A device and method for testing the convection heat transfer distribution of tire surfaces in a wind tunnel based on an infrared testing device

Abstract

The present invention discloses a device and method for testing the convective heat transfer distribution on the outer surface of a tire in a wind tunnel based on an infrared testing device, and relates to the technical field of wind tunnel testing. A device and method for testing the convective heat transfer distribution on the outer surface of a tire in a wind tunnel based on an infrared testing device comprises a wind tunnel, a rotating mechanism and an infrared thermal imager arranged in the wind tunnel; the rotating mechanism is used to drive the tire to rotate to simulate the tire driving state, and the infrared thermal imager is used to measure the tire tread temperature and sidewall temperature; wherein, a heating layer is attached to the inner side of the tire, and a heat insulating layer is attached to the inner side of the heating layer, and the inner side of the heat insulating layer is the inner tube of the tire. The present invention is a convective heat transfer coefficient testing device specially designed for tires, which can calculate the thermal conductivity resistance of the tire's multi-layer components respectively, and can more realistically simulate the tire driving state. The convective heat transfer coefficient testing method based on the convective heat transfer coefficient testing device has high accuracy when conducting convective heat transfer coefficient tests on tires.

Description

Technical Field

[0001] The present invention relates to the technical field of wind tunnel testing, and in particular to a device and method for testing the convection heat transfer distribution on the outer surface of a tire in a wind tunnel based on an infrared testing device. Background Art

[0002] Tires are the only part of a vehicle that comes into contact with the ground, and their performance directly impacts driving comfort and safety. Due to the viscoelastic nature of rubber, tire temperatures can reach approximately 100°C during use. High temperatures can accelerate tire aging and even cause accidents. Therefore, understanding the distribution of the convective heat transfer coefficient on the tire surface is crucial.

[0003] Patent number 201210193633.X, patent name is a method for determining the convection heat transfer coefficient of tire temperature field analysis, which uses the simulation software CFD method to calculate the flow of air around the tire and the heat transfer between the tire and the tire, thereby determining the tire surface convection heat transfer coefficient, the tire surface temperature and the surface heat flux density; the tire surface convection heat transfer coefficient h can be calculated using the formula To calculate, where T w is the tire surface temperature T f is the ambient air temperature, and q is the heat flux density on the tire surface.

[0004] However, the inventors believe that the above-mentioned simulation software CFD method cannot truly simulate the driving state of the tire, and there are currently few experimental testing methods for the tire convective heat transfer coefficient. Therefore, how to design a method that can truly simulate the driving state of the tire and effectively test the convective heat transfer coefficient of the tire is a technical problem that technicians in this field urgently need to solve.

[0005] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0006] In response to the above technical problems, the embodiments of the present invention provide a tire outer surface convection heat transfer distribution test device and a test method in a wind tunnel based on an infrared test device to solve the problems raised in the above background technology.

[0007] The present invention provides the following technical solutions:

[0008] A device for testing the convection heat transfer distribution of a tire's outer surface in a wind tunnel based on an infrared testing device comprises a wind tunnel, a rotating mechanism disposed in the wind tunnel, and an infrared thermal imager. Testing in a wind tunnel can realistically simulate tire driving conditions while reducing the influence of other heat transfer factors.

[0009] The rotating mechanism is used to drive the tire to rotate to simulate the tire driving state, and the infrared thermal imager is used to measure the tire tread temperature and sidewall temperature;

[0010] Among them, a heating layer is attached to the inner side of the tire, and an insulation layer is attached to the inner side of the heating layer. The inner side of the insulation layer is the inner tube of the tire; a temperature sensor is installed between the outer side of the heating layer and the rubber interlayer on the tire; the use of the insulation layer reduces heat loss.

[0011] Preferably, the heating layer adopts an electric heating layer similar to a heating blanket, and the insulation layer adopts a nano aerogel felt silica insulation film.

[0012] Preferably, the rotating mechanism includes a rotating shaft, a hub and a motor; the rotating shaft is vertically rotatably connected to the base surface in the wind tunnel; the motor and the rotating shaft are driven and connected through two matching bevel gears, and the hub is fixed at the end of the rotating shaft, and the hub is used to install the tire.

[0013] Preferably, a wire lead-out nozzle is provided on the outer peripheral wall of the wheel hub, and a rubber ring and a sealing ring are fixedly provided on the outside of the wire lead-out nozzle in sequence; the wires of the heating layer and the temperature sensor are led out from the wire lead-out nozzle and pass through the rubber ring and the sealing ring in sequence to extend to the outside of the tire; the wires led out of the heating layer and the temperature sensor are electrically connected to the power supply and the computer respectively through slip rings; the wires of the heating layer and the temperature sensor are led out from a special nozzle to avoid destruction of the tire shape.

[0014] Preferably, after the tire is mounted on the wheel hub, the tire interior needs to be punched, and the air pressure inside the tire squeezes the heating layer and the heat insulating layer through the inner tube, so that the heating layer and the heat insulating layer fit tightly.

[0015] Preferably, the infrared thermal imagers include two, and the two infrared thermal imagers respectively measure the tread temperature and the sidewall temperature of the tire; the infrared thermal imagers are glued to the wind tunnel wall of the wind tunnel.

[0016] A method for testing the convective heat transfer distribution on the outer surface of a tire in a wind tunnel is provided, wherein the method uses the aforementioned convective heat transfer distribution testing device for the outer surface of a tire in a wind tunnel based on an infrared testing device, and comprises the following steps:

[0017] S61. Before the test begins, obtain the thickness of each tire layer, the thermal conductivity of each tire layer, and the air temperature in the wind tunnel;

[0018] S62, installing the tire on the driving position of the rotating mechanism;

[0019] S63, the rotating mechanism works to rotate the tire at a certain speed;

[0020] S64, turning on the heating layer to heat the tire, and recording the outer surface temperature and the inner surface temperature of the tire when the inner and outer surface temperatures of the tire are stable;

[0021] S65. Calculate the convective heat transfer coefficient according to the convective heat transfer coefficient formula. The convective heat transfer coefficient formula is as follows:

[0022]

[0023] Where: h is the measured convective heat transfer coefficient, T i is the tire inner surface temperature measured in steady state; T o is the tire outer surface temperature measured in steady state; T f is the external fluid temperature; d1, d2, d3, d n are the component thicknesses of the tire tread, λ1, λ2, λ3, λ n are the thermal conductivity of the component materials of the tire carcasses, respectively.

[0024] When the temperature sensor installed between the outside of the heating layer and the rubber interlayer on the tire is used to detect the temperature of the inner and outer surfaces of the tire, since the power of the heating layer is fixed, the heat flow is fixed, and the material of the rubber interlayer attached to it is also the same, so the temperature is also the same. When measuring the temperature, it is sufficient to record the temperature of any point. The temperature sensor uses a USB single-channel multi-channel K-type thermocouple thermometer to facilitate data transmission to the computer.

[0025] The thickness of each ply on the tire is the actual measured thickness of the tire, or can be obtained based on the tire's engineering drawings and tire simulation software; the thermal conductivity coefficient corresponding to each ply is obtained from a thermal conductivity measuring instrument; and the air temperature in the wind tunnel is obtained using the temperature measurement tool built into the wind tunnel.

[0026] The embodiments of the present invention provide a device and method for testing the convective heat transfer distribution on the outer surface of a tire in a wind tunnel based on an infrared testing device, which have the following beneficial effects: the present invention is a convective heat transfer coefficient testing device specially designed for tires, which can calculate the thermal conductivity resistance of each multi-layer component of the tire and can more realistically simulate the driving state of the tire. The convective heat transfer coefficient testing method based on the convective heat transfer coefficient testing device has high accuracy when testing the convective heat transfer coefficient of the tire. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a structural diagram of the present invention from perspective 1;

[0028] Figure 2 This is a structural diagram of the second angle of the present invention;

[0029] Figure 3 For the present invention Figure 1 Schematic diagram of the cross-section structure;

[0030] Figure 4 For the present invention Figure 3 Schematic diagram of part of the structure of the tire;

[0031] Figure 5 For the present invention Figure 4 A partial enlarged view of middle A;

[0032] Figure 6 For the present invention Figure 4 A partial enlarged view of B in the middle;

[0033] Figure 7 Schematic diagram of the cross-sectional structure of a measured tire of model 165 / 70R10 in the present invention;

[0034] Figure 8 For the present invention Figure 7 A partial enlarged view of C in the middle

[0035] Figure 9 Comparison results between experimental and simulation data of the relationship between the side local convection heat transfer coefficient and the radial side position when the velocity is 20m / s;

[0036] Figure 10 Comparison results of experimental and simulation data on the relationship between the local convective heat transfer coefficient of the tread and the tread position in the Z coordinate direction when the velocity is 20m / s. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0038] Example 1, see Figures 1-8 The embodiment of the present invention provides a device and method for testing the convection heat transfer distribution on the outer surface of a tire in a wind tunnel based on an infrared testing device to solve the above technical problems. The technical solution is as follows:

[0039] A tire outer surface convection heat transfer distribution test device in a wind tunnel based on an infrared test device, comprising: a wind tunnel 9, and a rotating mechanism and an infrared thermal imager 2 arranged in the wind tunnel 9;

[0040] The rotating mechanism is used to drive the tire 1 to rotate in the wind tunnel 9, and the infrared thermal imager 2 is used to measure the tread temperature and sidewall temperature of the tire 1;

[0041] A heating layer 4 is attached to the inner side of the tire 1, an insulating layer 5 is attached to the inner side of the heating layer 4, and the inner side of the insulating layer 5 is the inner tube 6 of the tire 1; a temperature sensor is provided between the outer side of the heating layer 4 and the rubber interlayer on the tire 1.

[0042] In this embodiment, the rotating mechanism includes a rotating shaft 15, a wheel hub and a motor 8; the rotating shaft 15 is vertically rotatably connected to the base surface in the wind tunnel 9; the motor 8 and the rotating shaft 15 are driven and connected through two matching bevel gears, and the wheel hub is fixed at the end of the rotating shaft 15, and the wheel hub is used to mount the tire 1.

[0043] In this embodiment, a wire lead-out air nozzle is provided on the outer peripheral wall of the wheel hub, and the wire lead-out air nozzle is located next to the normal air nozzle 10 on the wheel hub; wherein, a rubber ring 13 and a sealing ring 12 are fixedly provided on the outside of the wire lead-out air nozzle in sequence; the wires of the heating layer 4 and the temperature sensor are led out from the wire lead-out air nozzle and pass through the rubber ring 13 and the sealing ring 12 in sequence to extend to the outside of the tire 1; the wires led out of the heating layer 4 and the temperature sensor are electrically connected to the power supply 14 and the computer 7 respectively through the slip ring 3.

[0044] In this embodiment, after the tire 1 is installed on the wheel hub, the tire interior needs to be punched. The air pressure inside the tire 1 squeezes the heating layer 4 and the insulation layer 5 through the inner tube 6, so that the heating layer 4 and the insulation layer 5 fit tightly.

[0045] In this embodiment, there are two infrared thermal imagers, which respectively measure the tread temperature and the sidewall temperature of the tire 1 ; the infrared thermal imagers are glued to the wind tunnel wall of the wind tunnel 9 .

[0046] A method for testing the convective heat transfer distribution on the outer surface of a tire in a wind tunnel is provided, wherein the method uses the above-mentioned convective heat transfer distribution testing device for the outer surface of a tire in a wind tunnel based on an infrared testing device, and comprises the following steps:

[0047] S61. Before the test begins, obtain the thickness of each tire layer on the tire 1, the thermal conductivity coefficient corresponding to each tire layer, and the air temperature in the wind tunnel;

[0048] S62, installing the tire 1 on the driving position of the rotating mechanism;

[0049] S63, the rotating mechanism works to rotate the tire at a certain speed;

[0050] S64, turning on the heating layer to heat the tire 1, and recording the outer surface temperature and the inner surface temperature of the tire 1 when the inner and outer surface temperatures of the tire 1 are stable;

[0051] S65. Calculate the convective heat transfer coefficient according to the convective heat transfer coefficient formula. The convective heat transfer coefficient formula is as follows:

[0052]

[0053] Where: h is the measured convective heat transfer coefficient, T i is the tire inner surface temperature measured in steady state; T o is the tire outer surface temperature measured in steady state; T f is the external fluid temperature; d1, d2, d3, d n are the component thicknesses of the tire tread, λ1, λ2, λ3, λ n are the thermal conductivity of the component materials of the tire carcasses, respectively.

[0054] Example 2, see Figures 1-10 A comparative experiment was conducted on a tire of model 165 / 70R10, and the convective heat transfer coefficient of the tire was tested using the test method of the present invention and the simulation software CFD method.

[0055] The thermal conductivity of the various tread materials of a 165 / 70R10 tire at a temperature of 30°C is shown in Table 1 below; Figure 8 The distribution of each tread layer of the 165 / 70R10 tire is shown; among them, the thickness value of tread layer d1 is: 3.63mm; the thickness value of tread layer d2 is: 1.33mm; the thickness value of tread layer d3 is: 9.98mm; the thickness value of tread layer d4 is: 2.40mm; the thickness value of tread layer d5 is: 3.68mm; the thickness value of tread layer d6 is: 5.63mm.

[0056] 1. Testing Method of the Present Invention

[0057] S1. Before testing, obtain the thickness of each tread layer on the 165 / 70R10 tire, the corresponding thermal conductivity coefficient of each tread layer, and the air temperature in the wind tunnel;

[0058] The thickness of the tire layer d1 is 3.63 mm; the thickness of the tire layer d2 is 1.33 mm; the thickness of the tire layer d3 is 9.98 mm; the thickness of the tire layer d4 is 2.40 mm; the thickness of the tire layer d5 is 3.68 mm; and the thickness of the tire layer d6 is 5.63 mm. The thermal conductivity of each tire layer is shown in Table 1. The air temperature in the wind tunnel was measured to be 26°C.

[0059] S2, mounting the tire on the hub of the rotating mechanism;

[0060] S3, the rotating mechanism works to make the tire rotate at a certain speed;

[0061] S4. The heating layer heats the tire, and when the inner and outer surface temperatures of the tire are stable, the outer and inner surface temperatures of the tire are recorded;

[0062] According to the convective heat transfer coefficient formula Calculation results.

[0063] Table 1

[0064]

[0065] The test results of the test method of the present invention are shown in Tables 2 and 3 below; Table 2 below shows the experimental data on the relationship between the local convective heat transfer coefficient of the tire side and the side position in the radial direction at 20 m / s; Table 3 below shows the experimental data on the relationship between the local convective heat transfer coefficient of the tread and the tread position in the y-coordinate direction at 20 m / s.

[0066] Table 2

[0067] r / mm 125 160 195 230 265 300 335 370 h / (W·m-2·K-1) 79.2 79 79.2 79.5 79 79.2 78.4 77.8

[0068] Table 3

[0069] Y / mm 629 666 703 740 777 814 851 888 925 h / (W·m-2·K-1) 58 59 57.8 60.2 58.6 60.6 59.3 61 58.8

[0070] 2. Simulation software CFD test method

[0071] S1. Perform 2D meshing on the tire section and air domain, then assemble, rotate into 3D, assemble the rim, and place it in the cuboid air domain;

[0072] S2. Determine the turbulence model k-ω model and define the boundary conditions. Set the wall to no slip, the temperature to 300K, the fluid temperature to 300K, the flow boundary condition temperature at the inlet to the ambient temperature, the relative pressure applied to the front and rear walls of the air calculation domain to 0MPa, and apply a stable heat flux density of 100W / m to the inner surface of the tire. 2 , the tire is subjected to a wall boundary condition that rotates around the tire's central axis;

[0073] S3, rubber thermal resistance Calculate, according to the drawing, locate the type and thickness of the component at any position of the cross section, and input the corresponding thermal conductivity;

[0074] S4. Based on the determined computational domain, turbulence model, boundary conditions and formulas

[0075]

[0076] Calculate the convective heat transfer coefficient at different locations.

[0077] Where h is the calculated convective heat transfer coefficient; q is the temperature of the tire outer surface calculated by the computer based on heat flow and thermal resistance; T o The temperature of the tire outer surface calculated by the computer; T f is the external fluid temperature.

[0078] The test results of the simulation software CFD test method are shown in Tables 3 and 4 below; Table 3 below shows the experimental data on the relationship between the local convective heat transfer coefficient of the tire side and the side position in the radial direction at 20 m / s; Table 4 below shows the experimental data on the relationship between the local convective heat transfer coefficient of the tread and the tread position in the y-coordinate direction at 20 m / s.

[0079] Table 4

[0080] r / mm 125 160 195 230 265 300 335 370 h / (W·m-2·K-1) 79 78.9 79.1 78.5 78.7 79 79 77.5

[0081] Table 5

[0082] Y / mm 629 666 703 740 777 814 851 888 925 h / (W·m-2·K-1) 57.6 57.5 57.6 58 59.5 60.6 58 60 57

[0083] Analyze Table 2-5, and combine Figure 9-10 The results were analyzed, and it was found that: the experimental and simulation laws of the present invention are similar, and the experimental results are consistent with the theoretical simulation results, that is, the present invention has designed a method that can truly simulate the driving state of the tire and can effectively test the convective heat transfer coefficient of the tire; among them, the reason for the high experimental data in the test method of the present invention may be the lack of lateral thermal conductivity coefficient data of the material, so that the outer surface temperature obtained by the experiment is too low.

[0084] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0085] In the present invention, unless otherwise clearly stipulated and limited, the terms "install", "set", "connect", "fix", "screw" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0086] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solutions and concepts of the present invention, and all these changes or substitutions should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A method for testing the surface heat transfer distribution of a tire in a wind tunnel, using a wind tunnel tire surface heat transfer distribution testing device based on an infrared testing device, characterized in that: The following steps are involved: S11. Before the test begins, obtain the thickness of each tire layer, the thermal conductivity of each tire layer, and the air temperature in the wind tunnel; S12, installing the tire on the driving position of the rotating mechanism; S13, the rotating mechanism works to rotate the tire at a certain speed; S14, turning on the heating layer to heat the tire, and recording the outer surface temperature and the inner surface temperature of the tire when the inner and outer surface temperatures of the tire are stable; S15. Calculate the convective heat transfer coefficient according to the convective heat transfer coefficient formula. The convective heat transfer coefficient formula is as follows: Where: h is the measured convective heat transfer coefficient, T i is the tire inner surface temperature measured in steady state; T o is the tire outer surface temperature measured in steady state; T f is the external fluid temperature; d1, d2, d3, d n are the component thicknesses of the tire tread, λ1, λ2, λ3, λ n are the thermal conductivity of the component materials of the tire carcass, respectively; Among them, the tire surface convection heat transfer distribution test device in the wind tunnel based on the infrared test device includes: a wind tunnel, a rotating mechanism and an infrared thermal imager arranged in the wind tunnel; The rotating mechanism is used to drive the tire to rotate to simulate the tire driving state, and the infrared thermal imager is used to measure the tire tread temperature and sidewall temperature; A heating layer is attached to the inner side of the tire, an insulation layer is attached to the inner side of the heating layer, and the inner side of the insulation layer is the inner tube of the tire; a temperature sensor is provided between the outer side of the heating layer and the rubber interlayer on the tire.

2. The tire surface convection heat transfer distribution test method in a wind tunnel according to claim 1, characterized in that: The rotating mechanism includes a rotating shaft, a wheel hub and a motor; the rotating shaft is vertically connected to the base surface in the wind tunnel; the motor and the rotating shaft are driven and connected through two matching bevel gears, and the wheel hub is fixed at the end of the rotating shaft, and the wheel hub is used to install the tire.

3. The method for testing the surface heat transfer distribution of a tire in a wind tunnel according to claim 2, characterized in that: A wire outlet nozzle is provided on the outer peripheral wall of the wheel hub, and a rubber ring and a sealing ring are fixedly provided on the outside of the wire outlet nozzle in sequence; the wires of the heating layer and the temperature sensor are led out from the wire outlet nozzle and pass through the rubber ring and the sealing ring in sequence to extend to the outside of the tire; the wires led out of the heating layer and the temperature sensor are electrically connected to the power supply and the computer respectively through slip rings.

4. The method for testing the surface heat transfer distribution of a tire in a wind tunnel according to claim 2, characterized in that: After the tire is installed on the wheel hub, it needs to be punched inside the tire. The air pressure inside the tire squeezes the heating layer and the insulation layer through the inner tube, making the heating layer and the insulation layer fit tightly.

5. The method for testing the surface heat transfer distribution of a tire in a wind tunnel according to claim 1, characterized in that: The infrared thermal imagers include two, which respectively measure the tread temperature and sidewall temperature of the tire; the infrared thermal imagers are glued to the wind tunnel wall of the wind tunnel.

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