in this field. Summary of the Invention

[0004] In view of this, the present invention aims to provide a mesh generation method, apparatus, device, and medium for finite element analysis of quadrilateral structures of aircraft airfoils, which can ensure full quadrilateralization of mesh cells and consistency of mesh cells between different airfoil profiles, thereby realizing mesh generation for finite element analysis of quadrilateral structures of aircraft airfoils. The specific scheme is as follows:

[0005] In a first aspect, the present application discloses a mesh generation method for finite element analysis of a quadrilateral structure of an aircraft airfoil, comprising:

[0006] Obtaining the number and coordinate data of discrete grid points used to describe the geometric shape of an aircraft airfoil, and calculating the curvilinear distance between the discrete grid points and a trailing edge point of an upper airfoil surface based on the number and the coordinate data;

[0007] Establishing an airfoil geometry parameterized model using the curve distance, performing initial segmentation on the airfoil mesh to obtain quadrilateral regions, and calculating first control corner points at the leading edge and the trailing edge corresponding to the upper and lower airfoils, respectively, based on the airfoil geometry parameterized model, the coordinate data, and the curve distance;

[0008] generating second control corner points inside the airfoil based on the first control corner points, and generating first mesh edges around the airfoil contour using the first control corner points and the second control corner points;

[0009] generating intersecting edges at the leading edge and the trailing edge based on the first mesh edges, generating second mesh edges inside the airfoil using the second control corner points, and generating a target quadrilateral region based on the quadrilateral regions, the first mesh edges, the intersecting edges, and the second mesh edges;

[0010] Generate a quadrilateral mesh using the target quadrilateral region, construct a computational domain mesh based on the quadrilateral mesh, and perform repeated grid point deletion operations, grid point list update operations, and grid cell list update operations on the computational domain mesh to obtain a target grid point list and a target grid cell list;

[0011] A grid for finite element analysis of an aircraft airfoil quadrilateral structure is generated according to the target grid point list and the target grid unit list.

[0012] Optionally, obtaining the number and coordinate data of discrete grid points used to describe the geometric shape of the aircraft airfoil, and calculating the curvilinear distance between the discrete grid points and a trailing edge point of an upper surface of the airfoil based on the number and the coordinate data, includes:

[0013] Obtaining the number and coordinate data of discrete grid points from a preset data file or formula describing the airfoil geometry;

[0014] Determine the trailing edge point of the upper wing surface of the airfoil, and calculate the curvilinear distance between the discrete grid point and the trailing edge point of the upper wing surface of the airfoil based on the number and the coordinate data and using a curvilinear distance calculation formula; the curvilinear distance calculation formula is:

[0015] ;

[0016] ;

[0017] in, is the curve distance of the i-th discrete grid point, is the curve distance of the i-1th discrete grid point, n is the number of discrete grid points, is the straight-line distance between the i-1th discrete grid point and the i-th discrete grid point, is the coordinate data of the i-th discrete grid point, is the coordinate data of the i-1th discrete grid point.

[0018] Optionally, establishing an airfoil geometry parameterized model using the curve distance includes:

[0019] The airfoil geometry parameterized model is established by using the curve distance and a one-dimensional radial basis interpolation method; the expression of the airfoil geometry parameterized model is:

[0020] ;

[0021] Where f is the interpolation function, n is the number of discrete grid points, is the curve distance, is the interpolation coefficient, is the basis function, and d is the interpolation variable.

[0022] Optionally, the calculating of the first control corner points at the leading edge and the trailing edge corresponding to the upper wing surface and the lower wing surface respectively based on the airfoil geometric parameterized model, the coordinate data, and the curve distance includes:

[0023] determining a first control corner point at a trailing edge of an upper airfoil and a first control corner point at a trailing edge of a lower airfoil of the airfoil based on the coordinate data;

[0024] Performing plane coordinate calculation on the coordinate data, the preset trailing edge control angle point range, and the curve distance using the airfoil geometric parameterized model to obtain a first control angle point within the preset trailing edge control angle point range of the upper airfoil surface and a first control angle point within the preset trailing edge control angle point range of the lower airfoil surface;

[0025] The curve distance is iteratively calculated based on the bisection method to obtain the leading edge control corner point range, and the plane coordinate calculation is performed on the coordinate data, the leading edge control corner point range and the curve distance using the airfoil geometric parameterized model to obtain the first control corner point within the leading edge control corner point range of the upper wing surface and the first control corner point within the leading edge control corner point range of the lower wing surface.

[0026] Optionally, generating each second control corner point inside the airfoil based on each first control corner point includes:

[0027] Each of the first control corner points is advanced along the inner normal direction of the airfoil, the tangent direction of the airfoil, and the angle bisector direction of the line connecting the control corner points to generate each of the second control corner points inside the airfoil.

[0028] Optionally, generating a quadrilateral mesh using the target quadrilateral region includes:

[0029] Obtaining target quadrilateral region assembly information during the process of generating the target quadrilateral region;

[0030] A quadrilateral mesh is generated based on the target quadrilateral region assembly information using a two-dimensional transfinite interpolation method.

[0031] Optionally, constructing a computational domain grid based on the quadrilateral grid, performing repeated grid point deletion operations, grid point list update operations, and grid cell list update operations on the computational domain grid to obtain a target grid point list and a target grid cell list, includes:

[0032] Based on quadrilateral mesh, the computational domain mesh including mesh point list and mesh cell list is constructed in an unstructured manner using node list and cell list definition.

[0033] Deleting duplicate grid points in the grid point list of the computational domain grid, and updating the grid point list to obtain a target grid point list;

[0034] The grid cell list is updated according to the mapping relationship between the original grid point numbers and the updated grid point numbers to obtain a target grid cell list.

[0035] In a second aspect, the present application discloses a mesh generation device for finite element analysis of a quadrilateral structure of an aircraft airfoil, comprising:

[0036] a curvilinear distance calculation module, configured to obtain the number and coordinate data of discrete grid points used to describe the geometric shape of the aircraft airfoil, and calculate the curvilinear distance between the discrete grid points and the trailing edge point of the upper wing surface of the airfoil based on the number and the coordinate data;

[0037] a first control corner point calculation module, configured to establish an airfoil geometry parameterized model using the curve distance, perform initial segmentation on the airfoil mesh to obtain quadrilateral regions, and calculate first control corner points at the leading edge and the trailing edge corresponding to the upper and lower airfoils, respectively, based on the airfoil geometry parameterized model, the coordinate data, and the curve distance;

[0038] A first mesh edge generation module is configured to generate second control corner points inside the airfoil based on the first control corner points, and to generate first mesh edges around the airfoil contour using the first control corner points and the second control corner points;

[0039] a target quadrilateral region generating module, configured to generate intersecting edges at the leading edge and the trailing edge based on the first mesh edges, generate second mesh edges inside the airfoil using the second control corner points, and generate a target quadrilateral region based on the quadrilateral regions, the first mesh edges, the intersecting edges, and the second mesh edges;

[0040] an updating module, configured to generate a quadrilateral mesh using the target quadrilateral region, construct a computational domain mesh based on the quadrilateral mesh, and perform repeated grid point deletion operations, grid point list update operations, and grid cell list update operations on the computational domain mesh to obtain a target grid point list and a target grid cell list;

[0041] A grid generation module is used to generate a grid for finite element analysis of an aircraft airfoil quadrilateral structure according to the target grid point list and the target grid unit list.

[0042] In a third aspect, the present application discloses an electronic device, comprising:

[0043] Memory, used to store computer programs;

[0044] The processor is used to execute the computer program to implement the aforementioned mesh generation method for finite element analysis of the quadrilateral structure of the aircraft airfoil.

[0045] In a fourth aspect, the present application discloses a computer storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the steps of the mesh generation method for finite element analysis of the quadrilateral structure of an aircraft wing profile disclosed above are implemented.

[0046] It can be seen that the present application provides a grid generation method for finite element analysis of quadrilateral structures of aircraft airfoils, including obtaining the number and coordinate data of discrete grid points used to describe the geometric shape of the aircraft airfoil, and calculating the curve distance between the discrete grid points and the trailing edge points of the upper wing surface of the airfoil based on the number and the coordinate data; using the curve distance to establish an airfoil geometric parameterized model, performing an initial segmentation on the airfoil grid to obtain each quadrilateral area, and calculating each first control corner point at the leading edge and trailing edge corresponding to the upper wing surface and the lower wing surface respectively based on the airfoil geometric parameterized model, the coordinate data and the curve distance; generating each second control corner point inside the airfoil based on each first control corner point, and using each first control corner point and each second control corner point to calculate the first control corner point and the second control corner point respectively. Generate first mesh edges around the airfoil profile; generate intersecting edges at the leading edge and the trailing edge based on the first mesh edges, generate second mesh edges inside the airfoil using the second control corner points, and generate a target quadrilateral region based on the quadrilateral regions, the first mesh edges, the intersecting edges, and the second mesh edges; generate a quadrilateral mesh using the target quadrilateral region, and construct a computational domain mesh based on the quadrilateral mesh; perform repeated grid point deletion operations, grid point list update operations, and grid cell list update operations on the computational domain mesh to obtain a target grid point list and a target grid cell list; and generate a mesh for finite element analysis of the quadrilateral structure of an aircraft airfoil based on the target grid point list and the target grid cell list. The present application calculates the curve distance between the discrete grid points and the trailing edge points of the upper wing surface of the airfoil based on the number and coordinate data of the discrete grid points describing the geometric shape of the aircraft airfoil, can accurately describe the geometric shape of the airfoil, establish a geometric parameterized model of the airfoil, perform initial segmentation on the airfoil grid, obtain each quadrilateral area, calculate each first control corner point at the leading edge and trailing edge corresponding to the upper wing surface and the lower wing surface respectively, generate each second control corner point inside the airfoil, use each first control corner point and each second control corner point to generate each first grid edge around the airfoil contour, generate each intersecting edge at the leading edge and trailing edge according to each first grid edge, and use each second control corner point to generate the airfoil The second mesh edge inside the shape is used to generate a target quadrilateral area. The target quadrilateral area is used to generate a quadrilateral mesh to achieve quadrilateral mesh generation for each target quadrilateral area. The quadrilateral mesh is then assembled into an overall quadrilateral mesh to construct a computational domain mesh. Repeated grid point deletion operations, grid point list update operations, and grid cell list update operations are performed on the computational domain mesh to obtain a target grid point list and a target grid cell list. The mesh for the finite element analysis of the quadrilateral structure of the aircraft airfoil is generated to ensure full quadrilateralization of the grid cells and consistency of the grid cells between different airfoil sections, thereby achieving mesh generation for the finite element analysis of the quadrilateral structure of the aircraft airfoil. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0048] Figure 1 This is a flow chart of a mesh generation method for finite element analysis of a quadrilateral structure of an aircraft airfoil disclosed in this application;

[0049] Figure 2 This is an airfoil position description diagram disclosed in this application;

[0050] Figure 3 This is an example diagram of region segmentation disclosed in this application;

[0051] Figure 4 This is an example diagram of a control corner point disclosed in this application;

[0052] Figure 5 This is an example diagram of a mesh edge disclosed in this application;

[0053] Figure 6 An assembled partitioned quadrilateral grid diagram disclosed in this application;

[0054] Figure 7 A unified computational domain quadrilateral grid diagram disclosed in this application;

[0055] Figure 8 This is a schematic structural diagram of a grid generation device for finite element analysis of a quadrilateral structure of an aircraft airfoil disclosed in this application;

[0056] Figure 9 This is a structural diagram of an electronic device provided in this application.

[0057] The following are marked in the accompanying drawings:

[0058] 1- trailing edge, 2- upper wing surface, 3- leading edge, 4- lower wing surface, 5- airfoil profile, 6- quadrilateral area 1, 7- quadrilateral area 2, 8- quadrilateral area 3, 9- quadrilateral area 4, 10- quadrilateral area 5, 11- quadrilateral area 6, 12- control corner point 1, 13- control corner point 2, 14- control corner point 3, 15- control corner point 4, 16- control corner point 5, 17- control corner point 6, 18- control corner point 7, 19 -Control corner point eight, 20-Control corner point nine, 21-Control corner point ten, 22-Grid edge one, 23-Grid edge two, 24-Grid edge three, 25-Grid edge four, 26-Grid edge five, 27-Grid edge six, 28-Grid edge seven, 29-Grid edge eight, 30-Grid edge nine, 31-Grid edge ten, 32-Grid edge eleven, 33-Grid edge twelve, 34-Grid edge thirteen, 35-Grid edge fourteen, 36-Grid edge fifteen. DETAILED DESCRIPTION

[0059] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0060] Currently, there are two main methods for generating quadrilateral meshes for airfoils: one is to use manual interaction, by dividing the airfoil into multiple sub-regions, and then splicing and splitting each sub-region to generate a quadrilateral mesh; the other is to use the boundary layer advancing and tiling method, arranging grid points on the boundary contour of the airfoil, and then advancing along the direction of the internal normal to generate a quadrilateral mesh. However, the first method can ensure that the generated units are all quadrilaterals, but it requires a lot of manual intervention and is relatively time-consuming; the second method can achieve automatic generation, but in areas where there are conflicts in the advancing direction, the quadrilateral mesh may degenerate into triangles, and full quadrilateralization cannot be guaranteed. In addition, the meshes of different airfoil sections may face inconsistencies in the number of nodes, the number of units, and the node connection relationship, resulting in the difficulty of connecting to form hexahedral units. As can be seen from the above, how to ensure the full quadrilateralization of mesh units and the consistency of mesh units between different airfoil sections, and realize mesh generation for finite element analysis of aircraft airfoil quadrilateral structures are problems to be solved in this field.

[0061] See also Figure 1 As shown, an embodiment of the present invention discloses a mesh generation method for finite element analysis of a quadrilateral structure of an aircraft airfoil, which may specifically include:

[0062] Step S11: obtaining the number and coordinate data of discrete grid points used to describe the geometric shape of the aircraft airfoil, and calculating the curvilinear distance between the discrete grid points and the trailing edge point of the upper wing surface of the airfoil based on the number and the coordinate data.

[0063] In this embodiment, the number and coordinate data of discrete grid points are obtained from a preset data file or formula describing the geometric shape of the airfoil; the trailing edge point of the upper airfoil surface of the airfoil is determined, and the curvilinear distance between the discrete grid point and the trailing edge point of the upper airfoil surface is calculated based on the number and the coordinate data using a curvilinear distance calculation formula; the curvilinear distance calculation formula is:

[0064] ;

[0065] ;

[0066] in, is the curve distance of the i-th discrete grid point, is the curve distance of the i-1th discrete grid point, n is the number of discrete grid points, is the straight-line distance between the i-1th discrete grid point and the i-th discrete grid point, is the coordinate data of the i-th discrete grid point, is the coordinate data of the i-1th discrete grid point.

[0067] Specifically, if the coordinates of the discrete points describing the airfoil geometry are recorded in a data file, then according to the file name, the number n of the airfoil discrete grid points is read first, and then the coordinate data of the discrete grid points are read in sequence. In order to facilitate the implementation of parameterization in the subsequent steps, the starting position of the discrete grid points starts from the trailing edge point of the upper wing surface and traverses counterclockwise to the trailing edge point of the lower wing surface. Data that do not conform to the starting position and arrangement direction can be adjusted to meet the requirements through a simple sorting algorithm; if the airfoil geometry is described by a formula, define the number of discrete points n, and then start from the trailing edge point of the upper wing surface of the airfoil and traverse counterclockwise to sequentially generate the coordinate data of all the discrete grid points that describe the airfoil geometry. For example, if the number of discrete points is 201, first read the number of airfoil discrete grid points 201, and then read the coordinate data of the discrete grid points in sequence. .

[0068] In this embodiment, the airfoil position is described as follows: Figure 2 As shown, number 1 is the trailing edge of the airfoil, number 2 is the upper wing surface, number 3 is the leading edge of the airfoil, number 4 is the lower wing surface, number 5 is the airfoil profile, and the curve distance is calculated. It starts from the trailing edge point of the upper wing surface and calculates the curvilinear distance between the discrete grid points and the trailing edge point of the upper wing surface point one by one. When the discrete grid points are dense enough, the geometric shape of the airfoil can be described more accurately.

[0069] Step S12: Use the curve distance to establish an airfoil geometry parameterized model, perform initial segmentation on the airfoil mesh to obtain each quadrilateral area, and calculate the first control corner points at the leading edge and trailing edge corresponding to the upper and lower wing surfaces respectively based on the airfoil geometry parameterized model, the coordinate data and the curve distance.

[0070] In this embodiment, the airfoil geometry parameterized model is established by using the curve distance and a one-dimensional radial basis interpolation method; the expression of the airfoil geometry parameterized model is:

[0071] ;

[0072] Where f is the interpolation function, n is the number of discrete grid points, is the curve distance, is the interpolation coefficient, is the basis function, and d is the interpolation variable.

[0073] n numbers on the known airfoil The coordinate value of the value position , a geometric parameterized model of the airfoil can be established by one-dimensional interpolation; there are many ways of one-dimensional interpolation, such as polynomial, Lagrange, spline, etc. The expression of the geometric parameterized model of the airfoil established by the one-dimensional radial basis interpolation method in the present invention is shown above, wherein, is the interpolation coefficient, which is determined by the known n The coordinate value of the value position Determine the coefficients of x and y 、 They are calculated by the following formulas:

[0074] ;

[0075] ;

[0076] ;

[0077] ;

[0078] in, , basis functions Different types can be selected, and the present invention selects the compactly supported basis function Wendland's C2;

[0079] like Represents the curve distance of the known 201 points, then 、 They are calculated by the following formulas:

[0080] ;

[0081] ;

[0082] ;

[0083] .

[0084] Then, the airfoil grid is initially segmented to obtain various quadrilateral areas, and the first control corner point at the trailing edge of the upper wing surface and the first control corner point at the trailing edge of the lower wing surface of the airfoil are determined based on the coordinate data; the coordinate data, the preset trailing edge control corner point range and the curve distance are calculated in plane coordinates using the airfoil geometric parameterization model to obtain the first control corner point within the preset trailing edge control corner point range of the upper wing surface and the first control corner point within the preset trailing edge control corner point range of the lower wing surface; the curve distance is iteratively calculated based on the bisection method to obtain the leading edge control corner point range, and the coordinate data, the leading edge control corner point range and the curve distance are calculated in plane coordinates using the airfoil geometric parameterization model to obtain the first control corner point within the leading edge control corner point range of the upper wing surface and the first control corner point within the leading edge control corner point range of the lower wing surface.

[0085] The specific initial segmentation process is as follows: To more easily control the distribution of airfoil mesh cells, the entire airfoil is divided into six quadrilateral regions. One quadrilateral region is divided near the trailing edge, and the remaining area is divided into five quadrilateral regions, one in the middle and four surrounding the middle quadrilateral region. The six quadrilateral regions have a total of 10 control corners and 15 edges. Of the 10 control corners, 6 are located on the airfoil, and 4 are located within the airfoil. Of the 15 edges, 6 are located on the airfoil, 5 intersect the airfoil, and 4 are located within the airfoil.

[0086] For example, the region segmentation example is Figure 3 As shown, numbers 6-11 represent six divided quadrilateral regions: quadrilateral region 1 (6), quadrilateral region 2 (7), quadrilateral region 3 (8), quadrilateral region 4 (9), quadrilateral region 5 (10), and quadrilateral region 6 (11). One quadrilateral region is divided near the trailing edge, and the remaining area is divided into five quadrilateral regions: one in the middle, and four surrounding the middle quadrilateral region. These six quadrilateral regions have a total of 10 control corners and 15 edges. Six of the 10 control corners are located on the airfoil, and four are internal. Six of the 15 edges are located on the airfoil, five intersect the airfoil, and four are internal.

[0087] In this embodiment, the control corner points are exemplified as follows: Figure 4 As shown, control corner point one 12, control corner point two 13, control corner point three 14, control corner point four 15, control corner point five 16, control corner point six 17, control corner point seven 18, control corner point eight 19, control corner point nine 20, and control corner point ten 21. Control corner point one 12 and control corner point six 17 are two control corner points at the trailing edge, control corner point two 13 and control corner point five 16 are two control corner points near the trailing edges of the upper and lower airfoils, control corner point three 14 and control corner point four 15 are two control corner points near the leading edges of the upper and lower airfoils, and these six corner points constitute the six control corner points on the airfoil. The process of determining the first control corner point at the trailing edge of the upper airfoil and the first control corner point at the trailing edge of the lower airfoil is as follows: the control corner point one 12 at the trailing edge of the upper airfoil and the control corner point six 17 at the trailing edge of the lower airfoil take the coordinates of the trailing edge positions of the upper and lower airfoils, i.e., the first and last points describing the geometric shape of the airfoil, so that , .

[0088] The process of determining the first control corner point within the preset trailing edge control corner point range of the upper wing surface and the first control corner point within the preset trailing edge control corner point range of the lower wing surface is as follows: setting the two control corner points near the trailing edges of the upper and lower wing surfaces is used to adjust the airfoil mesh distribution and improve the orthogonality of the mesh units. For example, when the two control corner points near the trailing edges of the upper and lower wing surfaces are respectively located at a distance of approximately 0.12c from the trailing edge position (the preset trailing edge control corner point range is 0.12c), the generated airfoil quadrilateral unit mesh quality is better, and c is the chord length of the airfoil. That is, the curve distance d of the control corner point 2 13 near the trailing edge of the upper wing surface is 0.12c, and the curve distance d of the control corner point 5 16 near the trailing edge of the lower wing surface is ,in It is the curve distance between the last point of the 201 discrete points of the airfoil and the trailing edge of the upper airfoil. The value of is 2.04c. So the curve distance d of the control corner point 5 is 1.92. Substitute the expression of the airfoil geometric parameter model, combined with 、 The four formulas at can be used to obtain the plane coordinates of control corner point 2 and control corner point 5. 、 for:

[0089] ;

[0090] .

[0091] The process for determining the first control corner point within the leading edge control corner range of the upper and lower airfoils is as follows: The two control corner points near the leading edges of the upper and lower airfoils are used to establish an internal O-shaped topology and eliminate the problem of poor element quality when directly generating quadrilateral meshes. For example, when the two control corner points near the leading edges of the upper and lower airfoils are located 0.03c from the leading edge (the leading edge control corner range is 0.03c), the quality of the quadrilateral elements is better. First, the curvilinear distance d of the leading edge point from the trailing edge of the upper airfoil is calculated. The detailed calculation process is described in the following steps. The curvilinear distance d of the control corner point near the leading edge of the upper airfoil is 1.03c - 0.03c = 1.00c, and the curvilinear distance d of the control corner point near the leading edge of the lower airfoil is 1.03c + 0.03c = 1.06c. The leading edge points of the airfoil are not directly specified and cannot be directly calculated using geometric discrete point data. The present invention assumes that the point with y=0 near the leading edge point is the leading edge point, and then obtains the curve distance of the leading edge point through bisection iteration. The specific iterative process is:

[0092] (1) Define a point on each of the upper and lower wing surfaces near the leading edge of the airfoil. Their curvilinear distances from the trailing edge of the upper wing surface are: and ,set up and The initial values ​​are 0.8c and 1.2c respectively.

[0093] (2) The expression of the airfoil geometry parameterized model is based on Calculate the y coordinate of the upper wing point .if Less than 0, then , and recalculate and judge , until Greater than 0.

[0094] (3) The expression of the airfoil geometry parameterized model is based on Calculate the y coordinate of the lower wing point .if Greater than 0, then , and recalculate and judge , until Greater than 0.

[0095] (4) Define the midpoint of the curve , calculated using the expression of the airfoil geometry parameterized model The y coordinate of the current location .

[0096] (5) If ,but ; ,but , jump to step (4) and repeat, where is a very small positive number, the present invention defines .

[0097] (6) , the process ends.

[0098] Then, the coordinates of the control corner point 3 near the leading edge of the upper wing are It can be calculated by the following formula:

[0099] ;

[0100] Similarly, the coordinates of the control corner point 4 near the leading edge of the upper wing are It can be calculated by the following formula:

[0101] ;

[0102] in, is the curvature distance of the upper wing leading edge.

[0103] Step S13: generating second control corner points inside the airfoil based on the first control corner points, and generating first mesh edges around the airfoil profile using the first control corner points and the second control corner points.

[0104] In this embodiment, each of the first control corner points is advanced along the inner normal direction of the airfoil, the tangent direction of the airfoil, and the angle bisector direction of the line connecting the control corner points to generate each second control corner point inside the airfoil, and each of the first control corner points and each of the second control corner points is used to generate each first mesh edge around the airfoil contour.

[0105] Specifically, such as Figure 4 As shown, control corner point seven 18 and control corner point ten 21 are two control corner points near the upper and lower wing surfaces of the trailing edge, which are obtained by pushing them inward. Control corner point eight 19 and control corner point nine 20 are two control corner points near the upper and lower wing surfaces of the leading edge, which are obtained by pushing them inward. The four control corner points inside the airfoil are obtained by pushing control corner point two 13, control corner point three 14, control corner point four 15, and control corner point five 16 on the airfoil. Among them, the internal control corner point eight 19 and control corner point nine 20 near the leading edge of the airfoil are obtained by pushing control corner point three 14 and control corner point four 15 along the inner normal direction of the airfoil. The internal control corner point seven 18 and control corner point ten 21 near the trailing edge of the airfoil are obtained by pushing control corner point two 13 and control corner point five 16 along the angular bisector of the line connecting the airfoil tangent and control corner point two 13 and control corner point five 16.

[0106] The tangent line at the control corner point on the airfoil surface is approximated by the following method: the curve distance d of the control corner point is deviated forward and backward respectively. , that is, the curve distance of the starting point of the tangent , the curve distance of the tangent end point .in, For a very small curve distance deviation, the present invention selects =0.001c. The coordinates of the starting and ending points of the tangent can be obtained by using the expression of the airfoil geometric parameterized model. 、 , then the unit tangent vector that controls the position of the corner point can be expressed as:

[0107] ;

[0108] in, and are the components of the unit tangent vector in the horizontal and vertical directions.

[0109] The unit tangent vector of the airfoil control corner position can be used to obtain the unit internal normal vector:

[0110] ;

[0111] in, and are the components of the tangent line of the coordinate (x, y) on the airfoil curve in the horizontal and vertical directions.

[0112] For example, if the internal advancement distance is 0.015c, better mesh cell quality can be obtained. Therefore, the coordinates of control corner points 8 and 9 can be expressed as:

[0113] ;

[0114] ;

[0115] in, and To control the x-direction component and y-direction component of the tangent line of corner point 3, and To control the x- and y-direction components of the tangent of corner point 4.

[0116] The specific value is determined by the thickness of the airfoil. The greater the thickness, the longer the propulsion distance that can be selected. The unit vector of the line connecting the control corner point 2 and the control corner point 5 can be expressed as:

[0117] ;

[0118] in, and are the components of the unit vector in the horizontal and vertical directions.

[0119] The propulsion direction of control corner point 2 and control corner point 5 toward the inside of the airfoil is along the angle bisector of the line between the airfoil tangent and control corner point 2 and control corner point 5. The propulsion direction can be calculated as:

[0120] ;

[0121] right 、 After normalization, the unit vectors for the propulsion of the control corner point 2 and the control corner point 5 to the interior of the airfoil are obtained as follows:

[0122] ;

[0123] Similarly, the internal advancement distance of control corner point 7 and control corner point 10 is also selected as 0.015c. Therefore, the coordinates of control corner point 7 and control corner point 10 can be expressed as:

[0124] ;

[0125] .

[0126] In this embodiment, the mesh edge is as follows: Figure 5 As shown, the process for generating the first mesh edges around the airfoil profile is as follows: There are six mesh edges around the airfoil profile, mesh edge 1 22, mesh edge 2 23, mesh edge 3 24, mesh edge 4 25, mesh edge 5 26, and mesh edge 6 27, represented by edge 1, edge 2, edge 3, edge 4, edge 5, and edge 6. The starting control corner point of edge 1 is numbered 12, and the ending control corner point is numbered 13. The starting control corner point of edge 2 is numbered 13, and the ending control corner point is numbered 14. The starting control corner point of edge 3 is numbered 14, and the ending control corner point is numbered 15. The starting control corner point of edge 4 is numbered 15, and the ending control corner point is numbered 16. The starting control corner point of edge 5 is numbered 16, and the ending control corner point is numbered 17. The starting control corner point of edge 6 is numbered 17, and the ending control corner point is numbered 12. Among them, grid edges one to five are distributed on the airfoil and are curved grid edges; grid edge six 27 is composed of a straight line between two points and is a straight grid edge; the grid points on grid edge one 22, grid edge three 24, grid edge five 26, and grid edge six 27 are evenly distributed; the grid points on grid edge two 23 and grid edge four 25 are non-uniformly distributed.

[0127] For the curve grid edge 1, grid edge 3, and grid edge 5 with uniform grid points, first start from the starting point X S Curved distance from the trailing edge of the upper wing and end point X e Curved distance from the trailing edge of the upper wing Linear interpolation is used to obtain the curve distance of the i-th grid point on the grid edge , expressed as:

[0128] ;

[0129] in, Indicates the number of grid points on the grid edge. According to practice, it is more appropriate to set the number of grid points on grid edge 1 and grid edge 5 to 5 and the number of grid points on grid edge 3 to 4. Then, based on the expression of the airfoil geometric parameterized model, 、 The four formulas at To calculate the coordinates of the grid points, we can use the following formula Replaced by 4 and 5, it is expressed as:

[0130] ;

[0131] For the non-uniformly distributed grid points on the curved grid sides 2 and 4, the starting and ending grid sizes are assigned based on the continuity conditions of the adjacent grid sides. The distribution coefficient coe for each grid point is then calculated based on the number of grid nodes, the starting grid size, and the ending grid size according to the hyperbolic distribution law. The curve distance of each grid point is calculated. The number of grid points on grid sides 2 and 4 is set to 60, so it can be expressed as:

[0132] ;

[0133] Specifically, it can be expressed as:

[0134] ;

[0135] From this the coordinates of each grid point.

[0136] For the straight line uniformly distributed grid edge six, it is more reasonable to set the number of grid points of the grid edge six to 4. The coordinates of the i-th grid point can be directly obtained by linear interpolation of the coordinates of the two points. The coordinates can be expressed as:

[0137] ;

[0138] Specifically, it can be expressed as:

[0139] ;

[0140] in, , is the number of grid points on edge6.

[0141] Step S14: Generate intersecting edges at the leading edge and the trailing edge based on the first mesh edges, generate second mesh edges inside the airfoil using the second control corner points, and generate a target quadrilateral area based on the quadrilateral areas, the first mesh edges, the intersecting edges, and the second mesh edges.

[0142] In this embodiment, the process of generating each intersecting edge at the trailing edge is as follows: Figure 5 As shown, the three mesh edges intersecting the airfoil near the trailing edge are mesh edge 7 28, mesh edge 10 31, and mesh edge 11 32, represented by edge 7, edge 10, and edge 11. For example, the number of mesh points on mesh edge 11 32 is the same as that on mesh edge 1 22, which is set to 4. It is more reasonable to also set the number of mesh points on mesh edge 7 28 and mesh edge 10 31 to 4. The starting control corner point of edge 7 is numbered 13 and the ending control corner point is numbered 18. The starting control corner point of edge 10 is numbered 16 and the ending control corner point is numbered 21. The starting control corner point of edge 11 is numbered 16 and the ending control corner point is numbered 13. The three mesh edges edge 7, edge 10, and edge 11 are all straight mesh edges, and the mesh points on the mesh edges are evenly distributed. The coordinates of the mesh points on each mesh edge can be expressed as:

[0143] ;

[0144] ;

[0145] ;

[0146] Specifically, it can be expressed as:

[0147] ;

[0148] ;

[0149] .

[0150] In this embodiment, the process of generating each intersecting edge at the leading edge is as follows: Figure 5 As shown, the two mesh edges near the leading edge that intersect the airfoil are mesh edge 8 29 and mesh edge 9 30, denoted by edge 8 and edge 9. The number of grid points for mesh edges 8 29 and 9 30 is the same as for mesh edges 7 28 and 10 31, set to 4. The starting control corner point for edge 8 is numbered 14, and the ending control corner point is numbered 19. The starting control corner point for edge 9 is numbered 15, and the ending control corner point is numbered 20. Both mesh edges edge 8 and edge 9 are straight mesh edges, and the mesh points on each mesh edge are evenly distributed. The coordinates of the mesh points on each mesh edge can be expressed as:

[0151] ;

[0152] ;

[0153] Specifically, it can be expressed as:

[0154] ;

[0155] .

[0156] In this embodiment, the process of generating the second mesh edge inside the airfoil is as follows: Figure 5 As shown, the four mesh edges inside the airfoil are edge 12 33, edge 13 34, edge 14 35, and edge 15 36, denoted by edge 12, edge 13, edge 14, and edge 15. The number of mesh points in edge 12 33 and edge 14 35 is the same as that in edge 2 23 and edge 4 25, set to 60. The number of mesh points in edge 13 34 and edge 15 36 is the same as that in edge 3 24 and edge 6 27, set to 4. The starting control corner point of edge 12 is numbered 18, and the ending control corner point is numbered 19. The starting control corner point of edge 13 is numbered 19, and the ending control corner point is numbered 20. The starting control corner point of edge 14 is numbered 20, and the ending control corner point is numbered 21. The starting control corner point of edge 15 is numbered 21, and the ending control corner point is numbered 18. Grid edge 12 33 , grid edge 13 34 , and grid edge 14 35 are curved grid edges, and grid edge 15 36 is a straight grid edge; grid points on grid edge 13 34 and grid edge 15 36 are evenly distributed, and grid points on grid edge 12 33 and grid edge 14 35 are unevenly distributed.

[0157] Grid edges 12, 13, and 14 can be copied from existing grid edges. Grid edge 13 copies grid edge 3, using a uniform grid point distribution and a copy ratio of 0.3. Grid edge 12 copies grid edge 2, with the grid size distribution at both ends taken from the connected grid edges 13 and 15, and a copy ratio of 0.5. Grid edge 14 copies grid edge 4, with the grid size distribution at both ends taken from the connected grid edges 13 and 15, and a copy ratio of 0.5. For grid edge 15, linear interpolation is used directly, expressed as:

[0158] ;

[0159] Specifically, it can be expressed as:

[0160] .

[0161] In this embodiment, the process of assembling and generating the six target quadrilateral regions of the airfoil is as follows: the entire airfoil is divided into six quadrilateral regions consisting of 15 mesh edges, namely quadrilateral region 1 6, quadrilateral region 2 7, quadrilateral region 3 8, quadrilateral region 4 9, quadrilateral region 5 10, and quadrilateral region 6 11, denoted by surf1, surf2, surf3, surf4, surf5, and surf6. Surf1 is surrounded by mesh edges 11, 5, 6, and 1; sur2 is surrounded by mesh edges 7, 2, 8, and 12; sur3 is surrounded by mesh edges 8, 3, 9, and 13; surf4 is surrounded by mesh edges 9, 4, 10, and 14; surf5 is surrounded by mesh edges 10, 11, 7, and 15; and surf6 is surrounded by mesh edges 12, 13, 14, and 15. Each quadrilateral region is defined according to the right-hand system, and the two mesh edges in the i direction are assembled first, and then the two mesh edges in the j direction. The mesh edges with directions opposite to the i and j directions are represented by a negative sign. The six target quadrilateral regions can be assembled as follows:

[0162] .

[0163] Step S15: Generate a quadrilateral mesh using the target quadrilateral area, and construct a computational domain mesh based on the quadrilateral mesh. Repeat the grid point deletion operation, grid point list update operation, and grid cell list update operation on the computational domain mesh to obtain a target grid point list and a target grid cell list.

[0164] In this embodiment, target quadrilateral region assembly information is obtained during the process of generating the target quadrilateral region; a quadrilateral mesh is generated based on the target quadrilateral region assembly information using a two-dimensional transfinite interpolation method, and a computational domain mesh including a grid point list and a grid cell list is constructed based on the quadrilateral mesh in an unstructured manner defined by a node list and a cell list; duplicate grid points in the grid point list of the computational domain mesh are deleted, and the grid point list is updated to obtain a target grid point list; and the grid cell list is updated according to a mapping relationship between the original grid point numbers and the updated grid point numbers to obtain a target grid cell list.

[0165] Specifically, according to the target quadrilateral region assembly information in the process of generating the target quadrilateral region, a two-dimensional transfinite interpolation method is adopted to generate a quadrilateral unit grid of each quadrilateral region.

[0166] In order to subsequently generate structural finite element files and conduct deformation and stress analysis, the quadrilateral meshes of the six quadrilateral areas are assembled into a computational domain mesh, which is described and output using an unstructured method defined by a grid point list and a grid cell list.

[0167] The structured quadrilateral units generated in each quadrilateral area are converted to unstructured definitions. The number of grid points in the i direction of the quadrilateral is ni, and the number of grid points in the j direction is nj. After conversion to unstructured definitions, the number of grid nodes nv is ni*nj, the number of grid cells nc is (ni-1)*(nj-1), the grid point numbered (i, j) is numbered (j-1)*ni+i in the new grid point list, and the grid cell numbered (i, j) is numbered (j-1)*(ni-1)+i in the new grid cell list. The four grid points that construct the unit are numbered (j-1)*ni+i, (j-1)*ni+i+1, j*ni+i+1, and j*ni+i in the new grid point list.

[0168] After the conversion, each quadrilateral area has its own grid point list and grid cell list. The grid point lists and grid cell lists of the six quadrilateral areas are then merged and assembled, and the grid point numbers and cell numbers are updated. Add a grid point list (total number of nodes is nv2) and a grid cell list (total number of cells is nc2) to the existing grid point list (total number of nodes is nv1) and grid cell list (total number of cells is nc1). The number of each node in the added grid point list is updated from the original i to i+nv1, and the number of each cell in the added grid cell list is updated from the original j to j+nc2. The four grid point numbers in each cell are also increased by nv1. The number of nodes in the new grid point list is nv1+nv2, and the number of cells is nc1+nc2. Continue the above steps to assemble all the grid point lists and grid cell lists into a unified grid point list and grid cell list. The assembled partitioned quadrilateral mesh is as follows. Figure 6 As shown, the unified computational domain quadrilateral mesh is as follows Figure 7 shown.

[0169] Because the quadrilateral regions share common mesh edges, duplicate mesh nodes may appear in the directly assembled mesh point list. This will result in an error during structural finite element analysis, and the duplicate mesh points must be deleted. The assembled mesh point list is searched, duplicate mesh points are marked, and their numbers are recorded. The marked duplicate mesh nodes are deleted, the mesh point list is updated, and the mapping between the original and new mesh node numbers is recorded. Based on this mapping, the mesh point number of each mesh element in the mesh element list is updated.

[0170] Step S16: generating a grid for finite element analysis of the quadrilateral structure of an aircraft airfoil according to the target grid point list and the target grid cell list.

[0171] In this embodiment, based on the target grid point list and the target grid cell list, combined with the loads and constraints of the structural finite element analysis, the node positions where the loads and constraints are applied are added to generate a grid file for the structural finite element analysis, which is used to obtain the deformation and stress of the airfoil structure under the action of the load.

[0172] In this embodiment, the number and coordinate data of discrete grid points used to describe the geometric shape of an aircraft airfoil are obtained, and based on the number and the coordinate data, curvilinear distances between the discrete grid points and the trailing edge points of the upper airfoil surface of the airfoil are calculated; a geometric parameterized model of the airfoil is established using the curvilinear distances, and the airfoil grid is initially segmented to obtain quadrilateral regions; first control corner points at the leading edge and trailing edge corresponding to the upper airfoil and the lower airfoil, respectively, are calculated based on the geometric parameterized model of the airfoil, the coordinate data, and the curvilinear distances; second control corner points within the airfoil are generated based on the first control corner points, and first grid edges around the airfoil profile are generated using the first control corner points and the second control corner points; The invention relates to a method for generating intersecting edges at a leading edge and a trailing edge based on each of the first mesh edges, generating a second mesh edge inside the airfoil using each of the second control corner points, and generating a target quadrilateral region based on each of the quadrilateral regions, each of the first mesh edges, each of the intersecting edges, and each of the second mesh edges; generating a quadrilateral mesh using the target quadrilateral region, and constructing a computational domain mesh based on the quadrilateral mesh; performing repeated mesh point deletion operations, mesh point list update operations, and mesh cell list update operations on the computational domain mesh to obtain a target mesh point list and a target mesh cell list; and generating a mesh for finite element analysis of a quadrilateral structure of an aircraft airfoil based on the target mesh point list and the target mesh cell list. The present application calculates the curve distance between the discrete grid points and the trailing edge points of the upper wing surface of the airfoil based on the number and coordinate data of the discrete grid points describing the geometric shape of the aircraft airfoil, can accurately describe the geometric shape of the airfoil, establish a geometric parameterized model of the airfoil, perform initial segmentation on the airfoil grid, obtain each quadrilateral area, calculate each first control corner point at the leading edge and trailing edge corresponding to the upper wing surface and the lower wing surface respectively, generate each second control corner point inside the airfoil, use each first control corner point and each second control corner point to generate each first grid edge around the airfoil contour, generate each intersecting edge at the leading edge and trailing edge according to each first grid edge, and use each second control corner point to generate the airfoil The second mesh edge inside the shape is used to generate a target quadrilateral area. The target quadrilateral area is used to generate a quadrilateral mesh to achieve quadrilateral mesh generation for each target quadrilateral area. The quadrilateral mesh is then assembled into an overall quadrilateral mesh to construct a computational domain mesh. Repeated grid point deletion operations, grid point list update operations, and grid cell list update operations are performed on the computational domain mesh to obtain a target grid point list and a target grid cell list. The mesh for the finite element analysis of the quadrilateral structure of the aircraft airfoil is generated to ensure full quadrilateralization of the grid cells and consistency of the grid cells between different airfoil sections, thereby achieving mesh generation for the finite element analysis of the quadrilateral structure of the aircraft airfoil.

[0173] See also Figure 8 As shown, an embodiment of the present invention discloses a mesh generation device for finite element analysis of a quadrilateral structure of an aircraft airfoil, which may specifically include:

[0174] a curvilinear distance calculation module 41 for obtaining the number and coordinate data of discrete grid points used to describe the geometric shape of the aircraft airfoil, and calculating the curvilinear distance between the discrete grid points and the trailing edge point of the upper wing surface of the airfoil based on the number and the coordinate data;

[0175] a first control corner point calculation module 42 for establishing an airfoil geometry parameterized model using the curve distance, performing an initial segmentation on the airfoil mesh to obtain quadrilateral regions, and calculating first control corner points at the leading edge and the trailing edge corresponding to the upper and lower airfoils, respectively, based on the airfoil geometry parameterized model, the coordinate data, and the curve distance;

[0176] A first mesh edge generating module 43 is configured to generate second control corner points inside the airfoil based on the first control corner points, and to generate first mesh edges around the airfoil contour using the first control corner points and the second control corner points;

[0177] a target quadrilateral region generating module 44, configured to generate intersecting edges at the leading edge and the trailing edge based on the first mesh edges, generate second mesh edges inside the airfoil using the second control corner points, and generate a target quadrilateral region based on the quadrilateral regions, the first mesh edges, the intersecting edges, and the second mesh edges;

[0178] An updating module 45 is configured to generate a quadrilateral mesh using the target quadrilateral region, construct a computational domain mesh based on the quadrilateral mesh, and perform repeated grid point deletion operations, grid point list update operations, and grid cell list update operations on the computational domain mesh to obtain a target grid point list and a target grid cell list.

[0179] The grid generation module 46 is used to generate a grid for finite element analysis of the quadrilateral structure of the aircraft airfoil according to the target grid point list and the target grid cell list.

[0180] In this embodiment, the number and coordinate data of discrete grid points used to describe the geometric shape of an aircraft airfoil are obtained, and based on the number and the coordinate data, curvilinear distances between the discrete grid points and the trailing edge points of the upper airfoil surface of the airfoil are calculated; a geometric parameterized model of the airfoil is established using the curvilinear distances, and the airfoil grid is initially segmented to obtain quadrilateral regions; first control corner points at the leading edge and trailing edge corresponding to the upper airfoil and the lower airfoil, respectively, are calculated based on the geometric parameterized model of the airfoil, the coordinate data, and the curvilinear distances; second control corner points within the airfoil are generated based on the first control corner points, and first grid edges around the airfoil profile are generated using the first control corner points and the second control corner points; The invention relates to a method for generating intersecting edges at a leading edge and a trailing edge based on each of the first mesh edges, generating a second mesh edge inside the airfoil using each of the second control corner points, and generating a target quadrilateral region based on each of the quadrilateral regions, each of the first mesh edges, each of the intersecting edges, and each of the second mesh edges; generating a quadrilateral mesh using the target quadrilateral region, and constructing a computational domain mesh based on the quadrilateral mesh; performing repeated mesh point deletion operations, mesh point list update operations, and mesh cell list update operations on the computational domain mesh to obtain a target mesh point list and a target mesh cell list; and generating a mesh for finite element analysis of a quadrilateral structure of an aircraft airfoil based on the target mesh point list and the target mesh cell list. The present application calculates the curve distance between the discrete grid points and the trailing edge points of the upper wing surface of the airfoil based on the number and coordinate data of the discrete grid points describing the geometric shape of the aircraft airfoil, can accurately describe the geometric shape of the airfoil, establish a geometric parameterized model of the airfoil, perform initial segmentation on the airfoil grid, obtain each quadrilateral area, calculate each first control corner point at the leading edge and trailing edge corresponding to the upper wing surface and the lower wing surface respectively, generate each second control corner point inside the airfoil, use each first control corner point and each second control corner point to generate each first grid edge around the airfoil contour, generate each intersecting edge at the leading edge and trailing edge according to each first grid edge, and use each second control corner point to generate the airfoil The second mesh edge inside the shape is used to generate a target quadrilateral area. The target quadrilateral area is used to generate a quadrilateral mesh to achieve quadrilateral mesh generation for each target quadrilateral area. The quadrilateral mesh is then assembled into an overall quadrilateral mesh to construct a computational domain mesh. Repeated grid point deletion operations, grid point list update operations, and grid cell list update operations are performed on the computational domain mesh to obtain a target grid point list and a target grid cell list. The mesh for the finite element analysis of the quadrilateral structure of the aircraft airfoil is generated to ensure full quadrilateralization of the grid cells and consistency of the grid cells between different airfoil sections, thereby achieving mesh generation for the finite element analysis of the quadrilateral structure of the aircraft airfoil.

[0181] In some specific embodiments, the curve distance calculation module 41 may specifically include:

[0182] A quantity and coordinate data acquisition module is used to obtain the quantity and coordinate data of discrete grid points from a preset data file or formula describing the airfoil geometry;

[0183] The trailing edge point determination module is used to determine the trailing edge point of the upper wing surface of the airfoil, and calculate the curvilinear distance between the discrete grid point and the trailing edge point of the upper wing surface of the airfoil based on the quantity and the coordinate data and using a curvilinear distance calculation formula; the curvilinear distance calculation formula is:

[0184] ;

[0185] ;

[0186] in, is the curve distance of the i-th discrete grid point, is the curve distance of the i-1th discrete grid point, n is the number of discrete grid points, is the straight-line distance between the i-1th discrete grid point and the i-th discrete grid point, is the coordinate data of the i-th discrete grid point, is the coordinate data of the i-1th discrete grid point.

[0187] In some specific embodiments, the first control corner point calculation module 42 may specifically include:

[0188] The airfoil geometry parameterized model establishment module is used to establish the airfoil geometry parameterized model by using the curve distance and a one-dimensional radial basis interpolation method; the expression of the airfoil geometry parameterized model is:

[0189] ;

[0190] Where f is the interpolation function, n is the number of discrete grid points, is the curve distance, is the interpolation coefficient, is the basis function, and d is the interpolation variable.

[0191] In some specific embodiments, the first control corner point calculation module 42 may specifically include:

[0192] a module for determining a first control corner point at a trailing edge, configured to determine a first control corner point at a trailing edge of an upper wing surface and a first control corner point at a trailing edge of a lower wing surface of the airfoil based on the coordinate data;

[0193] a first control angle point determination module within the trailing edge control angle point range, configured to perform plane coordinate calculation on the coordinate data, the preset trailing edge control angle point range, and the curve distance using the airfoil geometric parameterized model, to obtain a first control angle point within the preset trailing edge control angle point range of the upper wing surface and a first control angle point within the preset trailing edge control angle point range of the lower wing surface;

[0194] The first control corner point determination module within the leading edge control corner point range is used to iteratively calculate the curve distance based on the bisection method to obtain the leading edge control corner point range, and use the airfoil geometric parameterized model to perform plane coordinate calculation on the coordinate data, the leading edge control corner point range and the curve distance to obtain the first control corner point within the leading edge control corner point range of the upper wing surface and the first control corner point within the leading edge control corner point range of the lower wing surface.

[0195] In some specific embodiments, the first mesh edge generation module 43 may specifically include:

[0196] The second control corner point generation module is used to advance each of the first control corner points along the inner normal direction of the airfoil, the tangent direction of the airfoil, and the angle bisector direction of the line connecting the control corner points to generate each second control corner point inside the airfoil.

[0197] In some specific embodiments, the target quadrilateral region generating module 44 may specifically include:

[0198] An assembly information acquisition module is used to acquire target quadrilateral region assembly information during the process of generating the target quadrilateral region;

[0199] The quadrilateral mesh generation module is used to generate a quadrilateral mesh based on the target quadrilateral region assembly information by using a two-dimensional transfinite interpolation method.

[0200] In some specific embodiments, the updating module 45 may specifically include:

[0201] A computational domain mesh construction module is used to construct a computational domain mesh including a mesh point list and a mesh cell list based on a quadrilateral mesh and in an unstructured manner using a node list and a cell list definition;

[0202] A grid point list updating module is used to delete duplicate grid points in the grid point list of the computational domain grid and update the grid point list to obtain a target grid point list;

[0203] The grid cell list updating module is used to update the grid cell list according to the mapping relationship between the original grid point numbers and the updated grid point numbers to obtain a target grid cell list.

[0204] Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device 50 may specifically include: at least one processor 51, at least one memory 52, a power supply 53, a communication interface 54, an input / output interface 55, and a communication bus 56. The memory 52 is used to store a computer program, which is loaded and executed by the processor 51 to implement the relevant steps of the mesh generation method for finite element analysis of a quadrilateral structure of an aircraft airfoil performed by the electronic device as disclosed in any of the aforementioned embodiments.

[0205] In this embodiment, the power supply 53 is used to provide operating voltage for each hardware device on the electronic device 50; the communication interface 54 can create a data transmission channel between the electronic device 50 and the external device. The communication protocol it follows is any communication protocol that can be applied to the technical solution of this application and is not specifically limited here; the input and output interface 55 is used to obtain external input data or output data to the outside world. Its specific interface type can be selected according to specific application needs and is not specifically limited here.

[0206] In addition, the memory 52, as a carrier for resource storage, can be a read-only memory, random access memory, disk or CD, etc. The resources stored thereon include an operating system 521, a computer program 522 and data 523, etc. The storage method can be temporary storage or permanent storage.

[0207] The operating system 521 is used to manage and control the hardware devices and computer program 522 on the electronic device 50, so as to enable the processor 51 to calculate and process data 523 in the memory 52. ​​The operating system 521 can be Windows, Unix, Linux, etc. In addition to including computer programs capable of implementing the mesh generation method for finite element analysis of aircraft airfoil quadrilateral structures performed by the electronic device 50 as disclosed in any of the aforementioned embodiments, the computer program 522 may further include computer programs capable of performing other specific tasks. In addition to data transmitted from external devices and received by the mesh generation device for finite element analysis of aircraft airfoil quadrilateral structures, the data 523 may also include data collected by the input and output interface 55 of the device itself.

[0208] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0209] Furthermore, an embodiment of the present application also discloses a computer-readable storage medium, in which a computer program is stored. When the computer program is loaded and executed by a processor, the mesh generation method steps for finite element analysis of the aircraft wing quadrilateral structure disclosed in any of the aforementioned embodiments are implemented.

[0210] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0211] The above is a detailed introduction to the mesh generation method, device, equipment and storage medium for finite element analysis of the quadrilateral structure of an aircraft wing provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for general technical personnel in this field, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A mesh generation method for finite element analysis of quadrilateral structures of aircraft airfoils, characterized in that: include: Obtaining the number and coordinate data of discrete grid points used to describe the geometric shape of an aircraft airfoil, and calculating the curvilinear distance between the discrete grid points and a trailing edge point of an upper airfoil surface based on the number and the coordinate data; Establishing an airfoil geometry parameterized model using the curve distance, performing initial segmentation on the airfoil mesh to obtain quadrilateral regions, and calculating first control corner points at the leading edge and the trailing edge corresponding to the upper and lower airfoils, respectively, based on the airfoil geometry parameterized model, the coordinate data, and the curve distance; generating second control corner points inside the airfoil based on the first control corner points, and generating first mesh edges around the airfoil contour using the first control corner points and the second control corner points; generating intersecting edges at the leading edge and the trailing edge based on the first mesh edges, generating second mesh edges inside the airfoil using the second control corner points, and generating a target quadrilateral region based on the quadrilateral regions, the first mesh edges, the intersecting edges, and the second mesh edges; Generate a quadrilateral mesh using the target quadrilateral region, construct a computational domain mesh based on the quadrilateral mesh, and perform repeated grid point deletion operations, grid point list update operations, and grid cell list update operations on the computational domain mesh to obtain a target grid point list and a target grid cell list; A grid for finite element analysis of an aircraft airfoil quadrilateral structure is generated according to the target grid point list and the target grid unit list.

2. The mesh generation method for finite element analysis of an aircraft airfoil quadrilateral structure according to claim 1, characterized in that: The step of obtaining the number and coordinate data of discrete grid points used to describe the geometric shape of an aircraft airfoil, and calculating the curvilinear distance between the discrete grid points and a trailing edge point of an upper airfoil surface based on the number and the coordinate data, comprises: Obtaining the number and coordinate data of discrete grid points from a preset data file or formula describing the airfoil geometry; Determine the trailing edge point of the upper wing surface of the airfoil, and calculate the curvilinear distance between the discrete grid point and the trailing edge point of the upper wing surface of the airfoil based on the number and the coordinate data and using a curvilinear distance calculation formula; the curvilinear distance calculation formula is: ； ； in, is the curve distance of the i-th discrete grid point, is the curve distance of the i-1th discrete grid point, n is the number of discrete grid points, is the straight-line distance between the i-1th discrete grid point and the i-th discrete grid point, is the coordinate data of the i-th discrete grid point, is the coordinate data of the i-1th discrete grid point.

3. The mesh generation method for finite element analysis of an aircraft airfoil quadrilateral structure according to claim 1, characterized in that: The method of establishing an airfoil geometry parameterized model by utilizing the curve distance includes: The airfoil geometry parameterized model is established by using the curve distance and a one-dimensional radial basis interpolation method; the expression of the airfoil geometry parameterized model is: ； Where f is the interpolation function, n is the number of discrete grid points, is the curve distance, is the interpolation coefficient, is the basis function, and d is the interpolation variable.

4. The mesh generation method for finite element analysis of an aircraft airfoil quadrilateral structure according to claim 1, characterized in that: The calculating of the first control corner points at the leading edge and the trailing edge corresponding to the upper wing surface and the lower wing surface respectively based on the airfoil geometric parameterized model, the coordinate data, and the curve distance comprises: determining a first control corner point at a trailing edge of an upper airfoil and a first control corner point at a trailing edge of a lower airfoil of the airfoil based on the coordinate data; Performing plane coordinate calculation on the coordinate data, the preset trailing edge control angle point range, and the curve distance using the airfoil geometric parameterized model to obtain a first control angle point within the preset trailing edge control angle point range of the upper airfoil surface and a first control angle point within the preset trailing edge control angle point range of the lower airfoil surface; The curve distance is iteratively calculated based on the bisection method to obtain the leading edge control corner point range, and the plane coordinate calculation is performed on the coordinate data, the leading edge control corner point range and the curve distance using the airfoil geometric parameterized model to obtain the first control corner point within the leading edge control corner point range of the upper wing surface and the first control corner point within the leading edge control corner point range of the lower wing surface.

5. The mesh generation method for finite element analysis of an aircraft airfoil quadrilateral structure according to claim 1, characterized in that: The step of generating the second control corner points inside the airfoil based on the first control corner points includes: Each of the first control corner points is advanced along the inner normal direction of the airfoil, the tangent direction of the airfoil, and the angle bisector direction of the line connecting the control corner points to generate each of the second control corner points inside the airfoil.

6. The mesh generation method for finite element analysis of quadrilateral structure of aircraft airfoil according to claim 1, characterized in that: The generating of a quadrilateral mesh by using the target quadrilateral region includes: Obtaining target quadrilateral region assembly information during the process of generating the target quadrilateral region; A quadrilateral mesh is generated based on the target quadrilateral region assembly information using a two-dimensional transfinite interpolation method.

7. The mesh generation method for finite element analysis of an aircraft airfoil quadrilateral structure according to any one of claims 1 to 6, characterized in that: The step of constructing a computational domain grid based on the quadrilateral grid, performing repeated grid point deletion operations, grid point list update operations, and grid cell list update operations on the computational domain grid to obtain a target grid point list and a target grid cell list includes: Based on the quadrilateral grid and using the unstructured method of node list and cell list definition, the computational domain grid including grid point list and grid cell list is constructed; Deleting duplicate grid points in the grid point list of the computational domain grid, and updating the grid point list to obtain a target grid point list; The grid cell list is updated according to the mapping relationship between the original grid point numbers and the updated grid point numbers to obtain a target grid cell list.

8. A grid generation device for finite element analysis of quadrilateral structures of aircraft airfoils, characterized in that: include: a curvilinear distance calculation module, configured to obtain the number and coordinate data of discrete grid points used to describe the geometric shape of the aircraft airfoil, and calculate the curvilinear distance between the discrete grid points and the trailing edge point of the upper wing surface of the airfoil based on the number and the coordinate data; a first control corner point calculation module, configured to establish an airfoil geometry parameterized model using the curve distance, perform initial segmentation on the airfoil mesh to obtain quadrilateral regions, and calculate first control corner points at the leading edge and the trailing edge corresponding to the upper and lower airfoils, respectively, based on the airfoil geometry parameterized model, the coordinate data, and the curve distance; A first mesh edge generation module is configured to generate second control corner points inside the airfoil based on the first control corner points, and to generate first mesh edges around the airfoil contour using the first control corner points and the second control corner points; a target quadrilateral region generating module, configured to generate intersecting edges at the leading edge and the trailing edge based on the first mesh edges, generate second mesh edges inside the airfoil using the second control corner points, and generate a target quadrilateral region based on the quadrilateral regions, the first mesh edges, the intersecting edges, and the second mesh edges; an updating module, configured to generate a quadrilateral mesh using the target quadrilateral region, construct a computational domain mesh based on the quadrilateral mesh, and perform repeated grid point deletion operations, grid point list update operations, and grid cell list update operations on the computational domain mesh to obtain a target grid point list and a target grid cell list; A grid generation module is used to generate a grid for finite element analysis of an aircraft airfoil quadrilateral structure according to the target grid point list and the target grid unit list.

9. An electronic device, characterized in that: include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the mesh generation method for finite element analysis of an aircraft airfoil quadrilateral structure according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that Used to store a computer program; wherein, when the computer program is executed by a processor, the grid generation method for finite element analysis of an aircraft airfoil quadrilateral structure according to any one of claims 1 to 7 is implemented.

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