阅读说明：本技术 一种可校正导热误差的光纤光栅总温探针及其制作方法 (Fiber grating total temperature probe capable of correcting heat conduction error and manufacturing method thereof ) 是由 刘显明 昌小小 雷小华 章鹏 韩国庆 任怡霖 于 2021-08-13 设计创作，主要内容包括：本发明公开一种可校正导热误差的光纤光栅总温探针及其制作方法,探针包括滞止罩(1)、进气孔(2)、出气孔(3)、支撑管(5)、测温光纤光栅(7)、温度补偿光纤光栅(8)和传输光纤(9)；制作方法步骤为：1)加工出气孔(3)；2)在支撑管(5)外壁涂抹高温胶后插入滞止罩(1),用高温炉固化；3)在传输光纤(9)上刻写测温光纤光栅(7)和温度补偿光纤光栅(8)；4)将传输光纤(9)插入到支撑管(5)中；5)在传输光纤(9)和支撑管(5)内壁之间涂抹高温胶(4),用高温炉固化高温胶,在支撑管(5)尾端形成高温胶珠(6)。本发明能够及时修正总温测量时的导热误差,改善测温精度,提高测量数据准确性。(The invention discloses a fiber grating total temperature probe capable of correcting heat conduction errors and a manufacturing method thereof, wherein the probe comprises a stagnation cover (1), an air inlet hole (2), an air outlet hole (3), a support tube (5), a temperature measurement fiber grating (7), a temperature compensation fiber grating (8) and a transmission fiber (9); the manufacturing method comprises the following steps: 1) processing an air outlet (3); 2) after high-temperature glue is coated on the outer wall of the supporting tube (5), the stagnation cover (1) is inserted and cured by a high-temperature furnace; 3) a temperature measurement fiber grating (7) and a temperature compensation fiber grating (8) are engraved on the transmission fiber (9); 4) inserting a transmission fiber (9) into the support tube (5); 5) high-temperature glue (4) is coated between the transmission optical fiber (9) and the inner wall of the supporting tube (5), the high-temperature glue is solidified by a high-temperature furnace, and high-temperature glue beads (6) are formed at the tail end of the supporting tube (5). The invention can correct the heat conduction error in the total temperature measurement in time, improve the temperature measurement precision and improve the accuracy of the measurement data.)

1. A fiber grating total temperature probe capable of correcting heat conduction errors is characterized in that: the temperature-measuring device comprises a stagnation cover (1), an air inlet (2), an air outlet (3), a support tube (5), a temperature-measuring fiber grating (7), a temperature-compensating fiber grating (8) and a transmission fiber (9).

An air inlet (2) is formed in one end, opposite to the airflow, of the stagnation cover (1);

the side wall of the stagnation cover (1) is provided with a plurality of air outlet holes (3);

a supporting tube (5) is arranged in the stagnation cover (1);

the supporting tube (5) is bonded with the stagnation cover (1);

a transmission optical fiber (9) is placed in the supporting tube (5);

a temperature measurement fiber grating (7) and a temperature compensation fiber grating (8) are engraved on the transmission fiber (9);

the temperature measurement fiber bragg grating (7) is positioned between the air inlet hole (2) and the air outlet hole (3);

the temperature compensation fiber bragg grating (8) is positioned inside the front end of the supporting tube (5); the front end of the supporting tube is one end close to the air outlet;

the transmission optical fiber (9) is bonded with the inner wall of the support tube (5).

2. The fiber grating total temperature probe capable of correcting heat conduction errors according to claim 1, wherein: the stagnation cover (1) is a cylinder.

3. The fiber grating total temperature probe capable of correcting heat conduction errors according to claim 1, wherein: the number of the air outlet holes (3) is even.

4. The fiber grating total temperature probe capable of correcting heat conduction errors according to claim 1, wherein: a plurality of air outlet holes (3) are symmetrically distributed; the sum of the cross sections of all the air outlet holes is 30 percent of the cross section of the air inlet hole (2)_～40％。

5. The fiber grating total temperature probe capable of correcting heat conduction errors according to claim 1, wherein: the material of the support tube (5) comprises stainless steel.

6. The fiber grating total temperature probe capable of correcting heat conduction errors according to claim 1, wherein: the temperature measurement fiber grating (7) and the temperature compensation fiber grating (8) are temperature sensing elements.

7. The fiber grating total temperature probe capable of correcting heat conduction errors according to claim 1, wherein: the difference between the central wavelengths of the temperature measurement fiber grating (7) and the temperature compensation fiber grating (8) is more than 10 nm.

8. The fiber grating total temperature probe capable of correcting heat conduction errors according to claim 1, wherein: the supporting tube (5) and the stagnation cover (1) are glued by high-temperature glue (4); the high-temperature glue (4) forms high-temperature glue beads (6) at the tail end of the stagnation cover (1); the tail end of the stagnation cover (1) is the end which is not provided with the air inlet (2).

9. The fiber grating total temperature probe capable of correcting heat conduction errors according to claim 1, wherein: the supporting tube (5) and the transmission optical fiber (9) are glued through the high-temperature glue (4);

the high-temperature glue (4) forms high-temperature glue beads (6) at the tail end of the supporting tube (5).

10. The method for manufacturing a fiber grating total temperature probe capable of correcting heat conduction errors according to any one of claims 1 to 9, comprising the following steps:

1) processing an air outlet (3) on the side wall of the stagnation cover (1);

2) determining the gluing positions of the stagnation cover (1) and the support tube (5) and marking;

3) coating high-temperature glue (4) on the outer wall of the supporting tube (5);

4) inserting the supporting tube (5) into the stagnation cover (1), and curing the high-temperature glue (4) by using a high-temperature furnace to form high-temperature glue beads (6) at the tail end of the stagnation cover (1);

5) determining and marking the positions of a temperature measuring fiber grating (7) and a temperature compensating fiber grating (8) on a transmission fiber (9);

6) a temperature measurement fiber grating (7) and a temperature compensation fiber grating (8) are engraved on the transmission fiber (9);

7) inserting the transmission optical fiber (9) into the support tube (5), determining the relative position and marking;

8) high-temperature glue (4) is coated between the transmission optical fiber (9) and the inner wall of the supporting tube (5), the high-temperature glue is solidified by a high-temperature furnace, and high-temperature glue beads (6) are formed at the tail end of the supporting tube (5).

Technical Field

The invention relates to the technical field of flow field total temperature testing, in particular to a fiber grating total temperature probe capable of correcting heat conduction errors and a manufacturing method thereof.

Background

In the field of aerospace, the total temperature of high-speed airflow is an important test parameter and is mainly used for evaluating equipment performance, monitoring states and the like. The accurate measurement of the high-speed airflow temperature can provide necessary data support for the design, production, test, use and the like of the aircraft engine, and plays an important role in the verification of technical indexes and the reliability evaluation of the aircraft engine.

The total temperature of the high-speed airflow refers to the temperature which can be reached by the airflow in an adiabatic stagnation state, but in the actual measurement process, a plurality of measurement errors including heat conduction errors, speed errors, radiation errors, dynamic response errors and the like exist.

Fiber gratings are being used for high-speed airflow temperature measurement due to their advantages of small size, electromagnetic interference resistance, high sensitivity, no need for insulation treatment, and the like. In the process of measuring the total temperature, because a larger temperature deviation exists between the temperature sensing point and the tail end of the total temperature probe, the measuring result often contains a larger heat conduction error, so that the total temperature of the airflow can not be accurately measured by the fiber bragg grating total temperature probe, and the temperature measuring precision is reduced.

Existing low-order thermal conductivity models typically model the total temperature probe as a heat sink and are subject to convective heat transfer along the sensor surface. The solution to the one-dimensional heat transfer equation with convection is a two-point side-value problem requiring knowledge of the temperature or heat transfer conditions at the tip (grating) and tail of the total temperature probe. For most practical total temperature probes, temperature measurements are taken at or near the tail of the probe to obtain a tail temperature boundary condition.

Disclosure of Invention

The invention aims to provide a fiber grating total temperature probe capable of correcting heat conduction errors, which comprises a stagnation cover, an air inlet hole, an air outlet hole, a support tube, a temperature measurement fiber grating, a temperature compensation fiber grating and a transmission fiber.

The stagnation cover is a cylinder body.

An air inlet is arranged at one end of the stagnation cover opposite to the air flow.

The side wall of the stagnation cover is provided with a plurality of air outlet holes.

The number of the air outlet holes is even.

A plurality of air outlets are symmetrically distributed. The sum of the cross sections of all the air outlet holes is 30 percent of the cross section of the air inlet hole_～40％。

A support tube is placed in the stagnation cover.

The supporting tube is bonded with the stagnation cover through high-temperature glue.

The high-temperature glue forms high-temperature glue beads at the tail end of the stagnation cover. The tail end of the stagnation cover is the end which is not provided with the air inlet.

The material of the support tube comprises stainless steel.

A transmission optical fiber is placed in the supporting tube;

the transmission optical fiber is inscribed with a temperature measurement fiber grating and a temperature compensation fiber grating;

the temperature measurement fiber bragg grating is positioned between the air inlet hole and the air outlet hole;

the temperature compensation fiber bragg grating is positioned in the front end of the supporting tube, and the front end of the supporting tube is close to one end of the air outlet hole;

the supporting tube and the transmission optical fiber are glued through high-temperature glue;

the high-temperature glue forms high-temperature glue beads at the tail end of the supporting tube;

the temperature measuring fiber grating and the temperature compensating fiber grating are temperature sensing elements.

The difference between the central wavelengths of the temperature measurement fiber grating and the temperature compensation fiber grating is more than 10 nm.

The manufacturing method of the fiber grating total temperature probe capable of correcting the heat conduction error comprises the following steps:

1) and air outlet holes are processed on the side wall of the stagnation cover.

2) The positions of the stagnation cover and the support tube are glued and marked.

3) And coating high-temperature glue on the outer wall of the supporting tube.

4) And inserting the supporting tube into the stagnation cover, and curing the high-temperature glue by using a high-temperature furnace to form high-temperature glue beads at the tail end of the stagnation cover.

5) And determining the positions of the temperature measurement fiber grating and the temperature compensation fiber grating on the transmission fiber and marking.

6) And (3) writing a temperature measurement fiber grating and a temperature compensation fiber grating on the transmission fiber.

7) The delivery fiber is inserted into the support tube, the relative position is determined and marked.

8) And (3) coating high-temperature glue between the transmission optical fiber and the inner wall of the supporting tube, and curing the high-temperature glue by using a high-temperature furnace to form high-temperature glue beads at the tail end of the supporting tube.

The technical effects of the invention are undoubted, and the effective effects of the invention are as follows:

1) the invention provides a fiber grating total temperature probe capable of correcting heat conduction errors, which can correct the heat conduction errors in total temperature measurement in time, improve temperature measurement precision and improve measurement data accuracy.

2) The invention can accurately transmit optical signals and resist electromagnetic interference;

3) the two temperature sensing gratings disclosed by the invention both adopt short-distance gratings, so that the error caused by uneven temperature distribution on the gratings is reduced;

4) the two gratings simultaneously and respectively measure the temperature of the tail end of the air flow and the probe, the measured tail end temperature provides a heat transfer boundary condition, and the conduction error can be calculated in real time;

5) the components at the tail part of the total temperature probe disclosed by the invention are bonded by high-temperature glue, so that the sealing property and the integrity are ensured;

6) the temperature compensation fiber grating disclosed by the invention has more accurate conduction error calculation at the high-temperature glue bonding part at the tail part of the total temperature probe.

Drawings

FIG. 1 is a cross-sectional view of a fiber grating total temperature probe capable of correcting thermal conduction errors;

FIG. 2 is a diagram of a total temperature probe with fiber grating capable of correcting thermal conduction errors;

FIG. 3 is a schematic diagram of the total temperature probe of fiber grating for measuring the temperature of the air flow according to the present invention;

FIG. 4 is a schematic diagram of fiber grating temperature measurement;

FIG. 5 is a schematic diagram of the fiber grating total temperature probe of the present invention for measuring the temperature of the flow channel in an aircraft engine;

FIG. 6 is a flow chart of a method for manufacturing a fiber grating total temperature probe capable of correcting thermal conduction errors.

In the figure: stagnation cover 1, inlet port 2, venthole 3, high temperature glue 4, stay tube 5, high temperature glue pearl 6, temperature measurement fiber grating 7, temperature compensation fiber grating 8, transmission fiber 9.

Detailed Description

The present invention is further illustrated by the following examples, but it should not be construed that the scope of the above-described subject matter is limited to the following examples. Various substitutions and alterations can be made without departing from the technical idea of the invention and the scope of the invention is covered by the present invention according to the common technical knowledge and the conventional means in the field.

Example 1:

referring to fig. 1, the fiber bragg grating total temperature probe capable of correcting heat conduction errors comprises a stagnation cover 1, an air inlet 2, an air outlet 3, a support tube 5, a temperature measurement fiber bragg grating 7, a temperature compensation fiber bragg grating 8 and a transmission fiber 9.

An air inlet 2 is arranged at one end of the stagnation cover 1 opposite to the air flow.

The sidewall of the stagnation cover 1 is provided with a plurality of air outlet holes 3.

The stagnation cover 1 is a cylinder.

The number of the air outlet holes 3 is even.

A plurality of air outlets 3 are symmetrically distributed. The sum of the cross sections of all the air outlet holes is 30 to 40 percent of the cross section of the air inlet hole 2.

A support tube 5 is placed inside the stagnation cover 1.

The support tube 5 is glued to the stagnation housing 1.

The supporting tube 5 is bonded with the stagnation cover 1 through high-temperature glue 4.

The high-temperature glue 4 forms a high-temperature glue bead 6 at the tail end of the stagnation cover 1, and the effect of sealing the stagnation cover 1 is achieved. The tail end of the stagnation cover 1 is the end of the stagnation cover 1 which is not provided with the air inlet 2.

The material of the support tube 5 comprises stainless steel.

A transmission optical fiber 9 is arranged in the supporting tube 5;

a temperature measurement fiber grating 7 and a temperature compensation fiber grating 8 are engraved on the transmission fiber 9;

the temperature measurement fiber bragg grating 7 is positioned between the air inlet hole 2 and the air outlet hole 3;

the temperature compensation fiber bragg grating is positioned in the front end of the supporting tube 5, and the front end of the supporting tube is marked as one end close to the air outlet;

the temperature measurement fiber grating 7 and the temperature compensation fiber grating 8 are temperature sensing elements.

The difference between the central wavelengths of the temperature measurement fiber grating 7 and the temperature compensation fiber grating 8 is more than 10 nm.

The supporting tube 5 and the transmission optical fiber 9 are glued by high-temperature glue 4;

the high-temperature glue 4 forms high-temperature glue beads 6 at the tail end of the support tube 5;

the high-temperature glue 4 forms a high-temperature glue bead 6 at the tail end of the support tube 5. The high-temperature rubber beads 6 close the tail end of the supporting tube 5.

Example 2:

the manufacturing method of the fiber grating total temperature probe capable of correcting the heat conduction error comprises the following steps:

1) air outlet holes 3 are processed on the side wall of the stagnation cover 1.

2) The position of the adhesion of the stagnation cover 1 and the support tube 5 is determined and marked.

3) And high-temperature glue 4 is coated on the outer wall of the support tube 5.

4) The supporting tube 5 is inserted into the stagnation cover 1, the high-temperature glue 4 is solidified by a high-temperature furnace, and the high-temperature glue beads 6 are formed at the tail end of the stagnation cover 1.

5) And determining the positions of the temperature measurement fiber grating 7 and the temperature compensation fiber grating 8 on the transmission fiber 9 and marking.

6) The temperature measurement fiber grating 7 and the temperature compensation fiber grating 8 are engraved on the transmission fiber 9.

7) The transmission optical fiber 9 is inserted into the supporting tube 5, and the relative position is determined and marked by a precise displacement platform, so that the temperature measurement fiber grating is positioned between the air inlet hole and the air outlet hole.

8) High-temperature glue 4 is coated between the transmission optical fiber 9 and the inner wall of the supporting tube 5, and the high-temperature glue is solidified by a high-temperature furnace to form high-temperature glue beads 6 at the tail end of the supporting tube 5.

Example 3:

a fiber bragg grating total temperature probe capable of correcting heat conduction errors comprises a stagnation cover 1, an air inlet 2, an air outlet 3, a supporting tube 5, a temperature measurement fiber bragg grating 7, a temperature compensation fiber bragg grating 8 and a transmission fiber 9.

An air inlet 2 is arranged at one end of the stagnation cover 1 opposite to the air flow.

The sidewall of the stagnation cover 1 is provided with a plurality of air outlet holes 3.

The stagnation cover 1 is a cylinder.

The number of the air outlet holes 3 is even.

A plurality of air outlets 3 are symmetrically distributed. The sum of the cross sections of all the air outlet holes 3 is 30 to 40 percent of the cross section of the air inlet hole 2.

A support tube 5 is placed inside the stagnation cover 1.

The support tube 5 is glued to the stagnation housing 1.

The supporting tube 5 and the stagnation cover 1 are glued through high-temperature glue 4.

The high-temperature glue 4 forms a high-temperature glue bead 6 at the tail end of the stagnation cover 1. The tail end of the stagnation cover 1 is the end which is not provided with the air inlet 2.

The material of the support tube 5 comprises stainless steel.

A transmission optical fiber 9 is arranged in the supporting tube 5;

a temperature measurement fiber grating 7 and a temperature compensation fiber grating 8 are engraved on the transmission fiber 9;

the temperature measurement fiber bragg grating 7 is positioned between the air inlet hole 2 and the air outlet hole 3;

the temperature compensation fiber grating 8 is positioned in the front end of the support tube 5, and the front end of the support tube is marked as one end close to the air outlet;

the temperature measurement fiber grating 7 and the temperature compensation fiber grating 8 are temperature sensing elements.

The difference between the central wavelengths of the temperature measurement fiber grating 7 and the temperature compensation fiber grating 8 is more than 10 nm.

The supporting tube 5 and the transmission optical fiber 9 are glued by high-temperature glue 4;

the high-temperature glue 4 forms high-temperature glue beads 6 at the tail end of the support tube 5;

the manufacturing method of the fiber grating total temperature probe capable of correcting the heat conduction error comprises the following steps:

1) and processing an air outlet 3 on the side wall of the stagnation cover 1 by utilizing an electric spark micropore processing technology.

2) The positions of the adhesion of the stagnation cover 1 and the support tube 5 are determined by a micrometer under an electron microscope and marked.

3) And high-temperature glue 4 is coated on the outer wall of the support tube 5.

4) The supporting tube 5 is inserted into the stagnation cover 1, the high-temperature glue 4 is solidified by a high-temperature furnace, and the high-temperature glue beads 6 are formed at the tail end of the stagnation cover 1.

5) And determining the positions of the temperature measurement fiber grating 7 and the temperature compensation fiber grating 8 on the transmission fiber 9 by using a micrometer under an electron microscope and marking.

6) The temperature measurement fiber grating 7 and the temperature compensation fiber grating 8 are engraved on the transmission fiber 9.

7) The transmission fiber 9 is inserted into the support tube 5 and marked after the relative position is determined with a precision displacement stage.

8) High-temperature glue 4 is smeared between the transmission optical fiber 9 and the inner wall of the supporting tube 5 by using an electron microscope and a precise displacement platform, the high-temperature glue 4 is solidified by using a high-temperature furnace, and high-temperature glue beads 6 are formed at the tail end of the supporting tube 5.

Example 4:

referring to fig. 2, a thermal conductivity error correction principle of a fiber grating total temperature probe capable of correcting thermal conductivity error is as follows:

when the fiber grating total temperature probe is used for measuring the gas temperature, the measuring end of the fiber grating total temperature probe needs to exchange heat with the measured gas flow and also needs to transfer heat to the tail part with lower temperature of the total temperature probe, so the temperature of the measuring end needs to be reduced. Assuming that the length of the fiber grating measuring point from the temperature compensation fiber grating is l, and the temperature of the measured air flow is t₁And the external ambient temperature is t₀，t₁＞t₀Since the heat is conducted out along the sensor, the temperature t of the grating measuring point of the sensor₂Will be lower than the temperature t of the measured fluid₁This difference t₁-t₂Namely the heat conduction error along the length direction of the temperature measuring tube. According to the stable heat conduction theory of the long rod with the uniform cross section and the heat dissipation function on the surface in the heat transfer science, the relation formula of the heat conduction error can be obtained as follows:

in the formula (I), the compound is shown in the specification,called hyperbolic cosine function;

wherein alpha is the convective heat transfer coefficient/w.m^-2·℃^-1(ii) a Lambda is the thermal conductivity of the optical fiber/w.m^-1·℃^-1(ii) a U is the perimeter/m of the cross section of the optical fiber; a is the cross-sectional area/m of the optical fiber²。

Therefore, if t is measured₀And t₂The value of (a) can be used to calculate the accuracy t according to the above formula₁And (4) correcting the measurement result.

Example 5:

referring to fig. 3 and 4, the working principle of the fiber grating total temperature probe capable of correcting the heat conduction error is as follows:

a fiber grating is essentially a section of fiber with a periodically varying core index, typically only a few millimeters in length. When a beam of broad spectrum light (such as an incident spectrum in the figure) passes through the fiber grating, strong reflection is generated on the light meeting the phase matching condition of the fiber grating; for light that does not meet the condition, only a very weak portion is emitted back due to phase mismatch. The monochromatic light reflected back by the grating (as reflected in the figure) behaves as a narrow band mirror.

Central wavelength lambda of reflected light, refractive index variation period lambda of grating and effective refractive index n of fiber core_effThe following relationships exist:

λ＝2Λn_eff (2)

wherein λ is FBG inverseWavelength of radiation, Λ being the grating period, n_effIs the effective refractive index of the fiber grating.

When the temperature around the fiber grating changes, the grating period and the effective refractive index of the fiber core are changed, so that the reflected wavelength is changed. The change of the Bragg wavelength of the fiber Bragg grating is in a linear change relation with the change of the environmental temperature, and the corresponding temperature can be measured by detecting the Bragg wavelength of the fiber Bragg grating, namely

T＝ΔT+T₀＝Δλ/K_T+λ₀ (3)

In the formula, K_TThe temperature sensitive coefficient of the fiber grating.

When the air inlet hole of the probe faces to the incoming flow direction of the air flow, the high-speed air flow is decelerated and stopped at the probe end, kinetic energy is converted into internal energy, heat is transferred to the temperature-measuring fiber grating through the air and the metal pipe, and the temperature of the temperature-measuring fiber grating changes, so that the grid pitch lambda of the temperature-measuring fiber grating₁Or effective refractive indexChanges the Bragg wavelength lambda of the fiber grating₁Corresponding changes also occur. Meanwhile, the temperature at the tail end of the total temperature probe can also enable the Bragg wavelength lambda of the temperature compensation fiber grating₂A change occurs. By λ₁、λ₂The current air temperature t can be obtained by the change₂And total temperature probe tail end temperature t₀Thus, the real temperature t of the air flow is determined according to the formula (1)₁。

Example 6:

referring to fig. 1, the fiber grating total temperature probe capable of correcting heat conduction errors comprises a stagnation cover 1, an air inlet 2, an air outlet 3, high-temperature glue 4, a support tube 5, high-temperature glue beads 6, a temperature measurement fiber grating 7, a temperature compensation fiber grating 8 and a transmission fiber 9;

the stagnation cover 1 is a cylinder;

an air inlet 2 is arranged at one end of the stagnation cover 1 opposite to the air flow;

the side wall of the stagnation cover 1 is provided with a plurality of air outlet holes 2;

a supporting tube 5 is arranged in the stagnation cover 1;

the supporting tube 5 is a stainless steel tube;

the supporting tube 5 is bonded with the stagnation cover 1 through high-temperature glue 4;

a transmission optical fiber 9 is arranged in the supporting tube 5;

the transmission optical fiber 9 is bonded with the inner wall of the support tube 5 through high-temperature glue 4;

a temperature measuring fiber grating 7 is engraved between the air inlet 2 and the air outlet 3 on the transmission fiber 9;

a temperature compensation fiber grating 8 is engraved at the tail end of the transmission fiber 9 close to the total temperature probe;

example 7:

the fiber grating total temperature probe capable of correcting the heat conduction error has the specific structure shown in the embodiment 6, wherein the number of the air outlet holes is 2, the area of each air outlet hole is 15-20% of the area of the air inlet hole, and the area ratio can obtain the best stagnation effect. The air inlet holes are chamfered at 45 degrees.

Example 8:

the specific structure of the fiber bragg grating total temperature probe capable of correcting the heat conduction error is shown in embodiment 6, wherein the temperature measurement fiber bragg grating is arranged at the top end of the transmission fiber, so that the temperature can be rapidly measured; the temperature compensation fiber grating is positioned at the tail part of the total temperature probe which is sealed into a whole through high-temperature glue, so that more accurate heat conduction errors are obtained. Both gratings are short-range gratings, which can reduce errors caused by non-uniform grating temperature distribution.

Example 9:

the specific structure of the fiber grating total temperature probe capable of correcting the heat conduction error is shown in an embodiment 6, wherein the central wavelengths of the temperature measurement fiber grating and the temperature compensation fiber grating have a difference of more than 10nm, so that the influence of light band overlapping on measurement is prevented.

Example 10:

referring to fig. 5, the process of measuring the high-speed dynamic temperature of the fiber grating total temperature probe capable of correcting the heat conduction error applied to the interior of the aircraft engine is as follows:

firstly, a fiber bragg grating total temperature probe capable of correcting heat conduction errors is installed on a support, the support is inserted into an inner cavity of an aero-engine, an air inlet of a stagnation cover is opposite to the incoming flow direction of high-speed airflow, an armored transmission optical fiber is connected to a demodulator, and the demodulator is connected with a computer through a network cable.

The stagnation cover stagnates the high-speed airflow, the kinetic energy is converted into internal energy, the heat is transferred to the temperature measurement fiber grating through heat transfer, and meanwhile, the temperature of the tail end of the probe is measured through the temperature compensation fiber grating. The broadband light provided by the demodulator is transmitted into the fiber bragg grating by the transmission optical fiber, the fiber bragg grating senses temperature change and reflects narrow-band light containing temperature information, and the demodulator reads spectral information of the reflected light and transmits the spectral information to a computer through a network cable. And demodulating the spectrum signal by the computer to obtain corresponding temperature information, and calculating the temperature deviation according to the heat conduction error relational expression to realize the correction of the total temperature measurement heat conduction error.

Example 11:

referring to fig. 6, the method for manufacturing the fiber grating total temperature probe capable of correcting the thermal conduction error includes the following steps:

1) processing an air outlet on the side wall of the stagnation cover by utilizing an electric spark micropore processing technology;

2) determining the positions of the stagnation cover and the support tube by using a micrometer under an electron microscope and marking;

3) coating high-temperature glue on the outer wall of the supporting tube;

4) inserting the supporting tube into the stagnation cover, and curing high-temperature glue by using a high-temperature furnace to form high-temperature glue beads at the tail end of the stagnation cover;

5) determining the positions of the temperature measurement fiber grating and the temperature compensation fiber grating on the transmission fiber by a micrometer under an electron microscope and marking;

6) a temperature measurement fiber grating and a temperature compensation fiber grating are engraved on the transmission fiber;

7) inserting the transmission optical fiber into the support tube, controlling the insertion length of the optical fiber by using a precise displacement table, and marking after determining the relative position;

8) high-temperature glue is coated between the transmission optical fiber and the inner wall of the supporting tube by using an electron microscope and a precise displacement platform, and the high-temperature glue is solidified by using a high-temperature furnace to form high-temperature glue beads at the tail end of the supporting tube. Forming the fiber grating total temperature probe capable of correcting the heat conduction error.