An optical experimental system and experimental method for measuring the total temperature of a supersonic flow field

Abstract

The invention discloses an optical test system and a test method for measuring the total temperature of a supersonic flow field, and relates to the field of supersonic flow field measurement, comprising: a static temperature measurement system, a velocity measurement system and a timing controller; the static temperature measurement system is used for generating narrowband pump light, detection light and broadband Stokes light, and converging the narrowband pump light, detection light and broadband Stokes light into a measured position of the flow field to generate anti-Stokes light, and collecting the anti-Stokes light after filtering to obtain the static temperature at the measured position; the velocity measurement system is used for generating laser focusing into the flow field, collecting and obtaining the motion information of a marked substance, and calculating the airflow velocity at the measured position based on the motion information of the marked substance; the timing controller is used for controlling the static temperature measurement system and the velocity measurement system to work synchronously, and obtaining the static temperature at the measured position and the airflow velocity at the measured position at the same time; the calculation unit is used for calculating the total temperature of the corresponding area of ​​the measured position based on the static temperature at the measured position and the airflow velocity at the measured position; the invention can solve the problems that the current contact measurement may invade and destroy the flow field structure and the intruding parts may be ablated and fail under high total temperature conditions.

Description

Technical Field

[0001] The present invention relates to the field of supersonic flow field measurement, and specifically, to an optical test system and test method for measuring the total temperature of a supersonic flow field. Background Art

[0002] In the supersonic flow state, the total parameters of the airflow (such as total temperature, total pressure, Mach number) are important physical quantities characterizing its characteristics. For ground supersonic tests, obtaining the total parameters of the supersonic flow is very important for determining the test state and analyzing the test results. The acquisition of the total temperature in the supersonic combustion flow field and the supersonic cold flow field (without combustion chemical reaction) is basically mainly through the contact total temperature probe measurement technology. It can be seen from the reports on the optimized design of the total temperature measurement structure that currently, the user side is still improving its anti-damage performance and airflow stagnation efficiency through the optimized design of the total temperature probe structure. For detailed information, see the literature Zhang Zhuoli, Wang Jiawei, Dong Weichao, Huang Kaifang. Optimization Design of the Thermocouple Structure of a Total Temperature and Total Pressure Sensor [J]. China Measurement & Test, 2023, 49(12): 73-78. However, the contact total temperature measurement method has two obvious disadvantages. One is that the flow structure of the supersonic flow field will be damaged by the intruding probe, thereby affecting various parameters of the flow field at the local and downstream positions of the probe. The other is that for the measured object with a very high total temperature of the oncoming flow, the contact structure body itself will face the problems of ablation and failure. Summary of the Invention

[0003] The purpose of the present invention is to solve the problems that the current contact measurement will invade and damage the flow field structure and the intruding part will be ablated and fail under high total temperature conditions.

[0004] To achieve the above-mentioned invention purpose, the present invention provides an optical test system for measuring the total temperature of a supersonic flow field, and the system includes:

[0005] A static temperature measurement system, a velocity measurement system, and a timing controller;

[0006] The static temperature measurement system is used to generate narrowband pump light, probe light, and broadband Stokes light, and converge the narrowband pump light, probe light, and broadband Stokes light into the measured position of the flow field to generate anti-Stokes light, and collect and process the filtered anti-Stokes light to obtain the static temperature at the measured position;

[0007] The velocity measurement system is used to generate a laser and focus it into the flow field, collect the motion information of the labeled substance, and calculate the airflow velocity at the measured position based on the motion information of the labeled substance;

[0008] The timing controller is used to control the synchronous operation of the static temperature measurement system and the velocity measurement system to obtain the static temperature at the measured position and the airflow velocity at the measured position at the same moment;

[0009] A calculation unit for calculating the total temperature of the corresponding area of the measured position based on the static temperature at the measured position and the air flow velocity at the measured position.

[0010] Among them, the present invention is based on a non-contact optical testing technology. Without invading the flow field, the flow field velocity is obtained by marking nitrogen in the flow field, the static temperature at the measurement position is obtained by using nitrogen in the flow field based on the principle of coherent anti-Stokes Raman scattering, and the total temperature of the flow field is obtained by synchronously measuring the velocity and the static temperature. It provides an experimental measurement method for evaluating the oncoming flow parameters of the flow field, and fundamentally solves the problems of invasive destruction of the flow field and ablation of the invasive parts under high total temperature conditions.

[0011] Among them, in some embodiments, the static temperature measurement system includes:

[0012] An Nd:YAG laser, a first laser beam splitter M1, a fuel laser, a first total reflection mirror M2, a laser beam expander system, a second total reflection mirror M5, an inclined reflection mirror M6, a first focusing mirror M7, a second focusing mirror M8, a second laser beam splitter M9, a light shield, a filtering system, a third focusing mirror M10, a collection end, an optical fiber, a spectrometer, a first ICCD, and a first computer;

[0013] The Nd:YAG laser emits a first laser as a pump light source. The first laser is split by the first laser beam splitter M1 to obtain a second laser and a third laser. The second laser is injected into the fuel laser. The fuel laser serves as a Stokes light source. After passing through the fuel laser, the second laser outputs broadband Stokes light and injects it into the inclined reflection mirror M6. The third laser is a narrowband pump light and a probe light. After being reflected by the first total reflection mirror M2, the third laser enters the laser beam expander system for beam expansion processing to obtain a fourth laser. The fourth laser is reflected by the second total reflection mirror M5 and then injected into the inclined reflection mirror M6. The inclined reflection mirror M6 is used to transmit the broadband Stokes light and reflect the narrowband pump light and the probe light. The fourth laser reflected by the inclined reflection mirror M6 and the broadband Stokes light transmitted by the inclined reflection mirror M6 are converged by the first focusing mirror M7 at the measured position of the flow field to generate anti-Stokes light. The beam containing the anti-Stokes light is emitted from the flow field and then injected into the second focusing mirror M8. The second focusing mirror M8 converges the beam on the second laser beam splitter M9. The second laser beam splitter M9 reflects the non-anti-Stokes light in the beam to the light shield, and transmits the anti-Stokes light in the beam to the filtering system. The laser processed by the filtering system is focused on the collection end by the third focusing mirror M10. The collection end transmits the laser to the spectrometer through an optical fiber signal. The spectrometer forms an image of the laser signal through the first ICCD, and the first computer calculates the static temperature at the measured position based on the imaging result of the first ICCD.

[0014] Among them, in some embodiments, the velocity measurement system includes:

[0015] Femtosecond laser, third total reflection mirror M11, fourth focusing mirror M12, second ICCD, and second computer;

[0016] The femtosecond laser outputs laser light that is incident on the third total reflection mirror M11. After being reflected by the third total reflection mirror M11, the laser light is incident on the fourth focusing mirror M12. The fourth focusing mirror M12 focuses the laser light into the flow field. The second ICCD collects the motion information of the labeled substance, and the second computer calculates the airflow velocity at the measured position based on the motion information of the labeled substance.

[0017] Among them, in some embodiments, the timing controller controls the femtosecond laser to emit laser light first, and after a preset time period, the timing controller controls the second ICCD to take pictures.

[0018] Among them, in some embodiments, the second computer calculates the airflow velocity at the measured position based on the starting position, motion time, and ending position of the labeled substance.

[0019] Among them, in some embodiments, the laser beam expander system includes: a concave lens M3 and a fifth focusing mirror M4. The concave lens M3 is used to diverge the third laser, and the fifth focusing mirror M4 is used to converge the diverged laser.

[0020] Among them, in some embodiments, the flow field contains nitrogen, and the airflow in the flow field is a supersonic airflow.

[0021] Among them, in some embodiments, the timing controller is used to control the Nd:YAG laser to turn on in the time period from t o to t1, and control the first ICCD to turn on in the time period from t o to t1, so that when the temperature measurement system excites the measured flow field with the laser, the detector can synchronously record the temperature information; control the femtosecond laser to turn on in the time period from t1 to t2, and control the second ICCD to turn on in the time period from t3 to t4, so that the displacement of the substance marked by the femtosecond laser in the flow field can be recorded by the detector after a certain time, and then the velocity can be calculated.

[0022] Among them, in some embodiments, the calculation method of the total temperature of the area corresponding to the measured position is:

[0023]

[0024] T * = T · (1 + 0.2 · Ma 2 );

[0025] Among them, c is the speed of sound, T is the static temperature, Ma is the Mach number, V is the velocity, and T * is the total temperature.

[0026] The present invention also provides a test method for the optical test system for measuring the total temperature of a supersonic flow field, and the method includes:

[0027] Step1: Set up the optical test system;

[0028] Step2: Turn on the static temperature measurement system, and confirm the temperature measurement position at the measured position through the fluorescence generated by the laser on the positioning paper;

[0029] Step3: Turn off the static temperature measurement system and turn on the velocity measurement system, and confirm the velocity measurement position at the measured position through the fluorescence generated by the laser on the positioning paper;

[0030] Step4: Make the measurement point positions of the static temperature measurement system and the velocity measurement system coincide by adjusting and fixing the lens frames of each lens of the static temperature measurement system and the lens frames of each lens of the velocity measurement system;

[0031] Step5: Adjust the static temperature measurement system and the velocity measurement system to the standby state;

[0032] Step6: Turn on the flow field;

[0033] Step7: Turn on the optical test system;

[0034] Step8: After a period of time, turn off the optical test system and the flow field in sequence;

[0035] Step9: Process the results, calculate the static temperature at the measured position and the air flow velocity at the measured position respectively, and calculate the total temperature of the corresponding area at the measured position.

[0036] One or more technical solutions provided by the present invention have at least the following technical effects or advantages:

[0037] The non-contact measurement adopted by the present invention can fundamentally solve the problems of invasive destruction of the flow field and ablation of invasive parts under high total temperature conditions without invading the flow field. Description of the Drawings

[0038] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, and constitute a part of the present invention, but do not limit the embodiments of the present invention;

[0039] Figure 1 It is a schematic diagram of the composition of an optical test system for measuring the total temperature of a supersonic flow field;

[0040] Figure 2 It is a schematic diagram of the timing relationship of each component in the system;

[0041] Figure 3 It is a schematic diagram of the measurement position at the test site;

[0042] Figure 4 It is a schematic diagram of the velocity distribution at the measured position;

[0043] Figure 5 It is a schematic diagram of the Stokes light intensity distribution at the measured position. Specific implementation manners

[0044] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0045] Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention may be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0046] Embodiment 1;

[0047] The schematic diagram of the composition of the total temperature measurement test system in the embodiment of the present invention is as Figure 1 shown, where M1 / M9 are the first and second laser beam splitters respectively, M2 / M5 / M11 are the first, second and third total reflection mirrors respectively, M3 is a concave lens, M4 / M7 / M8 / M10 / M12 are the fifth, first, second, third and fourth focusing lenses respectively, M6 is an inclined reflection mirror, LBES is a laser beam expansion system, EDS is a beam expansion and delay system, SP is a light shielding plate, and FS is a filtering system.

[0048] Generally speaking, the present invention includes a static temperature measurement system and a velocity measurement system. The working time of the two systems is controlled by a timing controller to make them work synchronously, so as to obtain the static temperature and velocity at the same moment; by adjusting the optical path system, the focal points of the optical paths of the two systems are basically located in the same region in space, so as to ensure that the measurement positions of the two systems are basically coincident.

[0049] The static temperature measurement system includes an excitation light source, an optical path system, data acquisition, and timing control. The excitation light source includes a narrowband Nd:YAG laser and a broadband dye laser, which serve as the pump light source and the Stokes light source respectively. The laser of the pump light source is a narrowband laser with a central wavelength of 532 nm. After passing through the M1 laser beam splitter, a part of it enters the dye laser. After the action of the dye, broadband Stokes light is output. The other part of the narrowband laser serves as the pump light and the probe light. The pump light and the probe light reach the M6 inclined mirror after beam expansion and reflection. The characteristic of this mirror is that it can transmit broadband Stokes light and reflect narrowband pump light / probe light. The two laser beams reaching M6 are converged at the measured position in the flow field after passing through the M7 focusing lens. At this position, the two focused laser beams interact with each other in an environment containing N2, generating an anti-Stokes light beam. The spectrum of this light signal is strongly related to the local temperature, and the temperature can be inversely calculated therefrom. The light passing through the flow field reflects the light other than the anti-Stokes light through the M9 laser beam splitter, and at the same time transmits the anti-Stokes light. The transmitted anti-Stokes light may be mixed with stray light in other bands. The stray light is filtered out by the filtering system, and the clean anti-Stokes light is collected through the M10 focusing lens. The collection end transmits the light into the spectrometer through an optical fiber. The spectrometer unfolds the light and images it through the first ICCD. The imaging result of the first ICCD is multi-parameter fitted with the theoretical calculation spectrum to obtain the temperature at the focal position. For the specific method, see the literature Yang Wenbin, Qi Xinhua, Li Meng, etc. CARS Measurement of the Temperature Field Distribution at the Combustor Exit of a Scramjet Engine [J]. Journal of Propulsion Technology, 2022, 43(9): 210190.

[0050] The velocity measurement system includes a femtosecond laser, an optical path system, an imaging system, and timing control. After the femtosecond laser outputs a laser with a central wavelength of 800 nm, it is reflected by the M11 total reflection mirror and focused by the M12 focusing lens to form a region with a relatively high energy density in the flow field. All focusing lenses have fixed focal points, and the energy density of the laser is the highest at the intersection point. However, in the velocity measurement system introduced in the present invention, the energy density of the laser within a certain region near the focal point may mark N2, and the air flow velocity can be calculated by further recording the spatial displacement of the marked substance through the second ICCD. Through the timing controller, the working time of the second ICCD and the femtosecond laser is controlled, so that the femtosecond laser emits light first, and after a certain time, it is recorded by the second ICCD. In this way, the three information of the starting position, moving time, and ending position of the marked substance are all known, and the velocity at the measured position can be obtained through the simple relationship between displacement, time, and velocity.

[0051] Among them, the total temperature of the corresponding region at the measured position is calculated and obtained by the calculation unit based on the static temperature at the measured position and the air flow velocity at the measured position. The calculation unit can be a computer, a calculator, a processor, a chip, etc., and the specific limitation is not made in the embodiments of the present invention.

[0052] The main steps of the experiment are as follows:

[0053] Step1: Build the experimental system according to Figure 1 as shown;

[0054] Step2: Turn on the static temperature measurement system, and confirm the temperature measurement position at the measured position by the fluorescence generated by the laser on the positioning paper;

[0055] Step3: Turn off the static temperature measurement system and turn on the velocity measurement system, and confirm the velocity measurement position at the measured position by the fluorescence generated by the laser on the positioning paper;

[0056] Step4: Adjust the frames of the lenses of the static temperature measurement system and the frames of the lenses of the velocity measurement system so that the measurement points of the two systems basically coincide;

[0057] Step5: Set the static temperature and velocity measurement systems to the standby state;

[0058] Step6: Start the flow field;

[0059] Step7: Start the measurement system;

[0060] Step8: After a period of time, turn off the measurement system and the flow field in sequence;

[0061] Step9: Process the results, and calculate the static temperature, velocity and total temperature respectively.

[0062] Please refer to Figure 2 , Figure 2 , which is the timing control schematic diagram of the timing controller. The timing controller is respectively connected to the Nd:YAG laser, the first ICCD, the femtosecond laser and the second ICCD. The timing controller is used to control the Nd:YAG laser to turn on in the time period from t o to t1, control the first ICCD to turn on in the time period from t o to t1, control the femtosecond laser to turn on in the time period from t1 to t2, and control the second ICCD to turn on in the time period from t3 to t4.

[0063] Please refer to Figure 3 , Figure 3 , which is the schematic diagram of the measurement position at the test site. Figure 3 In it, a is the original figure, b is the figure with the coordinate origin and the specific measurement position indicated. The present invention realizes the synchronous measurement of velocity and static temperature at the measurement points shown in Figure 3 , and then obtains the total temperature through the mutual relationship between the speed of sound (c), static temperature (T), Mach number (Ma) and total temperature (T * ).

[0064] For the convenience of display,Figure 3 The schlieren test results of the measured flow field are given. As shown in the figure: The supersonic airflow flows up and down in the restricted space from left to right. There is a structure in the center of the flow field. The upstream of the flow field is connected to a supersonic nozzle with a designed Mach number of 2.0. The origin of the flow field is the center position at the end of the central structure. The measurement position of this test is at the position of 88.9 mm in the flow direction and 10 mm longitudinally. It can be seen from the schlieren results that the measured flow field is in a supersonic flow state (because there are shock waves in the flow field).

[0065] Figure 4 The schematic diagram of the velocity distribution at the measured position is given. As shown in the figure, the velocity distribution is recorded in the region from 9.25 mm to 10.51 mm in the y direction with a total length of 1.26 mm, indicating that the femtosecond laser successfully marked N2 in this region and was recorded by the second ICCD. The velocity range in this region is from 515 m / s to 534 m / s, and the average velocity is 527.8 m / s.

[0066] Figure 5 The schematic diagram of the Stokes light intensity distribution at the measured position is given. The scatter points are the measured light intensities, and the solid line is the result of multi-parameter fitting based on the spectral calculation of the scatter points according to the theory. The fitting temperature is 172 K, and this temperature is the static temperature at the measured position.

[0067] According to the acoustic velocity calculation formula of the gas, the Mach number calculation formula, and the relationship between the total temperature and the static temperature, the calculation process of the total temperature in the measured region is as follows:

[0068]

[0069] T * = T · (1 + 0.2 · Ma 2 ) = 172 · (1 + 0.2 · 2.01 2 ) = 311 K (3)

[0070] In formula (1), c is the acoustic velocity, T is the static temperature. In formula (2), Ma is the Mach number, V is the velocity. In formula (3), T * is the total temperature. Through calculation, it is obtained that the total temperature in the measured region of about 2 mm is about 311 K. When accelerating normal temperature air to the supersonic state, its total temperature should be close to the normal temperature. The difference between the total temperature obtained from this test and the room temperature of 298 K is about 4%, which proves that the results of the present invention are highly reliable.

[0071] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0072] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims

1. An optical test system for measuring the total temperature of a supersonic flow field, characterized in that, The system includes: a static temperature measurement system, a velocity measurement system, and a timing controller; The static temperature measurement system is used to generate narrowband pump light, probe light, and broadband Stokes light, and converge the narrowband pump light, probe light, and broadband Stokes light into the measured position of the flow field to generate anti-Stokes light, and collect and process the filtered anti-Stokes light to obtain the static temperature at the measured position; The velocity measurement system is used to generate a laser and focus it into the flow field, collect the motion information of the labeled substance, and calculate the air velocity at the measured position based on the motion information of the labeled substance; The timing controller is used to control the synchronous operation of the static temperature measurement system and the velocity measurement system to obtain the static temperature at the measured position and the air velocity at the measured position at the same moment; a calculation unit, which is used to calculate the total temperature of the corresponding area of the measured position based on the static temperature at the measured position and the air velocity at the measured position.

2. The optical test system for measuring the total temperature of a supersonic flow field according to claim 1, wherein, The static temperature measurement system includes: a Nd:YAG laser, a first laser beam splitter M1, a fuel laser, a first total reflection mirror M2, a laser beam expander system, a second total reflection mirror M5, an inclined reflection mirror M6, a first focusing mirror M7, a second focusing mirror M8, a second laser beam splitter M9, a light shield, a filtering system, a third focusing mirror M10, a collection end, an optical fiber, a spectrometer, a first ICCD, and a first computer; The Nd:YAG laser emits a first laser as a pump light source. After the first laser is split by the first laser beam splitter M1, a second laser and a third laser are obtained. The second laser is injected into the fuel laser. The fuel laser serves as a Stokes light source. After passing through the fuel laser, the second laser outputs broadband Stokes light and injects it into the inclined reflection mirror M6. The third laser is narrowband pump light and probe light. After being reflected by the first total reflection mirror M2, the third laser enters the laser beam expander system for beam expansion processing to obtain a fourth laser. After being reflected by the second total reflection mirror M5, the fourth laser is injected into the inclined reflection mirror M6. The inclined reflection mirror M6 is used to transmit the broadband Stokes light and reflect the narrowband pump light and probe light. The fourth laser reflected by the inclined reflection mirror M6 and the broadband Stokes light transmitted by the inclined reflection mirror M6 are converged at the measured position of the flow field by the first focusing mirror M7 to generate anti-Stokes light. The beam containing the anti-Stokes light is emitted from the flow field and injected into the second focusing mirror M8. The second focusing mirror M8 converges the beam onto the second laser beam splitter M9. The second laser beam splitter M9 reflects the non-anti-Stokes light in the beam to the light shield, and transmits the anti-Stokes light in the beam to the filtering system. The laser processed by the filtering system is focused on the collection end by the third focusing mirror M10. The collection end transmits the laser to the spectrometer through an optical fiber signal. The spectrometer images the laser signal through the first ICCD. The first computer calculates the static temperature at the measured position based on the imaging result of the first ICCD.

3. The optical test system for measuring the total temperature of a supersonic flow field according to claim 2, characterized in that, The velocity measurement system includes: a femtosecond laser, a third total reflection mirror M11, a fourth focusing mirror M12, a second ICCD, and a second computer; The laser output by the femtosecond laser enters the third total reflection mirror M11. After being reflected by the third total reflection mirror M11, the laser enters the fourth focusing mirror M12. The fourth focusing mirror M12 focuses the laser to the measured position in the flow field. The second ICCD collects the motion information of the labeled substance, and the second computer calculates the air flow velocity at the measured position based on the motion information of the labeled substance.

4. An optical test system for measuring the total temperature of a supersonic flow field according to claim 3, characterized in that, The timing controller controls the femtosecond laser to emit laser first, and after a preset time period, the timing controller controls the second ICCD to take pictures.

5. The optical test system for measuring the total temperature of a supersonic flow field according to claim 3, wherein The second computer calculates the air flow velocity at the measured position based on the starting position, motion time, and ending position of the labeled substance.

6. An optical test system for measuring the total temperature of a supersonic flow field according to claim 2, wherein, The laser beam expander system includes: a concave lens M3 and a fifth focusing mirror M4. The concave lens M3 is used to diverge the third laser, and the fifth focusing mirror M4 is used to converge the diverged laser.

7. An optical test system for measuring the total temperature of a supersonic flow field according to claim 1, characterized in that, The flow field contains nitrogen, and the air flow in the flow field is a supersonic air flow.

8. The optical test system for measuring the total temperature of a supersonic flow field according to claim 3, wherein, The timing controller is used to control the Nd:YAG laser to turn on during the time period from t o to t1, control the first ICCD to turn on during the time period from t o to t1, control the femtosecond laser to turn on during the time period from t1 to t2, and control the second ICCD to turn on during the time period from t2 to t3.

9. An optical test system for measuring the total temperature of a supersonic flow field according to claim 1, characterized in that, The calculation method for the total temperature of the area corresponding to the measured position is: ； ； ； Wherein, c is the speed of sound, T is the static temperature, Ma is the Mach number, V is the velocity, T * is the total temperature.

10. A test method for an optical test system for measuring the total temperature of a supersonic flow field according to any one of claims 1-9, characterized in that, The method includes: Step1: Set up the optical test system; Step2: Turn on the static temperature measurement system, and confirm the temperature measurement position through the fluorescence generated by the laser on the positioning paper at the measured position; Step3: Turn off the static temperature measurement system and turn on the velocity measurement system, and confirm the velocity measurement position through the fluorescence generated by the laser on the positioning paper at the measured position; Step4: Adjust and fix the lens frames of each lens of the static temperature measurement system and the lens frames of each lens of the velocity measurement system so that the measurement point positions of the static temperature measurement system and the velocity measurement system coincide; Step5: Set the static temperature measurement system and the velocity measurement system to the standby state; Step6: Turn on the flow field; Step7: Turn on the optical test system; Step8: Turn off the optical test system and the flow field in sequence after a period of time; Step9: Result processing, calculate the static temperature at the measured position, the air flow velocity at the measured position, and calculate the total temperature of the area corresponding to the measured position respectively.

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