Logarithmic distribution-based hub boundary element mesh generation method, medium and device

Abstract

The specification provides a logarithmic distribution-based hub boundary element grid generation method, medium and equipment, which relates to the technical field of propeller simulation. The method comprises: based on the propeller blade boundary element grid, using the hub leading edge grid generation algorithm, calculating the axial coordinate, radial radius and circumferential angle of the leading edge grid. Based on the hub thickness transition zone grid generation algorithm, boundary node direct assignment and intermediate node linear interpolation, the hub thickness transition zone basic grid is generated. Based on the logarithmic distribution optimization grid distribution, the circumferential index is traversed, and the axial grid layer of different dimensions in the hub thickness transition zone basic grid is subjected to hierarchical differential logarithmic coordinate correction. Based on the hub trailing edge grid generation algorithm, the axial coordinate, radial radius and circumferential angle of the trailing edge grid are calculated to generate a hub boundary element grid that does not contain a very high aspect ratio (or length-width ratio) and geometrically exhibits an extremely slender hub, with high grid quality.

Description

Technical Field

[0001] This invention relates to the field of propeller simulation technology, and in particular to a method, medium, and device for generating hub boundary element meshes based on logarithmic distribution. Background Technology

[0002] When calculating the hydrodynamic performance of a propeller using the boundary element method (also known as the "surface element method"), it is necessary to generate boundary element meshes, namely, blade meshes, hub meshes, and wake vortex meshes. Generally, the hub mesh is generated after the blade mesh. Furthermore, the hub mesh has a requirement: the mesh nodes at the junction of the hub and the blades must correspond one-to-one. The generated hub mesh should also ensure that it does not contain meshes with extremely high aspect ratios (or aspect ratios) or those that are geometrically extremely thin, in order to facilitate numerical calculations.

[0003] Currently, based on the already generated propeller blade boundary element mesh (the coordinates of all nodes have been stored as a three-dimensional array, i.e.) , , , , , ,in, Store the X coordinates of all nodes on the suction surface. Store the Y coordinates of all nodes on the suction surface. Store the Z coordinates of all nodes on the suction surface. Store the X coordinates of all nodes on the pressure surface. Store the Y-coordinates of all nodes on the pressure surface. Store the Z-coordinates of all nodes on the pressure surface. The third dimension k of these arrays represents the blade number (k=1,2,...). ), the first dimension i (i=1,2,..., +1, The first dimension (i is the number of chordal grids) and the second dimension j (j=1,2,...,Mb+1, where Mb is the number of spanwise grids) represent the node number on the k-th blade, where i represents the chordal direction and j represents the spanwise direction, along with the known propeller diameter D and hub diameter. Number of blades Pitch at the leaf root This process generates the boundary element mesh for the propeller hub. Traditional hub mesh generation methods often employ a single uniform interpolation algorithm. At the leading edge, thickness transition zone, and trailing edge junction of the hub, where the mesh is denser at the blade guide edge, extremely elongated and distorted mesh elements with high aspect ratios and aspect ratios are easily generated. These distorted meshes have poor geometric quality and are prone to problems such as singular computational matrices, iteration divergence, accuracy distortion, and local computational failures during boundary element method hydrodynamic simulations, severely impacting the accuracy and reliability of propeller hydrodynamic simulation results.

[0004] Based on this, this specification provides a method, medium, and device for generating hub boundary element meshes based on logarithmic distribution. Summary of the Invention

[0005] To address the technical problem in existing technologies where the generation of hub boundary element meshes with extremely high aspect ratios at the connection point between the hub and the blade guide edge results in poor geometric quality and severely affects the accuracy and reliability of propeller hydrodynamic simulation results, this invention proposes a hub boundary element mesh generation method, medium, and device based on logarithmic distribution to solve the aforementioned technical problems in the prior art.

[0006] This specification provides a method for generating hub boundary element meshes based on logarithmic distribution, including:

[0007] S1. Preset propeller geometry and mesh discretization parameters to generate a three-dimensional coordinate array of propeller blade boundary element mesh; the three-dimensional coordinate array of propeller blade boundary element mesh includes axial mesh points and circumferential mesh points of different layers in the hub;

[0008] S2. Execute the hub leading edge mesh generation algorithm, traverse the axial mesh points and circumferential mesh points respectively, and calculate the axial coordinates, radial radius and circumferential angle of the leading edge mesh;

[0009] S3. Execute the hub thickness transition zone mesh generation algorithm, traverse the axial mesh points and circumferential mesh points respectively, and generate the basic mesh of the hub thickness transition zone by directly assigning values ​​to boundary nodes and linearly interpolating intermediate nodes.

[0010] S4. Based on logarithmic distribution optimization of mesh distribution, traverse the circumferential index, and perform layered differential logarithmic coordinate correction on the axial mesh layers of different dimensions in the basic mesh of the hub thickness transition zone, including:

[0011] Define the correction factor:

[0012] For the axial mesh layer in the basic mesh of the hub thickness transition zone :

[0013] (1)

[0014] For the axial mesh layer in the basic mesh of the hub thickness transition zone :

[0015] (2)

[0016] For the axial mesh layer in the basic mesh of the hub thickness transition zone :

[0017] (3)

[0018] in, Let j ∈ (2, ..., ) be the number of circumferential layers of the hub mesh. + 1), , The number of axial grid layers at the leading edge of the propeller hub. The axial coordinates are those before the basic mesh correction for the hub thickness transition zone. The axial coordinates are the corrected base mesh coordinates for the thickness transition zone of the propeller hub. , The introduced dimensional parameter represents the number of axial layers in the hub mesh. , , The number of segments in the circumferential grid. The number of chordal grids for the blades. This refers to the number of blades.

[0019] S5. Execute the propeller hub trailing edge mesh generation algorithm, calculate the axial coordinates, radial radius, and circumferential angle of the trailing edge mesh, and smooth the coordinates and angles of the trailing edge end mesh.

[0020] S6. Convert the cylindrical coordinate mesh parameters to rectangular coordinates to obtain the three-dimensional mesh coordinates of the single-channel propeller hub; based on the periodic symmetry characteristics of the propeller, generate a full-circumference multi-channel complete propeller hub boundary element mesh by extending the circumferential angle offset.

[0021] Optionally, the parameters include: propeller diameter D, hub diameter Number of blades Pitch at the leaf root Define the axial length of the hub leading edge. Axial length of propeller hub trailing edge Define the number of axial mesh layers at the leading edge. Number of axial mesh layers at the trailing edge =6. Number of circumferential grid segments Total number of grid layers along the axis Initialize the hub mesh coordinate zero matrix. , , , , , .

[0022] Optionally, the leading edge mesh axial coordinates in step S2 The calculation formula is:

[0023] (4)

[0024] Where i = 1, 2, ..., j = 1, 2, ... +1, Let X be the X coordinates of all nodes on the suction surface. This is the axial length of the leading edge of the propeller hub. This represents the number of mesh layers along the leading edge axial direction.

[0025] When i=1, the first-level coordinates are shrunk and corrected: , The coordinates of the first layer before correction. These are the corrected coordinates for the first layer.

[0026] Optionally, in step S2, the radial radius of the leading edge mesh... With circumferential angle The calculation formula is:

[0027] (5)

[0028] in, =1, 2, ... , , =1, 2, ... , +1; Let X be the X coordinates of all nodes on the suction surface. This is the axial length of the leading edge of the propeller hub. This represents the number of mesh layers along the leading edge axial direction.

[0029] (6)

[0030] in, = 1, 2, ... , , = 1, 2, ... , +1; The diameter of the propeller hub; The pitch at the leaf root; Let Z be the Z coordinates of all nodes on the suction surface; Let Y be the Y coordinate of all nodes on the suction surface;

[0031] When i=1, a smooth correction is made to the circumferential angle of the first layer:

[0032] (7)

[0033] in, = 1, 2, ... , +1.

[0034] Optionally, the axial coordinates of the basic mesh of the hub thickness transition zone in step S3 radial radius Circumferential angle The interpolation formula is:

[0035] Let nhm= +i

[0036] When i=1, 2, ... , +1, j= When +1,

[0037] (8)

[0038] (9)

[0039] (10)

[0040] When i=1, 2, ... , When +1, j=1,

[0041] (11)

[0042] (12)

[0043] (13)

[0044] When i=1, 2, ... , +1, j = , -1, ..., 2 hours

[0045] (14)

[0046] (15)

[0047] (16)

[0048] in, Let X be the X coordinates of all nodes on the pressure surface. The diameter of the propeller hub. Let Z be the Z coordinates of all nodes on the pressure surface. Let Y be the Y coordinate of all nodes on the pressure surface. Let X be the X coordinates of all nodes on the suction surface. Let Z be the Z coordinates of all nodes on the suction surface; Let Y be the Y coordinate of all nodes on the suction surface.

[0049] Optionally, the trailing edge mesh axial coordinates in step S5 radial radius Circumferential angle The calculation formula is:

[0050] Let the axial mesh layer in the trailing edge mesh = + + i

[0051] (17)

[0052] Where i = 2, 3, ..., + 1, j = 1, 2, ... , +1;

[0053] when i= When +1 is applied, the tail layer coordinates are shrunk and corrected.

[0054] = - 0.005 * (18)

[0055] (19)

[0056] Where i = 2, 3, ..., + 1, j = 1, 2, ... , +1;

[0057] (20)

[0058] Where i = 2, 3, ... , + 1, j = 1, 2, ... , +1;

[0059] when i = When +1, a smooth correction is made to the circumferential angle of the tail layer:

[0060] (twenty one)

[0061] in, Let X be the X coordinates of all nodes on the suction surface. This is the axial length of the propeller hub trailing edge. The number of mesh layers along the trailing edge. The diameter of the propeller hub. The pitch at the leaf root.

[0062] Optionally, in step S6, the cylindrical coordinates are converted to rectangular coordinates. , , The formula is:

[0063] (twenty two)

[0064] (twenty three)

[0065] (twenty four)

[0066] Where i = 1, 2, ..., + 1, j = 1, 2, ... , +1, This represents the total number of grid cells along the axis.

[0067] Optionally, the circumferential angle offset in step S6 is extended as follows: the single-channel hub mesh formed by the single-channel hub three-dimensional mesh coordinates is rotated and copied around the propeller rotation axis and placed in the area between every two blades to form a full-circumference multi-channel complete hub boundary element mesh. The rotation and copying is as follows:

[0068] (25)

[0069] in, For circumferential angle, The updated circumferential angle;

[0070] In calculation Then, based on the updated circumferential angle, the Y and Z coordinates are reconstructed, while the axial coordinates remain unchanged, i.e.:

[0071] when = 2, 3, ... , , i = 1, 2, ... , +1, j = 1, 2, ... , When +1,

[0072] (26)

[0073] (27)

[0074] (28)

[0075] in, This represents the total number of grid layers along the axis.

[0076] This specification provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for generating hub boundary element meshes based on logarithmic distribution.

[0077] This specification provides a propeller hydrodynamic numerical simulation device, including a processor and a memory. The memory stores a computer program, and the processor executes the computer program to implement the above-mentioned method for generating hub boundary element meshes based on logarithmic distribution, generate propeller hub boundary element meshes, and complete hydrodynamic simulation calculations using the boundary element method.

[0078] Beneficial effects:

[0079] The above-mentioned technical solutions adopted in this specification can achieve the following beneficial effects:

[0080] This invention proposes a method for generating a rotor hub boundary element mesh based on logarithmic distribution. It performs layered differential logarithmic coordinate correction on the axial mesh layers of different dimensions in the base mesh of the rotor hub thickness transition zone, so that the generated rotor hub mesh does not contain meshes with extremely high aspect ratio (or aspect ratio) and exhibit extremely thin geometry, which is beneficial for numerical calculation.

[0081] Meanwhile, this invention can add a logarithmic correction method to the original mesh generation main process architecture without making significant modifications to the original mesh generation logic, parameter definitions, and calculation formula system, nor without reconstructing the overall program architecture and hardware adaptation system. The regular and uniform high-quality boundary element mesh can effectively optimize the iterative conditions of boundary element numerical solution, reduce the probability of computational divergence, and improve the convergence and stability of numerical calculation, which is convenient for rapid promotion and application in the existing propeller hydrodynamic numerical simulation engineering system.

[0082] Third, this invention is highly versatile and features a well-regulated mesh, making it suitable for various propeller simulation scenarios. Based on an adaptive strategy of circumferential mesh segmentation and axial layering logarithmic correction, this invention can adapt to the mesh generation requirements of propeller hubs with different numbers and sizes of blades. Furthermore, by combining lead and trailing mesh contraction correction, circumferential angle smoothing optimization, and full-circumferential symmetrical expansion techniques, it achieves a smooth transition of the entire mesh across the hub's leading edge, transition zone, and trailing edge. This results in a standardized, high-quality, complete hub boundary element mesh, effectively reducing the workload of manual mesh optimization and improving the overall efficiency of propeller hydrodynamic simulation, thus possessing significant engineering practical value. Attached Figure Description

[0083] The accompanying drawings, which are included to provide a further understanding of this specification and form part of this specification, illustrate exemplary embodiments and are used to explain this specification, but do not constitute an undue limitation thereof. In the drawings:

[0084] Figure 1 This is a flowchart illustrating a method for generating hub boundary element meshes based on logarithmic distribution, as provided in this specification.

[0085] Figure 2This is a schematic diagram of a propeller blade boundary element mesh provided in this specification;

[0086] Figure 3 This is a schematic diagram of a high aspect ratio grid generated at the connection between the rotor hub and the blade guide edge, as provided in this specification.

[0087] Figure 4 This is a schematic diagram of a propeller hub boundary element mesh provided in this specification. Detailed Implementation

[0088] To make the objectives, technical solutions, and advantages of this specification clearer, the technical solutions of this specification will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, and not all of them. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this specification.

[0089] This specification provides a method, medium, and device for generating hub boundary element meshes based on logarithmic distribution. The technical solutions provided by the various embodiments of this specification are described in detail below with reference to the accompanying drawings.

[0090] like Figure 1 As shown, Figure 1 This is a flowchart illustrating a method for generating hub boundary element meshes based on logarithmic distribution, as provided in this specification. The method includes the following steps:

[0091] S1. Preset propeller geometry and mesh discretization parameters to generate a three-dimensional coordinate array of propeller blade boundary element mesh; the three-dimensional coordinate array of propeller blade boundary element mesh includes axial mesh points and circumferential mesh points of different layers in the hub;

[0092] S2. Execute the hub leading edge mesh generation algorithm, traverse the axial mesh points and circumferential mesh points respectively, and calculate the leading edge axial coordinates, leading edge mesh radial radius and circumferential angle;

[0093] S3. Execute the hub thickness transition zone mesh generation algorithm, traverse the axial mesh points and circumferential mesh points respectively, and generate the basic mesh of the hub thickness transition zone by directly assigning values ​​to boundary nodes and linearly interpolating intermediate nodes.

[0094] S4. Based on logarithmic distribution optimization of mesh distribution, traverse the circumferential index, and perform layered differential logarithmic coordinate correction on the axial mesh layers of different dimensions in the basic mesh of the hub thickness transition zone, including:

[0095] Define the correction factor:

[0096] For the axial mesh layer in the basic mesh of the hub thickness transition zone = +1:

[0097] (1)

[0098] For the axial mesh layer in the basic mesh of the hub thickness transition zone = +2:

[0099] (2)

[0100] For the axial mesh layer in the basic mesh of the hub thickness transition zone = +3:

[0101] (3)

[0102] Where j is the circumferential layer dimension of the hub mesh, j ∈ (2, + 1), , The number of axial grid layers at the leading edge of the propeller hub. The axial coordinates are those of the base mesh before correction in the hub thickness transition zone. The axial coordinates are the corrected base mesh coordinates for the thickness transition zone of the propeller hub. , The introduced dimensional parameter represents the number of axial layers in the hub mesh. , , The number of segments in the circumferential grid. The number of chordal grids for the blades. This refers to the number of blades.

[0103] S5. Execute the propeller hub trailing edge mesh generation algorithm, calculate the axial coordinates, radial radius, and circumferential angle of the trailing edge mesh, and smooth the coordinates and angles of the trailing edge end mesh.

[0104] S6. Convert the cylindrical coordinate mesh parameters to rectangular coordinates to obtain the three-dimensional mesh coordinates of the single-channel propeller hub; based on the periodic symmetry characteristics of the propeller, generate a full-circumference multi-channel complete propeller hub boundary element mesh by extending the circumferential angle offset.

[0105] Preferably, the above parameters include: propeller diameter D, hub diameter Number of blades Pitch at the leaf root Define the axial length of the rotor hub leading edge. Axial length of propeller hub trailing edge Define the number of axial mesh layers at the leading edge. Number of axial mesh layers at the trailing edge =6. Number of circumferential grid segments Total number of axial mesh layers Initialize the hub mesh coordinate zero matrix. , , , , , .

[0106] Preferably, in step S2, the axial coordinates of the leading edge mesh The calculation formula is:

[0107] (4)

[0108] Where i = 1, 2, ..., j=1, 2, ..., +1, Let X be the X coordinates of all nodes on the suction surface. This is the axial length of the leading edge of the propeller hub. This represents the number of mesh layers along the leading edge axial direction.

[0109] When i=1, the first-level coordinates are shrunk and corrected: , The coordinates of the first layer before correction. These are the corrected coordinates for the first layer.

[0110] Preferably, in step S2, the radial radius of the leading edge mesh... With circumferential angle The calculation formula is:

[0111] (5)

[0112] in, =1, 2, ... , , =1, 2, ... , +1; Let X be the X coordinates of all nodes on the suction surface. This is the axial length of the leading edge of the propeller hub. This represents the number of mesh layers along the leading edge axial direction.

[0113] (6)

[0114] in, = 1, 2, ... , , = 1, 2, ... , +1; The diameter of the propeller hub; The pitch at the leaf root; Let Z be the Z coordinates of all nodes on the suction surface; Let Y be the Y coordinate of all nodes on the suction surface;

[0115] Smooth correction of the circumferential angle of the first floor:

[0116] (7)

[0117] in, = 1, 2, ... , +1.

[0118] Preferably, the axial coordinates of the basic grid in the hub thickness transition zone in step S3 are... radial radius Circumferential angle The interpolation formula is:

[0119] Let nhm = + i

[0120] When i = 1, 2, ... , + 1, j= When +1,

[0121] (8)

[0122] (9)

[0123] (10)

[0124] When i=1, 2, ... , When +1, j=1,

[0125] (11)

[0126] (12)

[0127] (13)

[0128] When i=1, 2, ... , +1, j= , -1, ..., 2 hours

[0129] (14)

[0130] (15)

[0131] (16)

[0132] in, Let X be the X coordinates of all nodes on the pressure surface. The diameter of the propeller hub. Let Z be the Z coordinates of all nodes on the pressure surface. Let Y be the Y coordinate of all nodes on the pressure surface. Let X be the X coordinates of all nodes on the suction surface. Let Z be the Z coordinates of all nodes on the suction surface; Let Y be the Y coordinate of all nodes on the suction surface.

[0133] Preferably, the axial coordinates of the trailing edge mesh in step S5 radial radius Circumferential angle The calculation formula is:

[0134] Let the axial mesh layer in the trailing edge mesh = + +i

[0135] (17)

[0136] Where i = 2, 3, ..., + 1, j = 1, 2, ... , +1;

[0137] when i= When +1 is applied, the tail layer coordinates are shrunk and corrected.

[0138] = - 0.005 * (18)

[0139] (19)

[0140] Where i = 2, 3, ..., +1, j = 1, 2, ... , +1;

[0141] (20)

[0142] Where i = 2, 3, ... , + 1, j = 1, 2, ... , +1;

[0143] when i = When +1, a smooth correction is made to the circumferential angle of the tail layer:

[0144] (twenty one)

[0145] in, Let X be the X coordinates of all nodes on the suction surface. This is the axial length of the propeller hub trailing edge. The number of mesh layers along the trailing edge. The diameter of the propeller hub. The pitch at the leaf root.

[0146] Preferably, in step S6, the cylindrical coordinates are converted to rectangular coordinates. , , The formula is:

[0147] (twenty two)

[0148] (twenty three)

[0149] (twenty four)

[0150] Where i = 1, 2,..., + 1, j = 1, 2, ... , +1, This represents the total number of grid cells along the axis.

[0151] Preferably, the circumferential angle offset extension in step S6 is as follows: the single-channel hub mesh formed by the three-dimensional mesh coordinates of the single-channel hub is rotated and copied around the propeller rotation axis and placed in the area between every two blades to form a full-circumferential multi-channel complete hub boundary element mesh. The rotation and copying is as follows:

[0152] (25)

[0153] in, For circumferential angle, The updated circumferential angle;

[0154] In calculation Then, based on the updated circumferential angle, the Y and Z coordinates are reconstructed, while the axial coordinates remain unchanged, i.e.:

[0155] when = 2, 3, ... , , i = 1, 2, ... , +1, j = 1, 2, ... , When +1,

[0156] (26)

[0157] (27)

[0158] (28)

[0159] in, This represents the total number of grid layers along the axis.

[0160] In some embodiments of this specification, when the mesh at the blade guide edge is denser, such as Figure 2 As shown, Figure 2 This is a schematic diagram of a propeller blade boundary element mesh provided in this specification, based on... Figure 2 The propeller blade boundary element mesh shown is generated using a traditional hub meshing method, which easily produces meshes with extremely high aspect ratios at the junction of the hub and the blade guide edge, such as... Figure 3 As shown, Figure 3 This is a schematic diagram illustrating a high aspect ratio grid generated at the connection point between the rotor hub and the blade guide edge, as provided in this specification. Figure 3 The grid marked with a "red curve" represents a grid with an extremely high aspect ratio. The grid used in this specification... Figure 1 The hub mesh generation method shown, even when the mesh is dense at the blade guide edge, still produces a hub mesh that does not contain meshes with extremely high aspect ratios (or aspect ratios) and geometrically extremely thin dimensions, which is beneficial for numerical calculations. Figure 4 As shown, Figure 4 This is a schematic diagram of a propeller hub boundary element mesh provided in this specification. Figure 4 The image on the left is the overall grid diagram, while... Figure 4 The image on the right is a grid map of the region, and the area marked with a "red circle" in the image on the right is a magnified view of the area marked with a "red arrow" in the image on the left.

[0161] This specification also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements a method for generating hub boundary element meshes based on a logarithmic distribution.

[0162] This specification further provides a propeller hydrodynamic numerical simulation device, including a processor and a memory. The memory stores a computer program, and the processor executes the computer program to implement the above-mentioned method for generating hub boundary element meshes based on logarithmic distribution, generate propeller hub boundary element meshes, and complete hydrodynamic simulation calculations using the boundary element method.

[0163] It should be noted that the specific embodiments described above enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. Therefore, although the present invention has been described in detail with reference to the accompanying drawings and embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention. In short, all technical solutions and improvements that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the present invention patent.

Claims

1. A method for generating hub boundary element meshes based on logarithmic distribution, characterized in that, include: S1. Preset propeller geometry and mesh discretization parameters to generate a three-dimensional coordinate array of propeller blade boundary element mesh; the three-dimensional coordinate array of propeller blade boundary element mesh includes axial mesh points and circumferential mesh points of different layers in the hub; S2. Execute the hub leading edge mesh generation algorithm, traverse the axial mesh points and circumferential mesh points respectively, and calculate the axial coordinates, radial radius and circumferential angle of the leading edge mesh; S3. Execute the hub thickness transition zone mesh generation algorithm, traverse the axial mesh points and circumferential mesh points respectively, and generate the basic mesh of the hub thickness transition zone by directly assigning values ​​to boundary nodes and linearly interpolating intermediate nodes. S4. Based on logarithmic distribution optimization of mesh distribution, traverse the circumferential index, and perform layered differential logarithmic coordinate correction on the axial mesh layers of different dimensions in the basic mesh of the hub thickness transition zone, including: Define the correction factor: For the axial mesh layer in the basic mesh of the hub thickness transition zone : （1） For the axial mesh layer in the basic mesh of the hub thickness transition zone : （2） For the axial mesh layer in the basic mesh of the hub thickness transition zone : （3） in, Let j ∈ (2, ..., ) be the number of circumferential layers of the hub mesh. + 1), , The number of axial grid layers at the leading edge of the propeller hub. The axial coordinates are those before the basic mesh correction for the hub thickness transition zone. The axial coordinates are the corrected base mesh coordinates for the thickness transition zone of the propeller hub. , The introduced dimensional parameter represents the number of axial layers in the hub mesh. , , The number of segments in the circumferential grid. The number of chordal grids for the blades. This refers to the number of blades. S5. Execute the propeller hub trailing edge mesh generation algorithm, calculate the axial coordinates, radial radius, and circumferential angle of the trailing edge mesh, and smooth the coordinates and angles of the trailing edge end mesh. S6. Convert the cylindrical coordinate mesh parameters to rectangular coordinates to obtain the three-dimensional mesh coordinates of the single-channel propeller hub; based on the periodic symmetry characteristics of the propeller, generate a full-circumference multi-channel complete propeller hub boundary element mesh by extending the circumferential angle offset.

2. The method for generating hub boundary element mesh based on logarithmic distribution according to claim 1, characterized in that, The parameters include: propeller diameter D, hub diameter Number of blades Pitch at the leaf root Define the axial length of the rotor hub leading edge. Axial length of propeller hub trailing edge Define the number of axial mesh layers at the leading edge. Number of axial mesh layers at the trailing edge =6. Number of circumferential grid segments Total number of axial mesh layers Initialize the hub mesh coordinate zero matrix. , , , , , .

3. The method for generating hub boundary element mesh based on logarithmic distribution according to claim 1, characterized in that, Axial coordinates of the leading edge mesh in step S2 The calculation formula is: （4） Where i = 1, 2, ..., j = 1, 2, ... +1, Let X be the X coordinates of all nodes on the suction surface. This is the axial length of the leading edge of the propeller hub. This represents the number of mesh layers along the leading edge axial direction. When i=1, the first-level coordinates are shrunk and corrected: , The coordinates of the first layer before correction. These are the corrected coordinates for the first layer.

4. The method for generating hub boundary element mesh based on logarithmic distribution according to claim 1, characterized in that, Radial radius of the leading edge mesh in step S2 With circumferential angle The calculation formula is: （5） in, =1, 2, ... , , =1, 2, ... , +1; Let X be the X coordinates of all nodes on the suction surface. This is the axial length of the leading edge of the propeller hub. This represents the number of mesh layers along the leading edge axis. （6） in, = 1, 2, ... , , = 1, 2, ... , +1; The diameter of the propeller hub; The pitch at the leaf root; Let Z be the Z coordinates of all nodes on the suction surface; Let Y be the Y coordinate of all nodes on the suction surface; When i=1, a smooth correction is made to the circumferential angle of the first layer: (7) in, = 1, 2, ... , +1.

5. The method for generating hub boundary element mesh based on logarithmic distribution according to claim 1, characterized in that, Axial coordinates of the basic mesh in the hub thickness transition zone in step S3 radial radius Circumferential angle The interpolation formula is: Let nhm = +i When i=1, 2, ... , +1, j= When +1, （8） （9） （10） When i=1, 2, ... , When +1, j=1, （11） （12） （13） When i=1, 2, ... , +1, j = , -1, ..., 2 hours （14） （15） （16） in, Let X be the X coordinates of all nodes on the pressure surface. The diameter of the propeller hub. Let Z be the Z coordinates of all nodes on the pressure surface. Let Y be the Y coordinate of all nodes on the pressure surface. Let X be the X coordinates of all nodes on the suction surface. Let Z be the Z coordinates of all nodes on the suction surface; Let Y be the Y coordinate of all nodes on the suction surface.

6. The method for generating hub boundary element mesh based on logarithmic distribution according to claim 1, characterized in that, Axial coordinates of the trailing edge mesh in step S5 radial radius Circumferential angle The calculation formula is: Let the axial mesh layer in the trailing edge mesh = + （17） Where i = 2, 3, ..., + 1, j = 1, 2, ... , +1; when i= When +1 is applied, the tail layer coordinates are shrunk and corrected. = - 0.005 * （18） （19） Where i = 2, 3, ..., + 1, j = 1, 2, ... , +1; （20） Where i = 2, 3, ... , + 1, j = 1, 2, ... , +1; when i = When +1, a smooth correction is made to the circumferential angle of the tail layer: （21） in, Let X be the X coordinates of all nodes on the suction surface. This is the axial length of the propeller hub trailing edge. The number of mesh layers along the trailing edge. The diameter of the propeller hub. The pitch at the leaf root.

7. The method for generating hub boundary element mesh based on logarithmic distribution according to claim 1, characterized in that, In step S6, the cylindrical coordinates are converted to rectangular coordinates. , , The formula is: （22） （23） （24） Where i = 1, 2, ..., + 1, j = 1, 2, ... , +1, This represents the total number of grid cells along the axis.

8. The method for generating hub boundary element mesh based on logarithmic distribution according to claim 1, characterized in that, In step S6, the circumferential angle offset is extended as follows: the single-channel hub mesh, formed by the three-dimensional mesh coordinates of the single-channel hub, is rotated and copied around the propeller rotation axis and placed in the area between every two blades to form a full-circumferential multi-channel complete hub boundary element mesh. The rotation and copying is as follows: （25） in, For circumferential angle, The updated circumferential angle; In calculation Then, based on the updated circumferential angle, the Y and Z coordinates are reconstructed, while the axial coordinates remain unchanged, i.e.: when = 2, 3, ... , , i = 1, 2, ... , +1, j = 1, 2, ... , When +1, （26） （27） （28） in, This represents the total number of grid layers along the axis.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the hub boundary element mesh generation method based on logarithmic distribution as described in any one of claims 1-8.

10. A propeller hydrodynamic numerical simulation device, comprising a processor and a memory, wherein the memory stores a computer program, characterized in that, The processor executes the computer program to implement the method described in any one of claims 1-8, generating a propeller hub boundary element mesh and completing the boundary element method hydrodynamic simulation calculation.

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