Wind tunnel test apparatus and method for ice crystal testing and temperature sensor testing

Abstract

The present application relates to the technical field of wind tunnel test, and discloses a wind tunnel test device and method for ice crystal test and temperature sensor test, which comprises a backflow type wind tunnel, the backflow type wind tunnel comprises a first test section, a second test section, a power section, a rectification section and a temperature control section, a temperature sensor dynamic characteristic test equipment is arranged in the first test section, the first end of the second test section is communicated with the tail end of the first test section, an ice crystal test equipment is arranged in the second test section, the air inlet of the power section is communicated with the tail end of the second test section, and the air inlet is used for increasing the airflow velocity in the wind tunnel, the rectification section inlet is communicated with the air outlet of an axial flow fan, and the rectification section inlet is used for eliminating the distortion and turbulence in the airflow, the rectification section outlet is communicated with the first end of the first test section, a component for generating ice crystals in the ice crystal test equipment is connected with one side of the rectification section, and the temperature control section is arranged in series on the pipeline between the second test section and the power section, and is used for controlling the temperature of the airflow in the backflow type wind tunnel.

Description

Technical Field

[0001] This invention relates to the field of wind tunnel testing technology, and in particular to a wind tunnel testing apparatus and method for ice crystal testing and temperature sensor testing. Background Technology

[0002] In aerospace, energy equipment, and meteorological monitoring, dynamic characteristic testing of temperature sensors and optical observation experiments of ice crystals are two core research tasks. The optical observation experiments of ice crystals are used to study the formation mechanism, morphological evolution, and impact on optical devices of ice crystals in low-temperature and high-humidity environments. Currently, the ice crystal test process includes the formation process of ice crystals and the process of real-time dynamic recording using observation equipment. The dynamic characteristic testing of temperature sensors aims to evaluate the response speed and accuracy of sensors to temperature step changes. It is usually simulated by rapidly heating and cooling airflows to simulate actual working conditions. In ice crystal tests, temperature sensors that have passed dynamic characteristic testing are usually used to measure the ambient temperature of the ice crystal test environment with high precision. For ice crystal tests and dynamic characteristic testing of temperature sensors, DC wind tunnels are usually used to complete the tests respectively.

[0003] Traditional DC wind tunnels typically include an inlet section, a test section, and an outlet section. The equipment used to generate airflows at different temperatures required for the test is usually located in the inlet section. Components for dynamic characteristic testing of temperature sensors or ice crystal optical observation tests are located in the test section. During ice crystal optical observation tests, a water mist generator used to generate ice crystals is also located at the inlet end of the inlet section. In dynamic characteristic testing of temperature sensors, the DC wind tunnel achieves step signals by alternating airflows at different temperatures, or by rapidly heating the temperature using external heat sources such as lasers or high-temperature furnaces. Ice crystal optical observation tests rely on spraying to generate ice crystals in the test section, and then observe their morphology using optical equipment.

[0004] However, conducting the above two experiments requires the use of two independent DC wind tunnels to complete the experimental process separately. This is not only costly and energy-intensive, but also takes a long time to acquire experimental parameters. Furthermore, the independent use of DC wind tunnels cannot simulate the dynamic characteristics of temperature sensors under multiple scenarios. Moreover, due to the open-circuit circulation structure on both sides of the traditional DC wind tunnel, the airflow in the test section is easily affected by external wind speed and temperature fluctuations, making it difficult to maintain stable step boundary conditions and affecting the accuracy of the experiment. For example, interference from external temperature can easily lead to low temperature and humidity control accuracy, or make it difficult to meet the stringent requirements of ice crystal experiments for low temperature and high humidity environments. Summary of the Invention

[0005] This invention provides a wind tunnel testing apparatus and method for ice crystal testing and temperature sensor testing, which can create a stable testing environment for both tests.

[0006] This invention provides a wind tunnel testing apparatus for ice crystal testing and temperature sensor testing, comprising a recirculating wind tunnel, which includes a first test section, a second test section, a power section, a rectification section, and a temperature control section. A temperature sensor dynamic characteristic testing device is located within the first test section. The first end of the second test section is connected to the last end of the first test section. An ice crystal testing device is located within the second test section. The air inlet of the power section is connected to the last end of the second test section to increase the airflow velocity within the wind tunnel. The inlet of the rectification section is connected to the outlet of an axial flow fan to eliminate distortion and turbulence in the airflow. The outlet of the rectification section is connected to the first end of the first test section. A component in the ice crystal testing device used to generate ice crystals is connected to one side of the rectification section. The temperature control section is connected in series on the pipeline between the second test section and the power section to control the temperature of the airflow within the recirculating wind tunnel.

[0007] Preferably, the outlet of the rectifier section is connected to the beginning of the first test section via a contraction pipe.

[0008] Preferably, the end of the second test section is connected to the temperature control section via a diffusion pipe.

[0009] Preferably, the temperature control section includes: a dry high-temperature heater and a cooler. The air inlet of the dry high-temperature heater is connected to the contraction end of the contraction pipe through a pipe. When it is in operation, it increases the temperature of the airflow in the recirculation wind tunnel. The air inlet of the cooler is connected to the air outlet of the dry high-temperature heater through a pipe. When it is in operation, it decreases the temperature of the airflow in the recirculation wind tunnel.

[0010] Preferably, the power section includes an airflow channel and an axial-flow high-pressure fan connected thereto.

[0011] Preferably, the rectifying section includes a rectangular channel structure, a honeycomb unit, and a damping mesh. The honeycomb unit and the damping mesh are arranged sequentially from the air inlet to the air outlet of the channel structure. Both the honeycomb unit and the damping mesh are longitudinally extending mesh structures. The honeycomb unit has closely arranged hexagonal holes, and the damping mesh has closely arranged square holes. The nozzle of the aerosol spraying device used to generate ice crystals in the ice crystal test is connected to the rectifying section and is closer to the air outlet of the rectifying section than the damping mesh.

[0012] Preferably, it also includes a humidity sensor for real-time acquisition of the humidity of the airflow inside the recirculation wind tunnel and a flow sensor for acquisition of the airflow velocity.

[0013] Preferably, it also includes a PID control system, which collects humidity data monitored by a humidity sensor, temperature data monitored by a temperature sensor in a temperature sensor dynamic characteristic testing device, and airflow velocity data monitored by a flow sensor, and compares them with the corresponding set data to control the adaptive automatic adjustment of the power section, temperature control section, and ice crystal generation equipment.

[0014] The present invention also provides a test method for a wind tunnel testing apparatus for ice crystal testing and temperature sensor testing, comprising the following steps:

[0015] First, turn on the axial flow high-pressure fan, then turn on the dry high-temperature heater, and do not run the cooler. Ensure that the temperature of the high-temperature airflow in the recirculation wind tunnel reaches the temperature sensor dynamic characteristic test, complete a step dynamic characteristic test of the temperature sensor under high temperature environment, and record the parameters.

[0016] Reset the temperature sensor dynamic characteristic testing equipment, turn on the aerosol spraying equipment, complete a step dynamic characteristic test of the temperature sensor under high temperature and high humidity environment, and record the parameters;

[0017] Turn off the axial high-pressure blower, aerosol spraying equipment, and dry high-temperature heater, and wait for the airflow in the recirculation wind tunnel to cool down. Then turn on the axial high-pressure blower and the cooler in sequence to ensure that the airflow temperature drops to the requirements of the temperature sensor dynamic characteristic test. Complete a test of the temperature sensor step dynamic characteristics in a low-temperature environment and record the parameters.

[0018] Reset the temperature sensor dynamic characteristic testing equipment, turn on the aerosol spraying equipment, complete a test of the temperature sensor's step dynamic characteristics under low temperature, humid conditions and interference from water-like semi-condensed particles, record the parameters, and record the process of ice crystal formation in the second test section.

[0019] Compared with existing technologies, the advantages of this invention are as follows: Compared with traditional DC wind tunnels, this invention, by setting the temperature sensor dynamic characteristic testing equipment in the first test section and the ice crystal testing equipment in the second test section, can achieve the effect of simulating two related tests using only one wind tunnel structure. This is more cost-effective, efficient, and energy-saving. Its recirculation wind tunnel, through its power section and temperature control section, can apply power, temperature regulation, and humidity regulation to the internal sealed airflow, not only meeting the conditions for temperature sensor dynamic characteristic testing but also achieving the conditions for ice crystal formation. Furthermore, it utilizes the environmental conditions for ice crystal formation to provide realistic and diverse environmental conditions for temperature sensor dynamic characteristic testing, such as dry room temperature, dry low temperature, and humid room temperature. The system can withstand various typical operating conditions such as humidity and low temperature, enabling multi-dimensional accuracy testing of temperature sensors. Specifically, the recirculating wind tunnel, compared to the traditional open-circuit wind tunnel structure, has a sealed and recirculating internal structure, avoiding interference with airflow speed, temperature, and humidity. This maintains stable step boundary conditions for the temperature sensor, resulting in higher accuracy of the two test results. The internally sealed airflow can quickly enter the rectification section under the acceleration of the axial high-pressure fan. The rectification section eliminates distortion and turbulence in the airflow, providing a more uniform basic flow field. The airflow is further accelerated by the contraction section, finely adjusting its flow characteristics to provide a high-speed, stable, and uniform flow field environment for the first and second test sections, facilitating the implementation of the two tests.

[0020] When operating in an environment where ice crystals form, this device allows for the consideration of the influence of water mist or ice crystals on the temperature sensor during step temperature change tests. It enables the evaluation of the sensor's response delay and dynamic error under fog, frost, and icing conditions, truly reflecting the performance degradation characteristics in complex on-site environments. In summary, this device can provide an ideal fluid environment for step response tests of temperature sensors and tests involving ice crystal formation, significantly improving test accuracy and reliability. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a wind tunnel testing device for ice crystal testing and temperature sensor testing provided in an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of a honeycomb unit in a wind tunnel testing device for ice crystal testing and temperature sensor testing, provided in an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the system structure of a wind tunnel testing device for ice crystal testing and temperature sensor testing provided in an embodiment of the present invention;

[0024] Figure 4The flowchart illustrates a PID control system in a wind tunnel testing apparatus for ice crystal testing and temperature sensor testing, as provided in an embodiment of the present invention.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1. Recirculating wind tunnel; 11. First test section; 12. Second test section; 13. Power section; 14. Rectifier section; 141. Honeycomb unit; 142. Damping net; 15. Temperature control section; 151. Dry high-temperature heater; 152. Refrigerator; 2. Contraction pipe; 3. Diffusion pipe. Detailed Implementation

[0027] The following detailed description of a specific embodiment of the present invention is provided in conjunction with the accompanying drawings. However, it should be understood that the scope of protection of the present invention is not limited to the specific embodiment.

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the technical solution of this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0029] refer to Figure 1 and Figure 3 This invention provides a wind tunnel testing apparatus and method for ice crystal testing and temperature sensor testing, including a recirculation wind tunnel 1. The recirculation wind tunnel 1 includes: a first test section 11, a second test section 12, a power section 13, a rectification section 14, and a temperature control section 15. A temperature sensor dynamic characteristic testing device is installed in the first test section 11. The first end of the second test section 12 is connected to the tail end of the first test section 11. An ice crystal testing device is installed in the second test section 12. The air inlet of the power section 13 is connected to the tail end of the second test section 12 to increase the airflow velocity in the wind tunnel. The inlet of the rectification section 14 is connected to the outlet of an axial flow fan to eliminate distortion and turbulence in the airflow. The outlet of the rectification section 14 is connected to the first end of the first test section 11. The component in the ice crystal testing device used to generate ice crystals is connected to one side of the rectification section 14. The temperature control section 15 is connected in series in the pipeline between the second test section 12 and the power section 13 to control the temperature of the airflow in the recirculation wind tunnel 1.

[0030] In the above embodiments, since the calibration accuracy of the temperature sensor directly affects the reliability of the ice crystal test, if the dynamic error of the temperature sensor is large during the ice crystal growth test, it may lead to misjudgment of the ice crystal formation temperature threshold, thereby affecting the accuracy of the test results. At the same time, this device can combine the dynamic characteristic test of the temperature sensor with the ice crystal test through the recirculation wind tunnel 1. It can take the extreme and complex environment of ice crystal formation as one of the working conditions of the dynamic characteristic test of the temperature sensor. By using the extreme working condition test scenario, the performance evaluation of the temperature sensor test under different temperatures, conditions and environments can be realistically simulated. In the ice crystal test, the sensor needs to maintain stable output under conditions such as freezing and water mist deposition, which puts higher requirements on the practical engineering applicability of the sensor.

[0031] Therefore, compared with traditional DC wind tunnels, this invention, by placing the temperature sensor dynamic characteristic testing equipment in the first test section 11 and the ice crystal testing equipment in the second test section 12, can achieve the effect of simulating two related tests using only one wind tunnel structure. This is more cost-effective, efficient, and energy-efficient. Its recirculation wind tunnel 1, through the power section 13 and temperature control section 15, can apply power, temperature regulation, and humidity regulation to the internal sealed airflow, not only meeting the conditions for temperature sensor dynamic characteristic testing but also achieving the conditions for ice crystal formation. Furthermore, it utilizes the environmental conditions for ice crystal formation to provide realistic and diverse environmental conditions for temperature sensor dynamic characteristic testing, such as dry ambient temperature, dry low temperature, humid ambient temperature, and humid low temperature. Typical operating conditions are used to test the accuracy of temperature sensors from multiple dimensions. Specifically, the recirculating wind tunnel 1, compared to the traditional DC open-circuit wind tunnel structure, has a sealed and recirculating internal structure, which avoids interference with airflow speed, temperature, and humidity. It can maintain stable step boundary conditions for the temperature sensor, so as to make the results of the two tests more accurate. The internally sealed airflow can quickly enter the rectification section 14 under the acceleration of the axial high-pressure fan. The rectification section 14 eliminates distortion and turbulence in the airflow to provide a relatively uniform basic flow field. After passing through the contraction section, the airflow is further accelerated and its flow characteristics are finely adjusted, providing a high-speed, stable and uniform flow field environment for the first test section 11 and the second test section 12, which is conducive to the implementation of the two tests.

[0032] When operating in an environment where ice crystals form, this device allows for the consideration of the influence of water mist or ice crystals on the temperature sensor during step temperature change tests. It enables the evaluation of the sensor's response delay and dynamic error under fog, frost, and icing conditions, truly reflecting the performance degradation characteristics in complex on-site environments. In summary, this device can provide an ideal fluid environment for step response tests of temperature sensors and tests involving ice crystal formation, significantly improving test accuracy and reliability.

[0033] refer to Figure 1 and Figure 2 The rectifying section 14 includes a rectangular channel structure, a honeycomb unit 141, and a damping mesh 142. The honeycomb unit 141 and the damping mesh 142 are arranged sequentially from the air inlet to the air outlet of the channel structure. Both the honeycomb unit 141 and the damping mesh 142 are longitudinally extending mesh structures. The mesh of the honeycomb unit 141 is a tightly arranged hexagonal hole, and the mesh of the damping mesh 142 is a tightly arranged square hole. The nozzle of the aerosol spraying device used to generate ice crystals in the ice crystal test is connected to the channel structure and is closer to the air outlet of the channel structure than the damping mesh 142.

[0034] In the above embodiments, the core function of the rectifying section 14 is to create a uniform, stable, low-turbulence flow field parallel to the axis for the airflow. The honeycomb structure 141 homogenizes the velocity distribution, dissipates turbulent kinetic energy, and reduces turbulence intensity. Specifically, because the pipe forces the airflow along its axis, the honeycomb structure 141 effectively "straightens" the airflow, significantly reducing the lateral velocity component and large-scale vortices. Simultaneously, the honeycomb structure 141 breaks down and segments some of the incoming large-scale turbulent structures, decomposing them into smaller-scale turbulent structures. This allows these smaller-scale turbulences to be more easily dissipated by the damping mesh 142. The damping mesh 142 is composed of one or more layers of fine metal wires or other high- and low-temperature resistant materials woven into a grid. Its main effect is to significantly reduce the turbulence intensity or turbulence degree of the airflow, making the velocity distribution on the cross-section more uniform. When airflow passes through the mesh of the damping mesh 142, it homogenizes the airflow velocity. Specifically, in areas with high-speed airflow, the resistance is greater and the velocity decreases more when passing through the mesh, while in areas with low-speed airflow, the resistance is smaller and the velocity decreases less. This nonlinear resistance characteristic helps to smooth out the velocity differences across the cross section, making the downstream velocity distribution more uniform. It also enables turbulent dissipation of airflow. Specifically, when airflow passes through the mesh, it generates a large number of tiny shear layers and wakes. These small-scale flow structures have high vorticity and rapidly dissipate turbulent kinetic energy. This process effectively attenuates the turbulent pulsations in the airflow and can further break up the turbulent structure. Specifically, the mesh can also further cut and break up the relatively large-scale turbulent structure that may remain downstream of the honeycomb device 141 into smaller-scale structures to suppress turbulent regeneration. The tiny, rapidly dissipating turbulent structures generated by the damping mesh 142 have a certain inhibitory effect on the development of downstream turbulence.

[0035] Further, refer to Figure 1 and Figure 3 The outlet of the rectifier section 14 is connected to the beginning of the first test section 11 via the contraction pipe 2.

[0036] In the above embodiments, the contraction pipe 2 is a hollow channel. Its main function is to perform preliminary rectification, acceleration and smoothing of the airflow. Utilizing the special structure of its structure, it can efficiently convert pressure energy into the wind speed kinetic energy required by the first test section 11 and the second test section 12. Moreover, it can further reduce turbulence, eliminate vortices, and ensure velocity uniformity and streamline parallelism on the basis of the rectification section 14. At the same time, it can minimize flow loss through optimized design and improve the energy efficiency of the entire wind tunnel system.

[0037] Further, refer to Figure 1 and Figure 3 The tail end of the second test section 12 is connected to the temperature control section 15 through the diffusion pipe 3.

[0038] In the above embodiments, the diffuser duct 3 is also a hollow channel structure. Its main function is to convert the kinetic energy of the high-speed airflow after passing through the second test section 12 back into pressure energy, reduce the backflow resistance and flow velocity, so that when the airflow passes through the temperature control section 15, the temperature can be increased or decreased sufficiently, which is beneficial to meeting the temperature requirements of subsequent tests.

[0039] Further, refer to Figure 1 and Figure 3 The temperature control section 15 includes a dry high-temperature heater 151 and a cooler 152. The air inlet of the dry high-temperature heater 151 is connected to the contraction end of the contraction pipe 2 through a pipe. When it is in operation, it increases the temperature of the airflow in the recirculation wind tunnel 1. The air inlet of the cooler 152 is connected to the air outlet of the dry high-temperature heater 151 through a pipe. When it is in operation, it decreases the temperature of the airflow in the recirculation wind tunnel 1.

[0040] In the above embodiments, the airflow inside the recirculation wind tunnel 1 can be heated by using a dry high-temperature heater 151. Specifically, the airflow inside the recirculation wind tunnel 1 can be heated to 80°C to 85°C. The cooler 152 installed can cool the airflow inside the recirculation wind tunnel 1 to -25°C to -30°C. Since the recirculation wind tunnel 1 is used, the airflow inside is in a sealed state and there is no large temperature difference. Therefore, the cooler 152 has lower energy consumption and lower overall cost compared to the traditional cooler 152 that applies -40°C to -50°C.

[0041] Specifically, the high-temperature heating tube in the dry high-temperature heater 151 is a commonly used U-shaped 220V, 500W aluminum fin heating tube. The high thermal conductivity aluminum material accelerates heat diffusion and enhances heat exchange efficiency. The cooler 152 also adopts common structures such as refrigerant, compressor, expansion valve and heat exchange fins, and uses the principle of heat exchange to achieve the cooling effect.

[0042] Further, refer to Figure 1The power section 13 includes an airflow channel and an axial flow high-pressure fan connected thereto.

[0043] In the above embodiments, the axial flow high-pressure fan can accelerate the airflow to 50m / s, thereby ensuring the stable output of the airflow. Specifically, it is a variable frequency motor with a power of ≥2.2kW and an inlet diameter of 1500mm.

[0044] Further, refer to Figure 3 and Figure 4 It also includes a PID control system. This system collects humidity data from a humidity sensor, temperature data from a temperature sensor in a dynamic characteristic testing device, and airflow velocity data from a flow sensor, and compares this data with corresponding setpoints to control the adaptive automatic adjustment of the power section 13, temperature control section 15, and ice crystal generation equipment. Specifically, the humidity sensor model is HC2A-IM102-M, with a humidity range of 0% to 100% RH; the flow sensor model is DL-2000 Pitot tube anemometer, with a range of 1 m / s to 100 m / s and a monitoring accuracy of 0.1 m / s.

[0045] In the above embodiments, the humidity sensor and flow sensor can monitor the airflow parameters in the recirculation wind tunnel 1. By working with the PID control system, they can provide more accurate airflow parameters for temperature, humidity and flow rate for subsequent experiments.

[0046] In the above embodiments, the control algorithm used is the proportional-integral-derivative (PID) control algorithm, and its core formula is:

[0047]

[0048] in:

[0049] : Controller output signals, such as fan speed, heater power, cooler power, etc.;

[0050] Error value at the current moment, that is, the difference between the set value and the actual measured value (such as the difference between the target temperature and the actual temperature).

[0051] : Proportional gain, which determines the strength of the system's response to the current error;

[0052] Integral gain eliminates steady-state error and adjusts the output by accumulating historical errors;

[0053] Differential gain suppresses system overshoot and adjusts the output by predicting the trend of error changes.

[0054] Specifically, the PID control system described in this embodiment has a physical form, with a control cabinet specifically set up outside the recirculation wind tunnel 1.

[0055] This invention also provides a wind tunnel testing apparatus and method for ice crystal testing and temperature sensor testing, comprising the following steps:

[0056] Check that all equipment and parameters are normal. If normal, proceed to the next step.

[0057] First, turn on the axial flow high-pressure fan, then turn on the dry high-temperature heater 151. The cooler 152 is not running. Ensure that the airflow temperature in the recirculation wind tunnel 1 rises. When the high-temperature airflow temperature in the recirculation wind tunnel 1 reaches the temperature sensor dynamic characteristic test, complete a step dynamic characteristic test of the temperature sensor under high temperature environment and record the parameters.

[0058] Reset the temperature sensor dynamic characteristic testing equipment, turn on the aerosol spraying equipment, complete a step dynamic characteristic test of the temperature sensor under high temperature and high humidity environment, and record the parameters;

[0059] Turn off the axial high-pressure blower, aerosol spraying equipment, and dry high-temperature heater 151, and wait for the airflow in the return wind tunnel 1 to cool down. Then turn on the axial high-pressure blower and cooler 152 in sequence to ensure that the airflow temperature in the return wind tunnel 1 drops to the requirements of the temperature sensor dynamic characteristic test, complete a test of the temperature sensor step dynamic characteristics under low temperature environment, and record the parameters.

[0060] Reset the temperature sensor dynamic characteristic testing equipment, turn on the aerosol spraying equipment to allow the aerosol to enter the rectifier section 14, complete a test of the temperature sensor's step dynamic characteristics under low temperature, humid conditions and with interference from water-like semi-condensed particles, and record the parameters.

[0061] In the above embodiments, when the mist enters the rectifier section 14 and comes into contact with the low-temperature airflow, it generates water-like semi-condensed particles at the temperature sensor in the first test section 11, thereby providing a more complex and diverse testing environment for the temperature sensor.

[0062] Furthermore, the process of ice crystal formation in the second test section 12 is recorded by image. Specifically, as the low-temperature airflow continues to blow, the semi-condensed water mist low-temperature airflow that has passed through the first test section 11 enters the second test section 12 and causes the complete condensation of ice crystals. At this time, the accumulation and formation of ice crystals is completed by observation photography equipment or high-speed shooting equipment.

[0063] In summary, as the aerosol spraying equipment is turned off or on, the aerosol and other particulate sprays are propelled into the rectifier section 14 by the fluid. Under the action of the axial high-pressure fan, the aerosol passes through the interior of the rectifier section 14 and enters the return wind tunnel 1, and then passes through the first test section 11 and the second test section 12 in sequence. This provides a variety of test environments for the dynamic characteristics testing of temperature sensors. At the same time, it can also complete the observation test of ice crystal formation and recording in the second test section 12 under relatively low temperature conditions.

[0064] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A wind tunnel testing apparatus for ice crystal testing and temperature sensor testing, characterized in that, Including a recirculation wind tunnel (1), the recirculation wind tunnel (1) includes: The temperature sensor dynamic characteristic testing equipment is set in the first test section (11); The first end of the second test section (12) is connected to the last end of the first test section (11), and the test equipment for the ice crystal test is set in the second test section (12); The power section (13) has an air inlet connected to the tail end of the second test section (12) to increase the airflow velocity in the wind tunnel. The power section (13) includes an airflow channel and an axial flow high-pressure fan connected thereto. The rectifier section (14) is connected to the air outlet of the power section (13) at its inlet to eliminate distortion and turbulence in the airflow. The outlet of the rectifier section (14) is connected to the head end of the first test section (11). The component in the ice crystal test equipment used to generate ice crystals is connected to one side of the rectifier section (14). The outlet of the rectifier section (14) is connected to the head end of the first test section (11) through the shrinkage pipe (2). The temperature control section (15) is connected in series on the pipeline between the second test section (12) and the power section (13) to control the temperature of the airflow in the recirculation wind tunnel (1). The tail end of the second test section (12) is connected to the temperature control section (15) through the diffuser pipe (3). The temperature control section (15) includes: The dry high-temperature heater (151) has its air inlet connected to the constriction end of the constriction pipe (2) through a pipe. When it is in operation, it increases the temperature of the airflow in the recirculation wind tunnel (1). The air inlet of the cooler (152) is connected to the air outlet of the dry high-temperature heater (151) through a pipeline, and the air outlet of the cooler (152) is connected to the air inlet of the power section (13) through a pipeline. When it is in operation, it reduces the temperature of the airflow in the recirculation wind tunnel (1).

2. The wind tunnel testing apparatus for ice crystal testing and temperature sensor testing as described in claim 1, characterized in that, The rectifying section (14) includes a rectangular channel structure, a honeycomb unit (141) and a damping mesh (142). The honeycomb unit (141) and the damping mesh (142) are arranged sequentially from the air inlet to the air outlet of the channel structure. Both the honeycomb unit (141) and the damping mesh (142) are longitudinally extending mesh structures. The mesh of the honeycomb unit (141) is a tightly arranged hexagonal hole, and the mesh of the damping mesh (142) is a tightly arranged square hole. The nozzle of the aerosol spraying device used to generate ice crystals in the ice crystal test is connected to the channel structure and is closer to the air outlet of the channel structure than the damping mesh (142).

3. The wind tunnel testing apparatus for ice crystal testing and temperature sensor testing as described in claim 1, characterized in that, It also includes a humidity sensor for real-time acquisition of the humidity of the airflow inside the recirculation wind tunnel (1) and a flow sensor for acquisition of the airflow velocity.

4. The wind tunnel testing apparatus for ice crystal testing and temperature sensor testing as described in claim 2, characterized in that, It also includes a PID control system, which collects humidity data monitored by a humidity sensor, temperature data monitored by a temperature sensor in a temperature sensor dynamic characteristic testing device, and airflow velocity data monitored by a flow sensor, and compares them with the corresponding set data to control the adaptive automatic adjustment of the power section (13), temperature control section (15) and ice crystal generation device.

5. A test method for a wind tunnel testing apparatus for ice crystal testing and temperature sensor testing as described in claim 4, characterized in that: Includes the following steps: First, turn on the axial flow high pressure fan, then turn on the dry high temperature heater (151), and do not run the cooler (152). Ensure that the temperature of the high temperature airflow in the return wind tunnel (1) reaches the temperature sensor dynamic characteristic test, complete a step dynamic characteristic test of the temperature sensor under high temperature environment, and record the parameters. Reset the temperature sensor dynamic characteristic testing equipment, turn on the aerosol spraying equipment, complete a step dynamic characteristic test of the temperature sensor under high temperature and high humidity environment, and record the parameters; Turn off the axial high-pressure blower, aerosol spraying equipment and dry high-temperature heater (151), wait for the airflow in the return wind tunnel (1) to cool down, turn on the axial high-pressure blower and cooler (152) in sequence, ensure that the airflow temperature drops to the requirements of the temperature sensor dynamic characteristic test, complete the test of the temperature sensor step dynamic characteristic under low temperature environment, and record the parameters. Reset the temperature sensor dynamic characteristic test equipment, turn on the aerosol spray equipment, complete a test of the temperature sensor step dynamic characteristics under low temperature, humid environment with water-like semi-condensed particles, record the parameters, and record the process of ice crystal formation in the second test section (12) by image recording.

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