阅读说明：本技术 发动机进气总温动态畸变测试的吸气式可插接热电偶探头 (Air suction type pluggable thermocouple probe for engine air inlet total temperature dynamic distortion test ) 是由 单智超 侯孟 唐磊 于 2020-11-27 设计创作，主要内容包括：本发明属于航空发动机进气动态温度畸变测试技术领域,具体涉及发动机进气总温动态畸变测试的吸气式可插接热电偶探头。吸气式可插接热电偶探头包括：热电偶支架1、微细热电偶2、电偶插座、电偶插针、集气头3、探头外壳体4、锁紧螺母11、定位环12、探头尾部壳体13、电偶延长线14、引气管15。(The invention belongs to the technical field of air inlet dynamic temperature distortion testing of an aircraft engine, and particularly relates to an air-breathing pluggable thermocouple probe for air inlet total temperature dynamic distortion testing of an engine. An aspirating, pluggable thermocouple probe comprising: thermocouple support 1, fine thermocouple 2, galvanic couple socket, galvanic couple contact pin, gas collection head 3, probe shell 4, lock nut 11, holding ring 12, probe afterbody casing 13, galvanic couple extension line 14, bleed pipe 15.)

1. An air-breathing pluggable thermocouple probe for dynamic distortion test of total temperature of air inlet of an engine is characterized by comprising: the thermocouple probe comprises a thermocouple support (1), a micro thermocouple (2), a thermocouple socket, a thermocouple pin, a gas collecting head (3), a probe outer shell (4), a locking nut (11), a positioning ring (12), a probe tail shell (13), a thermocouple extension line (14) and a gas guide pipe (15);

the gas collecting head (3) of the closing-in is fixed at the head of the probe outer shell (4), and the probe outer shell (4) is fixedly connected with the probe tail shell (13) through a locking nut (11); the probe tail shell (13) is sleeved with an inducing pipe (15) so as to be communicated with an air suction port of a vacuum pump through the inducing pipe (15); a plurality of clamping jaws are arranged at the middle part in the outer shell (4) of the probe along the circumferential direction;

the head of the thermocouple socket is pressed with two thermocouple brackets (1); the tops of the two thermocouple supports (1) are connected through a micro thermocouple (2); the tail part of the galvanic couple pin is pressed with two galvanic couple extension lines (14); the galvanic couple socket is spliced with the galvanic couple contact pin; the plugged couple socket and couple pin are positioned in a flow field channel formed by the inner parts of the probe outer shell (4) and the probe tail shell (13); the outer wall of the galvanic couple socket is provided with a circle of snap rings which are matched and fastened with the clamping jaws; the positioning ring (12) is of a hollow structure, an inner hole of the positioning ring (12) is used as a spigot at the tail part of the galvanic couple contact pin, and the positioning ring (12) is pressed on the step surface of the step hole in the shell (13) at the tail part of the probe by the galvanic couple contact pin;

when the vacuum pump is used for pumping air, the flow field as the inlet of the flow field channel is contracted due to the closing-up of the gas collecting head (3), and the subsequent channel is an expanded flow field channel.

2. The aspirating, pluggable thermocouple probe of claim 1, wherein the galvanic socket comprises: the electric coupler socket comprises a galvanic couple socket shell (5) provided with clamping jaws, a socket ceramic bushing (6) and a socket assembly (7); the galvanic pin comprises: a galvanic pin shell (10), a pin ceramic sleeve (9) and a pin assembly (8);

wherein, a socket assembly (7) is installed through the socket ceramic sleeve (6), one end of the socket assembly (7) is connected with two thermocouple supports (1) in a pressing mode, and the socket assembly (7) is connected with a contact pin assembly (8) in an inserting mode; the coupling socket shell (5) and the coupling pin shell (10) are centered through the seam allowance; the galvanic plug shell (10) is provided with a plug pin component (8) through a plug pin ceramic sleeve (9).

3. A gas aspirating, pluggable thermocouple probe according to claim 2, characterized by the fact that a sealing and insulating filler fills the gap between the pin receptacle assembly (7) and the galvanic couple holder (1) in the galvanic socket housing (5) and also the gap between the pin assembly (7) and the galvanic extension (14) in the galvanic pin housing (10).

4. The air-breathing pluggable thermocouple probe according to claim 2, wherein the air-collecting head (3) is designed to be a thick lip and used for capturing flow, enhancing the internal rectification effect and reducing the flow separation loss at the outer edge of the lip, the front part of the internal channel is provided with a straight pipe section for rectification and thermocouple installation, the rear part of the internal channel is provided with an expansion section matched with the thermocouple socket shell (5) to complete annular separation of air flow, the inner diameter of the front part of the straight pipe section of the air-collecting head (3) is designed to be matched with the flow area of the throat section, the heat exchange Ma of the micro thermocouple (2) inside the air-collecting head (3) in a supercritical state is guaranteed to be fixed at a certain value between 0.6 and 0.7 and not influenced by speed fluctuation, the convective heat exchange strength of a thermocouple junction is increased, and the fidelity of an engine intake dynamic temperature test signal is realized.

5. The aspirating, pluggable small inertia thermocouple probe of claim 2, wherein the socket assembly (7) and the pin assembly (8) are each machined from the same material as the two poles of the thermocouple holder (1), eliminating the additional potential of the galvanic circuit caused by the unsteady temperature field.

6. The air-breathing pluggable small-inertia thermocouple probe according to claim 2, wherein four annular channels formed by the clamping jaws, the clamping rings and the inner wall of the outer probe shell (4) form an inner flow throat section, and the outer contour of the galvanic couple socket shell (5) and the inner wall of the outer probe shell (4) form a contracted flow field channel with equal outer diameter and an expanded flow field channel with a part of equal outer diameter.

7. The air-breathing pluggable small inertia thermocouple probe according to claim 6, wherein the inner wall of the probe outer shell (4) and the outer contour of the galvanic pin shell (10) form an expansion flow field channel with a constant outer diameter; the inner wall of the probe tail shell (13) and four circumferential annular channels of the positioning ring (12) form an expanded flow field channel; the vacuum pump is arranged at the rear end of the shell (13) at the tail part of the probe; when the supercritical fluid field is operated, the vacuum pump is used for pumping the air guide pipe (15) connected with the tail shell (13) of the probe so as to manufacture the supercritical fluid field.

8. The air breathing pluggable small inertia thermocouple probe according to claim 1, wherein the thermocouple support (1) and the fine thermocouple (2) together constitute a head structure of the small inertia thermocouple, and a hot junction is installed at the center of an internal straight pipe section of the gas collecting head (3); the thermocouple support (1) and the micro thermocouple (2) are welded by high-temperature tin soldering, the micro thermocouple (2) forms a micro thermal junction by laser welding, and the support and the micro thermocouple jointly form a cross-flow butt welding structure, so that the strength and rigidity of the thermocouple junction are enhanced, and a strong and stable heat exchange working condition can be kept by combining the rectification action of the gas collecting head (3).

Technical Field

The invention belongs to the technical field of air inlet dynamic temperature distortion testing of an aircraft engine, and particularly relates to an air-breathing pluggable small-inertia thermocouple probe for air inlet total temperature dynamic distortion testing of an engine.

Background

The transient temperature is an important parameter for thermodynamic analysis of high-temperature flow fields and temperature-resistant devices in the application occasions of detonation combustion, high-speed heat exchange and the like, and particularly has a vital effect in various fields of national defense industry such as aerospace, gas turbines, missile explosives and the like. In a dynamic temperature distortion test of an aircraft engine, because influence data of an air inlet dynamic distortion temperature field on stability margin loss of the engine needs to be acquired, particularly a transient space distortion temperature field with a certain temperature rise rate, a temperature rise value and action time of an inlet AIP section needs to be accurately measured. In general, a small-diameter micro thermocouple is adopted to test an air inlet dynamic temperature field of an engine, but the small-inertia thermocouple has the defects of large time constant, dynamic test data distortion, poor space flow field applicability, troublesome data correction, auxiliary measuring tools, low strength/rigidity/reliability, easily damaged measuring points, low test efficiency and the like due to the fact that the structure is simple and no pneumatic and heat exchange design is carried out, and the dynamic temperature field with the temperature rise rate of about 3000K/s cannot be reliably measured due to the fact that the measuring points are damaged and cannot be replaced after being damaged. In order to solve some of the defects, the hot junction of the micro thermocouple wire is flattened by using the Russian design structure in China for reference to increase the convection heat transfer area, but the thermocouple reliability is reduced, namely the sheet junction is easy to deform and fall off due to aerodynamic force, the applicability is poor for a flow field measuring point with strong secondary flow, and the time constant is reduced but still cannot meet all test requirements. Therefore, a small inertia galvanic couple which can be reliably used for testing the dynamic temperature distortion of the air inlet of the engine needs to be developed, the defects of large time constant, poor reliability, poor space applicability, complex testing means, difficulty in replacement and the like of the galvanic couple are sufficiently overcome, and powerful testing technical support is provided for the temperature distortion test of the engine.

Disclosure of Invention

The purpose of the invention is as follows: the small inertia galvanic couple for the intake dynamic temperature distortion test of the engine is provided, and the defects of large test time constant, poor reliability, poor flow field universality, dynamic data distortion, complex test means, difficulty in replacement and the like of the conventional small inertia galvanic couple are overcome.

The technical scheme is as follows:

the technical scheme adopted for achieving the purpose of the invention is that the air-breathing pluggable thermocouple probe for the dynamic distortion test of the total intake temperature of the engine comprises a thermocouple bracket 1, a micro thermocouple 2, a thermocouple socket, a thermocouple pin, a gas collecting head 3, a probe outer shell 4, a locking nut 11, a positioning ring 12, a probe tail shell 13, a thermocouple extension line 14 and a gas guide pipe 15;

the gas collecting head 3 of the closing-in is fixed at the head of the probe outer shell 4, and the probe outer shell 4 is fixedly connected with the probe tail shell 13 through a locking nut 11; the probe tail shell 13 is sleeved with an induction pipe 15 so as to be communicated with an air suction port of a vacuum pump through the induction pipe 15; a plurality of clamping jaws are arranged at the middle part in the outer shell 4 of the probe along the circumferential direction;

the head of the thermocouple socket is pressed with two thermocouple brackets 1; the tops of the two thermocouple supports 1 are connected through a micro thermocouple 2; two galvanic couple extension lines 14 are pressed at the tail parts of the galvanic couple pins; the galvanic couple socket is spliced with the galvanic couple contact pin; the inserted galvanic couple socket and the galvanic couple contact pin are positioned in a flow field channel formed by the interior of the probe outer shell 4 and the probe tail shell 13; the outer wall of the galvanic couple socket is provided with a circle of snap rings which are matched and fastened with the clamping jaws; the positioning ring 12 is in a hollow structure, an inner hole of the positioning ring 12 is used as a spigot at the tail part of the galvanic couple contact pin, and the positioning ring 12 is pressed on the step surface of a step hole in the shell 13 at the tail part of the probe by the galvanic couple contact pin;

when the vacuum pump is used for pumping air, the flow field serving as the inlet of the flow field channel is contracted due to the closing-up of the gas collecting head 3, and the subsequent channel is an expanded flow field channel.

Further, the galvanic couple socket includes: the electric coupling socket comprises a coupling socket shell 5 provided with clamping jaws, a socket ceramic bushing 6 and a socket assembly 7; the galvanic pin comprises: a galvanic couple pin shell 10, a pin ceramic sleeve 9 and a pin assembly 8;

wherein, a socket assembly 7 is arranged through the socket ceramic sleeve 6, one end of the socket assembly 7 is pressed with two thermocouple supports 1, and the socket assembly 7 is inserted with a pin assembly 8; the galvanic couple socket shell 5 and the galvanic couple pin shell 10 are centered through a spigot; the galvanic pin housing 10 mounts the pin assembly 8 through the pin ceramic sleeve 9.

Further, a sealing insulating filler is filled in a gap between the pin assembly 7 and the galvanic couple support 1 in the galvanic couple socket housing 5, and is also filled in a gap between the pin assembly 7 and the galvanic couple extension line 14 in the galvanic couple pin housing 10.

Further, the gas collecting head 3 is designed to be a thick lip and used for capturing flow, enhancing the internal rectification effect and reducing the flow separation loss of the outer edge of the lip, the front part of the internal channel is provided with a straight pipe section for rectification and mounting of a thermocouple, the rear part of the expansion section is matched with the thermocouple socket shell 5 to complete annular separation of air flow, the inner diameter of the front part of the straight pipe section of the gas collecting head 3 is designed to be matched with the flow area of the throat section, the heat exchange Ma of the micro thermocouple 2 in the gas collecting head 3 in a supercritical state is guaranteed to be fixed at a certain value between 0.6 and 0.7 and not affected by speed fluctuation, meanwhile, the convection heat exchange strength of a thermocouple junction is increased, and the fidelity of an engine intake dynamic temperature test signal is guaranteed.

Further, the socket assembly 7 and the pin assembly 8 are respectively manufactured by using the same material as the two poles of the thermocouple holder 1, and the additional potential of the galvanic couple loop caused by the unsteady temperature field is eliminated.

Furthermore, four annular channels formed by the clamping jaws, the clamping rings and the inner wall of the probe outer shell 4 form an inner flow throat section, and the outer contour of the galvanic couple socket shell 5 and the inner wall of the probe outer shell 4 form a contraction flow field channel with equal outer diameter and an expansion flow field channel with partial equal outer diameter;

furthermore, the inner wall of the probe outer shell 4 and the outer contour of the galvanic couple pin shell 10 form an expansion flow field channel with equal outer diameter; the inner wall of the probe tail shell 13 and the circumferential four annular channels of the positioning ring 12 form an expanded flow field channel; the vacuum pump is arranged at the rear end of the probe tail shell 13; in operation, the vacuum pump is used to pump the bleed air pipe 15 connected to the probe tail housing 13 to create a supercritical fluid field.

Further, the thermocouple support 1 and the micro thermocouple 2 jointly form a head structure of a small inertia thermocouple, and a hot junction is arranged in the center of the inner straight pipe section of the gas collecting head 3; the thermocouple support 1 and the micro thermocouple 2 are welded by high-temperature tin soldering, the micro thermocouple 2 forms a micro thermal junction by laser welding, and the support and the micro thermocouple jointly form a cross-flow butt welding structure, so that the strength and rigidity of the thermocouple junction measuring point are enhanced, and a strong and stable heat exchange working condition can be kept by combining the rectification action of the gas collecting head 3.

The invention has the beneficial effects that:

compared with the traditional small inertia thermocouple and the existing thin-sheet small inertia thermocouple, the invention has the following advantages:

thermocouple time constant is small 1: as the head of the galvanic couple measuring point is designed into a cross-flow butt welding structure for combined welding of thick and thin couple wires, the diameter of the cross-flow butt welding structure can be usedThe left and right micro thermocouple wires are used as measuring end thermocouples, and the diameter of a welding spot is generally withinThe heat exchange intensity is higher because the convection mode is laminar flow heat exchange by winding parallel to the plane of the coupling wire; meanwhile, the thermocouple probe is designed into a suction type structure, the reasonable pneumatic design ensures that the Ma of the installation section of the micro thermocouple node is larger than the incoming flow Ma between 0.6 and 0.7, the convective heat transfer intensity at the node is further intensified, the time constant tau of the thermocouple is between 20ms and 25ms under the general condition, and is generally more than 45ms when the time constant incoming flow Ma which is far smaller than the time constant of the existing conventional structure and the thin-sheet node type small inertia thermocouple is 0.7, the time constant is further increased along with the reduction of the incoming flow Ma, and the dynamic temperature measurement of the temperature rise rate of the measuring point not lower than 3000K/s can be sufficiently met.

2, the flow field has better universality: because the thermocouple junction is designed into a cross-flow butt welding structure, the spatial insensitivity of the heat exchange coefficient is strong, the air flow captured by the air suction channel is rectified by a thick lip of the air collection head 3 in advance, the spatial insensitivity angle of the measuring point is further increased, and the number of the bypass flow Ma at the hot junction is basically constant, so that the small inertia couple measuring point can still reliably work aiming at the flow field measuring point with strong secondary flow, and the time constant is basically not influenced by weak turbulence and speed pulsation.

3, the reliability of the measuring point is higher: the head of the couple measuring point is designed into a form of combined welding of thick and thin couple wires, so that the dynamic performance of the couple is improved, and the strength and the rigidity of the root of the couple wire are also improved; the couple measuring points are protected by the gas collecting head, and the thick lip at the outer edge of the gas collecting head can effectively reduce mechanical vibration caused by airflow separation, so that the couple nodes are not easily damaged mechanically, and meanwhile, the flow in the probe in a supercritical state can resist speed pulsation and turbulence disturbance, thereby enhancing the coupling wire under pneumatic loadReliability, according to the calibration test results, diameter ofThe micro coupled wire node can be reliably used in a flow field with Ma being 0.7 for a long time; moreover, the pluggable galvanic couple probe structure enables the galvanic couple head component to be a universal component and can be replaced in time, and therefore the reliability of the galvanic couple test is further improved.

4 dynamic temperature test waveform is not distorted basically: in a dynamic temperature field, because the temperature of each point on a flow line is not uniform, the real transient temperature of each moment of a measuring point is obtained through contact measurement, the flow field cannot be greatly interfered, the head structure of a conventional couple probe can stop the incoming flow to cause the deceleration of a flow following point and the expansion of the flow pipe, so that the distortion of the waveform of the tested dynamic temperature is caused, the designed suction flow of the air-breathing small-inertia thermocouple is not less than the maximum supply flow of an undisturbed flow pipe all the time, the part of the air flow lacking in a cylindrical flow pipe is sucked into a lip from the peripheral space in front of a gas collecting head at a short distance through lip rectification, the influence on the waveform caused by the slight acceleration of the flow following point in the contraction flow pipe at the front end of the probe is ensured, and the measured dynamic temperature waveform is not distorted basically.

5 the distortion test is convenient to use: because the actually measured transient temperature data of the small inertia couple must be corrected by dynamic errors, the time constant of the couple node must be used for correction, the time constant is related to the heat exchange coefficient, Nu number and local Re number, and the change of the Ma number can cause the change of the characteristic number, so the local Ma number must be known for the calibrated small inertia couple to correct the test data, therefore, the small inertia couple with the conventional structure needs to increase auxiliary total pressure and static pressure test points for calculating the local Ma number of each test point position when performing dynamic temperature distortion flow field test, which puts forward additional requirements on test resources and flow field space. Due to the constraint of conservation of internal flow mass, the air-breathing small inertia electric couple hot junction reaching the supercritical state always works under a constant Ma number, so that the time constant is basically a fixed value on the premise of small fluctuation of the pressure and the temperature of the incoming flow, and the time constant under the temperature and pressure range can be directly corrected during the test by calibrating the time constant under the temperature and pressure range before the test, thereby greatly simplifying the test flow, saving the test and test resources and being convenient to use.

Drawings

FIG. 1 is a plan view of the external appearance of an air-breathing pluggable small inertia thermocouple probe for engine intake dynamic temperature distortion testing;

FIG. 2 is a detailed cross-sectional view of a front view of the probe.

In the figure: 1-a galvanic couple bracket, 2-a micro thermocouple, 3-a gas collecting head, 4-a probe outer shell, 5-a galvanic couple socket shell, 6-a socket ceramic sleeve, 7-a socket component, 8-a contact pin, 9-a contact pin ceramic sleeve, 10-a galvanic couple contact pin shell, 11-a locking nut, 12-a positioning ring, 13-a probe tail shell, 14-a galvanic couple extension line, 15-and a gas guide pipe.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments.

An air-breathing pluggable small-inertia thermocouple probe for testing air inlet dynamic temperature distortion of an engine comprises a thermocouple support 1, a micro thermocouple 2, a gas collecting head 3, a probe outer shell 4, a thermocouple socket shell 5, a socket ceramic sleeve 6, a socket component 7, a pin component 8, a pin ceramic sleeve 9, a thermocouple pin shell 10, a locking nut 11, a positioning ring 12, a probe tail shell 13, a thermocouple extension line 14, a gas guide pipe 15 and a vacuum pump, wherein the positive electrodes of the micro thermocouple 2 and the thermocouple support 1 are made of the same material, the negative electrodes of the micro thermocouple and the thermocouple support are made of the same material, the socket component 7 and the pin component 8 respectively comprise two sets, the positive electrode and the negative electrode of each set are respectively made of the same material, and the positive electrode and the negative electrode of each set.

The air suction type pluggable small-inertia thermocouple probe is a contraction-expansion flow field channel structure which is formed by 8 parts of components together, wherein a circular tube is used for collecting air firstly, then the air collection is separated into inner streams of a ring surface, and the inner streams are finally pumped into a vacuum pump, and the air suction type pluggable small-inertia thermocouple probe comprises an air collection head 3, a probe outer shell 4, a galvanic couple socket, a galvanic couple contact pin, a positioning ring 12, a probe tail shell 13, an air guide pipe 15 and the vacuum pump in sequence from an air inlet section. The air flow is captured by the air collecting head 3 and rectified, the rear part expansion section of the internal channel of the air collecting head 3 is matched with the galvanic couple socket shell 5 to complete the annular separation of the air flow, the convergence acceleration, the critical flow and the local supersonic speed expansion acceleration flow of the subsonic air flow are completed by the inner wall surface of the probe outer shell 4 matched with the galvanic couple socket shell 5, the further expansion acceleration flow of the supersonic air flow is completed by the inner wall surface of the probe outer shell 4 matched with the galvanic couple pin shell 10, the further expansion acceleration flow of the supersonic air flow is completed by the galvanic couple pin shell 10 matched with the positioning ring 12 and the probe tail shell 13, and the supersonic speed air extraction process is completed by the probe tail shell 13 matched with the air guide pipe 15 and the vacuum pump.

The air-breathing pluggable small-inertia thermocouple probe comprises an annular flow field channel outer wall surface formed by the air collecting head 3, the probe outer shell 4, the inner wall surface of the probe tail shell 13 and the outer walls of 124 annular channels of the positioning rings, and an annular flow field channel inner wall surface formed by the outer contour of the galvanic couple socket shell 5, the galvanic couple pin shell 10 and the inner walls of 124 annular channels of the positioning rings.

The gas collecting head 3 is designed to be a thick lip, the internal rectification effect is enhanced, the flow separation loss of the outer edge of the lip is reduced, the front part of an internal channel is provided with a straight pipe section for rectification and thermocouple installation, the inner diameter of the internal channel is matched with the flow area of the throat section, the heat exchange Ma of the micro thermocouple 2 in the gas collecting head 3 in a supercritical state is guaranteed to be fixed at a certain value between 0.6 and 0.7 and not influenced by speed fluctuation, meanwhile, the convection heat exchange strength of a thermocouple junction is increased compared with the incoming flow speed, and the fidelity of a test signal of the engine intake dynamic temperature intake Ma is less than or equal to 0.6 is realized.

The probe comprises a probe shell 4, a probe cover, a probe outer shell, a clamp ring, a contraction flow field channel and an expansion flow field channel, wherein four clamp claws are arranged on an inner channel of the probe outer shell 4 and used for tightly pressing a galvanic couple socket shell 5, a circle of clamp ring is arranged outside the galvanic couple socket shell 5 and is matched and fastened with the four clamp claws, the clamp ring and the 4 annular channels formed by the inner wall of the probe outer shell 4 form an inner flow throat section, the gradually-changed.

The inner wall of the probe outer shell 4 and the gradually-changed outer contour of the galvanic couple pin shell 10 form an expansion flow field channel with the same outer diameter;

the galvanic couple contact pin shell 10, the inner wall of the probe tail shell 13 and 4 circumferential annular channels of the positioning ring 12 form a downstream expansion flow field channel;

the vacuum pump is arranged at the rear end of the probe tail shell 13; when the vacuum pump works, the air-entraining pipe 15 connected with the tail shell 13 of the probe is evacuated through the vacuum pump;

the thermocouple support 1, the micro thermocouple 2, the thermocouple socket shell 5, the socket ceramic sleeve 6 and the socket component 7 form a thermocouple socket, namely, the head of the small inertia thermocouple can be plugged, the contact pin component 8, the contact pin ceramic sleeve 9 and the thermocouple contact pin shell 10 form a thermocouple contact pin, the positioning ring 12, the probe tail shell 13, the thermocouple extension line 14 and the gas guide pipe 15 form a pluggable small inertia thermocouple tail, and the head and the tail can be plugged and separated.

Through the tang location and locking between locking nut 11 with probe shell body 4 and probe afterbody casing 13, and then through the tang location and compress tightly between can peg graft electric couple head and the galvanic couple contact pin, finally pass through the tang location and compress tightly galvanic couple contact pin and holding ring 12, just so accomplished probe shell body 4, can peg graft little inertia galvanic couple head, can peg graft little inertia galvanic couple afterbody and locking nut 11 integrated, location and locking are locking, can replace can peg graft electric couple head subassembly completely according to the damaged condition in the experiment.

The socket assembly 7 and the contact pin assembly 8 form a plug assembly of a small inertia couple, the plug assemblies of the positive pole and the negative pole are respectively processed by using the same material as the two poles of the thermocouple support 1, and the additional potential of a couple loop caused by an unsteady temperature field is eliminated.

The thermocouple support 1 and the micro thermocouple 2 jointly form a head structure of a small inertia thermocouple, and a hot junction is arranged in the center of an internal straight pipe section of the gas collecting head 3; the thermocouple support 1 and the micro thermocouple 2 are welded by high-temperature tin soldering, the micro thermocouple 2 forms a micro thermal junction by laser welding, and the support and the micro thermocouple jointly form a cross-flow butt welding structure, so that the strength and rigidity of the thermocouple junction measuring point are enhanced, and a strong and stable heat exchange working condition can be kept by combining the rectification action of the gas collecting head 3; the galvanic couple support 1 and the socket assembly 7 are fixed through crimping of a crimping pliers, and the galvanic couple extension line 14 and the contact pin assembly 8 are fixed through crimping of the crimping pliers.

During measurement, the air suction type pluggable small inertia thermocouple probe is placed in a dynamic temperature measurement environment, a thermocouple extension line 14 is connected into a dynamic data acquisition system, a vacuum pump is started to perform air suction, the throat of a probe channel reaches a sonic velocity state according to calculated suction pressure and flow, a supercritical fluid field is formed by a test section containing the thermocouple at the front section of the throat section, a dynamic temperature signal output by the thermocouple in real time is subjected to hardware compensation, the dynamic temperature test deviation of the thermocouple is corrected through multiple steps by a computer, and finally a corrected incoming flow dynamic temperature signal is obtained.

The air suction type pluggable small-inertia thermocouple probe is subjected to air permeability detection after being assembled, and whether the air suction setting parameters of the vacuum pump enable the probe channel to enter a supercritical state or not can be detected through the flow meter.

Example 1 was carried out:

the embodiment discloses an air-breathing pluggable small-inertia thermocouple probe for testing air inlet dynamic temperature distortion of an aircraft engine, which comprises a thermocouple support 1, a micro thermocouple 2, an air collecting head 3, a probe outer shell 4, a thermocouple socket shell 5, a socket ceramic sleeve 6, a socket component 7, a pin component 8, a pin ceramic sleeve 9, a thermocouple pin shell 10, a locking nut 11, a positioning ring 12, a probe tail shell 13, a thermocouple extension line 14, an air guide pipe 15 and a vacuum pump, and is shown in the figures 1 to 2.

The thermocouple bracket 1 is made of K-shaped bare thermocouple wires or peeled plastic-coated thermocouple wires, and the diameter of the thermocouple bracket is selectedOrThe length is 9.5mm, the root part of the thermocouple is fixed with the socket component 7 by compression joint, wherein the positive electrode thermocouple bracket 1 is fixed with the socket component 7 processed by nickel chromium by compression joint, the negative electrode thermocouple bracket 1 is processed by nickel siliconThe socket component 7 is fixed by compression;

the micro thermocouple 2 is K-type bare thermocouple wire with the diameter selectedOrThe length of the anode and the cathode are both 1mm, the anode and the cathode are welded by laser welding, and the diameter of a spherical or cylindrical welding spot is not more thanThe positive electrode and the negative electrode of the micro thermocouple 2 are respectively welded at the end part of the thermocouple support 1 with the same pole by high-temperature electric soldering, and the length of redundant thermocouple wires is removed.

The socket ceramic sleeve 6 and the pin ceramic sleeve 9 are made of high-temperature ceramic Al₂O₃Is formed by sintering ceramic powder in a mould, the diameter of the ceramic tube is not more thanThe pin assembly is characterized in that the pin assembly is double holes, the pitch of the holes is smaller than 2mm, the diameter, the number and the depth of the stepped holes are correspondingly determined according to the shapes of the socket assembly 7 and the pin assembly 8, and the minimum wall thickness between the holes is not smaller than 0.3 mm.

The external appearance design of the socket component 7 and the pin component 8 refers to relevant design specifications, and the maximum external diameter does not exceed the maximum external diameterThe connector is made of nickel-chromium and nickel-silicon, the number of the socket assemblies 7 and the number of the pin assemblies 8 made of nickel-chromium should be as many as that of the socket assemblies 7 and the pin assemblies 8 made of nickel-silicon, and the matching tightness of the pins and the holes should meet relevant requirements, so that a plating layer is allowed to be arranged on the surface.

The thermocouple extension line 14 is made of peeled plastic-coated thermocouple wires, and the diameter of the plastic-coated thermocouple wires is selectedOrThe length is self-determined, and the positive pole and the negative pole of the pin are fixedly pressed with the pin assembly 8 processed by the same material.

The outer contour of the galvanic couple socket shell 5 is designed into a certain gradual-change profile according to the aerodynamic characteristics and the working flow of the internal flow, the outer diameter of the shell from the head part to the tail part is gradually increased, and the sudden change of the curvatures of the contour is avoided as much as possible; the outer surface of the shell is provided with a circle of snap rings, the outer diameter of the snap rings is used as the inner diameter of the throat annular channel and is matched with the inner diameter of the outer shell 4 of the probe to ensure the design flow, and the size is generally not more thanThe outer diameter of the downstream of the clamping ring is gradually reduced, so that the airflow gradually accelerates and expands after passing through the throat section to form a supersonic speed area to isolate aerodynamic interference from the downstream; the coupling socket shell 5 and the coupling pin shell 10 are centered through the seam allowance, so the design diameter and the fit tolerance of the seam allowance of the socket shell are noticed; the inner diameter of the shell and a socket ceramic bushing 6 are in transition fit design, after a pressed socket assembly 7 and a thermocouple support 1 penetrate through the socket ceramic bushing 6, the socket ceramic bushing 6 is installed in an inner hole of a galvanic couple socket shell 5, the head of the shell is subjected to necking treatment to further fix an internal assembly, and high-temperature cement glue 105-A is filled and sealed in a hole in the head of the shell to finish the insulation treatment of a galvanic couple and the shell;

the outer contour of the galvanic couple pin shell 10 is designed into a certain gradual-change profile according to the aerodynamic characteristics and the working flow of the internal flow, the outer diameter of the shell from the head part to the tail part is gradually reduced, the sudden change of the curvature of the contour is avoided as much as possible, and the outer diameter of the spigot at the head part of the shell is matched with the diameter of the outer wall of an upstream flow channel; the galvanic couple pin shell 10 and the galvanic couple socket shell 5 are centered through the seam allowance, so the design diameter and the fit tolerance of the seam allowance of the pin shell should be noticed; the inner diameter of the shell and a pin ceramic sleeve 9 are in transition fit design, after a pressed pin assembly 8 and a thermocouple extension line 14 penetrate through the pin ceramic sleeve 9, the pin ceramic sleeve 9 is installed in an inner hole of a thermocouple pin shell 10, high-temperature cement glue 105-A is filled and sealed in a cavity at the tail part of the shell to finish the insulation treatment of a thermocouple and the shell, and a plastic coating layer can be reserved to a final acquisition system after the pin ceramic sleeve 9 is led out of a plastic coated thermocouple wire;

the inlet of the gas collecting head 3 is designed to be a thick lip, and the diameter of the lip is not less thanThe flow separation device is used for capturing flow, enhancing the internal rectification effect and reducing the flow separation loss at the outer edge of the lip; the front part of the internal channel is designed into a straight pipe section for rectification and thermocouple installation, the inner diameter of the straight pipe section is designed to be matched with the flow area of the throat section, the heat exchange Ma of the micro thermocouple 2 in the gas collecting head 3 in a supercritical state is ensured to be fixed at a certain value between 0.6 and 0.7, and the diameter is generally not more thanThe rear part expansion section is matched with the galvanic couple socket shell 5 to complete annular separation of air flow, and sudden expansion separation of the air flow caused by sudden change of the curvature of the inner profile is avoided; the diameter of the outer contour can be designed to be gradually enlarged or equal, and curvature mutation is also required to be avoided; the gas collecting head 3 is connected with the probe outer shell 4 in a positioning way through a spigot, the spigot size is required to be designed, the gas collecting head and the spigot are welded and connected through laser welding after being assembled and positioned, and the penetration depth is not less than 0.8 mm;

the outer diameter of the probe shell body 4 is matched with the outer diameter of the gas collecting head and is in smooth transition, and the probe shell body is generally designed into an equal-diameter structure, and the diameter of the probe shell body is not more thanThe outer wall of the tail part of the shell is provided with a circle of snap rings which are matched and fastened with a locking nut 11, the outer shell 4 of the probe and the shell 13 of the tail part of the probe are positioned through a seam allowance, the insertion depth of the seam allowance is not less than 2mm, the periphery of the seam allowance is designed to be in small clearance fit, and the seam allowance is locked through the locking nut 11; the inner channel is provided with four clamping jaws for compressing the clamping rings of the galvanic couple socket shell 5, the clamping jaws, the clamping rings and the four annular channels formed by the inner walls of the probe shell 4 form an inner flow throat section, the throat section area is matched with the straight pipe section area of the gas collection head, and the clamping jaws are guaranteedThe blocking ratio of the throat ring surface is not more than 30%, Ma of the straight pipe section in the gas collecting head is fixed at a certain value between 0.6 and 0.7, and meanwhile, the area of each flow section of the whole flow passage is checked to ensure that the critical section is present at the design position and Ma in front of each subsonic section throat is less than or equal to 0.5; the inner wall of the probe outer shell 4 and the outer contour of the galvanic couple socket shell 5 form a contraction flow field channel with equal outer diameter and an expansion flow field channel with a part of equal outer diameter, and the inner wall of the probe outer shell 4 and the outer contour of the galvanic couple pin shell 10 form an expansion flow field channel with equal outer diameter;

the thread design of the shell 13 at the tail part of the probe is matched with the locking nut 11, and the diameter of a circular tube of the outer contour is consistent and not more thanA hexagonal head is required to be arranged and is arrangedThe lock thread hole; the front section of the internal channel is positioned with the outer shell 4 of the probe through a spigot, the matching size needs to be designed, and the diameter of the front section channel is not more thanThe rear section channel is a round pipe, and the inner diameter can be designed to be

The positioning ring 12 is designed into a double-ring surface structure, the middle part of the positioning ring is connected through spokes, an outer ring is designed to be in small clearance fit with an inner hole at the front section of the probe tail shell 13 and is positioned through a stepped hole of the probe tail shell 13, an inner ring is designed to be a stepped hole, the inner ring is centered with the tail part of the galvanic couple pin shell through a spigot and is designed to be in transition fit, and after the spigot is inserted, the end surface limit is prevented from being limited on the section of the positioning ring 12; the positioning ring 12 is circumferentially provided with four annular channels, the flow area of the annular channels is ensured to be 2 times of the throat area, and the middle hole of the inner ring is designed to beFor leading out a galvanic couple extension line 14; statorThe thickness of the position ring is designed to be 2.5 mm-3 mm, and then the position ring has enough strength and rigidity; the inner wall of the probe tail shell 13 and four circumferential annular channels of the positioning ring 12 form a flow field channel which is further expanded;

the structural dimension of the lock nut 11 can be designed according to relevant standards, the thread dimension is not larger than M12, and a hexagonal head needs to be drilledThe lock thread hole; the nut is used for locking the probe outer shell 4 and the probe tail shell 13, so that the head of the pluggable thermocouple and the thermocouple pin are positioned and pressed through the seam allowance, finally the thermocouple pin and the positioning ring 12 are positioned and pressed through the seam allowance, and the locking screw is screwed for locking and loosening prevention, so that the integration, positioning and locking loosening prevention of the probe outer shell 4, the pluggable small inertia thermocouple head, the pluggable small inertia thermocouple tail and the locking nut 11 are completed, and the pluggable thermocouple head component can be completely replaced according to the damage condition in the test;

during assembly, firstly, a thermocouple socket containing thermocouple support 1, a micro thermocouple 2, a thermocouple socket shell 5, a socket ceramic sleeve 6, a socket component 7, a thermocouple pin containing pin component 8, a pin ceramic sleeve 9, a thermocouple pin shell 10 and a thermocouple extension line 14 are assembled respectively, then, the thermocouple pin, a positioning ring 12 and a probe tail shell 13 are assembled to form a small insertable inertia thermocouple tail, then, the thermocouple socket is arranged at the tail of the small insertable inertia thermocouple and connected with a connector and is centered through a spigot, then, a welded gas collecting head 3 and a probe outer shell 4 are sleeved from the outside of the thermocouple socket to the positioning snap ring and are centered with the spigot of the probe tail shell 13, finally, a locking nut 11 is sleeved into the probe outer shell 4 and is matched and fastened with the thread of the probe tail shell 13 until the nut clamps the snap ring of the outer contour of the probe outer shell 4 and is pressed tightly, and finally, screwing locking threads to prevent loosening. During testing, the tail part of the probe tail shell 13 is connected with the air guide pipe 15, and the probe inner channel is sucked to a supercritical state through the vacuum pump, so that data acquisition can be carried out.

In the invention, a contraction-expansion channel for air extraction is formed among the air collecting head, the galvanic couple pin/socket shell, the probe outer shell and the probe tail shell and is used for manufacturing a supercritical fluid field in the probe so as to fix the number of the streaming Ma of a galvanic couple measuring point (resisting the influence of the fluctuation of the incoming flow speed), improve the convective heat transfer strength and protect a micro couple wire; the critical section design of the internal flow channel ensures that the pumping flow (the flow captured by the lip of the gas collection head) under the supercritical state of the probe is not less than the flow of a flow pipe (an undisturbed cylindrical flow pipe, which is equivalent to the fact that the incoming flow is completely captured and does not generate subsonic overflow) corresponding to the lip area, so as to ensure that the dynamic temperature waveform of the measuring point is not distorted; the galvanic couple contact pin/socket is processed by adopting the same material as a galvanic couple, so that the additional thermoelectric potential caused by temperature gradient at two ends of a connector in a dynamic temperature flow field is eliminated, a micro galvanic couple measuring head can be replaced in time after being damaged in a distortion test, and the test efficiency and the test reliability are ensured; the thermocouple head adopts a design structure that a micro thermocouple wire and a large-diameter thermocouple wire support are welded in a combined mode, and the hot junction of the micro thermocouple wire always works in a cross-flow butt welding mode through rectification of the lip of the gas collecting head, so that the convective heat transfer strength of the junction is increased, and the strength and the rigidity of the thermocouple root are improved. The design characteristics of the air suction type pluggable small inertia thermocouple probe can solve the testing problem of an air inlet dynamic temperature distortion field of an engine, the design of an air suction structure enables the time constant of a testing point to be reduced to be within 25ms, the thermocouple working environment is stable and good in reliability, the thermocouple probe can be replaced in time in a test, the unsteady state temperature field measurement with the temperature rise rate of more than 3000K/s can be realized by combining the structural design of the probe, and an important testing technical guarantee is provided for the stability test of the engine under the condition of air inlet dynamic temperature distortion.

The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.