An automobile fan simulation analysis method and device and a storage medium

Abstract

The application discloses a simulation analysis method and device for an automobile fan and a storage medium, and comprises the following steps: S1, establishing a basic vehicle analysis model; S2, establishing a fan independent analysis model; S3, establishing a fan default vehicle analysis model; S4, analyzing and solving the basic vehicle analysis model to obtain initial flow field information; S5, analyzing and solving the fan independent analysis model to obtain the second initial boundary of the fan default vehicle analysis model; S6, analyzing and solving the fan default vehicle analysis model to obtain flow field information; and S7, repeatedly coupling and solving the fan independent analysis model and the fan default vehicle analysis model until convergence is achieved, and obtaining the analysis result of the converged vehicle flow field temperature field. The application can improve the calculation precision while ensuring the calculation efficiency, and accurately simulates the aerodynamic performance of the fan.

Description

Technical Field

[0001] This invention relates to the field of aerodynamic performance evaluation of automotive fans, specifically to simulation analysis methods, devices, and storage media for automotive fans. Background Technology

[0002] The function of automotive cooling fans is to accelerate airflow, improve the heat dissipation performance of high and low temperature radiators and condensers, and cool down the overall environment and components of the engine compartment. As the power source of airflow in the engine compartment, the selection of fan models is crucial, as it plays a vital role in the airflow and heat diffusion within the engine compartment. The calculation accuracy of the fan model directly determines the accuracy of the analysis of the flow field and temperature field of the entire vehicle engine compartment.

[0003] There are three main methods for simulating fan rotation effects in computational fluid dynamics: rigidbody (RBM), fan momentum source (FRM), and moving reference frame (MRF). The FRM is suitable for fanless solid models, relying on experimental data to simulate airflow, resulting in unrealistic airflow and making it unsuitable for routine engineering analysis. The RBM is suitable for transient calculations, where the mesh moves in real-time, realistically simulating fan blade rotation with high accuracy, but it consumes significant computational resources. The MRF is suitable for steady-state analysis. The core idea of ​​the MRF is to isolate the rotating region and establish a local coordinate system. During calculation, the mesh does not actually move but generates centrifugal and Coriolis forces through the rotation of the local coordinate system, thus achieving the effect of fan rotation. It is widely used in industry analysis, but its accuracy is not very high, and it has a significant impact on local flow in the engine compartment, especially for structures with integrated cooling module radiators, where there are significant differences in temperature distribution between upper and lower layers. The MRF fan model has a significant impact on the accuracy of overall vehicle flow and temperature field analysis.

[0004] There is relatively little research on fan algorithms within the industry. CN112445467A discloses a method for generating automotive fan module software, including the following steps: establishing an automotive fan model in the Simulink environment, where the automotive fan model includes an input part, a logic function control part, and an output part; establishing a logic function control submodule in the logic function control part; testing whether the established automotive fan model is correct; if the established automotive fan model is correct, obtaining the Simulink-based control algorithm software program code; integrating the code; and experimentally verifying the integrated code in an automotive controller. This method can achieve one-click compilation and linking of simulation models and different programs, solving the problem of manual conversion from algorithm simulation models to software code, thereby avoiding errors in later manual programming, ensuring the correctness of the generated software, improving software development efficiency, and ensuring that the generated software has modularity, hierarchy, clear logic functions, and strong readability. However, it only modularizes the fan and does not delve into the aerodynamic performance algorithm research of the actual fan model. To improve the accuracy of the flow field and temperature field analysis calculations in the vehicle engine compartment, and to avoid the time-consuming drawback of the RBM algorithm, further research is needed. CN112949224A discloses an optimization design method for a cooling fan of a small air-cooled internal combustion engine based on a response surface model. The method includes the following steps: S1, parametric design of a 3D fan model; S2, numerical simulation analysis of the cooling fan flow field, using CFD numerical simulation to analyze the fan flow field and obtain parameters such as static pressure, flow rate, and static pressure efficiency; S3, experimental testing to compare the simulation results and determine the reliability of the simulation analysis; S4, building a multi-objective optimization design platform for the fan based on Isight software, integrating the 3D digital design software CATIA and the numerical simulation analysis software ANSYS Workbench; S5, selecting the main geometric parameters of the fan blade structure as design variables, and experimentally designing the sample matrix using the optimal Latin hypercube method; S6, batch solving for sample point data of the response surface approximation model; S7, establishing an approximate response surface model based on the sample analysis data; S8, using a genetic algorithm to explore the optimal design of the cooling fan's geometric structure and find the optimal design. This method obtains the quantitative relationship between fan performance parameters and fan geometric structure parameters by establishing an approximate mathematical model of the response surface, and uses a genetic algorithm to obtain the optimal design of the cooling fan structure.This includes: parametrically designing a 3D model of the fan, numerically analyzing the fan flow field, obtaining fan performance parameters, and verifying them; selecting fan blade geometric parameters as design variables and fan performance parameters as output results, using the optimal Latin hypercube method for sample collection and experimental design, and conducting batch simulation analysis of the fan flow field; establishing a response surface approximation model based on the results data, using static pressure and flow rate as objective functions and static pressure efficiency as constraint functions, building a multi-objective optimization design platform for the fan, using the non-dominated sorting genetic algorithm (NSGA-II) to perform optimization analysis on the cooling fan structural parameters, and obtaining the optimal fan structural design scheme through the Pareto solution set. This is undoubtedly a valuable attempt in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a simulation analysis method, device, and storage medium for automotive fans, which can improve calculation accuracy while ensuring computational efficiency and accurately simulate the aerodynamic performance of the fan.

[0006] The simulation analysis method for automotive fans described in this invention includes the following steps:

[0007] S1. Establish a basic vehicle analysis model. The basic vehicle analysis model includes a fan core rotation region, a fan rotation effect influence region, a fan upstream buffer region, a fan downstream buffer region, and a mainstream fan local region. The mainstream fan local region is the boundary frame connected to the fan upstream buffer region and the fan downstream buffer region.

[0008] S2, Establish an independent fan analysis model, which includes the fan core rotation region, the fan rotation effect influence region, the upstream buffer region of the fan, and the downstream buffer region of the fan.

[0009] S3, establish the default vehicle analysis model for the fan, that is, remove the core rotation area of ​​the fan and the area affected by the fan rotation effect from the basic vehicle analysis model, and retain the upstream buffer area of ​​the fan, the downstream buffer area of ​​the fan and all other components;

[0010] S4, analyze and solve the basic vehicle analysis model to obtain the initial boundary of the fan independent analysis model and the first initial boundary of the fan default vehicle analysis model;

[0011] S5, the fan independent analysis model receives the initial boundary of the fan independent analysis model from the basic vehicle analysis model and analyzes and solves it to obtain the second initial boundary of the default vehicle analysis model of the fan;

[0012] S6. Import the first initial boundary and the second initial boundary of the default vehicle analysis model of the fan into the default vehicle analysis model of the fan, and analyze and solve to obtain the flow field information.

[0013] S7 uses a fan-independent analysis model and a default vehicle analysis model for the fan to perform multiple coupled calculations until convergence, resulting in the converged analysis results of the vehicle's flow field and temperature field.

[0014] Furthermore, the basic vehicle analysis model in S4 is analyzed and solved using the MRF algorithm.

[0015] Furthermore, in S5, the fan independent analysis model is analyzed and solved using the RBM algorithm. After the solution is completed, relevant physical quantity information is obtained by the field means operation. Time-averaging processing is performed through the field function to obtain the calculated physical quantities after time-averaging processing, and the second initial boundary of the default whole vehicle analysis model of the fan is derived.

[0016] Furthermore, in the fan independent analysis model in S2, the fan core rotation region is based on the region enveloping the fan blades.

[0017] Furthermore, the area affected by the fan rotation effect includes the periphery of the core fan rotation area, and the area affected by the fan rotation effect is connected to the upstream buffer area and the downstream buffer area of ​​the fan. The front side of the area affected by the fan rotation effect extends to the inner side of the front side of the fan frame, and the rear side of the area affected by the fan rotation effect includes the fan frame, the fan motor and the heat shield, extending as far as possible to the rear of the vehicle body to avoid interference with the rear engine compartment components of the fan.

[0018] Furthermore, both the upstream and downstream buffer areas of the fan are thin-layer structures with a thickness of 5–8 mm.

[0019] Furthermore, the fan core rotation region in the fan independent analysis model in S2 adopts the Rotation motion model, and data transmission between the fan core rotation region, the fan rotation effect influence region, the upstream buffer region and the downstream buffer region is established through the interface.

[0020] Furthermore, the initial boundary of the fan-independent analysis model in S4 includes the upstream initial boundary table and the downstream initial boundary table of the fan-independent analysis model; the first initial boundary of the fan-default vehicle analysis model in S4 includes the first upstream initial boundary table and the first downstream initial boundary table of the fan-default vehicle analysis model; the second initial boundary of the fan-default vehicle analysis model in S5 includes the second upstream initial boundary table and the second downstream initial boundary table of the fan-default vehicle analysis model.

[0021] Furthermore, the flow field information obtained in S6 is the upstream boundary table and the downstream boundary table of the fan-independent analysis model.

[0022] Furthermore, the coupling in S7 specifically involves: first, importing the flow field information, namely the upstream boundary table and the downstream boundary table of the fan independent analysis model, into the fan independent analysis model for analysis and solution, to obtain the upstream boundary table and the downstream boundary table of the fan default vehicle analysis model.

[0023] Then, the flow field information, the upstream boundary table of the fan's default vehicle analysis model, and the downstream boundary table of the fan's default vehicle analysis model are mixed and imported into the fan's default vehicle analysis model for analysis and solution, thereby realizing the coupled solution of the fan's independent analysis model and the fan's default vehicle analysis model.

[0024] A simulation analysis device for an automotive fan, capable of implementing the simulation analysis method for an automotive fan as described in this invention, includes: a model building module for building a basic vehicle analysis model, a fan-independent analysis model, and a default vehicle analysis model for the fan; and an analysis and solution module for analyzing and solving the basic vehicle analysis model, the fan-independent analysis model, and the default vehicle analysis model for the fan to obtain flow field information.

[0025] A storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the simulation analysis method for an automotive fan as described in this invention.

[0026] Compared with the prior art, the present invention has the following beneficial effects.

[0027] 1. Compared with existing MRF and RBM standalone algorithms, this invention can obtain high-precision fan aerodynamic performance while ensuring computational efficiency, providing a precise and reliable new method for accurately predicting cabin airflow and temperature distribution. The computation time is comparable to that of the industry MRF algorithm and about 1 / 6 of that of the RBM algorithm.

[0028] 2. The RBM quasi-steady-state algorithm used in this invention achieves over 95% of the accuracy of the full-model RBM transient algorithm, representing a significant improvement in computational accuracy compared to the MRF algorithm. This is because the RBM algorithm's mesh moves in real-time, realistically simulating fan blade rotation. The MRF model operates by applying mesh flux in a rotating reference frame, which is applied to regions including sector geometry. The fan's rotation effect is modeled through relative rotation between the rotating reference frame and the non-rotating global reference frame. The fan's absolute velocity is converted into a relative velocity formula, and the momentum equation within the rotating coordinate system is solved using the relative velocity. Therefore, for uneven back pressure conditions around the upstream and downstream regions of the fan, the rotation provided by the MRF model is insufficient, resulting in inaccurate capture of the airflow at the fan's upstream and downstream locations. The simulation analysis method for automotive fans proposed in this invention provides more accurate capture of the airflow at the fan's upstream and downstream locations, especially for the airflow regions at the top and bottom of the engine. For the previously difficult-to-solve problem of high risk of thermal static displacement of rear engine and the industry-wide problem of low material limits and high thermal protection risk of natural rubber components such as chassis components, suspension pads, various rubber bushings, and ball joints, practical and effective engineering solutions have been found.

[0029] 3. This invention imports the first and second initial boundaries of the default vehicle analysis model into the default vehicle analysis model, and analyzes and solves to obtain flow field information. Specifically, the flow field information obtained from the initial analysis of the default vehicle analysis model includes two parts: one part comes from the first initial boundary of the default vehicle analysis model obtained from the analysis of the basic vehicle analysis model, and the other part comes from the second initial boundary of the default vehicle analysis model obtained from the analysis of the independent fan analysis model. Theoretically, it is possible to perform calculations using only the flow field information derived from the independent fan analysis model, but the model calculation is unstable. By adjusting the flow field information mixing factor, the model becomes more stable and converges faster. Attached Figure Description

[0030] Figure 1 This is a flowchart illustrating the implementation of the present invention;

[0031] Figure 2 A half-section view of the fan region of the basic vehicle analysis model;

[0032] Figure 3 This is a cross-sectional view of the fan region in the mainstream area of ​​the basic vehicle analysis model;

[0033] Figure 4 This diagram illustrates the boundary data interaction between the fan-independent analysis model and the default vehicle analysis model for the fan.

[0034] Figure 5 This is a diagram showing the airflow distribution at the fan outlet.

[0035] Figure 6 This is a diagram of the fan exhaust airflow distribution using the conventional MRF algorithm.

[0036] In the diagram, 1—fan core rotation area, 2—fan rotation effect influence area, 3—upstream buffer area of ​​the fan, 4—downstream buffer area of ​​the fan, 5—local area of ​​the fan in the mainstream region. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0038] See Figure 1 The simulation analysis method for a car fan, as shown, includes the following steps:

[0039] S1. Import the 3D CAD data of the entire vehicle into STARCCM+ software. After geometric cleanup, establish a basic vehicle analysis model. See also... Figure 2 and Figure 3 The basic vehicle analysis model includes a fan core rotation region 1, a fan rotation effect influence region 2, a fan upstream buffer region 3, a fan downstream buffer region 4, and a mainstream fan local region 5. The mainstream fan local region 5 is the boundary frame connected to the fan upstream buffer region 3 and the fan downstream buffer region 4.

[0040] S2. Establish an independent fan analysis model, which includes a core fan rotation region, a fan rotation effect influence region, an upstream buffer region, and a downstream buffer region. The core fan rotation region is defined by the area enveloping the fan blades. The fan rotation effect influence region includes the periphery of the core fan rotation region and is connected to the upstream and downstream buffer regions via connecting surfaces. The front side of the fan rotation effect influence region extends towards the inner front side of the fan frame, and the rear side includes the fan frame, fan motor, and heat shield, extending as far as possible towards the rear of the vehicle body to avoid interference with the rear engine compartment components. Both the upstream and downstream buffer regions are thin-layer structures with a thickness of 5–8 mm.

[0041] The fan core rotation region shown adopts the Rotation motion model, and data transmission between the fan core rotation region, the fan rotation effect influence region, the upstream buffer region and the downstream buffer region is established through the interface.

[0042] S3. Establish the default vehicle analysis model for the fan, which means removing the core fan rotation area and the fan rotation effect area from the basic vehicle analysis model, while retaining the upstream buffer area, downstream buffer area, and all other components. In this way, the independent fan analysis model and the default vehicle analysis model for the fan both have the upstream and downstream buffer areas of the fan, which facilitates data exchange and coupling calculations in the later stages.

[0043] S4. The MRF algorithm is used to analyze and solve the basic vehicle analysis model to obtain the initial boundary of the fan-independent analysis model and the first initial boundary of the fan-default vehicle analysis model, namely the upstream initial boundary table of the fan-independent analysis model, the downstream initial boundary table of the fan-independent analysis model, the first upstream initial boundary table of the fan-default vehicle analysis model, and the first downstream initial boundary table of the fan-default vehicle analysis model. The initial boundary of the fan-independent analysis model is used as the initial boundary condition for the first analysis and calculation of the fan-independent analysis model, and the first initial boundary of the fan-default vehicle analysis model is used as the initial boundary condition of the fan-default vehicle analysis model.

[0044] S5, the fan independent analysis model receives the initial boundary of the fan independent analysis model from the basic vehicle analysis model and uses the RBM algorithm to analyze and solve it. After the solution is completed, the relevant physical quantity information is obtained according to the fieldmeans operation. The time-averaged processing is performed through the field function to obtain the calculated physical quantity after time-averaged processing, and the second initial boundary of the default vehicle analysis model of the fan is derived.

[0045] S6. Import the first and second initial boundaries of the fan-independent vehicle analysis model into the fan-independent vehicle analysis model. Establish relevant physical quantity functions through FieldFunction to achieve flow field information mixing. Analyze and solve to obtain flow field information, which includes the upstream boundary table and downstream boundary table of the fan-independent analysis model.

[0046] S7: First, import the flow field information, i.e., the upstream boundary table and downstream boundary table of the fan independent analysis model, into the fan independent analysis model for analysis and solution, to obtain the upstream boundary table and downstream boundary table of the default vehicle analysis model. Then, mix the flow field information, the upstream boundary table and downstream boundary table of the default vehicle analysis model, and import them into the default vehicle analysis model for analysis and solution, realizing the coupled solution of the fan independent analysis model and the default vehicle analysis model. Similarly, couple the flow field information obtained from the previous analysis and solution of the default vehicle analysis model with the upstream and downstream boundary tables of the default vehicle analysis model obtained from the analysis and solution of the fan independent analysis model based on this flow field information, and solve until convergence. That is, through multiple coupled solutions and calculations of the fan independent analysis model and the default vehicle analysis model until convergence, the converged vehicle flow field and temperature field analysis results are obtained. See [link to fan outlet velocity distribution] for details. Figure 5 Compared to conventional MRF algorithms used in the industry, fan exhaust... Figure 6 , Figure 5 The fan shown is calculated using a real fan rotation model, making the airflow closer to reality, the overall airflow more uniform, and the influence of the fan frame spokes more accurately.

[0047] A simulation analysis device for an automotive fan, capable of implementing the simulation analysis method for an automotive fan as described in this invention, includes: a model building module for building a basic vehicle analysis model, a fan-independent analysis model, and a default vehicle analysis model for the fan; and an analysis and solution module for analyzing and solving the basic vehicle analysis model, the fan-independent analysis model, and the default vehicle analysis model for the fan to obtain flow field information.

[0048] A storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the simulation analysis method for an automotive fan as described in this invention.

[0049] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A simulation analysis method for an automotive fan, characterized in that, Includes the following steps: S1. Establish a basic vehicle analysis model. The basic vehicle analysis model includes a fan core rotation region, a fan rotation effect influence region, a fan upstream buffer region, a fan downstream buffer region, and a mainstream fan local region. The mainstream fan local region is the boundary frame connected to the fan upstream buffer region and the fan downstream buffer region. S2, Establish an independent fan analysis model, which includes the fan core rotation region, the fan rotation effect influence region, the upstream buffer region of the fan, and the downstream buffer region of the fan. S3, establish the default vehicle analysis model for the fan, that is, remove the core rotation area of ​​the fan and the area affected by the fan rotation effect from the basic vehicle analysis model, and retain the upstream buffer area of ​​the fan, the downstream buffer area of ​​the fan and all other components; S4, analyze and solve the basic vehicle analysis model to obtain the initial boundary of the fan independent analysis model and the first initial boundary of the fan default vehicle analysis model; S5, the fan independent analysis model receives the initial boundary of the fan independent analysis model from the basic vehicle analysis model and analyzes and solves it to obtain the second initial boundary of the default vehicle analysis model of the fan; S6. Import the first initial boundary and the second initial boundary of the default vehicle analysis model of the fan into the default vehicle analysis model of the fan, and analyze and solve to obtain the flow field information. S7 uses a fan-independent analysis model and a default vehicle analysis model for the fan to perform multiple coupled calculations until convergence, resulting in the converged analysis results of the vehicle's flow field and temperature field.

2. The simulation analysis method for automotive fans according to claim 1, characterized in that: The basic vehicle analysis model in S4 is analyzed and solved using the MRF algorithm.

3. The simulation analysis method for an automotive fan according to claim 1 or 2, characterized in that: The fan independent analysis model in S5 is analyzed and solved using the RBM algorithm. After the solution is completed, relevant physical quantity information is obtained by the fieldmeans operation. The time-averaged process is performed through the field function to obtain the calculated physical quantity after time-averaged processing, and the second initial boundary of the default whole vehicle analysis model of the fan is derived.

4. The simulation analysis method for an automotive fan according to claim 1 or 2, characterized in that: The core rotation region of the fan in the fan independent analysis model in S2 is based on the region that encloses the fan blades.

5. The simulation analysis method for an automotive fan according to claim 1 or 2, characterized in that: The fan rotation effect area in S2 includes the periphery of the core fan rotation area, and the fan rotation effect area is connected to the upstream buffer area and the downstream buffer area of ​​the fan. The front side of the fan rotation effect area extends to the inner side of the front side of the fan frame, and the rear side of the fan rotation effect area includes the fan frame, the fan motor and the heat shield, extending as far as possible to the rear of the vehicle body to avoid interference with the rear engine compartment components of the fan.

6. The simulation analysis method for an automotive fan according to claim 1 or 2, characterized in that: Both the upstream and downstream buffer areas of the fan in S2 are thin-layer structures with a thickness of 5-8 mm.

7. The simulation analysis method for an automotive fan according to claim 1 or 2, characterized in that: The fan core rotation region in the fan independent analysis model in S2 adopts the Rotation motion model, and data transmission between the fan core rotation region, the fan rotation effect influence region, the upstream buffer region and the downstream buffer region is established through the interface.

8. The simulation analysis method for an automotive fan according to claim 1 or 2, characterized in that: The initial boundary of the fan-independent analysis model in S4 includes the upstream initial boundary table and the downstream initial boundary table of the fan-independent analysis model. The first initial boundary of the fan default vehicle analysis model in S4 includes the first upstream initial boundary table of the fan default vehicle analysis model and the first downstream initial boundary table of the fan default vehicle analysis model. The second initial boundary of the fan default vehicle analysis model in S5 includes the second upstream initial boundary table of the fan default vehicle analysis model and the second downstream initial boundary table of the fan default vehicle analysis model.

9. The simulation analysis method for an automotive fan according to claim 1 or 2, characterized in that, The flow field information obtained in S6 is the upstream boundary table and the downstream boundary table of the fan-independent analysis model.

10. The simulation analysis method for an automotive fan according to claim 9, characterized in that, The coupling in S7 specifically involves: first, importing the flow field information, namely the upstream boundary table and the downstream boundary table of the fan independent analysis model, into the fan independent analysis model for analysis and solution, to obtain the upstream boundary table and the downstream boundary table of the fan default vehicle analysis model. Then, the flow field information, the upstream boundary table of the fan's default vehicle analysis model, and the downstream boundary table of the fan's default vehicle analysis model are mixed and imported into the fan's default vehicle analysis model for analysis and solution, thereby realizing the coupled solution of the fan's independent analysis model and the fan's default vehicle analysis model.

11. A simulation analysis device for an automotive fan, characterized in that: The simulation analysis method for an automotive fan as described in any one of claims 1 to 10 includes: The model building module is used to build a basic vehicle analysis model, a fan-independent analysis model, and a fan-default vehicle analysis model. The analysis and solution module is used to analyze and solve the basic vehicle analysis model, the fan-independent analysis model, and the fan-default vehicle analysis model to obtain flow field information.

12. A storage medium, characterized in that: It stores computer execution instructions, which, when executed by a processor, are used to implement the simulation analysis method for an automotive fan as described in any one of claims 1 to 10.

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