Ultrahigh-temperature airflow total temperature probe based on single-crystal optical fiber built-in blackbody cavity and manufacturing method of ultrahigh-temperature airflow total temperature probe

Abstract

The invention discloses an ultra-high-temperature airflow total temperature probe based on a single-crystal optical fiber built-in blackbody cavity and a manufacturing method of the ultra-high-temperature airflow total temperature probe. The ultra-high-temperature airflow total temperature probe comprises high-temperature-resistant high-emissivity powder (1), a stagnation cover (2) and a single-crystal optical fiber (5). High-temperature-resistant high-emissivity powder is wrapped in the single-crystal optical fiber (5), so that a blackbody cavity used for sensing the high-temperature environment temperature is formed; the high-emissivity powder does not react with the single-crystal optical fiber; the end face, wrapping the high-emissivity powder, of the single-crystal optical fiber is an arc face. And the single crystal optical fiber (5) is fixed in the stagnation cover (2). The stagnation cover (2) is a hollow cylinder with an opening at one end; and an air outlet hole (3) is formed in the side wall of the stagnation cover (2). Microstructure processing is carried out on the end of the single-crystal optical fiber, the high-temperature-resistant high-emissivity powder is wrapped in the single-crystal optical fiber, the black body structure is more stable, and the temperature measurement range can reach the position close to the melting point of the single-crystal optical fiber.

Description

Technical Field

[0001] The present invention relates to the field of temperature measurement of aero-engine combustion chambers, and in particular to an ultra-high temperature airflow total temperature probe based on a single crystal optical fiber built-in blackbody cavity and a manufacturing method thereof. Background Art

[0002] As an important power unit of aircraft, the efficient and stable operation of the engine is the basic guarantee for the safe operation of aircraft and the full play of its maneuverability. At the same time, combustion efficiency is one of the most important technical indicators of aircraft engines, which directly determines the unit thrust performance of the engine. The increase in gas temperature can improve the efficiency of the engine. However, when the temperature inside the engine is too high, when it reaches or even exceeds the limit of its internal component materials, it will seriously affect the life of the blades and even cause catastrophic accidents such as turbine blade ablation, which is very costly. Therefore, monitoring the temperature of the combustion chamber of an aircraft engine is a necessary technical means to control the combustion efficiency of the engine and ensure the safe and reliable operation of the engine.

[0003] Due to the special environment of complex aircraft engine structure, narrow flow channel, high temperature, strong corrosion, electromagnetic interference noise, traditional sensors such as thermocouples have been difficult to achieve high-quality monitoring of engine temperature parameters. With the continuous upgrading of the engine, the internal temperature of the engine has gradually increased, and the temperature of the turbine outlet has reached the temperature measurement limit of the thermocouple. When the temperature is higher than 1100℃, the temperature measurement performance of the thermocouple drops rapidly, but the turbine inlet and outlet temperature of the fourth-generation fighter engine has reached 1977K. Therefore, when the turbine inlet temperature is too high, only the temperature-position relationship empirical curve at the downstream position of the turbine inlet can be measured using thermocouples to obtain the temperature value at the turbine inlet. However, due to the individual differences of each engine, the error of the empirical curve and the influence of the performance changes of the engine after long-term operation, it is difficult to achieve accurate measurement of the engine turbine inlet temperature.

[0004] With the development of fiber optic sensing technology, fiber optic temperature sensors have been widely used in aviation, aerospace, security, industry and environmental monitoring due to their small size and anti-electromagnetic interference advantages. In particular, the emergence of sapphire optical fiber has brought unprecedented development to high-temperature sensors for aircraft engines. At present, the main use of sapphire optical fiber for aircraft engine combustion chamber temperature monitoring is to sputter a high-temperature resistant precious metal iridium film at the end of the sapphire optical fiber to form a black body cavity, and the temperature measurement range can reach 400-1900℃. However, the black body material of this structure is easy to oxidize and fall off, and the service life of the sensor is limited. Summary of the invention

[0005] The invention aims to provide an ultra-high temperature airflow total temperature probe based on a single crystal optical fiber with a built-in black body cavity, comprising high temperature resistant high emissivity powder, a stagnation cover and a single crystal optical fiber.

[0006] The single crystal optical fiber wraps the high-temperature resistant high-emissivity powder inside, thereby forming a black body cavity for sensing the high temperature environment temperature; the high-emissivity powder does not react with the single crystal optical fiber;

[0007] The end face of the single crystal optical fiber coated with high emissivity powder is a circular arc surface;

[0008] The single crystal optical fiber is fixed inside the stagnation cover.

[0009] The stagnation cover is a hollow cylinder with an open end.

[0010] The side wall of the stagnation cover is provided with an air outlet.

[0011] Furthermore, the high temperature resistant and high emissivity powder includes but is not limited to tungsten powder, iridium powder, and pickaxe powder.

[0012] Furthermore, the material of the single crystal optical fiber is a high melting point transparent oxide material, and the high melting point transparent oxide material includes aluminum oxide.

[0013] Furthermore, the material of the stagnation cover includes high temperature resistant metal material or ceramic material.

[0014] Furthermore, the end opening of the stagnation cover serves as an air inlet.

[0015] Furthermore, a plurality of air outlet holes are symmetrically provided on the side wall of the stagnation cover.

[0016] Furthermore, the air outlet and air inlet of the stagnation hood are used to stagnate high-speed airflow, thereby improving the accuracy of temperature measurement results.

[0017] Furthermore, a water cooling channel for cooling is arranged inside the stagnation cover.

[0018] Furthermore, the water cooling channel avoids the air outlet of the stagnation cover.

[0019] Furthermore, high temperature glue is also included.

[0020] The high temperature glue is used to fix the relative position of the stagnation cover and the single crystal optical fiber.

[0021] Furthermore, the single crystal optical fiber is used to receive and transmit radiation light carrying temperature information.

[0022] A method for manufacturing the ultra-high temperature airflow total temperature probe comprises the following steps:

[0023] 1) Prepare materials, including high temperature resistant transparent oxide single crystal optical fiber, high temperature resistant transparent oxide powder, high temperature resistant high emissivity powder, ceramic tube, and high temperature glue;

[0024] 2) Making a stagnation cover: processing the air outlet and water cooling channel on the wall of the ceramic tube;

[0025] 3) Making a blackbody cavity: Etch a groove on the end face of a single crystal optical fiber, first pour high temperature resistant high emissivity powder into the groove, then add high temperature resistant transparent oxide powder on the high temperature resistant high emissivity powder, melt the single crystal optical fiber at the end and the high temperature resistant transparent oxide powder and then cool it, so that the single crystal optical fiber is wrapped with the high temperature resistant high emissivity powder.

[0026] 4) Observe the operation under a microscope, insert the single crystal optical fiber with a black body structure at the end into the stagnation cover, so that the black body structure is between the air inlet and outlet of the stagnation cover, mark the position of the high-temperature glue and then take out the single crystal optical fiber.

[0027] 5) Apply high temperature glue at the marked position of the single crystal optical fiber.

[0028] 6) Observe the operation under a microscope, insert the glued single crystal optical fiber into the corresponding position of the stagnation cover, cure the high temperature glue, and form a high temperature probe.

[0029] The technical effect of the present invention is undoubted, and the beneficial effects of the present invention are as follows:

[0030] 1) Single crystal optical fiber is used as a medium for sensing and transmitting signals, is resistant to electromagnetic interference, and has a wide temperature measurement range;

[0031] 2) Microstructure processing is performed on the end of the single crystal optical fiber, and high-temperature resistant and high-emissivity powder is wrapped inside the single crystal optical fiber. The blackbody structure is more stable and the temperature measurement range can reach near the melting point of the single crystal optical fiber.

[0032] 3) A blackbody structure is made at the end of a single crystal optical fiber to sense temperature more quickly.

[0033] 4) Temperature sensing transmission is completed in the optical fiber, light is used as the transmission signal, there is no need to insulate the sensor, and the signal transmission line is simple.

[0034] 5) Add a water cooling channel to the stagnation cover structure to eliminate the occurrence of the temperature measurement range failing to reach the theoretical value of the sensor element due to damage to the stagnation cover at high temperatures.

[0035] In summary, the present invention provides an ultra-high temperature airflow total temperature probe made by filling high temperature resistant high emissivity powder inside a single crystal optical fiber. The high temperature resistant high emissivity powder has the characteristics of high melting point, high emissivity and does not react with the single crystal optical fiber material. It is placed in one end of the single crystal optical fiber without considering the problem of high temperature oxidation, which greatly improves the temperature measurement range of the optical fiber total temperature probe. The end face of the optical fiber wrapped with the high temperature resistant high emissivity powder is processed into an arc shape, which can receive the energy emitted by the high temperature resistant high emissivity powder to a greater extent and improve the signal quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is the structural diagram of the ultra-high temperature single crystal optical fiber temperature sensor based on blackbody radiation;

[0037] Figure 2 It is the spectrum diagram of black body radiation at different temperatures;

[0038] Figure 3 This is a schematic diagram of the ultra-high temperature single crystal optical fiber temperature sensor based on black body radiation of the present invention being used for temperature measurement in an aircraft engine combustion chamber;

[0039] Figure 4 Create a flow chart for an ultra-high temperature single-crystal fiber temperature sensor based on blackbody radiation.

[0040] In the figure, 1-high temperature resistant high emissivity powder, 2-stagnation cover, 3-air outlet, 4-air inlet, 5-single crystal optical fiber, 6-water cooling channel, 7-high temperature glue. DETAILED DESCRIPTION

[0041] The present invention is further described below in conjunction with the embodiments, but it should not be understood that the above subject matter of the present invention is limited to the following embodiments. Without departing from the above technical ideas of the present invention, various substitutions and changes are made according to the common technical knowledge and customary means in the art, which should all be included in the protection scope of the present invention.

[0042] Embodiment 1:

[0043] See also Figures 1 to 4 An ultra-high temperature airflow total temperature probe based on a single crystal optical fiber with a built-in black body cavity comprises a high temperature resistant high emissivity powder 1, a stagnation cover 2, and a single crystal optical fiber 5.

[0044] The single crystal optical fiber 5 wraps the high-temperature resistant high-emissivity powder inside, thereby forming a black body cavity for sensing the high temperature environment temperature; the high-emissivity powder does not react with the single crystal optical fiber;

[0045] The end face of the single crystal optical fiber coated with high emissivity powder is a circular arc surface;

[0046] The single crystal optical fiber 5 is fixed inside the stagnation cover 2 .

[0047] The stagnation cover 2 is a hollow cylinder with one end open.

[0048] The side wall of the stagnation cover 2 is provided with an air outlet 3 .

[0049] Embodiment 2:

[0050] An ultra-high temperature airflow total temperature probe based on a single crystal optical fiber with a built-in black body cavity, the technical content is the same as that of Example 1, further, the material of the single crystal optical fiber 5 is a high melting point transparent oxide material. The high melting point transparent oxide material includes aluminum oxide.

[0051] Embodiment 3:

[0052] An ultra-high temperature airflow total temperature probe based on a single crystal optical fiber built-in blackbody cavity, the technical content of which is the same as any one of Examples 1-2, and further, the material of the stagnation cover 2 includes a high temperature resistant metal material or a ceramic material.

[0053] Embodiment 4:

[0054] An ultra-high temperature airflow total temperature probe based on a single crystal optical fiber built-in blackbody cavity, the technical content of which is the same as any one of embodiments 1-3, and further, the end opening of the stagnation cover 2 serves as an air inlet 4.

[0055] Embodiment 5:

[0056] An ultra-high temperature airflow total temperature probe based on a single crystal optical fiber built-in blackbody cavity, the technical content of which is the same as any one of embodiments 1-4, and further, a plurality of air outlet holes 3 are symmetrically opened on the side wall of the stagnation cover 2.

[0057] Embodiment 6:

[0058] An ultra-high temperature airflow total temperature probe based on a single crystal optical fiber built-in blackbody cavity, the technical content of which is the same as any one of embodiments 1-5, and further, the air outlet 3 and the air inlet 4 of the stagnation cover 2 are used to stagnate high-speed airflow to improve the accuracy of the temperature measurement results.

[0059] Embodiment 7:

[0060] An ultra-high temperature airflow total temperature probe based on a single crystal optical fiber built-in blackbody cavity, the technical content of which is the same as any one of embodiments 1-6, and further, a water cooling channel 6 for cooling is arranged inside the stagnation cover 2.

[0061] Embodiment 8:

[0062] An ultra-high temperature airflow total temperature probe based on a single crystal optical fiber built-in blackbody cavity, the technical content of which is the same as any one of embodiments 1-7, and further, the water cooling channel 6 avoids the air outlet 3 of the stagnation cover 2.

[0063] Embodiment 9:

[0064] An ultra-high temperature airflow total temperature probe based on a single crystal optical fiber with a built-in blackbody cavity, the technical content of which is the same as any one of embodiments 1-8, and further includes high temperature glue 7.

[0065] The high temperature glue 7 is used to fix the relative position of the stagnation cover 2 and the single crystal optical fiber 5 .

[0066] Embodiment 10:

[0067] An ultra-high temperature airflow total temperature probe based on a single crystal optical fiber with a built-in blackbody cavity, the technical content of which is the same as any one of embodiments 1-9, and further, the single crystal optical fiber 5 is used to receive and transmit radiated light carrying temperature information.

[0068] Embodiment 11:

[0069] An ultra-high temperature airflow total temperature probe based on a single crystal optical fiber with a built-in blackbody cavity, the technical content of which is the same as any one of embodiments 1-10, and further, the single crystal optical fiber 5 is a sapphire optical fiber.

[0070] Embodiment 12:

[0071] An ultra-high temperature airflow total temperature probe based on a single crystal optical fiber with a built-in blackbody cavity, the technical content of which is the same as any one of Examples 1-11, and further, the high-emissivity powder includes but is not limited to high-melting-point high-emissivity tungsten powder, iridium powder, pickaxe powder, etc. that do not react with single crystal optical fiber materials.

[0072] Embodiment 13:

[0073] A method for manufacturing the ultra-high temperature airflow total temperature probe according to any one of embodiments 1 to 12 comprises the following steps:

[0074] 1) Prepare materials, including high temperature resistant transparent oxide single crystal optical fiber, high temperature resistant transparent oxide powder, high temperature resistant high emissivity powder, ceramic tube, and high temperature glue;

[0075] 2) Making a stagnation cover: processing the air outlet and water cooling channel on the wall of the ceramic tube;

[0076] 3) Making a blackbody cavity: Etch a groove on the end face of a single crystal optical fiber, first pour high temperature resistant high emissivity powder into the groove, then add high temperature resistant transparent oxide powder on the high temperature resistant high emissivity powder, melt the single crystal optical fiber at the end and the high temperature resistant transparent oxide powder and then cool it, so that the single crystal optical fiber is wrapped with the high temperature resistant high emissivity powder.

[0077] 4) Observe the operation under a microscope, insert the single crystal optical fiber with a black body structure at the end into the stagnation cover, so that the black body structure is between the air inlet and outlet of the stagnation cover, mark the position of the high-temperature glue and then take out the single crystal optical fiber.

[0078] 5) Apply high temperature glue at the marked position of the single crystal optical fiber.

[0079] 6) Observe the operation under a microscope, insert the glued single crystal optical fiber into the corresponding position of the stagnation cover, cure the high temperature glue, and form a high temperature probe.

[0080] Embodiment 14:

[0081] A method for manufacturing the ultra-high temperature airflow total temperature probe described in any one of Examples 1-12, the technical content is the same as Example 13, and further, the ceramic tube is replaced by a high temperature resistant metal tube.

[0082] Embodiment 15:

[0083] An ultra-high temperature airflow total temperature probe based on a single crystal optical fiber with a built-in black body cavity comprises a single crystal optical fiber, high temperature resistant high emissivity powder, a stagnation cover, an air inlet, an air outlet, and a water cooling channel.

[0084] The single crystal optical fiber material is a high melting point transparent oxide material, including but not limited to aluminum oxide.

[0085] Through optical fiber microstructure processing, high-temperature resistant and high-emissivity powder is wrapped inside the single-crystal optical fiber to form a blackbody cavity, which can sense high-temperature ambient temperature.

[0086] The material of the stagnation cover can be a high temperature resistant metal material or a ceramic material, and the ceramic material is taken as an example below.

[0087] Two air outlet holes are symmetrically processed on the side wall of the stagnation cover, and the angle between the air outlet hole and the air inlet hole is 135°.

[0088] An axial water cooling channel is processed on the side wall of the stagnation cover, and the water cooling channel avoids the air outlet.

[0089] Ultra-high temperature single crystal optical fiber temperature sensors based on blackbody radiation include but are not limited to the structures formed by the above-mentioned structures and materials. Fiber-wrapped blackbody structures formed by other materials and other optical fiber structures, and ultra-high temperature temperature sensors based on blackbody radiation formed by processing water cooling channels on stagnation covers of other materials are also within the scope of the present invention.

[0090] The function of each component in the present invention

[0091] 1. The high temperature resistant high emissivity powder is a temperature sensing element. The high temperature resistant high emissivity powder wrapped in the single crystal optical fiber and the surrounding single crystal optical fiber form a black body structure. When the black body structure is in a temperature environment, it will spontaneously radiate Gaussian light of a certain intensity to the surroundings. Part of the radiated light is received by the single crystal optical fiber at the tail end and transmitted through the transmission optical fiber. The intensity and central wavelength of the Gaussian light generated by the black body radiation have a certain corresponding relationship with the temperature.

[0092] 2. The single crystal optical fiber receives the radiation light carrying temperature information and transmits it to the back-end spectrum demodulation device. The demodulation device obtains the intensity and central wavelength of the radiation light to know the current ambient temperature of the black body. The end face of the end wrapped with high temperature resistant and high emissivity powder is processed into an arc surface, which is conducive to the maximum reception of radiation light by the optical fiber and improves the signal-to-noise ratio.

[0093] 3. The stagnation cover can stop high-speed airflow through the air inlet and outlet, making the temperature measurement more accurate. On the other hand, it can also support the single crystal optical fiber.

[0094] 4. High temperature glue is used to fix the relative position between the stop cover and the single crystal optical fiber;

[0095] 5. Generally, the melting point of the material used for the stagnation cover is lower than that of the single crystal optical fiber. Adding a water cooling channel to the stagnation cover can improve the temperature resistance of the stagnation cover.

[0096] Embodiment 16:

[0097] A method for manufacturing an ultra-high temperature single crystal optical fiber temperature sensor based on blackbody radiation as described in any one of Embodiments 1 to 15, comprising the following steps:

[0098] 1) Prepare materials (including high temperature resistant transparent oxide single crystal optical fiber, high temperature resistant transparent oxide powder, high temperature resistant high emissivity powder, ceramic tube, high temperature glue). The ceramic tube here can be replaced by a high temperature resistant metal tube.

[0099] 2) Making a stagnation cover: processing the air outlet and water cooling channel on the wall of the ceramic tube;

[0100] 3) Making a blackbody cavity: Etch a groove on the end face of a single crystal optical fiber, first pour a certain amount of high temperature resistant and high emissivity powder into the groove, then add high temperature resistant and transparent oxide powder on the high temperature resistant and high emissivity powder, melt the end single crystal optical fiber and the high temperature resistant and transparent oxide powder and then cool them down, so that the optical fiber is wrapped with the high temperature resistant and high emissivity powder.

[0101] 4) Observe the operation under a microscope, insert the single crystal optical fiber with a black body structure at the end into the stagnation cover, so that the black body structure is between the air inlet and outlet of the stagnation cover, mark the position of the high-temperature glue and then take out the single crystal optical fiber.

[0102] 5) Apply high temperature glue at the marked position of the single crystal optical fiber.

[0103] 6) Observe the operation under a microscope, insert the glued single crystal optical fiber into the corresponding position of the stagnation cover, cure the high temperature glue, and form a high temperature probe.

[0104] Embodiment 17:

[0105] The working principle of the ultra-high temperature single crystal optical fiber temperature sensor based on blackbody radiation described in any one of Embodiments 1-16 is as follows:

[0106] 1. Blackbody radiation temperature measurement principle

[0107] A black body is an ideal object imagined in thermodynamics to study the laws of thermodynamics. It has the property of completely absorbing radiation energy of all bands without any reflection. At the same time, the ability of a black body to emit electromagnetic radiation is the strongest. Planck's black body radiation law describes the distribution of radiation of black bodies of different temperatures at different wavelengths, which can be described by the following formula:

[0108]

[0109] Where c is the speed of electromagnetic waves in vacuum, c = 299792458 m / s;

[0110] h is Planck's constant, c = 6.6260876 × 10 -34 Js;

[0111] k is the Boltzmann constant, k = 1.3806503 × 10 -23 Js;

[0112] M(λ,T) is the radiation with target temperature T and wavelength λ.

[0113] Since black bodies do not exist in reality, the radiation emitted by the surface of an actual object will be less than the radiation of a black body at the same temperature. In engineering, the thermal radiation coefficient is often used to represent the radiation characteristics of an object. The parameter that describes the size of the object's spectral emission capacity is called emissivity, which is represented by the symbol ε. It can be defined by equation (2).

[0114] ε=M(λ,T) / M0(λ,T) (2)

[0115] M(λ,T) is the radiation of the object, and M0(λ,T) is the radiation of the black body.

[0116] Therefore, the radiation amount of the object can be calculated using formula (3).

[0117]

[0118] From formula (3), we can see that the wavelength changes continuously, and there is a fixed radiation curve corresponding to a certain temperature. The higher the temperature, the greater the radiation brightness at all wavelengths. As the temperature rises, the peak wavelength of the curve moves toward the short-wave direction. The spectral radiation brightness of an object is only related to its temperature and has nothing to do with other parameters. By measuring the radiation of a single wavelength of an object or the value of the peak wavelength, the current temperature of the object can be inferred.

[0119] 2. Principle of measuring combustion chamber air flow temperature using ultra-high temperature single crystal optical fiber temperature sensor

[0120] The measurement of air flow temperature is a special temperature measurement, which is actually the measurement of the total temperature T of the air flow. t (i.e. static temperature T s and dynamic temperature T v The sum of the total temperature of the airflow is usually expressed as:

[0121]

[0122] Where, v represents the airflow density; c p represents the specific heat capacity at constant pressure; M is the Mach number of the airflow; κis the adiabatic index, for air κ=1.40.

[0123] When the single-crystal fiber temperature sensor probe is placed in the airflow field, the airflow velocity near the probe decreases, and the kinetic energy is converted into thermal energy. Ideally, the probe can achieve complete conversion of kinetic energy to thermal energy, which means that the temperature sensor senses the true total temperature of the airflow. In fact, the total temperature sensor cannot achieve complete stagnation of the airflow velocity, and there is always a part of the energy loss in the form of kinetic energy, which is converted into temperature form as velocity error. The mathematical expression of the total temperature measurement velocity error is:

[0124] ΔT v =T0-T m (5)

[0125] Where T0 is the true value of the total temperature of the airflow; T m It is the total airflow temperature test value.

[0126] The rate at which kinetic energy is converted into heat energy is usually described by the coefficient of restitution. The larger the coefficient of restitution, the higher the rate at which kinetic energy is converted into heat energy. The mathematical expression of the coefficient of restitution is:

[0127]

[0128] Substituting equation (4) into equation (6) yields the relationship between the recovery coefficient, total temperature and measurement temperature:

[0129]

[0130] By obtaining the sensor recovery coefficient at different total temperatures and Mach numbers through calibration experiments, the total temperature of the airflow can be obtained in an airflow with a known Mach number.

[0131] Embodiment 18:

[0132] A temperature measurement system based on the ultra-high temperature single crystal optical fiber temperature sensor according to any one of embodiments 1 to 17, comprising an ultra-high temperature single crystal optical fiber temperature sensor, a transmission optical fiber, a demodulator, and a computer;

[0133] The ultra-high temperature single crystal optical fiber temperature sensor is placed in the room where the temperature is to be measured, so that the stagnation cover faces the direction of the airflow;

[0134] The single crystal optical fiber of the ultra-high temperature single crystal optical fiber temperature sensor acquires a spectrum carrying temperature data and transmits it to a demodulator through a transmission optical fiber;

[0135] The single crystal optical fiber of the ultra-high temperature single crystal optical fiber temperature sensor is connected to the demodulator via a transmission optical fiber.

[0136] The demodulator demodulates the spectrum carrying temperature data and transmits it to a computer.

[0137] The computer calculates the demodulated data to obtain the ambient temperature of the blackbody cavity.

[0138] Embodiment 19:

[0139] The working process of the temperature measurement system described in Example 18 is as follows:

[0140] First, install the ultra-high temperature single-crystal optical fiber temperature sensor based on blackbody radiation on the bracket, and then insert the bracket into the engine combustion chamber so that the stagnation cover faces the direction of airflow. The tail end of the single-crystal optical fiber is connected to the demodulator through the transmission optical fiber, and the demodulator and computer are connected through a network cable.

[0141] During measurement, the temperature of the combustion chamber air flow is stagnant in the stagnation cover, the heat is transferred to the single crystal optical fiber, and the black body cavity radiates Gaussian light carrying temperature information to the surroundings. The Gaussian light is transmitted to the demodulator through the transmission optical fiber.

[0142] The computer collects the spectrum data of the demodulator at high speed, performs data analysis, and solves the intensity and central wavelength of the Gaussian light, thereby obtaining the ambient temperature of the blackbody cavity, that is, the total temperature of the airflow in the combustion chamber.

Claims

1. An ultra-high temperature airflow total temperature probe based on a single crystal optical fiber with a built-in blackbody cavity, characterized in that: It comprises high temperature resistant high emissivity powder (1), a stagnation cover (2), and a single crystal optical fiber (5); The single crystal optical fiber (5) wraps high-temperature resistant high-emissivity powder inside, thereby forming a black body cavity for sensing high-temperature ambient temperature; the high-emissivity powder does not react with the single crystal optical fiber. The end face of the single crystal optical fiber coated with high emissivity powder is an arc surface. The single crystal optical fiber (5) is fixed inside the stagnation cover (2); The stagnation cover (2) is a hollow cylinder with an open end; An air outlet hole (3) is provided on the side wall of the stagnation cover (2).

2. According to claim 1, an ultra-high temperature airflow total temperature probe based on a single crystal optical fiber with a built-in blackbody cavity, characterized in that: The high temperature resistant and high emissivity powder includes but is not limited to tungsten powder, iridium powder, and pickaxe powder.

3. According to claim 1, an ultra-high temperature airflow total temperature probe based on a single crystal optical fiber with a built-in blackbody cavity, characterized in that: The material of the single crystal optical fiber (5) is a high melting point transparent oxide material; the high melting point transparent oxide material includes aluminum oxide.

4. According to claim 1, an ultra-high temperature airflow total temperature probe based on a single crystal optical fiber with a built-in blackbody cavity, characterized in that: The material of the stagnation cover (2) includes a high temperature resistant metal material or a ceramic material.

5. The ultra-high temperature airflow total temperature probe based on a single crystal optical fiber built-in blackbody cavity according to claim 1, characterized in that: The end opening of the stagnation cover (2) serves as an air inlet hole (4).

6. The ultra-high temperature airflow total temperature probe based on a single crystal optical fiber built-in blackbody cavity according to claim 1, characterized in that: The side wall of the stagnation cover (2) is symmetrically provided with a plurality of air outlet holes (3); The air outlet (3) and the air inlet (4) of the stagnation cover (2) are used to stagnate high-speed airflow, thereby improving the accuracy of temperature measurement results.

7. The ultra-high temperature airflow total temperature probe based on a single crystal optical fiber built-in blackbody cavity according to claim 1, characterized in that: A water cooling channel (6) for cooling is arranged inside the stagnation cover (2). The water cooling channel (6) avoids the air outlet hole (3) of the stagnation cover (2).

8. The ultra-high temperature airflow total temperature probe based on a single crystal optical fiber built-in blackbody cavity according to claim 1, characterized in that: Also includes high temperature glue (7); The high temperature glue (7) is used to fix the relative position of the stagnation cover (2) and the single crystal optical fiber (5).

9. The ultra-high temperature airflow total temperature probe based on a single crystal optical fiber built-in blackbody cavity according to claim 1, characterized in that: The single crystal optical fiber (5) is used for receiving and transmitting radiation light carrying temperature information.

10. A method for manufacturing the ultra-high temperature airflow total temperature probe according to any one of claims 1 to 9, characterized in that: The following steps are involved: 1) Prepare materials, including high temperature resistant transparent oxide single crystal optical fiber, high temperature resistant transparent oxide powder, high temperature resistant high emissivity powder, ceramic tube, and high temperature glue; 2) Making a stagnation cover: processing the air outlet and water cooling channel on the wall of the ceramic tube; 3) Making a blackbody cavity: Etch a groove on the end face of a single crystal optical fiber, first pour high temperature resistant high emissivity powder into the groove, then add high temperature resistant transparent oxide powder on the high temperature resistant high emissivity powder, melt the single crystal optical fiber at the end and the high temperature resistant transparent oxide powder and then cool it, so that the single crystal optical fiber is wrapped with the high temperature resistant high emissivity powder. 4) Observe the operation under a microscope, insert the single crystal optical fiber with a black body structure at the end into the stagnation cover, so that the black body structure is between the air inlet and outlet of the stagnation cover, mark the position of the high-temperature glue and then take out the single crystal optical fiber. 5) Apply high temperature glue at the marked position of the single crystal optical fiber. 6) Observe the operation under a microscope, insert the glued single crystal optical fiber into the corresponding position of the stagnation cover, cure the high temperature glue, and form a high temperature probe.

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