Simulation evaluation method and system for wheel wind resistance and heat dissipation performance

Abstract

A method and system for simulating and evaluating wheel wind resistance and heat dissipation performance, the method comprising: simplifying a vehicle digital model in a manner that retains predetermined features of the vehicle digital model; then establishing a CFD wind resistance simulation analysis model and a wheel heat dissipation simulation analysis model; establishing a full-window wheel model and a large-window wheel model for wheels of predetermined wheel size, width, and tire type, importing these models into the CFD wind resistance simulation analysis model to analyze the wind resistance coefficient, and importing these two models into the wheel heat dissipation simulation model to analyze the heat dissipation performance; selecting the wind resistance coefficient of the full-window wheel as a minimum benchmark and the wind resistance coefficient of the large-window wheel as a maximum benchmark, evaluating wheels of the same wheel type with other design styles according to multiple wind resistance evaluation standards, and similarly evaluating the heat dissipation performance of the full-window wheel as the worst benchmark and the large-window wheel as the best benchmark, and similarly evaluating the heat dissipation performance according to multiple heat dissipation evaluation standards.

Description

Technical Field

[0001] The present invention belongs to the technical field of automobile aerodynamics, and in particular relates to a simulation evaluation method and system for wheel wind resistance and heat dissipation performance. Background Art

[0002] With energy and environmental issues becoming increasingly prominent and carbon emission requirements becoming increasingly stringent, energy conservation and emission reduction technologies have become a key focus of automotive development. Low-drag vehicle design, as a key method for reducing fuel and electrical energy consumption and improving driving range, is gaining increasing attention in the industry. Wheels, as a crucial component of a vehicle, can contribute 20%-30% of the vehicle's wind resistance, making low-drag wheel design a key requirement in automotive design. Traditional low-drag design methods rely on full-vehicle wind tunnel testing, which is time-consuming and costly, making it difficult to meet the rapidly accelerating demands of research and development. Using simulation methods for low-drag vehicle design can shorten R&D cycles and reduce costs, making it a crucial tool in the automotive development process.

[0003] Current methods for evaluating wheel drag primarily compare the changes in the vehicle's drag coefficient after installing different wheels. This approach, while complex in terms of vehicle modeling and computational complexity, also fails to provide a quantitative assessment of the wheel's drag performance. Furthermore, reducing the wheel's drag coefficient typically requires a reduction in the wheel's window area, which often compromises brake disc heat dissipation. However, currently, no simulation-based evaluation method exists for wheel heat dissipation performance. Summary of the Invention

[0004] To solve the above problems, the purpose of the present invention is to provide a simulation evaluation method and system for wheel wind resistance and heat dissipation performance, which can effectively take into account the evaluation of wheel wind resistance and heat dissipation performance.

[0005] According to one aspect of the present invention, a simulation evaluation method for wheel wind resistance and heat dissipation performance is provided, comprising the following modeling and simulation steps: simplifying the digital model of the entire vehicle in a manner that retains predetermined features of the digital model of the entire vehicle, including simplifying the digital model of the chassis and the digital model within the engine compartment; establishing a CFD wind resistance simulation analysis model and a wheel heat dissipation simulation analysis model based on the simplified entire vehicle model; establishing a full-window coverage wheel model and a large-window wheel model in which the wheel window area accounts for M / N of the wheel front face for wheels of predetermined wheel size, width, and tire model, importing the models into the CFD wind resistance simulation analysis model, and analyzing the drag coefficients of the two wheels, wherein M and N are natural numbers. , and the window-full-covered wheel model and the large-window wheel model are imported into the wheel heat dissipation simulation model to analyze the heat dissipation performance of the two wheels; the drag coefficient of the window-full-covered wheel is selected as the minimum value benchmark and the drag coefficient of the large-window wheel is selected as the maximum value benchmark, and the wheels of other design styles under the same wheel type are evaluated according to multiple levels of wind resistance evaluation standards; and the heat dissipation performance of the window-full-covered wheel is selected as the worst benchmark and the heat dissipation performance of the large-window wheel is selected as the best benchmark, and the wheels of other design styles under the same wheel type are evaluated according to multiple levels of heat dissipation evaluation standards.

[0006] Preferably, the method further includes the following evaluation step: importing the wheel digital model in the design to be evaluated into the CFD wind resistance simulation model and the wheel heat dissipation simulation model, calculating the wind resistance coefficient and the heat dissipation performance respectively, evaluating the wheel against the wind resistance evaluation standard and the heat dissipation evaluation standard, and selecting a wheel with better wind resistance and heat dissipation performance.

[0007] Preferably, the digital model simplification of the chassis includes: simplifying the digital model of the chassis, removing the axle and suspension structure, and retaining the brake disc structure; the digital model simplification of the engine compartment includes: simplifying the front-end module including the condenser porous medium, the radiator porous medium, the housing and the fan into a porous medium plate area, the size of the porous medium plate is consistent with the radiator; and simplifying the cylinder, gearbox and air filter that occupy a larger volume in the cabin into three rectangular blocks, so that the volume error of the corresponding original components is within 10 -4 m 3 Ignore the rest of the original internal parts.

[0008] Preferably, the establishment of the CFD wind resistance simulation analysis model includes: constructing a calculation domain with a length of 10 times the vehicle length, a width of 5.5 times the vehicle width, and a height of 5 times the vehicle height, placing the simplified vehicle model in the calculation domain for overall meshing, based on the finite volume method, selecting the RANS equation to calculate the model, selecting the Realizable K-Epsilon model as the turbulence model, selecting the Two-Layer All y+ as the wall function, setting the atmospheric pressure as the reference pressure, setting the boundary conditions of each wall in the calculation domain, setting the rotation speed of the wheel using the rotating wall method, setting the relative moving speed on the ground at a speed of 120 km / h, setting the normal inlet velocity at the inlet at a speed of 120 km / h, setting the outlet pressure to 0, setting the other surfaces of the calculation domain to symmetric planes, and finally discretizing the calculation domain.

[0009] Preferably, multiple wheels with different window area sizes are established, and the wind resistance simulation analysis model before simplification and the CFD wind resistance simulation analysis model are respectively imported for analysis and comparison, so as to verify that the vehicle model before and after simplification maintains consistency in the changing trend of the wind resistance coefficient of different wheels.

[0010] Preferably, the establishment of the wheel heat dissipation simulation analysis model includes: adding an energy equation on the basis of the CFD wind resistance simulation analysis model, extracting the brake disc surface mesh to establish a solid area, and analyzing the maximum temperature of the brake disc in a long downhill condition.

[0011] Preferably, the analysis of the drag coefficients of the two wheels includes: analyzing the drag coefficients of the two wheels, the window-full-covered wheel model and the large-window wheel model, at a predetermined driving speed of the vehicle, wherein the window-full-covered wheel model consists of a rim, a flange center hole and bolt holes, and the large-window wheel model consists of a rim, spokes, a window, a flange center hole and bolt holes.

[0012] Preferably, the analysis of the heat dissipation performance of the two wheels includes: analyzing the maximum temperature of the brake discs of the two wheels of the full-window coverage wheel model and the large-window wheel model when the vehicle is traveling at a speed of 10 m / s for 200 s under a long downhill condition with a slope of 10% and a slope length of 2 km.

[0013] Preferably, the step of evaluating with the wind resistance evaluation standard divided into multiple levels includes: based on the analysis of the wind resistance coefficients of the two wheels, setting the wind resistance coefficient Cd1 of the full-window covered wheel and the wind resistance coefficient Cd2 of the large-window wheel as reference values respectively, and then proportionally converting the wind resistance coefficient Cd of the wheel to be evaluated to obtain an equivalent value Cde of the wheel wind resistance coefficient, Cde=(Cd-Cd1) / (Cd2-Cd1), and dividing the Cde into multiple levels according to the different intervals from small to large, so as to evaluate the wind resistance level of the wheel to be evaluated under the same size conditions; the step of evaluating with the heat dissipation evaluation standard divided into multiple levels includes: based on the analysis of the heat dissipation performance of the two wheels, setting the maximum brake disc temperatures T1 and T2 of the full-window covered wheel and the large-window wheel as reference values respectively, and then proportionally converting the maximum brake disc temperature T of the wheel to be evaluated to obtain an equivalent value Te of the heat dissipation performance, Te= (T-T2) / (T1-T2) is divided into multiple levels according to the different intervals of Te from small to large, so as to evaluate the heat dissipation level of the wheel to be evaluated under the same size conditions.

[0014] According to another aspect of the present invention, a wheel wind resistance and heat dissipation performance simulation evaluation system is provided, which is used to implement any of the above-mentioned wheel wind resistance and heat dissipation performance simulation evaluation methods, including the following modules: a digital model simplification module, which simplifies the digital model of the entire vehicle in a manner that retains the predetermined features of the digital model of the entire vehicle, including the digital model simplification in the engine compartment and the digital model simplification of the chassis; a simulation modeling module, which establishes a CFD wind resistance simulation analysis model and a wheel heat dissipation simulation analysis model based on the simplified entire vehicle model; a coefficient analysis module, which establishes a window-covered wheel model and a large-window wheel model with a wheel window area accounting for M / N of the wheel front face for wheels of predetermined wheel size, width and tire model, and imports them into the CFD wind resistance simulation analysis model to analyze the drag coefficients of the two wheels, wherein M and N are natural numbers. , and the window-covered wheel model and the large-window wheel model are imported into the wheel heat dissipation simulation model to analyze the heat dissipation performance of the two wheels; an evaluation standard division module selects the wind resistance coefficient of the window-covered wheel as the minimum value benchmark and the wind resistance coefficient of the large-window wheel as the maximum value benchmark, and evaluates the wheels of other design styles under the same wheel type according to multiple wind resistance evaluation standards, and takes the heat dissipation performance of the window-covered wheel as the worst benchmark and the heat dissipation performance of the large-window wheel as the best benchmark, and evaluates the wheels of other design styles under the same wheel type according to multiple heat dissipation evaluation standards; a design evaluation module imports the wheel digital model in the design to be evaluated into the CFD wind resistance simulation model and the wheel heat dissipation simulation model, calculates the wind resistance coefficient and heat dissipation performance respectively, evaluates them against the wind resistance evaluation standard and the heat dissipation evaluation standard, and selects wheels with better wind resistance and heat dissipation performance.

[0015] The simulation evaluation method and system for wheel wind resistance and heat dissipation performance according to the present invention can effectively establish evaluation standards and quickly and appropriately optimize the wheel digital model under design. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 (A) and (B) are simplified schematic diagrams of the front-end module in the engine compartment according to an embodiment of the present invention.

[0017] Figure 2 This is a simplified schematic diagram of the cylinder, gearbox and air filter in the engine compartment according to an embodiment of the present invention.

[0018] Figure 3 (C) and (D) are simplified schematic diagrams of the chassis described in the embodiment of the present invention.

[0019] Figure 4 (E), (F), (G), and (H) are schematic diagrams of four wheel models with different window area sizes according to an embodiment of the present invention.

[0020] Figure 5 This is a schematic diagram of a wheel model with full window coverage according to an embodiment of the present invention.

[0021] Figure 6 This is a schematic diagram of a wheel model with a large window according to an embodiment of the present invention.

[0022] Figure 7 Schematic diagram of a wheel model to be evaluated according to an embodiment of the present invention.

[0023] Figure 8 The following schematically illustrates a simulation evaluation system for wheel wind resistance and heat dissipation performance according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The exemplary embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. The exemplary embodiments described below and shown in the accompanying drawings are intended to teach the principles of the present invention so that those skilled in the art can implement and use the present invention in several different environments and for several different applications. Therefore, the scope of protection of the present invention is defined by the appended claims, and the exemplary embodiments are not intended to be, and should not be considered to be, a restrictive description of the scope of protection of the present invention. Moreover, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not necessarily drawn in accordance with actual proportional relationships. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0025] Embodiments of the present invention can be applied to electronic devices, such as terminal devices, computer systems, and servers, and can operate with a wide variety of other general-purpose or specialized computing system environments or configurations. Examples of well-known terminal devices, computing systems, environments, and / or configurations suitable for use with terminal devices, computer systems, servers, and other electronic devices include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, microprocessor-based systems, set-top boxes, programmable consumer electronics, network personal computers, minicomputer systems, mainframe computer systems, and distributed cloud computing environments encompassing any of the foregoing. Terminal devices, computer systems, servers, and other electronic devices can be described in the general context of computer-executable instructions (such as program modules) executed by a computer system. Generally, program modules can include routines, programs, object programs, components, logic, data structures, and the like that perform specific tasks or implement specific abstract data types. Computer systems / servers can be implemented in distributed cloud computing environments, where tasks are performed by remote processing devices linked via a communication network. In distributed cloud computing environments, program modules can be located on local or remote computing system storage media, including storage devices.

[0026] The simulation evaluation method for wheel wind resistance and heat dissipation performance according to the present invention comprises the following steps:

[0027] A. Simplify the vehicle digital model while retaining its key features. This involves simplifying two key areas: the engine compartment and the chassis.

[0028] B. Based on the simplified vehicle model, establish a CFD (computational fluid dynamics) wind resistance simulation analysis model;

[0029] C. Based on the simplified vehicle model, establish a wheel heat dissipation simulation analysis model;

[0030] D. Create a fully covered wheel model and a large window wheel model where the window area accounts for M / N of the wheel front, for example, 6 / 7. These models are imported into a simplified wheel drag simulation analysis model to analyze the drag coefficients of these two wheels, where M and N are natural numbers. ;

[0031] E. Import the fully covered wheel and large window wheel models into the simplified wheel heat dissipation simulation model to analyze the heat dissipation performance of these two wheel types.

[0032] F. Using the full-coverage wheel's drag coefficient as the minimum and the large-window wheel's drag coefficient as the maximum, equivalent values of wheel drag performance were calculated. Wheels of the same design and style were then evaluated using a five-tier drag evaluation standard: good, better, medium, poor, and terrible.

[0033] G. Using the heat dissipation performance of fully covered wheels as the worst benchmark and the heat dissipation performance of large-window wheels as the best benchmark, equivalent values of wheel heat dissipation performance were calculated. Wheels of the same wheel type and design styles were also evaluated based on a five-level heat dissipation evaluation standard: good, better, medium, poor, and terrible.

[0034] H. For a wheel design, create a 3D digital model and import it into simplified wind resistance simulation models and heat dissipation simulation models. Calculate its wind resistance coefficient and heat dissipation performance, respectively. Evaluate it against the evaluation criteria and select a wheel with a low wind resistance coefficient and good heat dissipation performance.

[0035] The specific process of step A is as follows: Taking a compact car model as an example, the complete digital model of the car model is imported into the model processing software CATIA, and the digital model inside the engine compartment is simplified. The front-end modules such as the condenser porous medium, the radiator porous medium, the housing and the fan are simplified into a porous medium plate area. The size of the porous medium plate is consistent with that of the radiator, as shown in the figure. Figure 1; Simplify the cylinder, gearbox and air filter, which occupy a larger volume in the cabin, into three rectangular blocks, and ensure that their volumes are the same as the corresponding original components with an error of 10 -4 m 3 Ignore the rest of the original internal components, as shown in the figure Figure 2 ; Simplify the chassis digital model, remove the axle and suspension structure, and retain the brake disc structure, as shown in the figure Figure 3 .

[0036] The specific process of step B is as follows: first, construct a calculation domain with a length of 10 times the length of the vehicle, a width of 5.5 times the width of the vehicle, and a height of 5 times the height of the vehicle. Place the simplified vehicle model in the calculation domain and import it into the pre-processing software hypermesh for overall meshing. Based on the finite volume method, select the RANS equation to calculate the model, select the Realizable K-Epsilon model as the turbulence model, select Two-Layer All y+ as the wall function, set the atmospheric pressure as the reference pressure, set the boundary conditions of each wall in the calculation domain, set the rotation speed of the wheel using the rotating wall method, set the relative moving speed on the ground to 120km / h, set the normal inlet velocity at the inlet to 120km / h, set the outlet pressure to 0, and set the other surfaces of the calculation domain to symmetric planes. Discretize the calculation domain to obtain a simplified wheel wind resistance simulation analysis model for the whole vehicle. Taking a wheel with a size of 20×8.5 as an example, four wheels with different window area sizes are established, as shown in the diagram. Figure 4 As shown in the figure, the wheel window area accounts for 6 / 7, 4 / 7, 2 / 7 and 0 of the wheel front area respectively, which are imported into the vehicle wind resistance simulation analysis model before and after simplification for analysis and comparison. Through comparison and verification, it is ensured that the models before and after simplification maintain consistency in the changing trends of the wind resistance coefficients of different wheels.

[0037] The specific process in step C is as follows: Based on step B, the brake disc surface mesh is extracted to establish a solid area, a separated solid energy model is selected, the material is set to gray cast iron, a simplified wheel heat dissipation simulation analysis model of the entire vehicle is established, and the maximum temperature of the brake disc during a long downhill condition is analyzed. In this example, the long downhill condition is set to a slope of 10%, a slope length of 2km, and the maximum temperature of the brake disc during a driving time of 200s at a speed of 10m / s.

[0038] The specific process of step D is as follows: Taking a wheel with a size of 20×8.5 as an example, a window-covered wheel model is established, which is characterized by having no window and the wheel consisting of a rim, a flange center hole and bolt holes, such as Figure 5 As shown. A wheel model is established in which the window area accounts for 6 / 7 of the front area of the wheel, which is characterized by a large window. The wheel consists of a rim, a spoke, a window 1, a flange center hole and a bolt hole, as shown. Figure 6The two wheels are imported into a simplified wind resistance simulation analysis model to obtain their drag coefficients Cd1 and Cd2 at predetermined speeds. For example, when the vehicle is traveling at 120 km / h, the drag coefficients of the two wheels are 0.34 and 0.358, respectively.

[0039] The specific process in step E is as follows: the two wheels established in step D are imported into a simplified wheel heat dissipation simulation model, and the maximum temperatures of the brake discs of the two wheels are analyzed during a long downhill slope with a slope of 10% and a slope length of 2 km, with a speed of 10 m / s for 200 seconds. The maximum temperatures are 151°C and 233°C, respectively.

[0040] The specific process of step F is as follows: based on the calculation results of step D, the drag coefficients of the full-window covered wheel and the large-window wheel are set as 0.34 and 0.358 respectively as reference values, and then the drag coefficient Cd of the wheel to be evaluated is proportionally converted to obtain an equivalent value Cde of the wheel drag coefficient, Cde=(Cd-0.34) / (0.358-0.34). This value is used to provide a quantitative description of the wheel drag performance in the subsequent optimization process. On the other hand, the wheel drag performance is graded based on this value. The wheel drag performance is divided into multiple grades according to the different ranges of Cde from small to large. For example, according to Cde≤0.2, 0.2<Cde≤0.4, 0.4<Cde≤0.6, 0.6<Cde≤0.8, and 0.8<Cde, it is divided into five grades: good, better, medium, poor, and poor, thereby evaluating the drag level of the wheel under the same size conditions.

[0041] The specific process in step G is as follows: based on the calculation results of step E, the maximum brake disc temperatures of 233°C and 151°C for the fully windowed wheel and the large window wheel are respectively set as reference values, and then the maximum brake disc temperature T of the wheel to be evaluated is proportionally converted to obtain an equivalent value Te of the heat dissipation performance, Te=(T-151) / (233-151). The role of this value is, on the one hand, to provide a quantitative description of the wheel heat dissipation performance in the subsequent optimization process, and on the other hand, based on this value, the wheel heat dissipation performance is graded into multiple grades according to the different intervals of Te from small to large, for example, according to Te≤0.2, 0.2<Te≤0.4, 0.4<Te≤0.6, 0.6<Te≤0.8, and 0.8<Te, it is divided into five grades: good, better, medium, poor, and bad, thereby evaluating the heat dissipation level of the wheel under the same size conditions.

[0042] This example takes a 20×8.5 wheel as an example. Figure 7As shown, it is imported into the wind resistance and heat dissipation simulation model for calculation, and its wind resistance coefficient and brake disc maximum temperature are obtained to be 0.343 and 170°C respectively. After conversion, it can be obtained that the Cde and Te of the wheel are 0.167 and 0.23 respectively. The wind resistance performance of the wheel is good and the heat dissipation performance is relatively good, which meets the development requirements.

[0043] According to this embodiment, a simulation evaluation system for wheel wind resistance and heat dissipation performance is provided. Figure 8 As shown, the simulation evaluation method for realizing the above-mentioned wheel wind resistance and heat dissipation performance includes the following modules: a digital model simplification module, which simplifies the digital model of the whole vehicle in a manner of retaining the predetermined features of the digital model of the whole vehicle, including the digital model simplification in the engine compartment and the digital model simplification of the chassis; a simulation modeling module, which establishes a CFD wind resistance simulation analysis model and a wheel heat dissipation simulation analysis model based on the simplified whole vehicle model; a coefficient analysis module, which establishes a window-covered wheel model and a large-window wheel model with a wheel window area accounting for M / N of the wheel front face for wheels of predetermined wheel size, width and tire model, and imports them into the CFD wind resistance simulation analysis model to analyze the wind resistance coefficients of the two wheels, wherein M and N are natural numbers. , and the wheel models with fully covered wheel windows and the wheel models with large windows are imported into the simplified wheel heat dissipation simulation model to analyze the heat dissipation performance of the two wheels; an evaluation standard division module selects the wind resistance coefficient of the wheel with fully covered windows as the minimum value benchmark and the wind resistance coefficient of the wheel with large windows as the maximum value benchmark, and evaluates the wheels of other design styles under the same wheel type according to multiple levels of wind resistance evaluation standards, and takes the heat dissipation performance of the wheel with fully covered windows as the worst benchmark and the heat dissipation performance of the wheel with large windows as the best benchmark, and evaluates the wheels of other design styles under the same wheel type according to multiple levels of heat dissipation evaluation standards; a design evaluation module imports the wheel digital model in the design to be evaluated into the CFD wind resistance simulation model and the wheel heat dissipation simulation model, calculates its wind resistance coefficient and heat dissipation performance respectively, evaluates them against the wind resistance evaluation standard and the heat dissipation evaluation standard, and selects wheels with better wind resistance and heat dissipation performance.

[0044] It's also worth noting that the operating process of the wheel wind resistance and heat dissipation performance simulation evaluation device provided in this embodiment is identical to the operating process of the wheel wind resistance and heat dissipation performance simulation evaluation method described above, and will not be further elaborated here. The method and device of this disclosure may be implemented in a variety of ways. For example, the method and device of this disclosure may be implemented using software, hardware, firmware, or any combination of software, hardware, or firmware. Terms such as "A-H" in the embodiments of this disclosure are used solely to distinguish different steps, devices, or modules, and do not represent any specific technical meanings or necessarily indicate a logical order between them, unless otherwise specified. For example, the order between steps B and C, between steps D and E, and between steps F and G is not limited to a specific sequence. Furthermore, in some embodiments, the present disclosure may be implemented as a program recorded on a recording medium, comprising machine-readable instructions for implementing the method of this disclosure. Therefore, this disclosure also covers recording media storing programs for executing the method of this disclosure. It should also be noted that in the device and method of this disclosure, the components or steps may be decomposed and / or recombined. Such decompositions and / or recombinations shall be considered equivalents of this disclosure. The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein. It will be appreciated by those skilled in the art that, although the present invention has been described with reference to various specific embodiments, it will be understood that variations may be made within the spirit and scope of the described inventive concepts. Therefore, it is intended that the present invention is not limited to the described embodiments, but will have the full scope defined by the language of the appended claims.

Claims

1. A simulation evaluation method for wheel wind resistance and heat dissipation performance, characterized in that: It includes the following steps of modeling and simulation: The digital model of the whole vehicle is simplified in a way that preserves the predetermined features of the digital model of the whole vehicle, including the digital model simplification of the chassis and the digital model simplification inside the engine compartment; Based on the simplified digital model of the whole vehicle, a CFD air resistance simulation analysis model and a wheel heat dissipation simulation analysis model are established; For wheels with a predetermined wheel type size, width and tire model, a window-full-coverage wheel model and a large-window wheel model with the window area of the wheel accounting for M / N of the front of the wheel are established, and are imported into the CFD air resistance simulation analysis model to analyze the air resistance coefficients of these two types of wheels. Among them, M and N are natural numbers, N / 2 < M < N. And the window-full-coverage wheel model and the large-window wheel model are imported into the wheel heat dissipation simulation analysis model to analyze the heat dissipation performance of these two types of wheels; Select the air resistance coefficient of the window-full-coverage wheel as the minimum value benchmark and the air resistance coefficient of the large-window wheel as the maximum value benchmark to evaluate the air resistance evaluation criteria for wheels with other design styles under the same wheel type in multiple grades. And select the heat dissipation performance of the window-full-coverage wheel as the worst benchmark and the heat dissipation performance of the large-window wheel as the best benchmark to evaluate the heat dissipation evaluation criteria for wheels with other design styles under the same wheel type in multiple grades. The digital model simplification of the chassis includes: simplifying the digital model of the chassis by removing the axle and suspension structure and retaining the brake disc structure; the digital model simplification of the engine compartment includes: simplifying the front-end module including the condenser porous medium, the radiator porous medium, the housing and the fan into a porous medium plate area, the size of the porous medium plate is consistent with the radiator; and simplifying the cylinder, gearbox and air filter, which occupy a larger volume in the compartment, into three rectangular blocks, so that the volume error of the corresponding original components is within 10 -4 m 3 Ignore the rest of the original internal parts.

2. The simulation evaluation method for wheel wind resistance and heat dissipation performance according to claim 1, characterized in that: It also includes the following evaluation steps: Import the digital model of the wheels in the design to be evaluated into the CFD air resistance simulation analysis model and the wheel heat dissipation simulation analysis model, calculate the air resistance coefficient and the heat dissipation performance respectively, evaluate according to the air resistance evaluation criteria and the heat dissipation evaluation criteria, and select the wheels with better air resistance performance and heat dissipation performance.

3. The simulation evaluation method for wheel wind resistance and heat dissipation performance according to claim 1 or 2, characterized in that: The establishment of the CFD air resistance simulation analysis model includes: Constructing a computational domain with a length of 10 times the vehicle length, a width of 5.5 times the vehicle width, and a height of 5 times the vehicle height. Place the simplified digital model of the whole vehicle in this computational domain for overall grid division. Based on the finite volume method, select the RANS equation to calculate the model. The turbulence model selects the Realizable K-Epsilon model, the wall function selects the Two-Layer All y+, the reference pressure is set to atmospheric pressure, set the boundary conditions of each wall surface in the computational domain, the wheels are set with rotational wall speed using the rotating wall method, the ground is set with a relative moving speed of 120 km / h, the inlet is set with a normal inlet speed of 120 km / h, the outlet pressure is set to 0, and the other surfaces of the computational domain are set as symmetric planes. Finally, the computational domain is discretized.

4. The simulation evaluation method for wheel wind resistance and heat dissipation performance according to claim 3, characterized in that: Multiple wheels with different window area sizes are established and are respectively imported into the air resistance simulation analysis model before simplification and the CFD air resistance simulation analysis model for analysis and comparison, and verification is carried out in a way that the change trends of the air resistance coefficients of the digital models of the whole vehicle before and after simplification are kept consistent.

5. The simulation evaluation method for wheel wind resistance and heat dissipation performance according to claim 1, characterized in that: The establishment of the wheel heat dissipation simulation analysis model includes: On the basis of the CFD air resistance simulation analysis model, extract the surface grid of the brake disc to establish a solid region and analyze the highest temperature of the brake disc in the long downhill condition.

6. The simulation evaluation method for wheel wind resistance and heat dissipation performance according to claim 5, characterized in that: The analysis of the aerodynamic drag coefficients of these two types of wheels includes: analyzing the aerodynamic drag coefficients of the full-window-covered wheel model and the large-window wheel model when the vehicle is traveling at a predetermined speed. Among them, the full-window-covered wheel model consists of a rim, a flange center hole, and bolt holes, and the large-window wheel model consists of a rim, spokes, a window, a flange center hole, and bolt holes.

7. The simulation evaluation method for wheel wind resistance and heat dissipation performance according to claim 5, characterized in that: The analysis of the heat dissipation performance of these two types of wheels includes: analyzing the maximum temperature of the brake disc during the process when the vehicle speed is 10 m / s for 200 s under the long downhill condition with a slope of 10% and a slope length of 2 km for the full-window-covered wheel model and the large-window wheel model.

8. The simulation evaluation method for wheel wind resistance and heat dissipation performance according to any one of claims 5 to 7, characterized in that: The steps for evaluating according to the multi-graded aerodynamic drag evaluation criteria include: based on the analysis of the aerodynamic drag coefficients of these two types of wheels, respectively setting the aerodynamic drag coefficient Cd1 of the full-window-covered wheel and the aerodynamic drag coefficient Cd2 of the large-window wheel as reference values, and then performing proportional conversion on the aerodynamic drag coefficient Cd of the wheel to be evaluated to obtain the equivalent value Cde of the aerodynamic drag coefficient of the wheel, Cde = (Cd - Cd1) / (Cd2 - Cd1), and dividing it into multiple grades according to the different intervals from small to large where Cde belongs, so as to evaluate the aerodynamic drag level of the wheel to be evaluated under the condition of the same size; the steps for evaluating according to the multi-graded heat dissipation evaluation criteria include: based on the analysis of the heat dissipation performance of these two types of wheels, respectively setting the maximum temperature T1 and T2 of the brake disc of the full-window-covered wheel and the large-window wheel as reference values, and then performing proportional conversion on the maximum temperature T of the brake disc of the wheel to be evaluated to obtain the equivalent value Te of the heat dissipation performance, Te = (T - T2) / (T1 - T2), and dividing it into multiple grades according to the different intervals from small to large where Te belongs, so as to evaluate the heat dissipation level of the wheel to be evaluated under the condition of the same size.

9. A wheel wind resistance and heat dissipation performance simulation evaluation system, used to implement the wheel wind resistance and heat dissipation performance simulation evaluation method according to any one of claims 1 to 8, characterized in that: It includes the following modules: A digital model simplification module, which simplifies the vehicle digital model in a way that retains the predetermined features of the vehicle digital model, including the digital model simplification in the engine compartment and the digital model simplification of the chassis; A simulation modeling module, which establishes a CFD aerodynamic drag simulation analysis model and a wheel heat dissipation simulation analysis model based on the simplified vehicle model; A coefficient analysis module, which, for wheels with a predetermined wheel type size, width, and tire model, establishes a full-window-covered wheel model and a large-window wheel model with the window area of the wheel accounting for M / N of the front of the wheel, imports them into the CFD aerodynamic drag simulation analysis model, and analyzes the aerodynamic drag coefficients of these two types of wheels. Among them, M and N are natural numbers, N / 2 < M < N, and the full-window-covered wheel model and the large-window wheel model are imported into the wheel heat dissipation simulation analysis model to analyze the heat dissipation performance of these two types of wheels; An evaluation standard classification module selects the drag coefficient of the fully covered window wheel as the minimum benchmark and the drag coefficient of the large window wheel as the maximum benchmark, and evaluates wheels of the same wheel type with other design styles according to multiple levels of wind resistance evaluation standards. In addition, the heat dissipation performance of the fully covered window wheel is the worst benchmark and the heat dissipation performance of the large window wheel is the best benchmark, and evaluates wheels of the same wheel type with other design styles according to multiple levels of heat dissipation evaluation standards. A design evaluation module imports the wheel digital model in the design to be evaluated into the CFD wind resistance simulation analysis model and the wheel heat dissipation simulation analysis model, calculates the wind resistance coefficient and heat dissipation performance respectively, evaluates them against the wind resistance evaluation standard and the heat dissipation evaluation standard, and selects wheels with better wind resistance and heat dissipation performance.

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