Method and system for generating efficient cooling sheet lattice structure with directional flow channel

Abstract

The invention relates to a method and a system for generating a high-efficiency cooling sheet-shaped lattice structure with a directional flow channel, and the method comprises the steps: defining nodes and a connection relation in a cubic space, forming a lattice unit cell structure skeleton, and carrying out the deduplication, thereby obtaining a skeleton array; an optimized initial design is extracted from the obtained structural skeleton array by defining a target plane; constructing an optimization problem which takes maximized heat transfer as a target and takes a fluid region area and pressure loss as constraints; solving to obtain an optimized flow channel design and a corresponding skeleton parameter; a generation function is defined, a symbol distance field is constructed, a grid model of the sheet lattice structure is extracted from the symbol distance field, the flow channel diameter of the sheet lattice structure is controlled through skeleton parameters, and the sheet lattice structure with directional flow channel characteristics is generated; according to an input curved surface, a shape-preserving hexahedral mesh is constructed, regular sheet-shaped lattices which are located in a cubic space and are periodically arranged are mapped into a space of the shape-preserving hexahedral mesh, and a shape-preserving sandwich lattice structure is formed.

Description

Technical Field

[0001] The present invention relates to the technical field of materials engineering, and specifically to a method and system for generating an efficient heat dissipation sheet lattice structure with a directional flow channel. Background Technique

[0002] The statements in this part only provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] 3D printing is a technology that forms a three-dimensional entity by discrete-accumulation, enabling materials to be stacked point by point and layer by layer, and can quickly and precisely manufacture parts with complex shapes. In automotive engineering, 3D printing can be used to manufacture parts with a sheet lattice structure with a directional flow channel, which can be used to optimize the cooling system, improve the cooling efficiency, and reduce the engine temperature. In the design stage of such parts, the control parameters of the existing technology using the sheet structure design method based on TPMP (triply periodic minimal surface) are limited, and the generation efficiency of the method based on level set topology optimization is average compared with the parametric method, which will directly or indirectly affect the design efficiency. Summary of the Invention

[0004] In order to solve the technical problems existing in the above background technique, the present invention provides a method and system for generating an efficient heat dissipation sheet lattice structure with a directional flow channel, which can quickly and efficiently generate a sheet lattice structure according to the structural skeleton, adjust the structure through parameter control, and at the same time, the parametric description brings the advantages of efficient storage and slicing. It can also integrate the flow channel of thermal-fluid coupled topology optimization into the sheet lattice structure, giving full play to the advantages of the sheet lattice structure with continuous and smooth surface, large specific surface area, and excellent mechanical properties, and forming a lightweight sandwich structure design with both efficient heat dissipation performance and high stiffness.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The first aspect of the present invention provides a method for generating an efficient heat dissipation sheet lattice structure with a directional flow channel, including the following steps:

[0007] Define nodes and connection relationships in a cubic space to form a lattice unit cell structure skeleton; perform periodic arrangement and duplicate removal on the obtained unit cell skeleton to obtain a skeleton array; initialize generation parameters, define a target plane, and extract an optimized initial design from the obtained structural skeleton array;

[0008] Use the Navier-Stokes equation to describe incompressible steady laminar flow, construct an optimization problem with maximizing heat transfer as the objective and the fluid region area and pressure loss as constraints, and obtain an optimized flow channel design and corresponding skeleton parameters by solving the optimization problem;

[0009] According to the obtained skeleton parameters, define a generation function, construct a signed distance field, extract the mesh model of the flake lattice structure from the signed distance field, control the channel diameter of the flake lattice structure through the skeleton parameters, and generate a flake lattice structure with directional channel characteristics;

[0010] According to the input surface, construct a conformal hexahedral mesh, and map the regular flake lattice located in the cubic space and arranged periodically into the conformal hexahedral mesh space to form a conformal sandwich lattice structure.

[0011] Furthermore, perform periodic arrangement on the unit cell skeleton, remove the repeated skeletons, and after initializing the generation parameters, each rod in the skeleton is assigned a radius parameter d; define a target plane in the skeleton array, extract the skeleton in the target plane, and define a signed distance field according to the skeleton to obtain the initial design of the thermal-fluid coupled topology optimization.

[0012] Furthermore, use the Navier-Stokes equation to describe the incompressible steady laminar flow, and construct an optimization problem with the goal of maximizing heat transfer and the constraints of the fluid region area and pressure loss. Specifically:

[0013] Construct a fluid flow model, use the Navier-Stokes equation to describe the incompressible steady laminar flow, and use the Brinkman penalty term as the introduced virtual body force to represent the resistance to fluid flow and the loss of flow energy;

[0014] Based on the velocity field u obtained from the Navier-Stokes equation, calculate the temperature according to the energy conservation equation;

[0015] Construct an optimization problem with the goal of maximizing heat transfer and the constraints of the fluid region area and pressure loss.

[0016] Furthermore, by solving the optimization problem, obtain the optimized channel design and the corresponding skeleton parameters. Specifically: use the finite element method for solving, use automatic differentiation to calculate the sensitivity of the optimization variables to the pressure loss constraint and the temperature target, and use the moving asymptotes method to solve the optimization problem to obtain the set of optimized skeleton parameters {d i};

[0017] Furthermore, according to the obtained skeleton parameters, define a generation function and construct a signed distance field. Specifically: construct a parameterized generation model based on the skeleton; construct a smooth surface generation function according to the structural skeleton, radius parameter, and smooth parameter; and establish distance functions corresponding to the inner and outer boundaries of the flake structure by adding a thickness parameter to the distance function.

[0018] Further, extract the mesh model of the flake lattice structure from the signed distance field, control the flow channel diameter of the flake lattice structure through the skeleton parameters, and generate a flake lattice structure with directional flow channel characteristics; specifically: import the optimized set of skeleton parameters {d i} into the parametric generation model, realize flow control by controlling the pipe radius in the flake lattice structure, form a directional flow channel design, and generate a flake lattice structure with directional flow channel characteristics.

[0019] Further, construct a conformal hexahedral mesh according to the input surface, and map the regular flake lattice located in the cube space and arranged periodically into the conformal hexahedral mesh space to form a conformal sandwich lattice structure; specifically:

[0020] Input the target smooth surface, and use the harmonic parameterization method to map the target surface to a two-dimensional square plane to obtain the mapping relationship of each vertex;

[0021] According to the input resolution parameters nelx and nely, which respectively represent the number of elements on the x-axis and y-axis, distribute a regular grid of nelx×nely on the two-dimensional square plane;

[0022] Through three-point interpolation, according to the obtained mapping relationship, map the grid vertices on the plane back to the input solid surface to obtain the spatial coordinates of the grid vertices;

[0023] Calculate the normal vector at the position of the spatial grid vertices on the input surface, and offset the spatial grid vertices on the surface along the normal vector to obtain a conformal hexahedral mesh;

[0024] Perform conformal mapping on the mesh model of the flake lattice structure; calculate the cube unit corresponding to the unit cell to which the vertex of the mesh model belongs, calculate the relative coordinates (x, y, z) of the vertex in the cube unit, and use bilinear interpolation to obtain the coordinates (x′, y′, z′) of the vertex in the corresponding conformal hexahedral unit to obtain a conformal flake lattice structure.

[0025] The second aspect of the present invention provides an efficient heat dissipation flake lattice structure generation system with directional flow channels, including:

[0026] A skeleton generation module, configured to: define nodes and connection relationships in the cube space to form a lattice unit cell structure skeleton; perform periodic arrangement and deduplication on the obtained unit cell skeleton to obtain a skeleton array; initialize the generation parameters, define the target plane, and extract an optimized initial design from the obtained structural skeleton array;

[0027] The heat-fluid coupling topology optimization module is configured to: describe incompressible steady laminar flow using the Navier-Stokes equations, construct an optimization problem with the goal of maximizing heat transfer and constraints of fluid region area and pressure loss, and obtain an optimized channel design and corresponding skeleton parameters by solving the optimization problem;

[0028] The parameterized generation module is configured to: define a generation function according to the obtained skeleton parameters, construct a signed distance field, extract a mesh model of the sheet lattice structure from the signed distance field, and generate a sheet lattice structure with directional channel characteristics by controlling the channel diameter of the sheet lattice structure with the skeleton parameters;

[0029] The conformal mapping module is configured to: construct a conformal hexahedral mesh according to the input surface, and map the regular sheet lattice located in the cubic space and arranged periodically into the conformal hexahedral mesh space to form a conformal sandwich lattice structure.

[0030] The third aspect of the present invention provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the steps in the above-mentioned method for generating an efficient heat dissipation sheet lattice structure with directional channels are implemented.

[0031] The fourth aspect of the present invention provides a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the steps in the above-mentioned method for generating an efficient heat dissipation sheet lattice structure with directional channels are implemented.

[0032] Compared with the prior art, the above one or more technical solutions have the following beneficial effects:

[0033] 1. Using the input structural skeleton, the skeleton parameters are optimized by the heat-fluid coupling topology optimization method to obtain a fluid channel with minimized pressure loss and maximized heat transfer. By defining a parameterized generation method for the sheet structure and combining it with the optimized skeleton parameters, a sheet lattice structure with directional channel characteristics is generated. The process of obtaining the sheet lattice structure is faster and more efficient than the existing methods, and the structure of the lattice can be adjusted by parameter control. At the same time, the parameterized description method brings the advantages of efficient storage and slicing.

[0034] 2. Incorporating the channels optimized by the heat-fluid coupling topology into the sheet lattice structure gives full play to the excellent mechanical properties of the sheet lattice structure, such as continuous and smooth surface, large specific surface area, etc. It can also form a conformal lightweight heat dissipation sandwich structure according to the input surface, forming a lightweight sandwich structure design with both high heat dissipation performance and high stiffness, which can meet the requirements for strength and heat dissipation in vehicle engineering. Description of the Drawings

[0035] The accompanying drawings forming a part of this invention are used to provide a further understanding of the invention. The schematic embodiments and descriptions thereof of the invention are used to explain the invention and do not unduly limit the invention.

[0036] Figure 1 It is a schematic diagram of the generation process of an efficient heat dissipation sheet lattice structure with a directional flow channel provided by one or more embodiments of the present invention;

[0037] Figure 2 It is a schematic diagram of the initial design of the skeleton array and heat flow coupling topology optimization provided by one or more embodiments of the present invention;

[0038] Figure 3 and Figure 4 Both are schematic diagrams of the heat flow coupling topology optimization results provided by one or more embodiments of the present invention;

[0039] Figure 5 It is a schematic diagram of the parametric model of the sheet lattice structure provided by one or more embodiments of the present invention;

[0040] Figure 6 It is a schematic diagram of the parametric generation of the sheet lattice structure provided by one or more embodiments of the present invention;

[0041] Figure 7 It is a schematic diagram of the conformal structure generation provided by one or more embodiments of the present invention. Detailed Description of the Invention

[0042] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0043] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0044] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0045] Term Explanation:

[0046] TPMS: Triply periodic minimal surface, a surface on which the Gaussian curvature, mean curvature, and directional derivative of the mean curvature in the tangential direction of each point are simultaneously zero.

[0047] Three-dimensional Voronoi diagram: A continuous three-dimensional polyhedral structure composed of the perpendicular bisecting planes of the straight lines connecting two adjacent points.

[0048] The Navier-Stokes (Navier-Stokes equations) equations, abbreviated as the N-S equations, are a set of non-linear partial differential equations that describe the motion of viscous fluids (such as liquids and air).

[0049] As introduced in the background technology, the control parameters of the existing technology using the sheet structure design method based on TPMP (triply periodic minimal surface) are limited, and the method based on level set topology optimization has a general generation efficiency compared with the parametric method, which will directly or indirectly affect the design efficiency.

[0050] Therefore, the following embodiments provide a method and system for generating an efficient heat dissipation sheet lattice structure with a directional flow channel. Input the structure skeleton, use the thermal-fluid coupling topology optimization method to optimize the skeleton parameters, obtain the fluid flow channel with minimized pressure loss and maximized heat transfer, define the parametric generation method of the sheet structure, generate the sheet lattice structure with the characteristics of the directional flow channel according to the skeleton parameters, and form a conformal lightweight heat dissipation sandwich structure according to the input surface.

[0051] Embodiment 1:

[0052] A method for generating an efficient heat dissipation sheet lattice structure with a directional flow channel, comprising the following steps:

[0053] Definition of the lattice structure unit cell skeleton; Define nodes and connection relationships in the cubic space to form the lattice unit cell structure skeleton, and ensure that the input unit cell skeleton satisfies the periodic boundary conditions;

[0054] Generation of the lattice structure array skeleton; Perform periodic arrangement on the lattice unit cell skeleton, and remove duplicates of the overlapping skeletons to form the lattice skeleton array;

[0055] Define the target plane in the skeleton array, extract the skeleton in the target plane, and form the initial design of the thermal-fluid coupling topology optimization according to the skeleton to define the signed distance field;

[0056] Thermal-fluid coupling topology optimization flow channel design; Consider the incompressible steady laminar flow described by the Navier-Stokes equations, set the inlet and outlet boundary conditions and the heat source boundary conditions; Set the optimization objective to maximize heat transfer, constrain the fluid region area and pressure loss, calculate the sensitivity of the skeleton parameters with respect to the objective and constraints, and use the Method of Moving Asymptotes (MMA) to solve the objective function to obtain the optimized flow channel design;

[0057] Parametric generation of a sheet lattice structure; constructing a generation function of the sheet lattice structure based on the structural skeleton and optimized skeleton parameters, controlling the flow channel diameter of the sheet lattice structure through the skeleton parameters to form a directional flow channel design; constructing a signed distance field according to the generation function, and extracting the mesh model of the sheet lattice structure from the signed distance field using the Marching cubes algorithm;

[0058] Conformal mapping of a sheet lattice structure; inputting a surface, performing planar parameterization on the surface, mapping the planar grid to the spatial surface, constructing a conformal hexahedral grid, and mapping the sheet lattice structure mesh model into the conformal hexahedral grid using bilinear interpolation to form a conformal sandwich structure design.

[0059] The method of this embodiment can quickly and efficiently generate a sheet lattice structure according to the structural skeleton, and can adjust the structure through parameter control. At the same time, the parametric description brings the advantages of efficient storage and slicing.

[0060] The method of this embodiment can integrate the flow channels of thermo-fluid coupled topology optimization into the sheet lattice structure, giving full play to the advantages of the sheet lattice structure with continuous and smooth surface, large specific surface area, and excellent mechanical properties, and forming a lightweight sandwich structure design with both high heat dissipation performance and high stiffness.

[0061] As Figure 1 shown, the present embodiment provides a method for generating an efficient heat dissipation sheet lattice structure with directional flow channels, including the following steps:

[0062] S1: Parametric skeleton generation; the user inputs the nodes and connection relationships within the cubic space, defines the skeleton unit cell, ensures that the periodic boundary conditions are satisfied, performs periodic arrangement on the unit cell, removes the duplicate skeletons, forms the skeleton array of the lattice structure, and initializes the generation parameters; defines the target plane in the skeleton array, extracts the skeletons within the target plane, and forms the initial design of the thermo-fluid coupled topology optimization according to the skeletons to define the signed distance field;

[0063] S2: Thermo-fluid coupled topology optimization; considering the incompressible steady laminar flow described by the Navier-Stokes equation, setting the inlet and outlet boundary conditions and the heat source boundary conditions; setting the optimization objective to maximize heat transfer, constraining the fluid region area and pressure loss, calculating the sensitivity of the skeleton parameters with respect to the objective and constraints, and using the Method of Moving Asymptotes (MMA) to solve the objective function to obtain the optimized flow channel design;

[0064] S3: Directional flow channel heat dissipation lattice generation; according to the skeleton and parameters, defining the generation function, constructing the signed distance field, and extracting the mesh model of the sheet lattice structure from the signed distance field using the Marching cubes algorithm;

[0065] S4: Conformal mapping of the sandwich lattice structure; input the target surface, map it to the cube plane using planar parameterization, distribute grids on the plane, map the grid vertices back to the surface, construct a conformal hexahedral grid through normal offset, and map the heat dissipation lattice structure into the conformal hexahedron to form a conformal sandwich lattice structure.

[0066] Specifically, step S1 is as follows:

[0067] S1-1: The user inputs the nodes and connection relationships within the cubic space, defines the skeletal unit cell, and ensures that the periodic boundary conditions are satisfied;

[0068] S1-2: Perform periodic arrangement of the unit cells, remove duplicate skeletons, and form a skeletal array of the lattice structure as shown on the left, initialize the generation parameters, and assign a radius parameter d to each rod in the skeleton; Figure 2 S1-3: Define the target plane in the skeletal array, extract the skeletons within the target plane, define the signed distance field according to the skeletons, and form the initial design of the heat flow coupling topology optimization as shown on the right.

[0069] S1-3: Define the target plane in the skeletal array, extract the skeletons within the target plane, define the signed distance field according to the skeletons, and form the initial design of the heat flow coupling topology optimization as shown on the right. Figure 2 S1-3: Define the target plane in the skeletal array, extract the skeletons within the target plane, define the signed distance field according to the skeletons, and form the initial design of the heat flow coupling topology optimization as shown on the right.

[0070] Specifically, step S2 is as follows:

[0071] S2-1: Construct a fluid flow model, considering incompressible steady laminar flow. The fluid flow can be described by the Navier-Stokes equation as shown below:

[0072]

[0073] where u is the velocity field, p is the fluid pressure, ρ is the fluid density, η is the fluid dynamic viscosity, and I is the identity matrix.

[0074] S2-2: Introduce the design variables of topology optimization, introduce a virtual body force to represent the resistance to fluid flow and the loss of flow energy, also known as the Brinkman penalty term, which is defined as:

[0075] F TO =-αu;

[0076] where the Brinkman penalty coefficient α is defined as:

[0077]

[0078] Introduce the virtual body force into the Navier-Stokes equation and extend it to the entire design domain as shown below:

[0079]

[0080] When α = 0, the Navier–Stokes equations still describe fluid flow. When α = ∞, the fluid velocity is ensured to be 0 in the solid region.

[0081] S2-3: Construct a heat transfer model in the optimization space; calculate the temperature according to the energy conservation equation based on the velocity field u obtained from the Navier-Stokes equations, as shown in the following equation:

[0082]

[0083] where ρ is the fluid density, c p and k are the heat capacity and thermal conductivity interpolated from the optimization variable x respectively, T is the temperature field, and Q is the heat source.

[0084] S2-4: Construct an optimization problem with the goal of maximizing heat transfer and constraints of pressure loss and fluid region area, as shown in the following equation:

[0085]

[0086] Subject to:

[0087]

[0088] d min <d i <d max ;

[0089] where u is the velocity field, p is the fluid pressure, ρ is the fluid density, η is the dynamic viscosity of the fluid, p t is the target pressure loss, V f is the target volume fraction, T is the temperature field, Q is the heat source, d i is the radius parameter, d max and d min are the maximum and minimum values of the radius parameter respectively, φ p is the pressure loss function, defined as:

[0090] S2-5: Establish the mapping relationship between the skeleton radius parameter and the optimization unit; use numerical differentiation to calculate the partial derivative of the skeleton radius parameter with respect to the optimization unit.

[0091] S2-5: Solve the above control equations using the finite element method, calculate the sensitivities of the optimization variables to the pressure loss constraint and the temperature target using automatic differentiation, and solve the optimization problem using the moving asymptote method to obtain the optimized set of skeleton parameters {d i}. Figure 3 and Figure 4 show the parameterized skeleton flow channels obtained by topology optimization.

[0092] Step S3 is specifically as follows:

[0093] S3-1: Construct a skeleton-based parametric generation model as shown in the following formula:

[0094] ω = G(ζ, θ);

[0095] The lattice structure ω is described by the skeleton ζ and the generation parameter θ. As Figure 5 shown, the skeleton ζ consists of a set of edges {e}, providing the basic topological structure of the lattice, and the generation parameter θ is the rod diameter d, with a preset smoothness s and shell thickness t.

[0096] S3-2: According to the structural skeleton, radius parameter, and smooth parameter, construct a smooth surface generation function as shown in the following formula:

[0097]

[0098] y i = distance i (x) - d i ;

[0099] where s is the smooth parameter, defined at the joints of the structural skeleton, d i is the radius parameter, defined on the edges of the structural skeleton, and distance i (x) is defined as the distance from point x to the i-th edge.

[0100] S3-2: Flake lattice structure thickness control function. By adding a thickness parameter to the distance function, distance functions corresponding to the inner and outer boundaries of the flake structure are established respectively:

[0101]

[0102] where t is the thickness value of the flake structure defined by the user.

[0103] S3-3: Construct a signed distance function for the flake lattice structure;

[0104] S3-3-1: According to the smooth surface generation function proposed in step S3-1 and the thickness control function proposed in S3-2, establish signed distance functions corresponding to the inner and outer boundaries of the flake porous structure respectively, as shown in the following formula:

[0105]

[0106] where s 0 is the global smooth parameter.

[0107] S3-3-2: Based on the signed distance function corresponding to the inner and outer boundaries of the sheet-like lattice structure proposed in step S3-3-1, propose the signed distance function of the sheet-like lattice structure as shown in the following formula:

[0108]

[0109] S3-4: Based on the signed distance function of the sheet-like lattice structure proposed in step S3-3-2, establish a signed distance field, and use the Marching cubes algorithm to extract the mesh model. The mesh model is as Figure 6 shown.

[0110] S3-5: Import the skeleton radius parameter optimized in S2-5 into the generation model, realize the flow control by controlling the radius of the pipes in the sheet-like lattice structure, and form a directional flow channel design to improve the heat dissipation performance of the sheet-like lattice structure under forced convection conditions.

[0111] Step S4 is specifically as follows:

[0112] S4-1: Conformal mapping of the sheet-like lattice structure. The process is as Figure 7 shown;

[0113] S4-1-1: In this embodiment, taking the UAV model (unmanned aerial vehicle model) as an example, the user inputs the target smooth surface, and uses the harmonic parameterization method to map the target surface to a two-dimensional square plane to obtain the mapping relationship of each vertex;

[0114] S4-1-2: According to the resolution parameters nelx and nely input by the user, which represent the number of elements on the x-axis and y-axis respectively, distribute a regular grid of nelx×nely on the two-dimensional square plane;

[0115] S4-1-3: Through three-point interpolation, according to the mapping relationship obtained in S4-1-1, map the grid vertices on the plane back to the input solid surface to obtain the spatial coordinates of the grid vertices;

[0116] S4-1-4: Calculate the normal vector at the position of the spatial grid vertices on the input surface, and offset the spatial grid vertices on the surface along the normal vector. The offset distance is input by the user to obtain a conformal hexahedral mesh;

[0117] S4-1-4: Perform conformal mapping on the mesh model obtained in S3-5; calculate the cube unit corresponding to the unit cell to which the vertex of the mesh model belongs, calculate the relative coordinates (x, y, z) of the vertex in the cube unit, and use bilinear interpolation to obtain the coordinates (x′, y′, z′) of the vertex in the corresponding conformal hexahedral unit to obtain a conformal sheet-like lattice structure.

[0118] Through the above process, using the input structural skeleton, the heat-fluid coupled topology optimization method is used to optimize the skeleton parameters, obtaining a fluid flow channel that minimizes pressure loss and maximizes heat transfer. By defining a parametric generation method for the sheet structure, according to the skeleton parameters, a sheet lattice structure with directional flow channel characteristics is generated, and a conformal lightweight heat dissipation sandwich structure can be formed according to the input surface.

[0119] It can quickly and efficiently generate a sheet lattice structure according to the structural skeleton, and the structure can be adjusted by parameter control. At the same time, the parametric description brings the advantages of efficient storage and slicing.

[0120] It can integrate the flow channels optimized by heat-fluid coupled topology into the sheet lattice structure, giving full play to the advantages of the sheet lattice structure, such as continuous and smooth surface, large specific surface area, and excellent mechanical properties, to form a lightweight sandwich structure design with both high-efficiency heat dissipation performance and high stiffness.

[0121] Example Two:

[0122] A high-efficiency heat dissipation sheet lattice structure generation system with directional flow channels, including:

[0123] A skeleton generation module, used to generate the parametric skeleton of the sheet lattice structure. The user defines the nodes and connection relationships within the unit cell to form the unit cell skeleton, performs periodic arrangement on the unit cell skeleton and removes duplicates to generate a skeleton array, initializes the generation parameters, defines the target plane, and extracts the optimized initial design from the structural skeleton array;

[0124] A heat-fluid coupled topology optimization module, used to generate an optimized flow channel design. It constructs an optimization problem with the goal of maximizing heat transfer and the constraints of fluid region area and pressure loss, and uses the parametric shape optimization method to solve the objective function to obtain the optimized flow channel design and the corresponding skeleton parameters;

[0125] A parametric generation module, used to generate a sheet lattice structure with directional flow channel characteristics. It controls the flow channel diameter of the sheet lattice structure through the skeleton parameters, defines a generation function according to the structural skeleton and the optimized skeleton parameters, constructs a signed distance field, and extracts the lattice structure model from the signed distance field;

[0126] A conformal mapping module, used to map the regular sheet lattice arranged periodically in the cubic space to the conformal hexahedral mesh space. Through plane parameterization and coordinate mapping, a conformal sheet lattice structure design is formed for the sandwich structure design that takes into account both heat dissipation and lightweight strengthening.

[0127] Example Three:

[0128] This embodiment provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, it implements the steps in the method for generating an efficient heat dissipation sheet lattice structure with a directional flow channel as described in Embodiment 2 above.

[0129] Embodiment 4:

[0130] This embodiment provides a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the steps in the method for generating an efficient heat dissipation sheet lattice structure with a directional flow channel as described in Embodiment 2 above.

[0131] The steps involved in Embodiments 2 to 4 above correspond to those in Embodiment 1. For specific implementation manners, reference may be made to the relevant description part of Embodiment 1. The term "computer-readable storage medium" should be understood to include a single medium or multiple media containing one or more instruction sets; it should also be understood to include any medium that can store, encode, or carry an instruction set for execution by a processor and enable the processor to execute any method in the present invention.

[0132] The foregoing are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and changes can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for generating a high-efficiency heat dissipation sheet-like lattice structure with directional flow channels, characterized in that: The following steps are involved: Define the nodes and connection relationships in the cubic space to form a lattice unit cell structure skeleton; The obtained unit cell skeleton is periodically arranged and duplicated to obtain a skeleton array; the generation parameters are initialized, the target plane is defined, and the optimized initial design is extracted from the obtained structural skeleton array; The Navier-Stokes equations are used to describe incompressible steady laminar flow, and an optimization problem is constructed with the goal of maximizing heat transfer and the fluid area and pressure loss as constraints. By solving the optimization problem, the optimized flow channel design and corresponding skeleton parameters are obtained. According to the obtained skeleton parameters, a generating function is defined, a signed distance field is constructed, a grid model of a sheet lattice structure is extracted from the signed distance field, and the flow channel diameter of the sheet lattice structure is controlled by the skeleton parameters to generate a sheet lattice structure with directional flow channel characteristics; According to the input surface, a conformal hexahedral grid is constructed, and the regular lamellar lattice located in the cubic space and arranged periodically is mapped into the conformal hexahedral grid space to form a conformal sandwich lattice structure.

2. The method for generating a high-efficiency heat dissipation sheet-like lattice structure with directional flow channels according to claim 1, characterized in that: The unit cell skeleton is arranged periodically, the repeated skeleton is removed, and after the generation parameters are initialized, each rod in the skeleton is assigned a radius parameter d; the target plane is defined in the skeleton array, the skeleton in the target plane is extracted, and the signed distance field is defined according to the skeleton to obtain the initial design of the thermal-fluid coupled topology optimization.

3. The method for generating a high-efficiency heat dissipation sheet-like lattice structure with directional flow channels according to claim 1, characterized in that: The Navier-Stokes equation is used to describe the incompressible steady laminar flow, and an optimization problem is constructed with the goal of maximizing heat transfer and the fluid area and pressure loss as constraints. Specifically, Construct a fluid flow model, use the Navier-Stokes equations to describe incompressible steady laminar flow, and use the Brinkman penalty term as the introduced virtual volume force to represent the resistance to fluid flow and the loss of flow energy; The temperature is calculated based on the energy conservation equation according to the velocity field u obtained from the Navier-Stokes equation; Construct an optimization problem with the goal of maximizing heat transfer and the fluid area and pressure loss as constraints.

4. The method for generating a high-efficiency heat dissipation sheet-like lattice structure with directional flow channels according to claim 1, characterized in that: By solving the optimization problem, the optimized flow channel design and the corresponding skeleton parameters are obtained; specifically, the finite element method is used to solve the problem, the sensitivity of the optimization variables to the pressure loss constraint and the temperature target is calculated by automatic differentiation, and the moving asymptote method is used to solve the optimization problem to obtain the optimized skeleton parameter set {d i }.

5. The method for generating a high-efficiency heat dissipation sheet-like lattice structure with directional flow channels according to claim 1, characterized in that: According to the obtained skeleton parameters, the generating function is defined and the signed distance field is constructed, specifically: a parametric generating model based on the skeleton is constructed; a smooth surface generating function is constructed according to the structural skeleton, radius parameters and smooth parameters; and the distance functions corresponding to the inner and outer boundaries of the sheet structure are established by adding the thickness parameter to the distance function.

6. The method for generating a high-efficiency heat dissipation sheet-like lattice structure with directional flow channels according to claim 1, characterized in that: The grid model of the sheet lattice structure is extracted from the signed distance field, and the flow channel diameter of the sheet lattice structure is controlled by the skeleton parameters to generate a sheet lattice structure with directional flow channel characteristics; specifically, the optimized skeleton parameter set {d i }Imported into the parametric generation model, the flow control is achieved by controlling the pipe radius in the sheet lattice structure, a directional flow channel design is formed, and a sheet lattice structure with directional flow channel characteristics is generated.

7. The method for generating a high-efficiency heat dissipation sheet-like lattice structure with directional flow channels according to claim 1, characterized in that: According to the input surface, a conformal hexahedral grid is constructed, and the regular sheet lattice located in the cubic space and arranged periodically is mapped into the conformal hexahedral grid space to form a conformal sandwich lattice structure; specifically: Input the target smooth surface, and use the harmonic parameterization method to map the target surface to a two-dimensional square plane to obtain the mapping relationship of each vertex; According to the input resolution parameters nelx and nely, which represent the number of cells on the x-axis and y-axis respectively, a regular grid of nelx×nely is distributed on the two-dimensional square plane; Through three-point interpolation, according to the obtained mapping relationship, the mesh vertices on the plane are mapped back to the input solid surface to obtain the spatial coordinates of the mesh vertices; Calculate the normal vector at the position of the spatial mesh vertex on the input surface, offset the spatial mesh vertex on the surface along the normal vector, and obtain a conformal hexahedral mesh; Conformally mapping the grid model of the sheet lattice structure; Calculate the cubic unit corresponding to the unit cell to which the vertex of the mesh model belongs, calculate the relative coordinates (x, y, z) of the vertex in the cubic unit, use bilinear interpolation to obtain the coordinates (x′, y′, z′) of the vertex in the corresponding conformal hexahedral unit, and obtain a conformal sheet lattice structure.

8. A system for generating a high-efficiency heat dissipation sheet-like lattice structure with directional flow channels, characterized in that: include: The skeleton generation module is configured to: define nodes and connection relationships in the cubic space to form a lattice unit cell structure skeleton; The obtained unit cell skeleton is periodically arranged and duplicated to obtain a skeleton array; the generation parameters are initialized, the target plane is defined, and the optimized initial design is extracted from the obtained structural skeleton array; The thermal-fluid coupling topology optimization module is configured to: use the Navier-Stokes equations to describe incompressible steady-state laminar flow, construct an optimization problem with the goal of maximizing heat transfer and the fluid area and pressure loss as constraints, and obtain the optimized flow channel design and corresponding skeleton parameters by solving the optimization problem; The parameterized generation module is configured to: define a generation function according to the obtained skeleton parameters, construct a signed distance field, extract a grid model of the sheet lattice structure from the signed distance field, control the flow channel diameter of the sheet lattice structure through the skeleton parameters, and generate a sheet lattice structure with directional flow channel characteristics; The conformal mapping module is configured to: construct a conformal hexahedral grid according to the input surface, map the regular lamellar lattice that is located in the cubic space and arranged periodically into the conformal hexahedral grid space, and form a conformal sandwich lattice structure.

9. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the program is executed by a processor, the steps in the method for generating a high-efficiency heat dissipation sheet-like lattice structure with directional flow channels as described in any one of claims 1 to 7 are implemented.

10. A computer device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps in the method for generating a high-efficiency heat dissipation sheet-like lattice structure with directional flow channels as described in any one of claims 1 to 7 are implemented.

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