Finished vehicle wind resistance simulation automatic analysis method and system

Abstract

The invention discloses a whole vehicle wind resistance simulation automatic analysis method and system. The method comprises the following steps: establishing a three-dimensional geometric model; importing the geometric model into pre-processing software to carry out PID (Proportion Integration Differentiation) division; surface grid drawing is carried out on the model subjected to PID division; importing a surface grid file in the pretreatment software into simulation analysis software for setting boundary conditions; uploading a model file and a program control file output by the simulation analysis software to a computing platform; the computing platform automatically computes according to the program control file and outputs a post-processing result file; the output post-processing result file is analyzed; and performing iterative optimization according to an analysis result. According to the method, various simulation results are directly output on the calculation platform without downloading calculation model results or opening the models through software for operation, so that the whole vehicle wind resistance analysis process is greatly simplified, the analysis efficiency is improved, and the labor cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of automobile design, and in particular to an automated analysis method and system for whole vehicle wind resistance simulation. Background Art

[0002] In the process of automobile design, vehicle wind resistance analysis is an important link. The traditional vehicle wind resistance simulation analysis method requires a lot of time and manpower. First, engineers need to prepare the vehicle model and then perform volume meshing on the local server. Next, the vehicle wind resistance calculation model is submitted to the online cloud computing platform for solution. After the solution is completed, it is also necessary to download the calculation results, post-process the calculation results, and analyze the post-processing results. Finally, according to the conclusions of the analysis, adjust the optimization parameter values ​​to provide ideas for the next step of structural optimization.

[0003] This traditional method has the following problems:

[0004] 1. Time-consuming: Whether it is to divide the model body mesh locally or to obtain the post-processing result file, engineers usually need a lot of time and energy to operate the software.

[0005] 2. Slow data transmission: Large vehicle models are usually around 20G, and it takes a long time to download calculation results from the online simulation platform, which may take more than half an hour.

[0006] 3. Lots of manual operations: Engineers need to perform a lot of manual operations, including model preparation, meshing, result downloading, post-processing, etc., which undoubtedly greatly reduces the efficiency of vehicle wind resistance analysis.

[0007] Therefore, how to simplify the vehicle wind resistance analysis process, improve analysis efficiency, and reduce labor costs has become a technical problem that needs to be solved urgently. Summary of the invention

[0008] The purpose of the present invention is to provide a method and system for automatic simulation analysis of vehicle wind resistance, aiming to simplify the vehicle wind resistance analysis process, improve analysis efficiency and reduce labor costs.

[0009] To achieve the above objectives, in a first aspect, the present invention provides an automatic simulation analysis method for wind resistance of a vehicle, comprising:

[0010] Build three-dimensional geometric models;

[0011] Importing the geometric model into pre-processing software for PID division;

[0012] Draw the surface mesh of the divided PID model;

[0013] Import the surface mesh file in the pre-processing software into the simulation analysis software to set the boundary conditions;

[0014] Upload the model file and program control file output by the simulation analysis software to the computing platform;

[0015] The computing platform automatically calculates according to the program control file and outputs the post-processing result file;

[0016] Analyze the output post-processing result files;

[0017] Perform iterative optimization based on the analysis results.

[0018] In some embodiments of the present invention, the program control file includes: a header file for calling functions provided by the simulation analysis software; and a function for implementing the required simulation analysis function.

[0019] In some embodiments of the present invention, the header file of the program control file comes from a calling header file provided by the simulation analysis software itself.

[0020] In some embodiments of the present invention, the functional functions include: a volume mesh division function, which is used to automatically generate high-quality volume meshes; a volume mesh quality improvement function, which is used to optimize the volume mesh and improve its quality; a solution calculation function, which controls the solution process, including setting solver parameters and number of iteration steps; and a post-processing result output function, which is used to automatically generate the required post-processing results.

[0021] In some embodiments of the present invention, the computing platform automatically calculates according to the program control file, and outputs the post-processing result file, including: automatically generating a volume mesh according to the volume mesh partitioning function in the program control file; automatically improving the volume mesh quality according to the volume mesh quality improvement function in the program control file; automatically performing calculation and solving according to the solution calculation function in the program control file; and automatically outputting the post-processing result according to the post-processing result output function in the program control file.

[0022] In some embodiments of the present invention, the post-processing result file includes:

[0023] Calculate the residual curve to determine whether the calculation has converged;

[0024] Cumulative force curves, showing the aerodynamic forces on the vehicle in different directions over time;

[0025] Pressure cloud map, intuitively showing the pressure distribution on the vehicle body surface;

[0026] Vector cloud diagram, showing the velocity vector distribution of the flow field;

[0027] The turbulent kinetic energy cloud diagram shows the distribution of turbulent kinetic energy in the flow field.

[0028] In a second aspect, the present invention provides an automatic simulation and analysis system for wind resistance of a vehicle, comprising:

[0029] A geometric model building module is used to build geometric models in CAD software;

[0030] A PID partitioning module, used for importing the geometric model into the pre-processing software for PID partitioning;

[0031] The surface mesh drawing module is used to draw the surface mesh of the PID divided model;

[0032] The boundary condition setting module is used to import the surface mesh file in the pre-processing software into the simulation analysis software to set the boundary conditions;

[0033] A program control file storage module is used to store the written program control files;

[0034] A file uploading module, used to upload the sim file output by the simulation analysis software to the computing platform together with the program control file;

[0035] An automated calculation module performs automated calculations on the computing platform according to a program control file and outputs a post-processing result file;

[0036] Result analysis module, used to analyze the output post-processing result file;

[0037] Iterative optimization module, used to perform iterative optimization based on analysis results.

[0038] In some embodiments of the present invention, the program control file includes: a header file for calling functions provided by the simulation analysis software; and a function for implementing the required simulation analysis function.

[0039] In some embodiments of the present invention, the header file of the program control file comes from a calling header file provided by the simulation analysis software itself.

[0040] In some embodiments of the present invention, the functional functions include: a volume mesh division function, which is used to automatically generate high-quality volume meshes; a volume mesh quality improvement function, which is used to optimize the volume mesh and improve its quality; a solution calculation function, which controls the solution process, including setting solver parameters and number of iteration steps; and a post-processing result output function, which is used to automatically generate the required post-processing results.

[0041] In some embodiments of the present invention, the automatic execution module includes:

[0042] A volume mesh generation unit, used for automatically generating a volume mesh according to a volume mesh partitioning function in a program control file;

[0043] A mesh quality improvement unit is used to automatically improve the volume mesh quality according to the volume mesh quality improvement function in the program control file;

[0044] A calculation and solution unit, used for automatically performing calculation and solution according to the solution calculation function in the program control file;

[0045] The result output unit is used to automatically output the post-processing results according to the post-processing result output function in the program control file.

[0046] In some embodiments of the present invention, the post-processing result file includes:

[0047] Calculate the residual curve to determine whether the calculation has converged;

[0048] Cumulative force curves, showing the aerodynamic forces on the vehicle in different directions over time;

[0049] Pressure cloud map, intuitively showing the pressure distribution on the vehicle body surface;

[0050] Vector cloud diagram, showing the velocity vector distribution of the flow field;

[0051] The turbulent kinetic energy cloud diagram shows the distribution of turbulent kinetic energy in the flow field.

[0052] Beneficial effects of the present invention:

[0053] 1. Improve efficiency: Through automated volume mesh generation, calculation control and result output, manual work hours are greatly reduced, and the efficiency of vehicle wind resistance simulation analysis is significantly improved.

[0054] 2. Reduce labor costs: The automated process greatly reduces engineers’ manual operation time and reduces labor costs.

[0055] 3. Simplified process: The entire analysis process is smoother, and automation is achieved from model preparation to result output, simplifying the vehicle wind resistance analysis process.

[0056] 4. Quickly obtain results: The required calculation results can be directly output on the cloud platform, avoiding the time-consuming result download process.

[0057] 5. High flexibility: By writing program control files, you can flexibly set analysis parameters and output results according to actual needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions of the embodiments disclosed in the present invention, the drawings of the embodiments will be briefly introduced below. These drawings are only used for illustrative purposes and are not intended to limit the protection scope of the present invention.

[0059] Figure 1It is a flow chart of the automated analysis of vehicle wind resistance simulation according to the present invention. DETAILED DESCRIPTION

[0060] The technical solution of the present invention (including the preferred technical solution) is further described in detail below by means of the accompanying drawings and by listing some optional embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0061] Example 1

[0062] This embodiment provides a method for simulating and automating the analysis of vehicle wind resistance. Figure 1 As shown, the specific steps are as follows:

[0063] Step 1: Create a 3D geometric model.

[0064] In this embodiment, a geometric model is established in CATIA software.

[0065] Use CATIA software to build a complete three-dimensional vehicle geometry model, including the body surface, chassis, tires, engine compartment and other major components.

[0066] Step 2: Import the geometric model into the pre-processing software for PID division.

[0067] In this embodiment, the geometric model is imported into ANSA for PID partitioning. ANSA is a professional pre-processing software, which is mainly used for PID (Part Instance Data) partitioning.

[0068] Import the geometric model created in CATIA into ANSA software. The purpose of PID partitioning is to assign different attributes to different parts or areas to facilitate subsequent mesh generation and boundary condition setting.

[0069] Step 3: Draw the surface mesh of the divided PID model.

[0070] In ANSA, the surface mesh is drawn for the model that has completed PID division. The surface mesh is a surface mesh composed of triangular or quadrilateral units, which is used to describe the geometric characteristics of the whole vehicle. During the drawing process, attention should be paid to the quality and density of the mesh, including the size, shape and distribution of the units, especially in the key areas of the vehicle body, such as the front face, rearview mirror, tail, etc.

[0071] Step 4: Import the surface mesh file in the pre-processing software into the simulation analysis software to set the boundary conditions.

[0072] In this embodiment, the surface mesh file in ANSA is specifically imported into Star ccm+ to set the boundary conditions. Star ccm+ is a multi-physics field computational fluid dynamics (CFD) simulation software, which is mainly used to set the boundary conditions here.

[0073] Export the generated surface mesh file from ANSA and then import it into Star ccm+ software. According to the actual wind resistance analysis requirements, set various boundary conditions, such as inlet velocity, outlet pressure, wall conditions, etc. At the same time, it is also necessary to set the size of the calculation domain, turbulence model, solver parameters, etc.

[0074] Step 5: Upload the model file and program control file output by the simulation analysis software to the computing platform.

[0075] In this embodiment, specifically, the sim file output by Star ccm+ is uploaded to the computing platform together with the Java program control file.

[0076] After completing the boundary condition setting in Star-ccm+ software, save the model as a sim format file (including model, grid and boundary condition information). At the same time, write a Java program file to control the simulation process.

[0077] The computing platform may be a computing cloud platform, which generally has powerful computing capabilities and can quickly process large-scale CFD computing tasks.

[0078] In this embodiment, Java is used to write the program control file, and the Java program control file includes a header file and a function. The header file is used to call the functions provided by Star ccm+; the function is used to implement the required simulation analysis function.

[0079] In some optional embodiments of the present invention, the header files mainly come from the call header files provided by the Star ccm+ software itself, including various necessary classes and interfaces. Mainly including the following header files:

[0080] import star.base.neo.NeoObjectVector;

[0081] import star.common.Continuum;

[0082] import star.common.FvRepresentation;

[0083] import star.common.MeshContinuum;

[0084] import star.common.MeshManager;

[0085] import star.common.Region;

[0086] import star.common.Simulation;

[0087] import star.common.StarMacro;

[0088] import star.common.StepStoppingCriterion;

[0089] import star.flow.ForceCoefficient;

[0090] import star.meshing.MeshPipelineController;

[0091] import star.resurfacer.ResurfacerMeshingModel;

[0092] import star.vis.PrimitiveShapeReport;

[0093] import star.common.*;

[0094] import star.base.neo.*;

[0095] import star.vis.*;

[0096] import star.flow.*;

[0097] The functional functions mainly include the following parts: Volume mesh generation function: used to automatically generate high-quality volume mesh; Volume mesh quality improvement function: used to optimize the volume mesh and improve its quality;

[0098] Solution calculation function: controls the solution process, including setting solver parameters, iteration steps, etc.

[0099] Post-processing result output function: used to automatically generate the required post-processing results, such as pressure cloud diagrams, vector diagrams, etc.

[0100] Step 6: The computing platform automatically calculates according to the program control file and outputs the post-processing result file.

[0101] Specifically, after receiving the uploaded sim file and Java program control file, the computing platform automatically executes the following process:

[0102] (1) The volume mesh is automatically generated according to the volume meshing function in the Java program control file. The volume mesh is a spatial grid composed of three-dimensional units such as tetrahedrons and hexahedrons, which is used for fluid calculations.

[0103] (2) Automatically improve the volume mesh quality according to the volume mesh quality improvement function in the Java program control file. This step can optimize the shape and distribution of mesh cells and improve the accuracy and stability of the calculation.

[0104] (3) Automatically perform calculations according to the solution calculation function in the Java program control file. This step sets the solver parameters and performs an iterative calculation process until the convergence condition or the specified number of iterations is reached.

[0105] (4) Automatically output the post-processing results according to the post-processing result output function in the Java program control file. The system automatically generates post-processing result files, including but not limited to:

[0106] Calculation residual curve: used to determine whether the calculation has converged.

[0107] Cumulative force curve: shows the aerodynamic forces acting on the vehicle in different directions over time.

[0108] Pressure cloud map: intuitively displays the pressure distribution on the vehicle body surface.

[0109] Vector cloud map: displays the velocity vector distribution of the flow field.

[0110] Turbulent kinetic energy cloud map: shows the distribution of turbulent kinetic energy in the flow field.

[0111] Step 7: Analyze the output post-processing result file.

[0112] Specifically, engineers analyze the wind resistance characteristics of the vehicle based on the output post-processing result files. For example:

[0113] Determine whether the calculation has converged by calculating the residual curve;

[0114] Analyze the change of vehicle force over time through cumulative force curve;

[0115] Analyze the pressure distribution on the vehicle body surface through pressure cloud diagram;

[0116] Analyze the flow field characteristics around the vehicle body through vector cloud images;

[0117] The turbulence characteristics around the vehicle body are analyzed through the turbulence kinetic energy cloud map.

[0118] Step 8: Perform iterative optimization based on the analysis results.

[0119] Specifically, based on the analysis results of step 7, engineers can adjust the body shape, add or modify aerodynamic components (such as spoilers, fairings, etc.) in a targeted manner, and then repeat steps S1-S7 to perform a new round of wind resistance analysis until the expected aerodynamic performance target is achieved.

[0120] Example 2

[0121] This embodiment provides a vehicle wind resistance simulation automatic analysis system, including the following modules:

[0122] 1. Geometry model building module

[0123] Used to establish the vehicle geometry model in CATIA software. This module implements step 12 and PID division module in Example 1.

[0124] This module is based on ANSA software and is used to import the geometric model and perform PID partitioning. PID partitioning divides the entire vehicle model into different components or regions to prepare for subsequent mesh generation and analysis. This module implements step 2 in Example 1.

[0125] 3. Surface mesh drawing module

[0126] This module is also based on ANSA software and is used to draw the surface mesh of the divided PID model. This module implements step 3 in embodiment 1.

[0127] 4. Boundary condition setting module

[0128] This module is based on Star ccm+ software and is used to import the surface mesh file drawn in ANSA software into Star-ccm+ software for boundary condition setting. This module implements step 4 in Example 1.

[0129] 5. Program control file storage module

[0130] Used to store the written program control file. This module is used to store the Java program control file in step 5 of embodiment 1.

[0131] 6. File upload module

[0132] This module is responsible for uploading the sim file output by Star ccm+ and the Java program control file to the computing platform. This module implements step 5 in Example 1.

[0133] 7. Automated calculation module

[0134] This module runs on the computing platform and is responsible for performing automated calculations. It automatically generates volume meshes, performs calculations and outputs results according to the instructions of the uploaded Java program control file. This module implements step 6 in Example 1, specifically including:

[0135] A volume mesh generation unit, used for automatically generating a volume mesh according to a volume mesh division function in a Java program control file;

[0136] A mesh quality improvement unit, used for automatically improving the volume mesh quality according to the volume mesh quality improvement function in the Java program control file;

[0137] A calculation and solution unit, used for automatically performing calculation and solution according to a solution calculation function in a Java program control file;

[0138] The result output unit is used to automatically output the post-processing result according to the post-processing result output function in the Java program control file.

[0139] 8. Result analysis module

[0140] This module is used to analyze the post-processing result file output by the automated calculation. This module implements step 7 in Example 1. The post-processing result file includes:

[0141] Calculate the residual curve to determine whether the calculation has converged;

[0142] Cumulative force curves, showing the aerodynamic forces on the vehicle in different directions over time;

[0143] Pressure cloud map, intuitively showing the pressure distribution on the vehicle body surface;

[0144] Vector cloud diagram, showing the velocity vector distribution of the flow field;

[0145] The turbulent kinetic energy cloud diagram shows the distribution of turbulent kinetic energy in the flow field.

[0146] 9. Iterative Optimization Module

[0147] Used to perform iterative optimization based on the analysis results. It may include a knowledge base system that stores common optimization strategies and experiences to provide decision support for engineers. This module implements step 8 in Example 1.

[0148] The present invention realizes the automation of the entire simulation process by writing a Java program control file. Compared with the traditional method, the present invention has the following advantages:

[0149] 1. Improve efficiency: Automated volume mesh generation, calculation control and result output greatly reduce manual operation time and significantly improve the efficiency of vehicle wind resistance analysis.

[0150] 2. Reduce costs: Reduce manual intervention and reduce dependence on senior simulation engineers, thereby reducing labor costs.

[0151] 3. Standardized process: Through program control, the simulation analysis process is standardized, human errors are reduced, and the reliability and consistency of the results are improved.

[0152] 4. Resource optimization: Output results directly on the cloud platform, avoiding the download and transmission of large result files and optimizing the use of computing resources.

[0153] 5. Easy to iterate and optimize: The automated process makes it easier to perform multiple iterative analyses, which is conducive to rapid design optimization.

[0154] 6. Cross-platform compatibility: The use of Java programs enables this method to run on different operating systems and hardware platforms, with good compatibility and portability.

[0155] In summary, the method and system for automated simulation analysis of vehicle wind resistance provided by the present invention not only simplifies the analysis process and improves efficiency, but also provides a powerful tool for automobile design optimization, helps to speed up the development process of new models, and improves the aerodynamic performance of the vehicle.

[0156] Those skilled in the art will readily appreciate that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, combinations, replacements, improvements, etc. made within the spirit and principles of the present invention are included within the protection scope of the present invention.

Claims

1. A method for automatic simulation analysis of vehicle wind resistance, characterized in that: include: Build three-dimensional geometric models; Importing the geometric model into pre-processing software for PID division; Draw the surface mesh of the divided PID model; Import the surface mesh file in the pre-processing software into the simulation analysis software to set the boundary conditions; Upload the model file and program control file output by the simulation analysis software to the computing platform; The computing platform automatically calculates according to the program control file and outputs the post-processing result file; Analyze the output post-processing result files; Perform iterative optimization based on the analysis results.

2. The method for automatic simulation analysis of vehicle wind resistance according to claim 1, characterized in that: The program control files include: Header file, used to call the functions provided by the simulation analysis software; Function: used to realize the required simulation analysis function.

3. The method for automatic simulation analysis of vehicle wind resistance according to claim 2 is characterized in that: The header file of the program control file comes from the calling header file provided by the simulation analysis software itself.

4. The method for automatic simulation analysis of vehicle wind resistance according to claim 2 or 3, characterized in that: The functional functions include: Volume meshing function, used to automatically generate high-quality volume meshes; Volume mesh quality improvement function, used to optimize volume mesh and improve its quality; Solve the calculation function and control the solution process, including setting solver parameters and iteration steps; The post-processing result output function is used to automatically generate the required post-processing results.

5. The method for automatic simulation analysis of vehicle wind resistance according to claim 4 is characterized in that: The computing platform automatically calculates according to the program control file, and outputs the post-processing result file including: Automatically generate volume mesh according to the volume mesh division function in the program control file; Automatically improve the volume mesh quality according to the volume mesh quality improvement function in the program control file; Automatically perform calculations and solutions according to the solution calculation function in the program control file; The post-processing results are automatically output according to the post-processing result output function in the program control file.

6. A vehicle wind resistance automatic simulation analysis system, characterized in that: include: A geometric model building module is used to build geometric models in CAD software; A PID partitioning module, used for importing the geometric model into the pre-processing software for PID partitioning; The surface mesh drawing module is used to draw the surface mesh of the PID divided model; The boundary condition setting module is used to import the surface mesh file in the pre-processing software into the simulation analysis software to set the boundary conditions; A program control file storage module is used to store the written program control files; A file uploading module, used to upload the sim file output by the simulation analysis software to the computing platform together with the program control file; An automated calculation module performs automated calculations on the computing platform according to a program control file and outputs a post-processing result file; Result analysis module, used to analyze the output post-processing result file; Iterative optimization module, used to perform iterative optimization based on analysis results.

7. The vehicle wind resistance automatic simulation analysis system according to claim 6 is characterized in that: The program control files include: Header file, used to call the functions provided by the simulation analysis software; Function: used to realize the required simulation analysis function.

8. The vehicle wind resistance automatic simulation analysis system according to claim 7 is characterized by: The header file of the program control file comes from the calling header file provided by the simulation analysis software itself.

9. The vehicle wind resistance automatic simulation analysis system according to claim 7 or 8, characterized in that: The functional functions include: Volume meshing function, used to automatically generate high-quality volume meshes; Volume mesh quality improvement function, used to optimize volume mesh and improve its quality; Solve the calculation function and control the solution process, including setting solver parameters and iteration steps; The post-processing result output function is used to automatically generate the required post-processing results.

10. The vehicle wind resistance automatic simulation analysis system according to claim 8, characterized in that: The automatic execution module comprises: A volume mesh generation unit, used for automatically generating a volume mesh according to a volume mesh partitioning function in a program control file; A mesh quality improvement unit is used to automatically improve the volume mesh quality according to the volume mesh quality improvement function in the program control file; A calculation and solution unit, used for automatically performing calculation and solution according to the solution calculation function in the program control file; The result output unit is used to automatically output the post-processing results according to the post-processing result output function in the program control file.

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