Vehicle waterproof performance simulation test method and related device

Abstract

The invention discloses a vehicle waterproof performance simulation test method and a related device, and aims to simulate an exterior trim, a metal plate, an assembly gap of each component and the like of a vehicle by aiming at the fact that a whole vehicle geometric model is obtained based on the shape and the material of the vehicle. A simulation test environment is established based on an actual test environment, the actual test environment is a test environment for simulating a raining scene based on water drops sprayed by a nozzle, and the simulation test environment is a simulation test scene for the actual test environment. The pressure, the viscous force, the surface tension and the gravity of the simulation test environment are obtained, so that the moving track of each water drop sprayed by a nozzle in the simulation test environment on the whole vehicle geometric model is determined based on the pressure, the viscous force, the surface tension and the gravity, and then the whole vehicle geometric model is determined based on the moving track of each water drop on the whole vehicle geometric model. And determining the waterproof performance of the vehicle. The waterproof performance of the vehicle is determined based on the simulation mode, simulation testing can be carried out in the design and development stage, and therefore the water management problem can be effectively found in time.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control, and in particular to a vehicle waterproof performance simulation test method and related devices. Background Art

[0002] Vehicle water management is a comprehensive study of water flow paths, sealing performance, and component waterproofing properties in a variety of scenarios such as rain, wading, water pollution, car washing, and film pasting. It is a necessary link and key indicator in the vehicle development process, and it is also one of the performances that are closest to consumers. Therefore, vehicle water management research is of great significance in the vehicle development process.

[0003] In the related art, the empirical design method and / or experimental verification method are generally used to study the water management of the whole vehicle, but the empirical design method is too dependent on the experience of engineers and has poor reliability. Although the experimental verification method has improved reliability, this method is in the late stage of vehicle development and cannot timely and effectively discover water management problems in the design and development stage so as to propose corresponding solutions in a targeted manner. Summary of the invention

[0004] In response to the above problems, the present application provides a vehicle waterproof performance simulation test method and related devices, which are specifically manifested as a water management simulation test method and technology for the whole vehicle under rain conditions, which are used to timely and effectively discover water management problems in the design and development stage, so as to propose corresponding solutions in a targeted manner.

[0005] Based on this, the embodiments of the present application disclose the following technical solutions:

[0006] On the one hand, an embodiment of the present application provides a vehicle waterproof performance simulation test method, the method comprising:

[0007] Based on the shape and material of the vehicle, obtaining a whole vehicle geometric model for the vehicle;

[0008] A simulation test environment is established based on an actual test environment, wherein the actual test environment simulates a rain scene based on a nozzle spraying water droplets, so as to test the waterproof performance of the vehicle in the rain scene, and the simulation test environment includes a nozzle model and a calculation domain, wherein the nozzle model is used to simulate the spray effect of the nozzle, and the calculation domain is used to simulate the actual test environment;

[0009] Obtaining the pressure, viscosity, surface tension and gravity of the simulation test environment, wherein the pressure is used to describe the pressure of the calculation domain, the viscosity is used to describe the viscosity of water and air to the vehicle, and the surface tension is used to describe the surface tension between water and air;

[0010] Determining the running track of each water droplet sprayed by the nozzle on the geometric model of the whole vehicle based on the pressure, the viscous force, the surface tension and the gravity;

[0011] The waterproof performance of the vehicle is determined based on the running trajectories of the water droplets on the geometric model of the whole vehicle.

[0012] Optionally, determining the running trajectory of each water droplet sprayed by the nozzle on the geometric model of the whole vehicle based on the pressure, the viscous force, the surface tension and the gravity includes:

[0013] Based on the pressure, the viscous force, the surface tension and the gravity, the acceleration of the target water droplet ejected from the nozzle at the target time is calculated as follows:

[0014]

[0015] Among them, v i represents the speed of the target water drop, t represents the target time, and p i represents the pressure, that is, the pressure of the target water drop, τ i represents the viscous force, i.e., the viscous stress tensor of the target water droplet, ρ i represents the density of the target water droplet, Φ i represents the surface tension, that is, the surface tension tensor of the target water droplet, f i represents the gravity, that is, the volume force of the target water droplet;

[0016] Taking each water droplet ejected by the nozzle as the target water droplet, and obtaining the acceleration of each water droplet ejected by the nozzle;

[0017] According to the acceleration of each water droplet sprayed by the nozzle, the running track of each water droplet sprayed by the nozzle on the geometric model of the whole vehicle is determined.

[0018] Optionally, the viscous stress tensor of the target water droplet is determined as follows:

[0019]

[0020] Among them, μ s is the shear viscosity coefficient, μ b is the volume viscosity coefficient.

[0021] Optionally, the shear viscosity coefficient is 0.001 Pa·s, and the volume viscosity coefficient is 0.003 Pa·s.

[0022] Optionally, the surface tension tensor of the target water droplet is determined as follows:

[0023]

[0024] Among them, x ij represents the distance between the target water droplet and other water droplets, σ ​​represents the surface tension coefficient, ω represents the smooth kernel function, and h represents the smooth length of the smooth kernel function.

[0025] Optionally, the quality of the water droplets sprayed by the nozzle is determined as follows:

[0026]

[0027] Optionally, the simulation test environment is used to simulate a four-sided shower condition;

[0028] The length of the calculation domain is 7 meters, the width of the calculation domain is 4 meters, and the height of the calculation domain is 3 meters; the nozzle model includes a plurality of nozzles, the diameter of the nozzle is 3 mm, the spraying angle of the nozzle is 60 degrees, and the flow rate of the nozzle is 10 liters per minute;

[0029] The number of nozzles located above and below the calculation domain is 84 respectively, and the arrangement is 14 rows of nozzles in the x direction and 6 rows of nozzles in the y direction. The spacing between the nozzles in the x direction and the y direction is 400 mm respectively. The height of the nozzles located above the calculation domain from the ground is 2450 mm, and the height of the nozzles located below the calculation domain from the ground is -50 mm.

[0030] There are 84 nozzles on the left and right sides of the calculation domain, respectively, and the arrangement is 14 rows of nozzles in the x-direction and 6 rows of nozzles in the z-direction. The spacing between the nozzles in the x-direction is 400 mm, and the spacing between the nozzles in the z-direction is 300 mm. The height of the nozzles in the lowest row from the ground is 500 mm, and the spacing between the nozzles on the left and the nozzles on the right is 3000 mm.

[0031] On the other hand, the present application provides a vehicle waterproof performance simulation test device, the device comprising: an acquisition unit, an establishment unit and a determination unit;

[0032] The acquisition unit is used to acquire a whole vehicle geometric model for the vehicle based on the shape and material of the vehicle;

[0033] The establishment unit is used to establish a simulation test environment based on an actual test environment, wherein the actual test environment simulates a rain scene based on a nozzle spraying water droplets, so as to test the waterproof performance of the vehicle in the rain scene, and the simulation test environment includes a nozzle model and a calculation domain, wherein the nozzle model is used to simulate the spray effect of the nozzle, and the calculation domain is used to simulate the actual test environment;

[0034] The acquisition unit is further used to acquire the pressure, viscosity, surface tension and gravity of the simulation test environment, wherein the pressure is used to describe the pressure of the calculation domain, the viscosity is used to describe the viscosity of water and air to the vehicle, and the surface tension is used to describe the surface tension between water and air;

[0035] The determining unit is used to determine the running track of each water droplet sprayed by the nozzle on the geometric model of the whole vehicle based on the pressure, the viscous force, the surface tension and the gravity;

[0036] The determination unit is further used to determine the waterproof performance of the vehicle based on the running tracks of the various water droplets on the geometric model of the whole vehicle.

[0037] Optionally, the determining unit is specifically configured to:

[0038] Based on the pressure, the viscous force, the surface tension and the gravity, the acceleration of the target water droplet ejected from the nozzle at the target time is calculated as follows:

[0039]

[0040] Among them, v i represents the speed of the target water drop, t represents the target time, and p i represents the pressure, that is, the pressure of the target water drop, τ i represents the viscous force, i.e., the viscous stress tensor of the target water droplet, ρ i represents the density of the target water droplet, Φ i represents the surface tension, that is, the surface tension tensor of the target water droplet, f i represents the gravity, that is, the volume force of the target water droplet;

[0041] Taking each water droplet ejected by the nozzle as the target water droplet, and obtaining the acceleration of each water droplet ejected by the nozzle;

[0042] According to the acceleration of each water droplet sprayed by the nozzle, the running track of each water droplet sprayed by the nozzle on the geometric model of the whole vehicle is determined.

[0043] Optionally, the determining unit is further used to determine the viscous stress tensor of the target water droplet, and the calculation method is as follows:

[0044]

[0045] Among them, μ s is the shear viscosity coefficient, μ b is the volume viscosity coefficient.

[0046] Optionally, the shear viscosity coefficient is 0.001 Pa·s, and the volume viscosity coefficient is 0.003 Pa·s.

[0047] Optionally, the determining unit is further used to determine the surface tension tensor of the target water droplet, and the calculation method is as follows:

[0048]

[0049] Among them, x ij represents the distance between the target water droplet and other water droplets, σ ​​represents the surface tension coefficient, ω represents the smooth kernel function, and h represents the smooth length of the smooth kernel function.

[0050] Optionally, the determination unit is further used to determine the mass of water droplets sprayed from the nozzle, and the calculation method is as follows:

[0051]

[0052] Optionally, the simulation test environment is used to simulate four-sided shower conditions.

[0053] In another aspect, the present application provides a computer device, the device comprising a processor and a memory:

[0054] The memory is used to store program code and transmit the program code to the processor;

[0055] The processor is used to execute the method described in the above aspects according to the instructions in the program code.

[0056] On the other hand, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method described in the above aspects.

[0057] On the other hand, an embodiment of the present application provides a computer program product or a computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the method described in the above aspects.

[0058] The advantages of the above technical solution of this application are:

[0059] The vehicle geometry model is based on the shape and material of the vehicle, and can simulate the vehicle's exterior, sheet metal, assembly gaps of various components, etc. A simulation test environment is established based on the actual test environment. The actual test environment is a test environment based on the spray of water droplets from the nozzle to simulate the rain scene. The simulation test environment is a simulation test scene of the actual test environment. The pressure, viscosity, surface tension and gravity of the simulation test environment are obtained, and then the running trajectories of each water droplet sprayed by the nozzle in the simulation test environment on the vehicle geometry model are determined based on the pressure, viscosity, surface tension and gravity, and then the waterproof performance of the vehicle is determined based on the running trajectories of each water droplet on the vehicle geometry model.

[0060] Therefore, a simulation test environment consistent with the actual test environment and a vehicle geometry model consistent with the actual vehicle are established through simulation, the vehicle geometry model is placed in the simulation test environment, and water droplets are sprayed to the vehicle geometry model through a nozzle, so as to determine the vehicle's waterproof performance based on the running trajectory of each water droplet on the vehicle geometry model. By determining the vehicle's waterproof performance based on the simulation method, simulation tests can be performed in the design and development stage, so as to timely and effectively discover water management problems so as to propose corresponding solutions in a targeted manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0062] Figure 1 A flow chart of a vehicle waterproof performance simulation test method provided in an embodiment of the present application;

[0063] Figure 2 A schematic diagram of a simulation test environment provided for this application;

[0064] Figure 3 A schematic diagram of a nozzle provided for this application;

[0065] Figure 4 A schematic diagram of a process for solving the trajectory of a water droplet provided in the present application;

[0066] Figure 5 A schematic diagram of the water intake of an air conditioner provided for this application;

[0067] Figure 6 A schematic diagram of an air conditioning water inlet path provided in this application;

[0068] Figure 7A schematic diagram of a vehicle waterproof performance simulation test device provided in an embodiment of the present application;

[0069] Figure 8 A structural diagram of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0070] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0071] Combine the following Figure 1 , a vehicle waterproof performance simulation test method provided in an embodiment of the present application is introduced. Figure 1 The method shown in the figure, in one implementation, can be executed by a device such as an electronic control unit (ECU) or a server included in a vehicle. Figure 1 , this figure is a flow chart of a vehicle waterproof performance simulation test method provided in an embodiment of the present application, and the method may include S101-S105.

[0072] S101: Based on the shape and material of the vehicle, a whole vehicle geometric model is obtained.

[0073] The vehicle geometry model is a simulation of a real vehicle. It can simulate the exterior, sheet metal, and assembly gaps of various components of a real vehicle so that when water droplets fall, it can be tested whether the water droplets will flow into the air conditioner, pressure relief valve, water collection tank, and other parts.

[0074] As a possible implementation method, the vehicle can be modeled using software such as Catia to obtain Figure 2 The vehicle shown in is the whole vehicle geometry model. As a possible implementation method, only the modules that need to be tested can be included in the process of modeling the vehicle. For example, if only water is detected in the air conditioner, the whole vehicle geometry model obtained by modeling can only include the air conditioner module of the vehicle to reduce modeling time and cost.

[0075] It should be noted that different types of vehicles have different shapes and materials, so they generally correspond to different vehicle geometric models.

[0076] S102: Establishing a simulation test environment based on the actual test environment.

[0077] The actual test environment is used to simulate the rain scene that the vehicle may encounter during actual use. It is understandable that the actual test environment may be more severe than the rain scene that the vehicle may encounter during actual use. The actual test environment simulates the rain scene based on the way the nozzle sprays water droplets, thereby testing the waterproof performance of the vehicle in the rain scene.

[0078] Among them, the rain scene is the most common water management scene, which can be subdivided into top shower conditions, four-sided shower conditions and five-sided shower conditions. In the rain scene, we can study whether water enters the air inlet of the air conditioner, whether the water flow in the sump is unobstructed, whether water enters the passenger compartment, whether water accumulates on the threshold, whether water drips into the trunk when the tailgate is opened, and other issues.

[0079] The simulation test environment is used to simulate the actual test environment. The waterproof performance of the vehicle geometry model in the rain scenario tested in the simulation test environment can be compared with the waterproof performance of the actual vehicle in the rainforest scenario of the actual test environment, so as to adjust the simulation test environment and improve its reliability. In the future, the waterproof performance of the vehicle geometry model in the rain scenario tested in the simulation test environment can be used as a reference for the waterproof performance of the actual vehicle, so as to conduct simulation tests in the design and development stage, and then timely and effectively discover water management problems, so as to propose corresponding solutions in a targeted manner.

[0080] The simulation test environment includes a nozzle model and a computational domain. The nozzle model is used to simulate the spraying effect of the nozzle, and the computational domain is used to simulate the actual test environment. As a possible implementation method, if the actual test environment is used to simulate the four-sided shower condition, the simulation test environment can simulate and build an environment that is the same as the actual test environment. The following is an example of the simulation test environment.

[0081] The calculation domain refers to the experimental rain shower room in the actual test environment, whose length, width and height are 7 meters, 4 meters and 3 meters respectively. Figure 2 The vehicle geometry model is located in the computational domain. To simulate the four-sided showering condition, the four sides of the computational domain are equipped with nozzles. The nozzle diameter is 3 mm, the spraying angle is 60 degrees, and the flow rate is 10 liters per minute. Figure 3 shown.

[0082] The number of nozzles located above the computational domain (i.e., the surface corresponding to the top of the vehicle geometry model) is 84, and the number of nozzles located below the computational domain (i.e., the surface corresponding to the bottom of the vehicle geometry model) is 84. Above and below the computational domain, the nozzles are arranged in 14 rows in the x direction (i.e., the direction of the long side of the computational domain) and 6 rows in the y direction (i.e., the direction of the short side of the computational domain). The spacing between the nozzles in the x and y directions is 400 mm respectively. The height of the nozzles above the computational domain from the ground is 2450 mm, and the height of the nozzles below the computational domain from the ground is -50 mm.

[0083] The number of nozzles located on the left side of the computational domain (i.e., the surface corresponding to the left side of the vehicle geometry model) is 84, and the number of nozzles located on the right side of the computational domain (i.e., the surface corresponding to the right side of the vehicle geometry model) is 84. On the left and right sides of the computational domain, the nozzles are arranged in 14 rows in the x direction and 6 rows in the z direction (i.e., the direction where the high side of the computational domain is located). The spacing between the nozzles in the x direction is 400 mm, the spacing between the nozzles in the z direction is 300 mm, the height of the nozzles in the lowest row from the ground is 500 mm, and the spacing between the nozzles on the left and the nozzles on the right is 3000 mm.

[0084] S103: Obtaining pressure, viscosity, surface tension and gravity of the simulation test environment.

[0085] Among them, pressure is used to describe the pressure in the calculation domain, viscosity is used to describe the viscosity of water and air to the vehicle, and surface tension is used to describe the surface tension between water and air.

[0086] S104: Based on pressure, viscosity, surface tension and gravity, determine the running trajectory of each water droplet sprayed from the nozzle on the geometric model of the whole vehicle.

[0087] The momentum equation of water droplets in the computational domain can be established based on computational fluid dynamics. Among them, the trajectory of water droplets is related to pressure, and the pressure in the computational domain can be adjusted so that it can simulate raindrops falling in the atmosphere in a rain scene. It is also necessary to consider the characteristics of the liquid, that is, the viscosity. Different viscosity will result in different adhesion of water droplets on the surface of the car, which will affect the trajectory of water droplets. There is surface tension between water and air, and different surface tensions will also affect the trajectory of water droplets. Different volume forces will also affect the trajectory of water droplets. In the embodiment of the present application, volume force refers to gravity.

[0088] It should be noted that water droplets are low-viscosity fluids, and pressure plays a dominant role in the movement of low-viscosity fluids.

[0089] As a possible implementation method, the Smoothed Particle Hydrodynamics (SPH) method can be used to establish a computational fluid dynamics model. The SPH method is a gridless fluid dynamics method based on the Lagrangian coordinate system, which has outstanding advantages in solving droplet splashing, large fluid deformation, moving boundary and other phenomena. The SPH method discretizes the continuous fluid region into a series of particles with physical properties (speed, pressure, density, etc.). Specifically, based on pressure, viscosity, surface tension and gravity, the acceleration of the target water droplet ejected from the nozzle at the target time is calculated. If the i-th water droplet is the target water droplet, the calculation method is shown in formula (1):

[0090]

[0091] Among them, v i represents the speed of the target water drop, t represents the target time, and p i represents the pressure, i.e. the pressure of the target water droplet, τ i represents the viscous force, i.e., the viscous stress tensor of the target water droplet, ρ i represents the density of the target water droplet, Φ i represents the surface tension, i.e., the surface tension tensor of the target water droplet, f i represents gravity, which is the volume force of the target water droplet.

[0092] Therefore, each water droplet sprayed by the nozzle is taken as a target water droplet, and the acceleration of each water droplet sprayed by the nozzle is obtained; according to the acceleration of each water droplet sprayed by the nozzle, the running trajectory of each water droplet sprayed by the nozzle on the geometric model of the whole vehicle is determined.

[0093] As a possible implementation method, constraints can be added to formula (1) based on the continuity equation, which can also be called the mass conservation equation for water droplets, that is, the mass of the liquid does not increase or decrease. For example, the method for determining the mass of water droplets sprayed by the nozzle can be expressed as formula (2):

[0094]

[0095] Among them, ρ i represents the density of the target water drop, t represents the target time, v i Indicates the speed of the target water droplet.

[0096] As a possible implementation method, a solution model can be established for the viscous force term in formula (1). For incompressible Newtonian fluids, the viscous force is solved using the Newtonian model. For example, the determination method of the viscous stress tensor of the target water droplet can be expressed as formula (3):

[0097]

[0098] Among them, μ s is the shear viscosity coefficient, μ b is the volume viscosity coefficient.

[0099] It should be noted that the viscosity is used for the relationship between water and air on the vehicle body (solid), and needs to be calibrated based on experiments. Based on experimental findings, when the shear viscosity coefficient and the volume viscosity coefficient increase at the same time, the amount of water entering the air inlet of the air conditioner will decrease. As a possible implementation method, when the shear viscosity coefficient is 0.001Pa·s and the volume viscosity coefficient is 0.003Pa·s, the simulation test environment is more similar to the actual environment.

[0100] As a possible implementation method, a solution model can be established for the surface tension term in formula (1), and the surface tension can be solved using the Potential Force model. For example, the surface tension tensor of the target water droplet can be determined as formula (4):

[0101]

[0102] Among them, x ij represents the distance between the target water droplet and other water droplets, σ ​​represents the surface tension coefficient, ω represents the smooth kernel function, and h represents the smooth length of the smooth kernel function.

[0103] It should be noted that the tension coefficient is used to describe the relationship between water and air and can be 0.072N / m.

[0104] As a possible implementation method, computational fluid dynamics software can be used to calculate the acceleration of each water droplet, that is, to solve formula (1) and determine the droplet size, droplet density, shear viscosity coefficient, volume viscosity coefficient, surface tension coefficient, solution time, time step, convergence accuracy, etc. The solution process of the water droplet trajectory is as follows: Figure 4 As shown, each nozzle sprays water droplets, and the trajectory of each water droplet is as follows Figure 4 As shown, the calculated parameters can be expressed as Table 1.

[0105] Table 1 Solution calculation parameters

[0106] parameter Numeric unit Droplet density 998.2 kg / m3 Shear viscosity coefficient 0.001 Pa·s Volume viscosity coefficient 0.003 Pa·s Surface tension coefficient 0.072 N / m Solution time 20 s Time step 0.0001 s Convergence accuracy 0.01 -

[0107] S105: Determine the waterproof performance of the vehicle based on the running tracks of each water droplet on the geometric model of the whole vehicle.

[0108] For example, within a period of time, calculate which water droplets among all the water droplets sprayed have their running trajectories passing through the air inlet of the air conditioner, so as to determine the amount of water entering the air inlet of the air conditioner within a period of time, such as Figure 5 As shown in Figure 2, the water inlet path of the air conditioner is as follows: Figure 6 As shown. Figure 6 In the test, the air-conditioning air inlet is tested. The air-conditioning air inlet and other components can be adjusted based on the results of the vehicle's waterproof performance.

[0109] In addition, based on the trajectory of each water droplet, it is possible to determine whether water has entered the air-conditioning inlet, thereby guiding the structural design and layout of the air-conditioning inlet accessories; it is possible to determine whether water has entered the pressure relief valve, thereby guiding the structural design and layout of the pressure relief valve and surrounding sheet metal; it is possible to determine whether water flows smoothly in the sump, thereby guiding the design of the size of the drainage hole; it is possible to determine whether water drops into the trunk during the tailgate opening process, thereby guiding the tailgate sheet metal design.

[0110] It can be seen from the above technical solution that the geometric model of the whole vehicle is obtained based on the shape and material of the vehicle, and can simulate the vehicle's exterior, sheet metal, assembly gaps of various components, etc. A simulation test environment is established based on the actual test environment. The actual test environment is a test environment based on a sprinkler spraying water droplets to simulate a rain scene. The simulation test environment is a simulation test scene of the actual test environment. The pressure, viscosity, surface tension and gravity of the simulation test environment are obtained, and then based on the pressure, viscosity, surface tension and gravity, the running trajectory of each water droplet sprayed by the sprinkler in the simulation test environment on the whole vehicle geometric model is determined, and then based on the running trajectory of each water droplet on the whole vehicle geometric model, the waterproof performance of the vehicle is determined.

[0111] Therefore, a simulation test environment consistent with the actual test environment and a vehicle geometry model consistent with the actual vehicle are established through simulation, the vehicle geometry model is placed in the simulation test environment, and water droplets are sprayed to the vehicle geometry model through a nozzle, so as to determine the vehicle's waterproof performance based on the running trajectory of each water droplet on the vehicle geometry model. By determining the vehicle's waterproof performance based on the simulation method, simulation tests can be performed in the design and development stage, so as to timely and effectively discover water management problems so as to propose corresponding solutions in a targeted manner.

[0112] In addition to the vehicle waterproof performance simulation test method provided in the embodiment of the present application, a vehicle waterproof performance simulation test device is also provided, such as Figure 7 As shown, it includes: an acquisition unit 701, an establishment unit 702 and a determination unit 703;

[0113] The acquisition unit 701 is used to acquire a whole vehicle geometric model for the vehicle based on the shape and material of the vehicle;

[0114] The establishing unit 702 is used to establish a simulation test environment based on an actual test environment, wherein the actual test environment simulates a rain scene based on a nozzle spraying water droplets, so as to test the waterproof performance of the vehicle in the rain scene, and the simulation test environment includes a nozzle model and a calculation domain, wherein the nozzle model is used to simulate the spray effect of the nozzle, and the calculation domain is used to simulate the actual test environment;

[0115] The acquisition unit 701 is further used to acquire the pressure, viscosity, surface tension and gravity of the simulation test environment, wherein the pressure is used to describe the pressure of the calculation domain, the viscosity is used to describe the viscosity of water and air to the vehicle, and the surface tension is used to describe the surface tension between water and air;

[0116] The determining unit 703 is used to determine the running track of each water droplet sprayed by the nozzle on the geometric model of the whole vehicle based on the pressure, the viscosity, the surface tension and the gravity;

[0117] The determination unit 703 is further configured to determine the waterproof performance of the vehicle based on the running tracks of the water droplets on the geometric model of the vehicle.

[0118] The vehicle geometry model is based on the shape and material of the vehicle, and can simulate the vehicle's exterior, sheet metal, assembly gaps of various components, etc. A simulation test environment is established based on the actual test environment. The actual test environment is a test environment based on the spray of water droplets from the nozzle to simulate the rain scene. The simulation test environment is a simulation test scene of the actual test environment. The pressure, viscosity, surface tension and gravity of the simulation test environment are obtained, and then the running trajectories of each water droplet sprayed by the nozzle in the simulation test environment on the vehicle geometry model are determined based on the pressure, viscosity, surface tension and gravity, and then the waterproof performance of the vehicle is determined based on the running trajectories of each water droplet on the vehicle geometry model.

[0119] Therefore, a simulation test environment consistent with the actual test environment and a vehicle geometry model consistent with the actual vehicle are established through simulation, the vehicle geometry model is placed in the simulation test environment, and water droplets are sprayed to the vehicle geometry model through a nozzle, so as to determine the vehicle's waterproof performance based on the running trajectory of each water droplet on the vehicle geometry model. By determining the vehicle's waterproof performance based on the simulation method, simulation tests can be performed in the design and development stage, so as to timely and effectively discover water management problems so as to propose corresponding solutions in a targeted manner.

[0120] As a possible implementation manner, the determining unit 703 is specifically configured to:

[0121] Based on the pressure, the viscous force, the surface tension and the gravity, the acceleration of the target water droplet ejected from the nozzle at the target time is calculated as follows:

[0122]

[0123] Among them, v i represents the speed of the target water drop, t represents the target time, and p i represents the pressure, that is, the pressure of the target water drop, τ i represents the viscous force, i.e., the viscous stress tensor of the target water droplet, ρ i represents the density of the target water droplet, Φ i represents the surface tension, that is, the surface tension tensor of the target water droplet, f i represents the gravity, that is, the volume force of the target water droplet;

[0124] Taking each water droplet ejected by the nozzle as the target water droplet, and obtaining the acceleration of each water droplet ejected by the nozzle;

[0125] According to the acceleration of each water droplet sprayed by the nozzle, the running track of each water droplet sprayed by the nozzle on the geometric model of the whole vehicle is determined.

[0126] As a possible implementation, the determination unit 703 is further used to determine the viscous stress tensor of the target water droplet, and the calculation method is as follows:

[0127]

[0128] Among them, μ s is the shear viscosity coefficient, μ b is the volume viscosity coefficient.

[0129] As a possible implementation manner, the shear viscosity coefficient is 0.001 Pa·s, and the volume viscosity coefficient is 0.003 Pa·s.

[0130] As a possible implementation, the determining unit 703 is further used to determine the surface tension tensor of the target water droplet, and the calculation method is as follows:

[0131]

[0132] Among them, x ij represents the distance between the target water droplet and other water droplets, σ ​​represents the surface tension coefficient, ω represents the smooth kernel function, and h represents the smooth length of the smooth kernel function.

[0133] As a possible implementation, the determination unit 703 is further used to determine the mass of the water droplets sprayed by the nozzle, and the calculation method is as follows:

[0134]

[0135] As a possible implementation, the simulation test environment is used to simulate a four-sided shower condition.

[0136] As a possible implementation, the length of the calculation domain is 7 meters, the width of the calculation domain is 4 meters, and the height of the calculation domain is 3 meters; the nozzle model includes a plurality of nozzles, the diameter of the nozzle is 3 mm, the spraying angle of the nozzle is 60 degrees, and the flow rate of the nozzle is 10 liters per minute;

[0137] The number of nozzles located above and below the calculation domain is 84 respectively, and the arrangement is 14 rows of nozzles in the x direction and 6 rows of nozzles in the y direction. The spacing between the nozzles in the x direction and the y direction is 400 mm respectively. The height of the nozzles located above the calculation domain from the ground is 2450 mm, and the height of the nozzles located below the calculation domain from the ground is -50 mm.

[0138] There are 84 nozzles on the left and right sides of the calculation domain, respectively, and the arrangement is 14 rows of nozzles in the x-direction and 6 rows of nozzles in the z-direction. The spacing between the nozzles in the x-direction is 400 mm, and the spacing between the nozzles in the z-direction is 300 mm. The height of the nozzles in the lowest row from the ground is 500 mm, and the spacing between the nozzles on the left and the nozzles on the right is 3000 mm.

[0139] The present application also provides a computer device, see Figure 8 , which shows a structural diagram of a computer device provided in an embodiment of the present application, such as Figure 8 As shown, the device includes a memory 810 and a processor 820:

[0140] The memory 810 is used to store program codes and transmit the program codes to the processor;

[0141] The processor 820 is used to execute any one of the vehicle waterproof performance simulation test methods provided in the above embodiments according to the instructions in the program code.

[0142] An embodiment of the present application provides a computer-readable storage medium, which is used to store a computer program. The computer program is used to execute any one of the vehicle waterproof performance simulation test methods provided in the above embodiments.

[0143] The embodiment of the present application also provides a computer program product or a computer program, which includes a computer instruction stored in a computer-readable storage medium. The processor of the computer device reads the computer instruction from the computer-readable storage medium, and the processor executes the computer instruction, so that the computer device executes the vehicle waterproof performance simulation test method provided in various optional implementations of the above aspects.

[0144] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. For the system or device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0145] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0146] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0147] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0148] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A vehicle waterproof performance simulation test method, characterized in that: The method comprises: Based on the shape and material of the vehicle, obtaining a whole vehicle geometric model for the vehicle; A simulation test environment is established based on an actual test environment, wherein the actual test environment simulates a rain scene based on a nozzle spraying water droplets, so as to test the waterproof performance of the vehicle in the rain scene, and the simulation test environment includes a nozzle model and a calculation domain, wherein the nozzle model is used to simulate the spray effect of the nozzle, and the calculation domain is used to simulate the actual test environment; Obtaining the pressure, viscosity, surface tension and gravity of the simulation test environment, wherein the pressure is used to describe the pressure of the calculation domain, the viscosity is used to describe the viscosity of water and air to the vehicle, and the surface tension is used to describe the surface tension between water and air; Determining the running track of each water droplet sprayed by the nozzle on the geometric model of the whole vehicle based on the pressure, the viscous force, the surface tension and the gravity; The waterproof performance of the vehicle is determined based on the running trajectories of the water droplets on the geometric model of the whole vehicle.

2. The method according to claim 1, characterized in that Determining the running track of each water droplet sprayed by the nozzle on the geometric model of the whole vehicle based on the pressure, the viscous force, the surface tension and the gravity, including: Based on the pressure, the viscous force, the surface tension and the gravity, the acceleration of the target water droplet ejected from the nozzle at the target time is calculated as follows: Among them, v i represents the speed of the target water drop, t represents the target time, and p i represents the pressure, that is, the pressure of the target water drop, τ i represents the viscous force, i.e., the viscous stress tensor of the target water droplet, ρ i represents the density of the target water droplet, Φ i represents the surface tension, that is, the surface tension tensor of the target water droplet, f i represents the gravity, that is, the volume force of the target water droplet; Taking each water droplet ejected by the nozzle as the target water droplet, and obtaining the acceleration of each water droplet ejected by the nozzle; According to the acceleration of each water droplet sprayed by the nozzle, the running track of each water droplet sprayed by the nozzle on the geometric model of the whole vehicle is determined.

3. The method according to claim 2, characterized in that The viscous stress tensor of the target water droplet is determined as follows: Among them, μ s is the shear viscosity coefficient, μ b is the volume viscosity coefficient.

4. The method according to claim 3, characterized in that The shear viscosity coefficient is 0.001 Pa·s, and the volume viscosity coefficient is 0.003 Pa·s.

5. The method according to claim 2, characterized in that: The surface tension tensor of the target water droplet is determined as follows: Among them, x ij represents the distance between the target water droplet and other water droplets, σ ​​represents the surface tension coefficient, ω represents the smooth kernel function, and h represents the smooth length of the smooth kernel function.

6. The method according to claim 2, characterized in that The quality of the water droplets sprayed by the nozzle is determined as follows:

7. The method according to claim 1, characterized in that The simulation test environment is used to simulate four-sided shower conditions.

8. A vehicle waterproof performance simulation test device, characterized in that: The device comprises: an acquisition unit, an establishment unit and a determination unit; The acquisition unit is used to acquire a whole vehicle geometric model for the vehicle based on the shape and material of the vehicle; The establishment unit is used to establish a simulation test environment based on an actual test environment, wherein the actual test environment simulates a rain scene based on a nozzle spraying water droplets, so as to test the waterproof performance of the vehicle in the rain scene, and the simulation test environment includes a nozzle model and a calculation domain, wherein the nozzle model is used to simulate the spray effect of the nozzle, and the calculation domain is used to simulate the actual test environment; The acquisition unit is further used to acquire the pressure, viscosity, surface tension and gravity of the simulation test environment, wherein the pressure is used to describe the pressure of the calculation domain, the viscosity is used to describe the viscosity of water and air to the vehicle, and the surface tension is used to describe the surface tension between water and air; The determining unit is used to determine the running track of each water droplet sprayed by the nozzle on the geometric model of the whole vehicle based on the pressure, the viscous force, the surface tension and the gravity; The determination unit is further used to determine the waterproof performance of the vehicle based on the running tracks of the various water droplets on the geometric model of the whole vehicle.

9. A computer device, characterized in that: The device comprises a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the method according to any one of claims 1 to 7 according to the instructions in the program code.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium is used to store a computer program, and the computer program is used to execute the method according to any one of claims 1 to 7.

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