A cfd calculation method for heat dissipation of running shoes

Abstract

This application provides a CFD calculation method for heat dissipation in running shoes, including: Step S1, constructing a three-dimensional model of the running shoe system, the three-dimensional model of the running shoe system including a three-dimensional model of the running shoe and a three-dimensional model of the shoe last placed within the three-dimensional model of the running shoe; Step S2, performing preprocessing on the three-dimensional model of the running shoe system to obtain preprocessing results, wherein the preprocessing results include a structured three-dimensional mesh obtained by coupling the three-dimensional model of the running shoe system within a fluid domain model and then importing it into mesh generation software; Step S3, performing CFD calculations based on the preprocessing results to obtain calculation results. Implementing the technical solution of this application can yield more accurate data.

Description

Technical Field

[0001] This application relates to the field of computational fluid dynamics, and more particularly to a CFD calculation method for heat dissipation in running shoes. Background Technology

[0002] As people pay more attention to their health, the number of people exercising at home and outdoors is constantly increasing, and people are also paying more attention to the professionalism and comfort of sports equipment. Among them, running accounts for an increasingly large proportion, and people's requirements for the thermal comfort of running shoes are also getting higher and higher.

[0003] Temperature is one of the key objective factors affecting footwear comfort. The temperature inside the shoe cavity is an important indicator of the shoe's microclimate. The shoe's ability to exchange heat with its surroundings determines the wearer's comfort; that is, achieving a comprehensive biothermodynamic balance between the microenvironment of the foot, shoe, and shoe cavity. When running shoes have poor breathability, the heat generated during exercise accumulates inside the shoe and cannot dissipate, causing the shoe temperature to gradually rise, resulting in stuffy and uncomfortable feet. These conditions increase bacterial growth, leading to fungal infections and foot odor. Furthermore, a damp environment increases friction between the skin and the shoe, causing blisters and abrasions. Therefore, changes in the shoe's microclimate promote microbial growth, leading to odor and deterioration of foot health.

[0004] Currently, common methods for evaluating heat dissipation suffer from limitations. Traditional methods using thermometers and sensors cannot obtain detailed and comprehensive data and are inefficient. Furthermore, simulation-based research methods only consider heat conduction analysis under static conditions, neglecting real-world scenarios with strong convection and significantly simplifying the model, leading to substantial deviations in calculation results. Summary of the Invention

[0005] To address at least one technical problem in the prior art, this application provides a CFD calculation method for heat dissipation in running shoes.

[0006] According to one aspect of this application, a CFD calculation method for heat dissipation in running shoes is provided, comprising:

[0007] Step S1: Construct a three-dimensional model of the running shoe system, which includes a three-dimensional model of the running shoe and a three-dimensional model of the shoe last placed in the three-dimensional model of the running shoe.

[0008] Step S2: Preprocess the three-dimensional model of the running shoe system to obtain a preprocessing result, wherein the preprocessing result includes a structured three-dimensional mesh obtained by coupling the three-dimensional model of the running shoe system in a fluid domain model and then importing it into mesh generation software.

[0009] Step S3: Perform CFD (Computational Fluid Dynamics) calculations based on the preprocessing results to obtain the calculation results.

[0010] Optionally, step S1 includes:

[0011] A 3D scanner is used to scan the shoe last and running shoe to obtain a 3D model of the shoe last and a 3D model of the running shoe. The 3D model of the shoe last is placed on the 3D model of the running shoe according to the actual position.

[0012] The 3D model obtained from the scan is simplified to remove structures that do not affect heat dissipation calculations;

[0013] The scanned 3D model is divided into sections to distinguish different materials and the mesh and non-mesh parts of the shoe upper. The mesh parts of the shoe upper are replaced with porous media.

[0014] Optionally, step S2 includes:

[0015] A fluid domain model is established in the preprocessing software, and the three-dimensional model of the running shoe system is placed in the fluid domain model for coupling to obtain a three-dimensional geometric model.

[0016] The three-dimensional geometric model is imported into mesh generation software to generate structured three-dimensional meshes for the shoe last, running shoe, and external flow field, which serve as the preprocessing result.

[0017] Optionally, step S3 includes:

[0018] Determine the fluid control equations, Darcy coefficients for porous media, and turbulence model;

[0019] Set the material properties and air material properties of each part of the running shoe system;

[0020] Set the boundary conditions for the medium flow, the inlet velocity boundary condition, and the outlet pressure boundary condition.

[0021] Set solid and fluid conditions;

[0022] The simulation calculation continues until the residual curve converges stably, at which point the calculation ends to obtain the results.

[0023] Optionally, the turbulence model uses the k-ε model, the solution type is steady-state calculation, and the solution method is an implicit method based on the pressure coupling equations. The pressure, momentum, energy, and turbulent kinetic energy equations are all discretized using a second-order upwind scheme.

[0024] Optionally, the Darcy coefficient of the porous medium can be determined by using experimental data on pressure loss versus velocity through the source terms of the governing equations and momentum equations in the computational domain of the porous medium model.

[0025] Optionally, the material properties include solid material properties and dielectric material properties. The solid material properties include thermal conductivity, specific heat capacity, density, and molecular weight. The dielectric material properties include kinematic viscosity, linear Prandtl number, specific heat capacity, enthalpy, and molecular weight.

[0026] Optionally, the inlet velocity boundary condition is set to a velocity inlet of 3 m / s, and the outlet pressure boundary condition is set to a pressure outlet equal to atmospheric pressure.

[0027] Optionally, the fluid conditions are: air is selected, and the temperature is the same as the experimental temperature;

[0028] The solid conditions are as follows: define the material properties of the solid, set the same heat generation rate as the experiment on the shoe last as the heat source, set the material properties of different sections of the running shoe to be consistent with those of the real running shoe, and set the running shoe temperature to be consistent with the ambient air temperature.

[0029] Optionally, the method includes: step S4, performing post-processing based on the calculation results;

[0030] Step S4 includes: displaying a temperature distribution cloud map of the shoe last, running shoes, and medium, and / or, displaying a velocity vector map of the fluid medium, and / or, displaying a pressure distribution cloud map at each location of the model.

[0031] One or more technical solutions provided in this application embodiment couple the three-dimensional model of the running shoe system to the fluid domain model, fully considering the fluid flow and the convective heat transfer in the running shoe cavity, as well as the heat conduction between the shoe last and the running shoe, making it more consistent with the actual working conditions, so that the CFD calculation results are closer to the heat dissipation of the running shoe in the real scene, and more accurate data is obtained.

[0032] One or more technical solutions provided in the embodiments of this application use 3D scanning to build models, retaining the original appearance and shape of the models, thus demonstrating their accuracy.

[0033] One or more technical solutions provided in the embodiments of this application can reproduce the on-site experimental conditions by relying on operating software, guide the optimization design of running shoe heat dissipation, and demonstrate its speed and efficiency.

[0034] The one or more technical solutions provided in this application embodiment can clearly show the actual temperature distribution cloud map of running shoes and shoe lasts through numerical simulation, making it more intuitive. Different boundary conditions can be added for different working conditions, and various complex working conditions can be simulated, making it widely applicable. Attached Figure Description

[0035] The accompanying drawings illustrate exemplary embodiments of the present application and, together with the description thereof, serve to explain the principles of the present application. These drawings are included to provide a further understanding of the present application and are incorporated in and constitute a part of this specification.

[0036] Figure 1 A flowchart illustrating a CFD calculation method for heat dissipation in running shoes according to an exemplary embodiment of this application is shown;

[0037] Figure 2 A schematic diagram of a three-dimensional model of a running shoe system according to an exemplary embodiment of this application is shown;

[0038] Figure 3 A schematic diagram of running shoe partitions according to an exemplary embodiment of this application is shown;

[0039] Figure 4 A mesh partitioning diagram according to an exemplary embodiment of this application is shown;

[0040] Figure 5 A residual curve diagram according to an exemplary embodiment of this application is shown;

[0041] Figure 6 A temperature distribution cloud map of a shoe last according to an exemplary embodiment of this application is shown;

[0042] Figure 7 A cloud map showing the distribution of running shoes according to an exemplary embodiment of this application is shown;

[0043] Figure 8 This illustrates the temperature distribution within the cavity of a running shoe according to an exemplary embodiment of this application;

[0044] Figure 9 A vector diagram illustrating the heat dissipation flow of a running shoe according to an exemplary embodiment of this application is shown;

[0045] Figure 10 A pressure cloud diagram of a running shoe cross-section is shown according to an exemplary embodiment of this application. Detailed Implementation

[0046] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While some embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this application. It should be understood that the drawings and embodiments of this application are for illustrative purposes only and are not intended to limit the scope of protection of this application.

[0047] It should be understood that the steps described in the method embodiments of this application may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this application is not limited in this respect.

[0048] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc., mentioned in this application are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0049] It should be noted that the terms "a" and "a plurality of" used in this application are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0050] The names of the messages or information exchanged between multiple devices in the embodiments of this application are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0051] The solution of this application is described below with reference to the accompanying drawings. The implementing entity of the solution can be adjusted according to specific cases, such as a server, electronic device, or computer. It should be noted that the step numbers in this document are only for the convenience of explaining the specific embodiments and are not intended to limit the order in which the steps are performed.

[0052] like Figure 1 As shown, a CFD calculation method for heat dissipation in running shoes includes:

[0053] S1, Construct a 3D model of the running shoe system, such as Figure 2 As shown.

[0054] Specifically, the 3D model of the running shoe system includes a 3D model of the running shoe and a 3D model of the last placed within the 3D model of the running shoe. It is known that both the 3D model of the running shoe and the 3D model of the last are solid-domain 3D models, with the last placed within the running shoe in its actual position. More specifically, a 3D scanner can be used to scan the last, and then the running shoe can be scanned to obtain a 3D model of the running shoe and a 3D model of the last that are identical to the actual structure. The last is then placed within the running shoe in its actual position and coupled to obtain the 3D model of the running shoe (heat dissipation) system.

[0055] More specifically, the 3D model is simplified, removing structures with minimal impact on heat dissipation, such as the heel pull tab. The perforated areas are divided into zones based on the mesh area of ​​the running shoe, distributed along the front and sides. Different materials are used for the sole and upper, such as… Figure 3 As shown, it includes the shoe core pad area 1, the left and right perforated areas 2, the toe perforated area 3, and the sole area 4.

[0056] S2, perform preprocessing on the three-dimensional model of the running shoe system to obtain preprocessing results, wherein the preprocessing results include a structured three-dimensional mesh obtained by coupling the three-dimensional model of the running shoe system in a fluid domain model and then importing it into mesh generation software.

[0057] Specifically, a fluid domain model is established in the pre-processing software, and the 3D model of the running shoe system (3D model of the shoe last and 3D model of the running shoe) is coupled within the fluid domain model. The coupled 3D geometric model is then imported into the mesh generation software to generate a structured 3D mesh of the shoe last, running shoe, and external flow field. It can be seen that the 3D geometric model at this point is a foot (shoe last)-shoe-environment 3D model, and the structured 3D mesh at this point is the pre-processing result. The structured 3D mesh is as follows: Figure 4 As shown.

[0058] S3. Perform CFD calculations based on the preprocessing results to obtain the calculation results.

[0059] As can be seen, this step involves CFD calculation based on the preprocessing results. By simulating the heat dissipation process of running shoes under different conditions, the corresponding temperature distribution inside and outside the running shoes and the last is obtained, and the calculation results are obtained. The heat dissipation performance of running shoes is evaluated by using the temperature, pressure and speed of various parts of the running shoes in the calculation results. It has the advantages of short time, low cost and high efficiency, and is of great significance for evaluating the heat dissipation effect of running shoes.

[0060] Specifically, the fluid control equations, Darcy coefficients for porous media, and turbulence model are determined; material properties for each part of the running shoe heat dissipation system and air material properties are set; boundary conditions for medium flow, inlet velocity boundary conditions, and outlet pressure boundary conditions are set; solid and fluid conditions are set; simulation calculations are performed until the residual curves converge stably, at which point the calculation ends.

[0061] The fluid control equations include:

[0062] mass conservation equation:

[0063]

[0064] Momentum conservation equation:

[0065]

[0066] Energy conservation equation:

[0067]

[0068] Where x is the Cartesian coordinate in meters (m); u is the velocity in m / s; and ρ is the density in kg / m³. 3 g is the acceleration due to gravity, in m / s². 2 μ is the viscosity coefficient, in Pa·s; c p Specific heat capacity at constant pressure, unit J / (kg·K); T is temperature, unit K; Here is the dissipation function, in W / m. 3 λ is the thermal conductivity, in W / (m·K); p is the pressure, in N; subscript i represents different directions in the coordinate system; subscript j represents different components of velocity.

[0069] By performing simulations in computational fluid dynamics software, the distribution of basic physical quantities at various locations within the flow field can be obtained. The specific steps are as follows:

[0070] 1. The solver type is selected as a pressure-based solver algorithm, the time type is set to steady state, and the default operating pressure is 101325 Pa. Under convection conditions, according to the momentum theorem, the fluid velocity increases along the direction of gravity; therefore, gravitational acceleration needs to be considered, and it is set downwards, i.e., the Z-axis component is 9.81 [m / s²]. The pressure, momentum, energy, and turbulent kinetic energy equations are all discretized using a second-order upwind scheme.

[0071] 2. To address the heat dissipation issue in running shoes, it's necessary to determine whether the fluid is in a laminar or turbulent state, typically using the Reynolds number (Re).

[0072]

[0073] Let ρ represent fluid density (kg / m³), u represent flow velocity (m / s), L represent characteristic length (m), and μ represent dynamic viscosity [kg / (m·s)]. The Reynolds number Re is then calculated to be 4.9 × 10⁻⁶. 4 Therefore, a turbulence model is chosen, and the κ-ε model in the Reynolds time-averaged equation method is selected for turbulence solution.

[0074] 3. Correctly set the material properties according to the actual object. The properties of solid materials include: thermal conductivity, specific heat capacity, density, and molecular weight. The properties of medium materials include: kinematic viscosity, linear Prandtl number, specific heat capacity, enthalpy, and molecular weight.

[0075] 4. The shoe heat dissipation simulation employs velocity inlet boundary conditions and pressure outlet boundary conditions. In the wall boundary conditions, the area around and bottom of the bounding box is set as a single-sided wall. Solid domains and fluid domains, as well as solid domains and solid domains (e.g., the outer boundary of the shoe last and the air fluid domain, the outer boundary of the running shoe and the air fluid domain, the boundary between the shoe upper and the sole), are set as coupled walls. The porous area above the running shoe and the air fluid domain are set as internal surface boundaries. Specifically, the inlet boundary condition can be set to a velocity inlet of 3 m / s, and the outlet boundary condition can be set to a pressure outlet equal to atmospheric pressure.

[0076] 5. For fluid conditions, air was selected, and the temperature was defined to be consistent with the experimental temperature. For solid conditions, material properties corresponding to those of the actual object were assigned. The same heat generation rate as in the experiment was set on the shoe last as the heat source. Different sections of the running shoe were set with material properties consistent with those of a real running shoe, and the surface temperature of the running shoe was set to be consistent with the ambient air temperature. The porous condition was confirmed using the Darcy coefficient. Specifically, the Darcy coefficient of the porous medium was determined by identifying the source terms of the governing equations and momentum equations of the porous medium model in the computational domain, and by using experimental data on pressure loss versus velocity.

[0077] 6. Continue the simulation until the residual curve converges stably, then terminate the calculation. The residual curve graph is shown below. Figure 5 As shown, the residual curves include continuity, velocity (Ux, Uy, Uz), and pressure (p_rgh). All residual curves have essentially converged, indicating the calculation is complete. Figure 5 As shown.

[0078] S4, Post-processing based on the calculation results.

[0079] Specifically, it displays a temperature distribution cloud map of the shoe last, running shoe, and surrounding medium, allowing you to view the specific temperature distribution at each location, such as... Figure 6-8 As shown; this displays a velocity vector diagram of the fluid medium, allowing you to observe the flow conditions of the medium, such as... Figure 9 As shown; this displays a pressure distribution cloud map at various locations on the model, allowing you to view the specific pressure distribution at each location, such as... Figure 10 As shown.

[0080] The technical solution of this application embodiment constructs a three-dimensional model of the running shoe system, including a three-dimensional model of the shoe last. This three-dimensional model is coupled within a fluid domain model and then imported into mesh generation software to obtain a corresponding structured three-dimensional mesh. Computational Fluid Dynamics (CFD) calculations are performed based on this structured mesh. This eliminates interference from the external environment, allows for free parameter setting and flexible control of environmental conditions, and enables in-depth analysis of the entire flow field. Furthermore, wind speed during movement is taken into account, saving time and reducing costs. Therefore, studying the flow mechanism and heat dissipation performance of the running shoe cavity and external flow field through computational fluid dynamics simulation is of great significance for objectively evaluating the heat dissipation performance of running shoes and providing more intuitive and convenient guidance for the design of running shoe heat dissipation features.

Claims

1. A CFD calculation method for heat dissipation in running shoes, characterized in that, include: Step S1: Construct a three-dimensional model of the running shoe system. The three-dimensional model of the running shoe system includes a three-dimensional model of the running shoe and a three-dimensional model of the shoe last placed in the three-dimensional model of the running shoe, wherein a porous medium is used to replace the mesh part of the shoe upper. Step S2: Preprocess the three-dimensional model of the running shoe system to obtain the preprocessing result, wherein the preprocessing result includes the structured three-dimensional mesh of the shoe last, running shoe and external flow field obtained by coupling the three-dimensional model of the running shoe system in the fluid domain model and then importing it into the mesh generation software. Step S3: Perform CFD calculations based on the preprocessing results to obtain the calculation results; Step S3 includes: Determine the fluid control equations, Darcy coefficients for porous media, and turbulence model; Set the material properties and air material properties of each part of the running shoe system; Set the boundary conditions for the medium flow, the inlet velocity boundary condition, and the outlet pressure boundary condition. Set solid and fluid conditions; The simulation calculation continues until the residual curve stabilizes and converges, at which point the calculation ends to obtain the results. Specifically, the Darcy coefficient of the porous medium is determined by determining the governing equation and momentum equation source terms of the porous medium model in the computational domain, and by using experimental data on pressure loss versus velocity. The solid conditions are as follows: defining the material properties of the solid, setting the same heat generation rate as the experiment as the heat source on the shoe last, setting the material properties of different zones of the running shoe to be consistent with those of the real running shoe, and setting the running shoe temperature to be consistent with the ambient air temperature.

2. The CFD calculation method for heat dissipation in running shoes according to claim 1, characterized in that, Step S1 includes: A 3D scanner is used to scan the shoe last and running shoe to obtain a 3D model of the shoe last and a 3D model of the running shoe. The 3D model of the shoe last is placed on the 3D model of the running shoe according to the actual position. The 3D model obtained from the scan is simplified to remove structures that do not affect heat dissipation calculations; The scanned 3D model is divided into sections to distinguish different materials and to differentiate between the mesh and non-mesh parts of the shoe upper.

3. The CFD calculation method for heat dissipation in running shoes according to claim 1 or 2, characterized in that, Step S2 includes: A fluid domain model is established in the preprocessing software, and the three-dimensional model of the running shoe system is placed in the fluid domain model for coupling to obtain a three-dimensional geometric model. The three-dimensional geometric model is imported into mesh generation software to generate structured three-dimensional meshes for the shoe last, running shoe, and external flow field, which serve as the preprocessing result.

4. The CFD calculation method for heat dissipation in running shoes according to claim 1, characterized in that, The turbulence model uses the k-ε model, and the solution type is steady-state calculation. The solution method is an implicit method based on the pressure coupling equations. The pressure, momentum, energy, and turbulent kinetic energy equations are all discretized using the second-order upwind scheme.

5. The CFD calculation method for heat dissipation in running shoes according to claim 1, characterized in that, The material properties include solid material properties and dielectric material properties. The solid material properties include thermal conductivity, specific heat capacity, density, and molecular weight. The dielectric material properties include kinematic viscosity, linear Prandtl number, specific heat capacity, enthalpy, and molecular weight.

6. The CFD calculation method for heat dissipation in running shoes according to claim 1, characterized in that, The inlet velocity boundary condition is set to a velocity inlet of 3 m / s, and the outlet pressure boundary condition is set to a pressure outlet equal to atmospheric pressure.

7. The CFD calculation method for heat dissipation in running shoes according to claim 1, characterized in that, The fluid conditions are: air is selected, and the temperature is the same as the experimental temperature.

8. The CFD calculation method for heat dissipation in running shoes according to claim 1, characterized in that, The method includes: step S4, performing post-processing based on the calculation results; Step S4 includes: displaying a temperature distribution cloud map of the shoe last, running shoes, and medium, and / or, displaying a velocity vector map of the fluid medium, and / or, displaying a pressure distribution cloud map at each location of the model.

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