Airflow deviation angle measuring method, device and equipment based on infrared thermogram and medium

Abstract

The invention provides an airflow deviation angle measurement method, device and equipment based on an infrared thermal image and a medium, and the method comprises the steps: selecting a plane-symmetric test model, selecting a symmetric plane degraded to a symmetric axis direction as a shooting plane of the test model, and enabling the shooting plane, a lens plane and a shooting infrared window of an infrared thermal imager to be parallel; during a wind tunnel test, a wind tunnel insertion mechanism sends a test model to a test position and changes attack angles in a stepped manner, and an infrared thermogram of surface temperature distribution of the test model corresponding to each attack angle is obtained; finding out a symmetry axis according to the contour of the shooting surface, turning over the infrared thermal image about the symmetry axis, and subtracting the infrared thermal image before turning from the turned infrared thermal image to obtain a symmetry temperature image; and calculating the surface average temperature deviation corresponding to each attack angle according to the symmetry temperature diagram, and selecting the attack angle corresponding to the infrared thermogram with the minimum temperature deviation as the airflow deviation angle, so as to solve the problem that the airflow deviation angle cannot be effectively evaluated due to no balance type test such as infrared thermometry.

Description

Technical Field

[0001] The invention relates to the technical field of aerodynamic test measurement, and in particular to an airflow deflection angle measurement method, device, equipment and medium based on infrared thermal images. Background Art

[0002] Based on theoretical foundations such as the principle of relative motion and the similarity criterion, wind tunnel testing has become one of the three main means of solving aerodynamic problems. Wind tunnel testing designs and processes scaled models based on the shape of the aircraft, and uses the test model to conduct aerodynamic / thermal tests. In order to simulate the actual flight attitude, the wind tunnel is therefore equipped with an insertion mechanism that changes the model's angle of attack to change the attitude of the test model. Due to actual conditions such as model processing errors and slight errors in nozzle installation, the model is in the zero position of the insertion mechanism and generally has a non-zero angle relative to the airflow, which is called the airflow deflection angle. Due to the existence of the airflow deflection angle, the angle of attack changed by the insertion mechanism is not the real angle of attack, but the airflow deflection angle needs to be added to obtain the real angle of attack. Therefore, the airflow deflection angle affects the accuracy of the wind tunnel test results. At present, in wind tunnel tests, only force measurement tests can effectively interpolate and calculate the airflow deflection angle based on the balance data. For other tests that do not have a balance type, such as infrared thermal measurement, there is no effective way to evaluate the airflow deflection angle.

[0003] Infrared thermal imaging technology is a non-contact surface measurement technology that measures temperature and heat flow by measuring the radiation on the surface of an object. It usually uses an infrared thermal imager to directly measure the surface temperature of the model, and then calculates the heat flow based on the surface temperature of the model. It has been applied in wind tunnels to monitor the surface heat flow and flow state of the model. Compared with the balance force measurement method, infrared thermal imaging technology has the advantages of simple installation and measurement.

[0004] Therefore, it is urgent to propose a method for measuring the airflow deflection angle based on infrared thermal images to solve the technical problem that there is no effective way to evaluate the airflow deflection angle in the existing infrared thermal measurement technology, such as tests without a balance type. Summary of the invention

[0005] In order to overcome the problems existing in the related art, the present disclosure provides a method, device and medium for measuring the airflow deflection angle based on infrared thermal images, so as to solve the technical problems in the related art such as infrared thermal measurement without a balance type test and without an effective way to evaluate the airflow deflection angle.

[0006] One or more embodiments of this specification provide a method for measuring an airflow deflection angle based on an infrared thermal image, comprising the following steps:

[0007] A plane-symmetrical test model is selected, a symmetry plane degenerated into the direction of the symmetry axis is selected as a shooting plane of the test model, and the shooting plane, the lens plane and the shooting infrared window of the infrared thermal imager are placed parallel to each other;

[0008] During the wind tunnel test, the wind tunnel insertion mechanism sends the test model into the test position and changes the angle of attack in a stepwise manner, thereby obtaining an infrared thermal image of the surface temperature distribution of the test model corresponding to each angle of attack;

[0009] Finding a symmetry axis according to the contour of the photographing surface, flipping the infrared thermal image about the symmetry axis, and subtracting the infrared thermal image before flipping from the flipped infrared thermal image to obtain a symmetry temperature map;

[0010] The surface average temperature deviation corresponding to each attack angle is calculated according to the symmetry temperature map, and the attack angle corresponding to the infrared heat map with the minimum temperature deviation is selected as the airflow deflection angle.

[0011] Preferably, the stepwise change of the angle of attack specifically comprises the following steps:

[0012] The angle of attack was changed sequentially during the wind tunnel test according to an angle of attack sequence with an angle of attack range of -0.3° to 0.3°, an angle of attack interval of 0.1°, and a dwell time of 1 s at each angle of attack.

[0013] Preferably, the step of finding the axis of symmetry according to the contour of the shooting surface specifically comprises the following steps:

[0014] Two groups of feature points are found in the contour of the shooting surface, and then two midpoints are found respectively, and the two midpoints are connected to obtain a symmetry axis.

[0015] Preferably, flipping the infrared thermal image about the symmetry axis specifically comprises the following steps:

[0016] A symmetric transformation is performed on all pixel points on the infrared thermal image about the symmetry axis.

[0017] One or more embodiments of this specification provide an airflow deflection angle measurement device based on infrared thermal images, including a configuration module, a measurement module, a flip module, and a calculation module;

[0018] The configuration module is used to select a plane-symmetrical test model, select a symmetry plane that degenerates into the direction of the symmetry axis as a shooting plane of the test model, and place the shooting plane, the lens plane and the shooting infrared window of the infrared thermal imager in parallel;

[0019] When the measurement module is used in a wind tunnel test, a wind tunnel insertion mechanism sends the test model into a test position and changes the angle of attack in a stepwise manner, thereby obtaining an infrared thermal image of the surface temperature distribution of the test model corresponding to each angle of attack;

[0020] The flip module is used to find the symmetry axis according to the contour of the shooting surface, flip the infrared thermal image about the symmetry axis, and subtract the infrared thermal image before flipping from the infrared thermal image after flipping to obtain a symmetry temperature map;

[0021] The calculation module is used to calculate the surface average temperature deviation corresponding to each attack angle according to the symmetry temperature map, and select the attack angle corresponding to the infrared heat map with the minimum temperature deviation as the airflow deflection angle.

[0022] Preferably, the measuring module comprises a changing unit for sequentially changing the angle of attack during a wind tunnel test according to an angle of attack sequence with an angle of attack range of -0.3° to 0.3°, an angle of attack interval of 0.1°, and a dwell time of 1 s at each angle of attack.

[0023] Preferably, the flip module comprises a search unit for finding two groups of feature points in the contour of the shooting surface, and then finding two midpoints respectively, and connecting the two midpoints to obtain a symmetry axis.

[0024] Preferably, the flip module further comprises a flip unit for performing a symmetrical transformation on all pixels on the infrared thermal image about an axis of symmetry.

[0025] One or more embodiments of the present specification provide a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method for measuring airflow deflection angle based on infrared thermal images when executing the computer program.

[0026] One or more embodiments of the present specification provide a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-mentioned method for measuring airflow deflection angle based on infrared thermal images.

[0027] The present disclosure provides an airflow deflection angle measurement method, device, equipment and medium based on infrared thermal image, which has the advantages that by selecting a plane-symmetrical test model and selecting a symmetric plane that degenerates into the direction of the symmetry axis as the shooting surface of the test model, the symmetry property of the model itself can be fully utilized to place the shooting surface, the lens plane and the infrared window of the infrared thermal imager in parallel, so that the shooting angle and imaging conditions are relatively standardized and unified, and the image distortion caused by external factors such as shooting angle deviation and inaccurate temperature data collection are reduced; during the wind tunnel test, the wind tunnel insertion mechanism sends the test model into the test position and changes the angle of attack in a step-by-step manner to simulate a variety of different airflow working conditions, and obtains the infrared thermal image of the surface temperature distribution of the test model corresponding to each angle of attack, which can comprehensively collect data on the surface temperature change of the test model under the impact of different airflow angles, avoiding the situation where key information is missed by relying solely on a single angle of attack measurement; the symmetry axis is found according to the contour of the shooting surface, and the infrared thermal image is The symmetry axis is flipped, and the infrared thermal map after flipping is subtracted from the infrared thermal map before flipping to obtain a symmetric temperature map, which can remove the temperature information that is originally present in the symmetrical structure of the model itself and is symmetrically distributed under ideal conditions, thereby highlighting the temperature difference caused by asymmetric factors such as airflow deflection, so that when subsequently analyzing the relationship between temperature deviation and airflow deflection angle, more focus can be placed on the key temperature change part that truly reflects the airflow characteristics, thereby improving the measurement accuracy; the surface average temperature deviation corresponding to each angle of attack is calculated based on the symmetric temperature map, and the temperature change is quantified, so that the degree of temperature difference under different angles of attack can be judged based on the specific numerical value, and the angle of attack corresponding to the infrared thermal map with the smallest temperature deviation is selected as the airflow deflection angle. The temperature performance under various working conditions is comprehensively considered through an optimized screening mechanism, thereby avoiding the influence of random errors or local abnormal temperature changes on the results, and ensuring that the final airflow deflection angle result has high reliability and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate one or more embodiments of this specification 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 this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 A schematic flow chart of a method for measuring an airflow deflection angle based on an infrared thermal image provided in one or more embodiments of this specification;

[0030] Figure 2 A top view and a side view illustrating a method for measuring an airflow deflection angle provided in one or more embodiments of the present specification, Figure 2 (a) is a top view, Figure 2 (b) is a side view;

[0031] Figure 3 A schematic diagram of the symmetry judgment principle provided for one or more embodiments of this specification;

[0032] Figure 4 A schematic diagram of the structure of an airflow deflection angle measuring device based on infrared thermal images provided for one or more embodiments of this specification;

[0033] Figure 5 A schematic diagram of the structure of a computer device provided for one or more embodiments of this specification. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the technical solutions in one or more embodiments of this specification will be clearly and completely described below in conjunction with the drawings in one or more embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the protection scope of the present invention.

[0035] The present invention is described in detail below in conjunction with specific implementation methods and the accompanying drawings.

[0036] Method Embodiment

[0037] According to an embodiment of the present invention, a method for measuring airflow deflection angle based on infrared thermal image is provided. Figure 1 As shown, it is a schematic diagram of the flow chart of the airflow deflection angle measurement method based on infrared heat map provided in this embodiment. According to the airflow deflection angle measurement method based on infrared heat map of the embodiment of the present invention, the following steps are included:

[0038] S110. Select a test model with plane symmetry (such as a plate, cone, etc.). The surface of the processed test model is required to be symmetrical about the symmetry plane, and the degree of symmetry is ≤0.05mm. Select the symmetry plane that degenerates into the direction of the symmetry axis as the shooting surface of the test model. The shooting surface is any half of the model surface. The material of the shooting surface is required to meet the requirements of infrared thermal imaging with high emissivity and low heat transfer coefficient, and is generally PEEK (polyetheretherketone). Place the shooting surface, lens plane and infrared window of the infrared thermal imager parallel to each other. Figure 2As shown, the top view and side view of the method for measuring the airflow deflection angle provided in this embodiment, (a) is a top view, (b) is a side view, when the test model is installed, it is required that the shooting surface of the model is parallel to the shooting window when the model reaches the test position, and when the infrared thermal imager is installed, the lens plane is required to be parallel to the shooting window, and the installation error is required to be ≤3 points. At the same time, the field of view of the thermal imager is adjusted until the shooting surface of the model can be completely photographed.

[0039] S120. The test wind tunnel is a conventional hypersonic wind tunnel. The wind tunnel is a blowing wind tunnel. When the air source is sufficient, the continuous working time is in the order of minutes. The effective time of the test can include the time used to change multiple angles of attack in a single test. The wind tunnel is equipped with an insertion mechanism that can continuously change the angle of attack to ensure that the angle of attack can be changed multiple times in a step-by-step manner during the test. During the wind tunnel test, when the wind tunnel flow field is established and stabilized, the thermal imager starts shooting, and the wind tunnel insertion mechanism sends the test model into the test position and changes the angle of attack in a step-by-step manner (reasonably determine the parameters: the range of the angle of attack is (θ1, θ2), specifically based on the actual experience of estimating the range of the airflow deflection angle, the angle of attack interval is dθ, which determines the error of the method for estimating the airflow deflection angle, that is, the error of the method is ±dθ / 2, and the dwell time dt at each angle of attack needs to ensure that the thermal map distribution has stabilized and is not changing), and obtain the infrared thermal map of the surface temperature distribution of the test model corresponding to each angle of attack.

[0040] S130, observe the infrared thermal image measurement results, as the angle of attack changes from negative to positive, the temperature distribution of the shooting surface undergoes asymmetric-symmetric-asymmetric changes about the symmetry axis. Analyze the symmetry of the temperature distribution cloud map at each angle of attack, and the method for judging the symmetry of the thermal image is as follows: find the symmetry axis according to the contour of the shooting surface, flip the infrared thermal image about the symmetry axis, and subtract the infrared thermal image before flipping from the flipped infrared thermal image to obtain a symmetric temperature map.

[0041] S140. Calculate the average surface temperature deviation corresponding to each angle of attack based on the symmetry temperature map. The smaller the value, the better the symmetry of the model surface temperature distribution about the symmetry axis. Select the infrared thermal map with the smallest temperature deviation, that is, the thermal map result with the best symmetry. The angle of attack corresponding to this result is the airflow deflection angle of the test model.

[0042] The method provided in this embodiment selects a plane-symmetrical test model and selects a symmetry plane that degenerates into the direction of the symmetry axis as the shooting surface of the test model. It can make full use of the symmetry property of the model itself to place the shooting surface, the lens plane and the infrared window of the infrared thermal imager in parallel, so that the shooting angle and imaging conditions are relatively standardized and unified, and reduce problems such as image distortion and inaccurate temperature data collection caused by external factors such as shooting angle deviation; during the wind tunnel test, the wind tunnel insertion mechanism sends the test model into the test position and changes the angle of attack in a step-by-step manner to simulate a variety of different airflow working conditions, and obtains the infrared thermal map of the surface temperature distribution of the test model corresponding to each angle of attack, which can comprehensively collect data on the surface temperature change of the test model under the impact of different airflow angles, avoiding the situation where key information is missed by relying solely on a single angle of attack measurement; the symmetry axis is found according to the contour of the shooting surface, and the infrared thermal map is flipped about the symmetry axis, and the flipped The symmetric temperature map is obtained by subtracting the infrared thermal map before flipping from the infrared thermal map after flipping. This can remove the temperature information that is originally present in the symmetrical structure of the model and is symmetrically distributed under ideal conditions, thereby highlighting the temperature difference caused by asymmetric factors such as airflow deflection, so that when subsequently analyzing the relationship between temperature deviation and airflow deflection angle, more focus can be placed on the key temperature change part that truly reflects the airflow characteristics, thereby improving the measurement accuracy. The average surface temperature deviation corresponding to each angle of attack is calculated based on the symmetric temperature map, and the temperature change is quantified, so that the degree of temperature difference under different angles of attack can be judged based on the specific numerical value. The angle of attack corresponding to the infrared thermal map with the smallest temperature deviation is selected as the airflow deflection angle. The temperature performance under various working conditions is comprehensively considered through an optimized screening mechanism, thereby avoiding the influence of random errors or local abnormal temperature changes on the results, and ensuring that the final airflow deflection angle result has high reliability and accuracy.

[0043] In one embodiment, the stepwise change of the angle of attack specifically comprises the following steps:

[0044] The angle of attack was changed sequentially during the wind tunnel test according to an angle of attack sequence with an angle of attack range of -0.3° to 0.3°, an angle of attack interval of 0.1°, and a dwell time of 1 s at each angle of attack.

[0045] The method provided in this embodiment can accurately focus on the key angle of attack range, obtain multiple data points at reasonable and fine intervals, and ensure accurate temperature collection through appropriate residence time, efficiently complete the test process, and facilitate accurate measurement of the airflow deflection angle.

[0046] In one embodiment, Figure 3 The above is a schematic diagram of the symmetry judgment principle provided by this embodiment, and the finding of the symmetry axis according to the contour of the shooting surface specifically includes the following steps:

[0047] Two groups of feature points are found in the contour of the shooting surface, and then two midpoints are found respectively, and the two midpoints are connected to obtain a symmetry axis.

[0048] The method provided in this embodiment finds the symmetry axis through specific feature points and midpoint determination methods, provides an accurate basis for subsequent operations such as image flipping and temperature deviation analysis based on the symmetry axis, and helps to accurately measure the airflow deflection angle.

[0049] In one embodiment, flipping the infrared thermal image about the symmetry axis specifically comprises the following steps:

[0050] A symmetric transformation is performed on all pixel points on the infrared thermal image about the symmetry axis.

[0051] The method provided in this embodiment performs a symmetrical transformation on all pixel points of the infrared thermal image, thereby facilitating subsequent subtraction to remove the influence of the symmetrical part, highlighting the asymmetric temperature characteristics caused by the airflow deviation, and accurately measuring the airflow deviation angle.

[0052] Device Embodiment

[0053] According to an embodiment of the present invention, a device for measuring airflow deflection angle based on infrared thermal images is provided. Figure 4 As shown, it is a schematic diagram of the structure of the airflow deflection angle measuring device based on infrared thermal image provided in this embodiment. According to the airflow deflection angle measuring device based on infrared thermal image according to the embodiment of the present invention, it includes a configuration module 41, a measurement module 42, a flipping module 43 and a calculation module 44.

[0054] The configuration module 41 is used to select a plane-symmetrical test model, select a symmetry plane that degenerates into a symmetry axis direction as a shooting plane of the test model, and place the shooting plane, the lens plane and the shooting infrared window of the infrared thermal imager in parallel.

[0055] The measuring module 42 is used for wind tunnel testing. The wind tunnel insertion mechanism sends the test model into the test position and changes the angle of attack in a stepwise manner to obtain an infrared thermal image of the surface temperature distribution of the test model corresponding to each angle of attack.

[0056] The flip module 43 finds the symmetry axis according to the contour of the shooting surface, flips the infrared thermal image about the symmetry axis, and subtracts the infrared thermal image before flipping from the infrared thermal image after flipping to obtain a symmetry temperature map.

[0057] The calculation module 44 calculates the surface average temperature deviation corresponding to each attack angle according to the symmetry temperature map, and selects the attack angle corresponding to the infrared heat map with the minimum temperature deviation as the airflow deflection angle.

[0058] The device provided in this embodiment, the configuration module 41 selects a plane-symmetrical test model and selects the symmetry plane that degenerates into the direction of the symmetry axis as the shooting surface of the test model. It can make full use of the symmetry property of the model itself to place the shooting surface, the lens plane and the infrared window of the infrared thermal imager in parallel, so that the shooting angle and imaging conditions are relatively standardized and unified, and reduce the image distortion caused by external factors such as shooting angle deviation and inaccurate temperature data collection. Problems such as; when the measuring module 42 is tested in a wind tunnel, the wind tunnel insertion mechanism sends the test model into the test position and changes the angle of attack in a step-by-step manner to simulate a variety of different airflow working conditions, and obtains the infrared thermal map of the surface temperature distribution of the test model corresponding to each angle of attack, which can comprehensively collect data on the surface temperature change of the test model under the impact of different airflow angles, avoiding the situation where key information is missed by relying solely on a single angle of attack measurement; the flipping module 43 finds the axis of symmetry according to the contour of the shooting surface, and performs a rotation of the infrared thermal map about the axis of symmetry. The infrared thermal image before flipping is flipped and the infrared thermal image after flipping is subtracted from the infrared thermal image before flipping to obtain a symmetrical temperature map, which can remove the temperature information that originally exists in the symmetrical structure of the model itself and is symmetrically distributed under ideal conditions, thereby highlighting the temperature difference caused by asymmetric factors such as airflow deflection, so that when subsequently analyzing the relationship between temperature deviation and airflow deflection angle, more focus can be placed on the key temperature change part that truly reflects the airflow characteristics, thereby improving the measurement accuracy; the calculation module 44 calculates the surface average temperature deviation corresponding to each angle of attack according to the symmetrical temperature map, and quantifies the temperature change, so that the degree of temperature difference under different angles of attack can be judged according to the specific numerical value, and the angle of attack corresponding to the infrared thermal image with the smallest temperature deviation is selected as the airflow deflection angle. The temperature performance under various working conditions is comprehensively considered through the optimized screening mechanism, avoiding the influence of random errors or local abnormal temperature changes on the results, and ensuring that the final airflow deflection angle result has high reliability and accuracy.

[0059] In one embodiment, the measuring module 42 includes a changing unit for sequentially changing the angle of attack during a wind tunnel test according to an angle of attack sequence with an angle of attack range of -0.3° to 0.3°, an angle of attack interval of 0.1°, and a dwell time of 1 s at each angle of attack.

[0060] The device provided in this embodiment can accurately focus on the key angle of attack range, obtain multiple data points at reasonable and fine intervals, and ensure accurate temperature collection through appropriate residence time, efficiently complete the test process, and facilitate accurate measurement of airflow deflection angle.

[0061] In one embodiment, the flip module 43 includes a search unit for finding two groups of feature points in the contour of the shooting surface, and then finding two midpoints respectively, and connecting the two midpoints to obtain a symmetry axis.

[0062] The device provided in this embodiment finds the symmetry axis through specific feature points and midpoint determination methods, provides an accurate basis for subsequent operations such as image flipping and temperature deviation analysis based on the symmetry axis, and helps to accurately measure the airflow deflection angle.

[0063] In one embodiment, the flip module 43 further includes a flip unit for performing a symmetrical transformation on all pixel points on the infrared thermal image about the symmetry axis.

[0064] The device provided in this embodiment performs symmetrical transformation on all pixel points of the infrared thermal image, thereby facilitating subsequent subtraction to remove the influence of the symmetrical part, highlighting the asymmetric temperature characteristics caused by the airflow deflection, and accurately measuring the airflow deflection angle.

[0065] The embodiment of the present invention is an apparatus embodiment corresponding to the above-mentioned method embodiment. The specific operations of the processing steps of each module can be understood by referring to the description of the method embodiment, which will not be repeated here.

[0066] like Figure 5 As shown, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which implements the airflow deflection angle measurement method in the above-mentioned embodiment when the computer program is executed by a processor, or implements the airflow deflection angle measurement method based on infrared thermal image in the above-mentioned embodiment when the computer program is executed by a processor.

[0067] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0068] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The device and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and the contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A method for measuring airflow deflection angle based on infrared thermal image, characterized in that: The following steps are involved: A plane-symmetrical test model is selected, a symmetry plane degenerated into the direction of the symmetry axis is selected as a shooting plane of the test model, and the shooting plane, the lens plane and the shooting infrared window of the infrared thermal imager are placed parallel to each other; During the wind tunnel test, the wind tunnel insertion mechanism sends the test model into the test position and changes the angle of attack in a stepwise manner, thereby obtaining an infrared thermal image of the surface temperature distribution of the test model corresponding to each angle of attack; Finding a symmetry axis according to the contour of the photographing surface, flipping the infrared thermal image about the symmetry axis, and subtracting the infrared thermal image before flipping from the flipped infrared thermal image to obtain a symmetry temperature map; The surface average temperature deviation corresponding to each attack angle is calculated according to the symmetry temperature map, and the attack angle corresponding to the infrared heat map with the minimum temperature deviation is selected as the airflow deflection angle.

2. The method for measuring airflow deflection angle according to claim 1, characterized in that: The stepwise change of the angle of attack specifically comprises the following steps: The angle of attack was changed sequentially during the wind tunnel test according to an angle of attack sequence with an angle of attack range of -0.3° to 0.3°, an angle of attack interval of 0.1°, and a dwell time of 1 s at each angle of attack.

3. The method for measuring airflow deflection angle according to claim 1, characterized in that: The step of finding the axis of symmetry according to the contour of the shooting surface specifically comprises the following steps: Two groups of feature points are found in the contour of the shooting surface, and then two midpoints are found respectively, and the two midpoints are connected to obtain a symmetry axis.

4. The method for measuring airflow deflection angle according to claim 1, characterized in that: The flipping of the infrared thermal image about the symmetry axis specifically comprises the following steps: A symmetric transformation is performed on all pixel points on the infrared thermal image about the symmetry axis.

5. An airflow deflection angle measuring device based on infrared thermal image, characterized in that: It includes a configuration module, a measurement module, a flip module and a calculation module; The configuration module is used to select a plane-symmetrical test model, select a symmetry plane that degenerates into the direction of the symmetry axis as a shooting plane of the test model, and place the shooting plane, the lens plane and the shooting infrared window of the infrared thermal imager in parallel; When the measurement module is used in a wind tunnel test, a wind tunnel insertion mechanism sends the test model into a test position and changes the angle of attack in a stepwise manner, thereby obtaining an infrared thermal image of the surface temperature distribution of the test model corresponding to each angle of attack; The flip module is used to find the symmetry axis according to the contour of the shooting surface, flip the infrared thermal image about the symmetry axis, and subtract the infrared thermal image before flipping from the infrared thermal image after flipping to obtain a symmetry temperature map; The calculation module is used to calculate the surface average temperature deviation corresponding to each attack angle according to the symmetry temperature map, and select the attack angle corresponding to the infrared heat map with the minimum temperature deviation as the airflow deflection angle.

6. The airflow deflection angle measuring device according to claim 5, characterized in that: The measuring module comprises a changing unit for sequentially changing the angle of attack during a wind tunnel test according to an angle of attack sequence with an angle of attack range of -0.3° to 0.3°, an angle of attack interval of 0.1°, and a dwell time of 1 second for each angle of attack.

7. The airflow deflection angle measuring device according to claim 5, characterized in that: The flip module includes a search unit for finding two groups of feature points in the contour of the shooting surface, and then finding two midpoints respectively, and connecting the two midpoints to obtain a symmetry axis.

8. The airflow deflection angle measuring device according to claim 5, characterized in that: The flip module also includes a flip unit, which is used to perform a symmetrical transformation on all pixel points on the infrared thermal image about a symmetry axis.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method for measuring the airflow deflection angle based on infrared thermal images as described in any one of claims 1 to 4 is implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method for measuring airflow deflection angle based on infrared thermal images as claimed in any one of claims 1 to 4 are implemented.

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