A CAE-based light grid mist simulation method

Abstract

The application relates to a CAE-based light-emitting grid mist simulation method, which comprises the following steps: constructing a light-emitting grid product model based on three-dimensional data of the light-emitting grid and defining an analysis model; defining material parameters of parts of the light-emitting grid product model; defining outer wall surface simulation parameters of the light-emitting grid product model; defining the heat power of electronic components of the light-emitting grid product model; completing local mesh encryption of each part of the light-emitting grid product model; defining the inner surface of a mask of the light-emitting grid product model as a monitoring target, and defining a physical quantity as film thickness; setting solving parameters and performing calculation to obtain the film thickness of the inner surface of the mask of the light-emitting grid product model. The application can guide the internal structure design of the light-emitting grid and the layout of air holes on the shell.

Description

Technical Field

[0001] This invention relates to the field of computational-aided engineering (CAE) technology, and in particular to a CAE-based method for simulating fog on a luminous grid. Background Technology

[0002] With the development of new energy vehicles, traditional air intake grilles are no longer needed, and the application of illuminated grilles is becoming increasingly widespread. These illuminated grilles are required to dissipate fog promptly in various environments. On rainy days, the air humidity is high, and the temperature of rainwater is much lower than the air temperature inside the illuminated grille. Under these high humidity and temperature differences, fog easily forms on the inner surface of the illuminated grille cover, which severely affects light transmittance and the overall aesthetics of the car. To eliminate fog quickly, the internal structure of the illuminated grille and the arrangement of ventilation holes on the shell need to be rationally designed to ensure seamless airflow and rapid exchange of air between the inside and outside, allowing the fog to dissipate more quickly. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a CAE-based method for simulating fog on a light-emitting grid, which can guide the internal structural design of the light-emitting grid and the layout of the ventilation holes on the shell.

[0004] The technical solution adopted by this invention to solve its technical problem is: to provide a CAE-based method for simulating fog on a light-emitting grid, comprising the following steps:

[0005] A product model of the luminous grid is constructed based on the 3D data of the luminous grid, and the model definition is analyzed.

[0006] Define the material parameters of the components for the luminous grille product model;

[0007] Define the simulation parameters for the outer wall surface of the luminous grille product model;

[0008] Define the thermal power of electronic components in the luminous grid product model;

[0009] Local mesh refinement was performed on each component of the luminous grille product model;

[0010] The inner surface of the mask of the luminous grid product model is defined as the monitoring target, and the monitored physical quantity is defined as the film thickness.

[0011] Set the solution parameters and perform calculations to obtain a surface map of the film thickness on the inner surface of the mask of the luminous grid product model.

[0012] When defining the analysis model, the analysis type is defined as an internal transient simulation model, the radiation type is defined as a Monte Carlo radiation model, and the default solid material and default fluid are defined. The initial conditions are defined according to the actual situation for the internal and external initial temperature and humidity of the luminous grid product model.

[0013] The material parameters include density, thermal conductivity, and specific heat. When the material of the component is a transparent material, the material parameters also include absorption coefficient and refractive index.

[0014] When defining the simulation parameters of the outer wall surface of the luminous grille product model, the outer surface of the luminous grille product model is defined with respect to the changes in surface temperature and heat exchange coefficient over time according to rain and normal temperature conditions. The breathable membrane of the luminous grille product model is defined with respect to the changes in ambient temperature and humidity over time on the vehicle side. The ambient temperature and heat exchange coefficient of the remaining outer wall surfaces are defined according to the actual working conditions.

[0015] When defining the thermal power of electronic components in the luminous grid product model, for luminous electronic components, volumetric heat sources and radiative heat sources are set to simulate luminescence and heat generation respectively. For non-luminous electronic components, volumetric heat sources are defined according to actual power, and the switching status of volumetric heat sources over time is set according to working conditions.

[0016] When performing local mesh refinement on each component of the light-emitting grid product model, the mesh is refined according to the size of the component. For electronic components, the solid mesh is refined to level N, for PCB boards, the solid mesh is defined as level N-1, and for other components, the mesh is gradually reduced according to the contact relationship.

[0017] The CAE-based fog simulation method for luminous grids further includes: defining the radiation surface of each component in the luminous grid product model, defining the surface emission coefficient according to different materials and surface processes, and assigning it to each component.

[0018] The CAE-based luminous grid fog simulation method further includes: defining a breathable membrane for the luminous grid product model. When defining the breathable membrane, it is defined as a porous medium. The porous medium's permeation type is selected as isotropic. In the thermal resistance calculation formula, the relationship between pressure drop and flow rate is defined as a linear relationship according to the breathable membrane specification. The flow rate is selected as volumetric flow rate.

[0019] Beneficial effects

[0020] By employing the above-mentioned technical solutions, this invention has the following advantages and positive effects compared with existing technologies: This invention can simulate the defogging performance of a luminous grid under different working conditions, and guide the internal structural design of the luminous grid and the layout of the vents on the shell based on the simulation results. The internal simulation model used in this invention can accurately and easily define different temperatures and humidity levels on both sides of the luminous grid, while also effectively reducing modeling difficulty and computational workload, greatly improving efficiency. This invention uses a numerical simulation method, eliminating the need for physical models for experimental verification, which can significantly improve the R&D effect and reduce development costs of new products. Attached Figure Description

[0021] Figure 1 This is a flowchart of an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram illustrating the definition of the analysis model in an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram illustrating the material parameter definitions of components in an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram illustrating the definition of simulation parameters for the outer wall surface in an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram illustrating the thermal power definition of electronic components in an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of the completed mesh division of the light-emitting grid product model in an embodiment of the present invention;

[0027] Figure 7 This is a surface diagram of the film thickness on the inner surface of the mask obtained through simulation in an embodiment of the present invention. Detailed Implementation

[0028] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0029] This invention relates to a CAE-based method for simulating fogging of luminous grids, comprising the following steps: constructing a luminous grid product model based on 3D data of the luminous grid and defining the analysis model; defining material parameters for components of the luminous grid product model; defining simulation parameters for the outer wall surface of the luminous grid product model; defining the thermal power of electronic components in the luminous grid product model; refining the local mesh for each component of the luminous grid product model; defining the inner surface of the mask of the luminous grid product model as the monitoring target, and defining the monitored physical quantity as the film thickness; setting solution parameters and performing calculations to obtain the film thickness of the inner surface of the mask of the luminous grid product model. This embodiment can utilize FLOEFD fluid software to accurately solve the defogging characteristics of luminous grids under different conditions, thereby guiding product design and optimization, such as... Figure 1 As shown, the specific steps include:

[0030] Step 101: Create an analysis project from the wizard, constructing a product model of the luminous grid based on its 3D data. When creating the analysis project, as follows... Figure 2 As shown, select the internal transient simulation model as the analysis type, define the radiation type as the Monte Carlo radiation model, complete the definition of the default solid material and default fluid, and define the initial conditions for the initial temperature and humidity inside and outside the luminous grid according to the actual situation, and complete the wizard settings.

[0031] Step 102: Define the material parameters of each component based on the materials used in the luminous grid product model. These parameters include density, thermal conductivity, and specific heat. For transparent materials such as face masks, the absorption coefficient and refractive index also need to be defined. Figure 3 As shown.

[0032] Step 103: Define boundary conditions (i.e., simulation parameters of the outer wall surface). When defining, for example... Figure 4 As shown, for the outer surface of the mask, the surface temperature and heat exchange coefficient can be defined over time according to rain conditions and normal temperature conditions. For the breathable membrane, the ambient temperature and humidity on the vehicle side can be defined over time. For the other outer walls, the ambient temperature and heat exchange coefficient can be defined according to the actual working conditions.

[0033] Step 104: Define the thermal power of electronic components, such as... Figure 5 As shown, for light-emitting electronic components such as LED chips, volumetric heat sources and radiative heat sources need to be set to simulate light emission and heat generation, respectively. For other non-light-emitting electronic components, the volumetric heat source can be defined according to the actual power. The volumetric heat source can be configured to switch on and off over time according to the operating conditions.

[0034] Step 105: Define the radiation surface of each component. When defining, the surface emissivity can be defined according to the different materials and surface processes of each component, and assigned to each component.

[0035] Step 106: Define the breathable membrane. In this embodiment, the breathable membrane is defined as a porous medium. The porous medium is selected as isotropic for its permeation type. The thermal resistance calculation formula involves pressure drop, flow rate, and size. The relationship between pressure drop and flow rate can be linear according to the breathable membrane specification. The flow rate is volumetric flow rate.

[0036] Step 107: Perform local mesh refinement for each component. In this implementation, the mesh refinement can be based on the component size. For LEDs and other electronic components, the solid mesh needs to be refined to level 7, the PCB board solid mesh is defined as level 6, and the level decreases progressively for other components based on their contact relationships. After defining the mesh, run the mesh and check if the mesh division is reasonable. If it is unreasonable, the mesh can be optimized until the mesh division is reasonable. The divided mesh is as follows: Figure 6 As shown.

[0037] Step 108: Define the monitoring target. Define the inner surface of the luminous grid mask as the monitoring target. The physical quantity to be monitored is the film thickness, and the unit is selected as micrometers.

[0038] Step 109: Solve the parameters. Select the time step as 1 second. Set the convergence stopping condition according to the physical time of the calculation. For example, if the physical time is 3600 seconds, stop the calculation when the solution time reaches 3600 seconds.

[0039] Step 111: Post-processing and calculation. Define physical quantities and surface plots: Create a surface plot of the film thickness on the inner surface of the luminous grid mask. Execute iterative solutions; the iterative calculation stops when the maximum physical time reaches 3600s. View the simulation results (see...). Figure 7 ),from Figure 7 The distribution of the film thickness on the inner surface of the luminous grid mask can be seen, which can be used to optimize the internal structure design of the luminous grid and the layout of the vent holes on the shell.

[0040] It is easy to see that this invention provides a reasonable and effective CAE analysis method for studying the defogging performance of luminous grids. Based on this method, fog analysis of luminous grids can be performed efficiently to obtain accurate fog distribution on the inner surface of the luminous grid mask, providing strong support for the internal design of luminous grids and the layout of breathable membranes, saving product development cycle and reducing R&D costs.

Claims

1. A CAE-based method for simulating fog on luminous grids, characterized in that, Includes the following steps: A product model of the luminous grid is constructed based on the 3D data of the luminous grid, and the model definition is analyzed. Define the material parameters of the components for the luminous grille product model; The simulation parameters of the outer wall surface of the luminous grille product model are defined. When defining the simulation parameters of the outer wall surface of the luminous grille product model, the surface temperature and heat exchange coefficient of the outer surface of the mask of the luminous grille product model are defined as changing over time according to rain conditions and normal temperature conditions. The ventilation membrane of the luminous grille product model is defined as changing over time according to the ambient temperature and humidity of the vehicle side. The ambient temperature and heat exchange coefficient of the other outer wall surfaces are defined according to the actual working conditions. The thermal power of electronic components in the light-emitting grid product model is defined. When defining the thermal power of electronic components in the light-emitting grid product model, for light-emitting electronic components, volume heat source and radiation heat source are set to simulate light emission and heat generation respectively. For non-light-emitting electronic components, volume heat source is defined according to actual power, and the switching status of volume heat source over time is set according to working conditions. Local mesh refinement is performed on each component of the light-emitting grid product model; when performing local mesh refinement on each component of the light-emitting grid product model, the mesh is refined according to the size of the component of the light-emitting grid product model. For electronic components, the solid mesh is refined to level N, for PCB boards, the solid mesh is defined as level N-1, and for other components, the mesh is gradually reduced according to the contact relationship. The inner surface of the mask of the luminous grid product model is defined as the monitoring target, and the monitored physical quantity is defined as the film thickness. Set the solution parameters and perform calculations to obtain the film thickness on the inner surface of the mask of the luminous grid product model.

2. The CAE-based method for simulating fog on luminous grids according to claim 1, characterized in that, When defining the analysis model, the analysis type is defined as an internal transient simulation model, the radiation type is defined as a Monte Carlo radiation model, and the default solid material and default fluid are defined. The initial conditions are defined according to the actual situation for the internal and external initial temperature and humidity of the luminous grid product model.

3. The CAE-based method for simulating fog on luminous grids according to claim 1, characterized in that, The material parameters include density, thermal conductivity, and specific heat. When the material of the component is a transparent material, the material parameters also include absorption coefficient and refractive index.

4. The CAE-based method for simulating fog on luminous grids according to claim 1, characterized in that, Also includes: Define the radiating surface of each component in the luminous grid product model. When defining, define the surface emissivity according to different materials and surface processes, and assign it to each component.

5. The CAE-based method for simulating fog on luminous grids according to claim 1, characterized in that, Also includes: Define the breathable membrane of the luminous grid product model. When defining it, the breathable membrane is defined as a porous medium. The permeation type of the porous medium is selected as isotropic. In the thermal resistance calculation formula, the relationship between pressure drop and flow rate is defined as a linear relationship according to the breathable membrane specification. The flow rate is selected as volumetric flow rate.

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