High-low cycle composite test device based on airflow excitation

Abstract

The invention relates to a high-low cycle composite test device based on airflow excitation. The high-low cycle composite test device comprises a main heat exchange box body; the rotating plate is rotatably mounted in the main heat exchange box body; the driving assembly is fixed to one side of the main heat exchange box body and used for driving the rotating plate to rotate; the blades are annularly arranged on the side, away from the driving assembly, of the rotating plate; the air blowing assembly is arranged on the side, away from the rotating plate, of the blade; according to the high-low cycle composite test device based on airflow excitation, the speed increaser is arranged between the motor and the blade, so that the rotating speed of the blade is increased; the air blowing assembly is arranged on the other side of the blade, simulated airflow is applied to the blade rotating at a high speed, and the distance between the airflow and the blade, the spraying position and the spraying angle can be adjusted, so that the test environment is closer to the real working condition environment, and the accuracy of the test result of the vibration fatigue test of the rotating blade is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of fatigue testing, and particularly relates to a high-low cycle composite test device based on air flow excitation. Background Art

[0002] A rotating machine refers to a mechanical device that can perform rotational motion. Rotating machines are widely used in various fields, including industrial production, agricultural production, transportation, aerospace, etc. A rotating blade is a key component of a rotating machine, and the performance of the rotating blade has an important impact on the safety and reliability of the rotating machine. Fatigue is the main failure mode of the rotating blade, and fatigue caused by vibration is the main failure mechanism. The working conditions of the rotating blade are relatively complex, and there are many factors affecting the vibration of the blade. In actual work, the rotating blade not only bears the low-cycle load of the centrifugal force generated during high-speed rotation, but also bears the high-frequency vibration load exerted by working media such as air flow.

[0003] Currently, when some test devices conduct vibration fatigue tests on rotating blades, they usually only apply rotational vibration loads to the rotating blades to detect the bearing capacity of the rotating blades for vibration loads, and cannot apply an axially adjustable simulated air flow to the blades, resulting in a large difference between the test environment and the actual working condition environment. Therefore, the results obtained from the vibration fatigue tests using such test devices often deviate significantly from the actual working results. Summary of the Invention

[0004] The present invention provides a high-low cycle composite test device based on air flow excitation, which solves the defect that the existing test devices cannot simulate the most realistic working condition environment, resulting in inaccurate test results.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a high-low cycle composite test device based on air flow excitation, which includes:

[0006] A main heat exchange box body;

[0007] A rotating plate, which is rotatably installed in the main heat exchange box body;

[0008] A driving component, which is fixed on one side of the main heat exchange box body and is used to drive the rotating plate to rotate;

[0009] Blades, which are annularly arranged on the side of the rotating plate away from the driving component;

[0010] A blowing component, which is arranged on the side of the blade away from the rotating plate, and the blowing component blows air onto the surface of the rotating blade.

[0011] Optimally, the air blowing assembly includes a first slide plate movably arranged in the main heat exchange box body, a second slide plate movably arranged on the top of the first slide plate, a bracket liftably arranged on the top of the second slide plate, and an air blowing unit fixed on the side of the bracket close to the blade. The moving directions of the first slide plate and the second slide plate are perpendicular to each other.

[0012] Optimally, the air blowing unit includes a gas collecting ring fixed on one side of the bracket, a gas groove opened in the gas collecting ring, an air inlet nozzle fixed on the side of the gas collecting ring away from the blade, and an air outlet nozzle fixed on the side of the gas collecting ring close to the blade. Both the air inlet nozzle and the air outlet nozzle are communicated with the gas groove.

[0013] Optimally, the air blowing unit further includes through grooves coaxially and equidistantly opened on the side of the gas collecting ring close to the blade and plug heads installed in the through grooves. The air outlet nozzle is installed in the through grooves.

[0014] Optimally, the air outlet nozzle includes an air outlet nozzle body installed in the through groove, a gas flow channel penetrating through the air outlet nozzle body, a steering ball rotatably installed on the outer side of the air outlet nozzle body, and an air outlet groove penetrating through the steering ball and communicated with the gas flow channel.

[0015] Optimally, the air outlet nozzle body includes a first air nozzle part installed in the through groove, a second air nozzle part integrally connected to one side of the first air nozzle part, and a third air nozzle part integrally connected to one side of the second air nozzle part. The diameter of the second air nozzle part is larger than that of the first air nozzle part. The steering ball is rotatably installed on the side of the third air nozzle part away from the first air nozzle part.

[0016] Optimally, the gas flow channel includes an air inlet groove penetrating through the first air nozzle part and the second air nozzle part, a transition groove penetrating through the third air nozzle part, and a transition part connecting the air inlet groove and the transition groove and inclined. The diameter of the transition groove is larger than that of the air inlet groove.

[0017] Optimally, the air outlet nozzle further includes a sheath detachably connected to the third air nozzle part and a limiting part inclinedly opened on one side of the sheath. The limiting part abuts against the outer peripheral surface of the steering ball.

[0018] Optimally, the plug head includes an inner plug column installed in the through groove and an outer plug plate integrally connected to one side of the inner plug column. The diameter of the outer plug plate is larger than that of the inner plug column.

[0019] Optimally, the diameter of the air outlet groove is reduced.

[0020] Due to the application of the above technical solutions, the present invention has the following advantages compared with the prior art:

[0021] The high-low cycle composite test device based on air flow excitation of the present invention increases the rotational speed of the blade by arranging a speed increaser between the motor and the blade; a blowing component is arranged on the other side of the blade to apply simulated air flow to the high-speed rotating blade, and the distance between the air flow and the blade, the spraying position, and the spraying angle can all be adjusted, making the test environment closer to the real working condition environment and improving the accuracy of the test results for the vibration fatigue test of the rotating blade. Brief Description of the Drawings

[0022] Figure 1 is the front view of the present invention;

[0023] Figure 2 is the schematic diagram of the partial structure of the present invention;

[0024] Figure 3 is for the present invention Figure 1 the enlarged view of part A in;

[0025] Figure 4 is the cross-sectional view of the air collecting ring of the present invention;

[0026] Figure 5 is the cross-sectional view of the air collecting ring of the present invention;

[0027] Figure 6 is for the present invention Figure 5 the enlarged view of part B in;

[0028] Figure 7 is the cross-sectional view of the air outlet nozzle of the present invention;

[0029] Description of the Reference Numerals in the Drawings:

[0030] 1, main heat exchange box body; 2, auxiliary heat exchange box body; 3, inner support plate; 4, outer support plate; 5, motor; 6, first-stage speed increaser; 7, second-stage speed increaser; 8, first bearing platform; 9, fulcrum bracket; 10, rotating shaft; 11, rotating plate; 12, blade; 13, fastening bolt; 14, fastening nut; 15, detector; 16, second bearing platform; 17, bracket; 18, fixing plate; 19, fixing bolt; 20, air collecting ring; 21, air groove; 22, air inlet nozzle; 23, through groove; 24, plug; 241, inner plug column; 242, outer plug plate; 25, air outlet nozzle; 251, first nozzle part; 252, second nozzle part; 253, third nozzle part; 254, air inlet groove; 255, transition part; 256, transition groove; 257, abutting surface; 258, steering ball; 259, air outlet groove; 2510, sheath; 2511, limiting part; 26, first slide rail; 27, first slider; 28, first sliding plate; 29, second slide rail; 30, second slider; 31, second sliding plate; 32, lifting cylinder. Detailed Embodiments

[0031] The present invention will be further described below in conjunction with the embodiments shown in the accompanying drawings.

[0032] As Figure 1 , 2 shown, it is a schematic diagram of a high-low cycle composite test device based on air flow excitation of the present invention. This device is generally used to blow air on a blade rotating at high speed, so as to simulate the deformation of the blade rotating at high speed under the influence of air flow in a real environment.

[0033] The main heat exchange box body 1 is fixed on the test machine table by means of screw fastening. The inside of the main heat exchange box body 1 is a hollow structure, which is used to provide an installation space for the installation of the blade 12 and the air blowing assembly. The side wall of the main heat exchange box body 1 is rotatably connected with a test door through a hinge. By opening or closing the test door, it is convenient for the operator to take and place the blade 12.

[0034] The auxiliary heat exchange box body 2 is detachably fixed on the top of the main heat exchange box body 1 by means of screw fastening. A plurality of fans are installed on the top of the main heat exchange box body 1, and an air pipe connected to the outside is installed on the auxiliary heat exchange box body 2. As the test progresses inside the main heat exchange box body 1, the friction between the blade 12 rotating at high speed and the air causes the temperature inside the main heat exchange box body 1 to rise, which is not conducive to the continuation of the test. Therefore, the inside and outside heat exchange is carried out through the fans.

[0035] The outer support plate 4 is fixed on the outside of the main heat exchange box body 1, the motor 5 is fixed on the top of the outer support plate 4, and the first-stage speed increaser 6 and the second-stage speed increaser 7 are fixedly arranged at intervals on the top of the outer support plate 4. The output shaft of the motor 5 is connected to the input shaft of the first-stage speed increaser 6, the output shaft of the first-stage speed increaser 6 is connected to the input shaft of the second-stage speed increaser 7, and the output shaft of the second-stage speed increaser 7 is connected to the rotating shaft 10 of the fulcrum bracket 9. Through the two-stage speed increase of the first-stage speed increaser 6 and the second-stage speed increaser 7, the rotation speed of the rotating shaft 10 can be increased, so as to simulate the working condition of the blade 12 under high-speed rotation.

[0036] The first-stage speed increaser 6 and the second-stage speed increaser 7 have the same structure. The speed increaser is a commercially available standard part, and the rotation speed of the output shaft is increased by changing the transmission ratio.

[0037] The first bearing block 8 is fixed on the top of the inner support plate 3, the fulcrum bracket 9 is fixed on the top of the first bearing block 8, the rotating shaft 10 is rotatably installed in the fulcrum bracket 9 through a bearing, and is connected to the output shaft of the second-stage speed increaser 7 through a coupling. During the test, the motor 5 is started, and through the two-stage speed increase of the first-stage speed increaser 6 and the second-stage speed increaser 7, the torque is transmitted to the rotating shaft 10, and finally the high-speed rotation of the blade 12 is realized, so as to simulate the working condition of the blade 12 under high-speed rotation.

[0038] The rotating plate 11 is fixed to one end of the rotating shaft 10 away from the speed increaser. The blades 12 are arranged in a ring on the side of the rotating plate 11 away from the rotating shaft 10. When the rotating shaft 10 rotates at a high speed, the blades 12 are driven to rotate at a high speed through the rotating plate 11. By arranging multiple blades 12 in a ring on the rotating plate 11, the rotation tests of multiple blades 12 can be completed at one time, improving the test efficiency and saving costs (as Figure 1 shown, two blades 12 are fixed to one side of the rotating plate 11, and the included angle between the two blades 12 is 180°. In the actual test environment, three, four, five, etc. blades can be fixed).

[0039] Such as Figure 2 shown, the fastening bolt 13 passes through the rotating plate 11 and the blade 12, and the other end is supplemented with a gasket and a fastening nut 14 to complete the fixation of the blade 12. After the test is completed, the fastening bolt 13 and the fastening nut 14 are rotated counterclockwise to remove the blade 12.

[0040] The detector 15 is fixed in the main heat exchange box body 1 and vertically faces the blade 12, and is used to monitor the deformation amount of the high-speed rotating blade 12 after being affected by the simulated air flow (the detector 15 can be a CCD camera, and the CCD camera is used to take pictures and detect the blade 12 after the test).

[0041] The air blowing assembly is arranged in the main heat exchange box body 1 and is used to blow air to the high-speed rotating blade 12, thereby simulating the air flow influence on the high-speed rotating blade 12 in the real environment.

[0042] Such as Figure 3 shown, the first slide rail 26 is fixed in the main heat exchange box body 1 by means of screw fastening. The first slider 27 is slidably installed on the first slide rail 26. The first slide plate 28 is fixed to the top of the first slider 27. A first moving cylinder is fixed in the main heat exchange box body 1 and is used to drive the first slide plate 28 to move.

[0043] The second slide rail 29 is fixed to the top of the first slide plate 28 by means of screw fastening. The second slider 30 is slidably installed on the second slide rail 29. The second slide plate 31 is fixed to the top of the second slider 30. A second moving cylinder is fixed in the main heat exchange box body 1 and is used to drive the second slide plate 31 to move.

[0044] The moving directions of the first slide plate 28 and the second slide plate 31 are perpendicular to each other. There are multiple jacking cylinders 32, and they are fixed to the top of the second slide plate 31. The second bearing platform 16 is fixed to the piston rod of the jacking cylinder 32. The bracket 17 is fixed to the top of the second bearing platform 16 by means of screw fastening. The fixing bolt 19 passes through the fixing plate 18 and is fixed to the bracket 17 to complete the fixation of the fixing plate 18.

[0045] By setting the first slide plate 28, the distance between the air blowing assembly and the blade 12 is changed, increasing the complexity and diversity of the test environment; by setting the second slide plate 31 and the lifting cylinder 32, the height position of the air blowing assembly is adjusted, thereby meeting the tests of blades 12 with different diameters and improving the versatility of the test.

[0046] As Figure 3 - 5 shown, the air collecting ring 20 is annular and is fixed to the outside of the fixing plate 18 by welding. The fixing plate 18 is a circular plate and is fixed to the air collecting ring 20 by welding. The air groove 21 is annular and is opened on the inner side of the air collecting ring 20. The air inlet nozzle 22 is integrally connected to the side of the air collecting ring 20 away from the blade 12. The air inlet nozzle 22 is connected to an external air pump, and the air pump passes the gas into the air groove 21 through the air inlet nozzle 22, and then sprays it onto the high-speed rotating blade 12 through the air outlet nozzle 25, thereby simulating the airflow influence on the high-speed rotating blade 12 in the real environment.

[0047] The air outlet nozzles 25 are arranged in a ring on the side of the air collecting ring 20 close to the blade 12. By arranging a plurality of air outlet nozzles 25 on one side of the air collecting ring 20, the number of times the blade 12 rotates one circle and contacts the airflow is increased, improving the test efficiency (as Figure 1 shown, two air outlet nozzles 25 are fixed on one side of the air collecting ring 20, and the included angle between the two air outlet nozzles 25 is 180°. In the actual test environment, three, four, five, etc. can be fixed).

[0048] The through grooves 23 are coaxially and equidistantly opened on the side of the air collecting ring 20 close to the blade 12 and are communicated with the air groove 21. As Figure 5 shown, the through grooves 23 are arranged at intervals in the vertical direction of the air collecting ring 20. The air outlet nozzles 25 are installed in the through grooves 23 by interference fit and are communicated with the air groove 21. The air pump passes the gas into the air groove 21 through the air inlet nozzle 22, and then sprays it onto the high-speed rotating blade 12 through the air outlet nozzles 25, thereby simulating the airflow influence on the high-speed rotating blade 12 in the real environment.

[0049] Since a plurality of through grooves 23 are arranged at intervals in the vertical direction of the air collecting ring 20, the air outlet nozzles 25 can be installed in different through grooves 23, thereby changing the position where the airflow sprays onto the blade 12 and increasing the diversity of the test. To prevent the airflow from leaking from the remaining through grooves 23, resulting in insufficient airflow pressure, plugs 24 are installed in the remaining through grooves 23 to block the corresponding through grooves 23.

[0050] The plugs 24 and the air outlet nozzles 25 are both made of rubber and are inserted into the through grooves 23 by interference fit. Applying an external force can pull out the plugs 24 and the air outlet nozzles 25, and then change the installation position of the air outlet nozzles 25, thereby changing the position where the airflow sprays onto the blade 12 and increasing the diversity of the test.

[0051] The plug 24 includes an inner plug post 241 and an outer plug plate 242. The length of the inner plug post 241 is not less than the length of the through slot 23. When the inner plug post 241 is inserted into the through slot 23, the inner plug post 241 is in full contact with the side wall of the through slot 23. The maximum contact area can increase the friction between the two, preventing the air flow in the air groove 21 from ejecting the plug 24.

[0052] The outer plug plate 242 is integrally connected to one side of the inner plug post 241, and the diameter of the outer plug plate 242 is greater than that of the inner plug post 241. By providing the outer plug plate 242, the inner plug post 241 inserted into the through slot 23 is limited, preventing it from being pushed too deep into the air groove 21; at the same time, the outer plug plate 242 also facilitates the operator to pull out the inner plug post 241.

[0053] As Figure 7 shown, the air outlet nozzle 25 includes a first nozzle part 251, a second nozzle part 252, a third nozzle part 253, an air inlet groove 254, a transition part 255, a transition groove 256, a contact surface 257, a steering ball 258, an air outlet groove 259, a sheath 2510, and a limiting part 2511. The second nozzle part 252 is integrally connected to one side of the first nozzle part 251. The first nozzle part 251 is inserted into the through slot 23, and the length of the first nozzle part 251 is not less than the length of the through slot 23. When the first nozzle part 251 is inserted into the through slot 23, the first nozzle part 251 is in full contact with the side wall of the through slot 23. The maximum contact area can increase the friction between the two, preventing the air flow in the air groove 21 from ejecting the air outlet nozzle 25.

[0054] The second nozzle part 252 is integrally connected to one side of the first nozzle part 251, and the diameter of the second nozzle part 252 is greater than that of the first nozzle part 251. By providing the second nozzle part 252, the first nozzle part 251 inserted into the through slot 23 is limited, preventing it from being pushed too deep into the air groove 21; at the same time, the second nozzle part 252 also facilitates the operator to pull out the first nozzle part 251.

[0055] The third nozzle part 253 is integrally connected to the side of the second nozzle part 252 away from the first nozzle part 251. The outer peripheral surface of the third nozzle part 253 is provided with an external thread for screwing the sheath 2510, and at the same time facilitating the disassembly of the sheath 2510, thereby steering the steering ball 258 and changing the angle of the air flow sprayed onto the blade 12 (the sheath 2510 and the third nozzle part 253 are not limited to the threaded connection method, and an interference fit insertion can also be used).

[0056] The air inlet groove 254 horizontally penetrates through the first nozzle part 251 and the second nozzle part 252, and the transition groove 256 horizontally penetrates through the third nozzle part 253, and the diameter of the transition groove 256 is greater than that of the air inlet groove 254. The transition part 255 is inclined at the connection between the air inlet groove 254 and the transition groove 256.Figure 7 From this perspective, the air flow travels from the intake groove 254 to the transition groove 256. At the inclined transition part 255, the diameter gradually expands. The air flow in the intake groove 254 can more easily enter the transition groove 256 through the transition part 255. Since the diameter of the transition groove 256 is larger than that of the intake groove 254, the flow rate of the air flow entering the transition groove 256 is slower, reducing the impact on the steering ball 258 and avoiding affecting the angle of the steering ball 258 that has been adjusted in advance.

[0057] On the inner side wall of the transition groove 256 away from the intake groove 254, there is an abutting surface 257. The outer peripheral surface of the steering ball 258 is spherical and is arranged in the transition groove 256 and cooperates with the abutting surface 257. The air outlet groove 259 penetrates through the steering ball 258. Figure 7 From the perspective shown, the diameter of the air outlet groove 259 gradually decreases from left to right (that is, the diameter of the air outlet groove 259 near the intake groove 254 is larger than the diameter of the air outlet groove 259 away from the intake groove 254). By setting the air outlet groove 259 with a gradually decreasing diameter, when the air flow sprays onto the blade, by reducing the cross-sectional area, the spraying speed of the air flow is increased.

[0058] The steering ball 258 can rotate within the vertical direction along the abutting surface 257, thereby changing the inclination angle of the air outlet groove 259 and the orientation of the air flow spray, and further simulating the influence on the blade under air flows at different angles. After the angle of the steering ball 258 is adjusted, the protective sleeve 2510 can be installed.

[0059] The protective sleeve 2510 is screwed on the outside of the third air nozzle part 253 by means of thread fitting, and is used to abut against the steering ball 258 to prevent the steering ball 258 from falling out of the transition groove 256. The limiting part 2511 is inclinedly provided on the inner side of the protective sleeve 2510. Figure 7 From this perspective, the diameter of the limiting part 2511 decreases from left to right. By setting the inclined limiting part 2511, when the protective sleeve 2510 is screwed, the limiting part 2511 will abut against the outer peripheral surface of the steering ball 258. On the one hand, it prevents the steering ball 258 from falling out; on the other hand, it prevents the steering ball 258 from rotating in the transition groove 256, resulting in a change in the inclination angle of the air outlet groove 259.

[0060] The working principle of the high-low cycle composite test device based on air flow excitation of the present invention is as follows:

[0061] First, fix the blade 12 on one side of the rotating shaft 10, start the motor 5, and transmit the torque to the rotating shaft 10 through two successive speed increases by the first-stage speed increaser 6 and the second-stage speed increaser 7, finally realizing the high-speed rotation of the blade 12, and further simulating the working conditions of the blade 12 under high-speed rotation.

[0062] Then turn on the external air pump. The air pump passes the gas into the air tank 21 through the air inlet nozzle 22, and then sprays it onto the high-speed rotating blade 12 through the air outlet nozzle 25, thereby simulating the airflow influence on the high-speed rotating blade 12 in the real environment. Finally, the detector 15 is used to detect the deformation degree of the blade 12 under the influence of the airflow.

[0063] The above embodiments are only used to illustrate the technical concept and characteristics of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. It is not intended to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A high-low cycle composite test device based on airflow excitation, characterized in that it include: Main heat exchange box (1); A rotating plate (11), the rotating plate (11) being rotatably mounted in the main heat exchange box (1); A driving assembly, the driving assembly being fixed to one side of the main heat exchange box (1) and being used to drive the rotating plate (11) to rotate; Blades (12), the blades (12) being arranged in a ring on a side of the rotating plate (11) away from the driving assembly; An air blowing component is arranged on a side of the blade (12) away from the rotating plate (11), and the air blowing component blows air toward the surface of the rotating blade (12).

2. A high-low cycle composite test device based on airflow excitation according to claim 1, characterized in that: The blowing assembly comprises a first slide plate (28) movably arranged in a main heat exchange box (1), a second slide plate (31) movably arranged on the top of the first slide plate (28), a bracket (17) movably arranged on the top of the second slide plate (31), and a blowing unit fixed to a side of the bracket (17) close to the blade (12), wherein the moving directions of the first slide plate (28) and the second slide plate (31) are perpendicular.

3. A high-low cycle composite test device based on airflow excitation according to claim 2, characterized in that: The air blowing unit comprises an air collecting ring (20) fixed on one side of the bracket (17), an air groove (21) provided in the air collecting ring (20), an air inlet nozzle (22) fixed on the side of the air collecting ring (20) away from the blade (12), and an air outlet nozzle (25) fixed on the side of the air collecting ring (20) close to the blade (12), wherein the air inlet nozzle (22) and the air outlet nozzle (25) are both connected to the air groove (21).

4. A high-low cycle composite test device based on airflow excitation according to claim 3, characterized in that: The blowing unit further comprises through grooves (23) coaxially and equidistantly provided on a side of the gas collecting ring (20) close to the blades (12) and a plug (24) installed in the through grooves (23); the air outlet nozzle (25) is installed in the through grooves (23).

5. The high-low cycle composite test device based on airflow excitation according to claim 4, characterized in that: The air outlet nozzle (25) comprises an air outlet nozzle body installed in the through groove (23), a gas flow channel penetrating the air outlet nozzle body, a steering ball (258) rotatably installed on the outside of the air outlet nozzle body, and an air outlet groove (259) penetrating the steering ball (258) and communicating with the gas flow channel.

6. A high-low cycle composite test device based on airflow excitation according to claim 5, characterized in that: The air outlet nozzle body comprises a first air nozzle portion (251) installed in the through groove (23), a second air nozzle portion (252) integrally connected to one side of the first air nozzle portion (251), and a third air nozzle portion (253) integrally connected to one side of the second air nozzle portion (252), wherein the diameter of the second air nozzle portion (252) is greater than the diameter of the first air nozzle portion (251), and the steering ball (258) is rotatably installed on a side of the third air nozzle portion (253) away from the first air nozzle portion (251).

7. The high-low cycle composite test device based on airflow excitation according to claim 6, characterized in that: The gas flow channel comprises an air inlet groove (254) penetrating the first air nozzle portion (251) and the second air nozzle portion (252), a transition groove (256) penetrating the third air nozzle portion (253), and a transition portion (255) connecting the air inlet groove (254) and the transition groove (256) and arranged obliquely, wherein the diameter of the transition groove (256) is greater than the diameter of the air inlet groove (254).

8. The high-low cycle composite test device based on airflow excitation according to claim 6, characterized in that: The air outlet nozzle (25) further comprises a protective sleeve (2510) detachably connected to the third air nozzle portion (253) and a limiting portion (2511) obliquely opened on one side of the protective sleeve (2510), wherein the limiting portion (2511) abuts against the outer peripheral surface of the steering ball (258).

9. The high-low cycle composite test device based on airflow excitation according to claim 4, characterized in that: The plug (24) comprises an inner blocking column (241) installed in the through groove (23) and an outer blocking plate (242) integrally connected to one side of the inner blocking column (241); the diameter of the outer blocking plate (242) is greater than the diameter of the inner blocking column (241).

10. The high-low cycle composite test device based on airflow excitation according to claim 5, characterized in that: The diameter of the air outlet groove (259) is reduced.

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