A wind tunnel test gas-magnetic coupling delivery test system and method

Abstract

The present invention relates to a wind tunnel test gas-magnetic coupling launching test system and method, including the steps of: ventilating the air outlet of the air cylinder and retracting the ejection rack; energizing the electromagnetic locking structure, loading the projectile into the ejection rack and locking it; starting the wind tunnel, ventilating the air intake groove after the flow field is stable, and the piston rod and the ejection rack move downward; powering off the electromagnetic locking structure; measuring the speed value of the ejection rack by the fiber optic sensor; inputting the speed value into the electromagnetic coupling compensation mathematical model to calculate the compensation current and setting the compensation current; energizing the electromagnetic compensation structure to interact with the permanent magnet on the projectile to compensate the launching speed of the projectile; when the launching speed meets the requirements, powering off the electromagnetic compensation structure, starting the high-speed camera to capture the trajectory of the projectile, and ending the test. The present invention uses electromagnetic force to lock the launched object, uses the gas-magnetic coupling method to launch the projectile, forms a closed-loop feedback in the launching process, and realizes the high-precision simulation of the initial parameters of the launching test.

Description

Technical Field

[0001] The present invention relates to a wind tunnel test gas-magnetic coupling launch test system and method, belonging to the field of experimental aerodynamics. Background Technique

[0002] The wind tunnel launch test technology is an important means for studying the separation safety problem of projectiles. It is an unsteady test technology based on the kinematic similarity theory and has great advantages in studying the separation characteristics of projectiles. Therefore, it is of great significance to predict the separation trajectory of projectiles through wind tunnel tests and carry out research on high-precision wind tunnel launch test technology.

[0003] At present, the wind tunnel launch test mainly adopts open-loop control, making the launch process uncontrollable in open loop. There are problems such as poor test repeatability and low control accuracy of launch speed and angular velocity. On the one hand, these problems will lead to insufficient accuracy of test data, reducing the reference value of the data obtained from the launch test and affecting the judgment of the safety boundary of the real launch process by researchers, which may cause major accidents and losses. On the other hand, it will lead to a low test success rate and cause great economic losses. Therefore, studying a new type of wind tunnel launch test method is helpful to improve the accuracy of launch test data and is of great significance to the simulation ability of wind tunnel launch tests. Summary of the Invention

[0004] The technical problem solved by the present invention is: for the wind tunnel free flight test, design a wind tunnel test gas-magnetic coupling launch test system and method to achieve high-precision simulation of the initial parameters of the wind tunnel launch test and improve the accuracy of the wind tunnel launch test data.

[0005] The technical solution adopted by the present invention is: a wind tunnel test gas-magnetic coupling launch test system, including a test section, an ejection mechanism, an aircraft model, an angle of attack mechanism, and a wind tunnel measurement and control system; the internal flow field of the test section is controlled by the wind tunnel measurement and control system, one end of the angle of attack mechanism is fixed in the test section, and the other end is connected to the aircraft model, and the ejection mechanism is installed on the aircraft model; it also includes a gas-magnetic coupling ejection control system and an electromagnetic compensation structure;

[0006] The ejection mechanism uses air pressure to do work to generate thrust and launch the projectile. Among them, the launch speed is proportional to the air pressure; and it measures the actual speed value of the projectile.

[0007] The gas-magnetic coupling ejection control system controls the air pressure of the ejection mechanism, sets the ejection pressure of the ejection mechanism according to the required speed value; receives the actual speed value of the projectile under the action of the ejection pressure, and obtains the compensation current using the gas-magnetic coupling compensation mathematical model according to the error between the required speed value and the actual speed value, and drives the electromagnetic compensation structure according to the compensation current.

[0008] The gas-magnetic coupling compensation mathematical model characterizes the corresponding relationship between the velocity error and the compensation current under the currently set ejection pressure.

[0009] The electromagnetic compensation structure generates an electromagnetic field after being energized, and changes the direction of the electromagnetic force by changing the direction of the energizing current to form attraction or repulsion; a compensation current is applied to the electromagnetic compensation structure to correct the actual velocity value of the launched projectile.

[0010] Further, for a wind tunnel test gas-magnetic coupling launch test system according to the claim, it is characterized in that the electromagnetic compensation structure includes M, where M is an even number greater than 0; each electromagnetic compensation structure includes a second iron core, a second coil, and a permanent magnet.

[0011] The second iron core is a cylindrical structure with a base, the base of which is connected to the lower end face of the ejection rack, and the inside of the second iron core is a coaxial cylindrical cavity, and a cylindrical section is provided at the center of the cavity.

[0012] The second coil is wound in the same direction on the cylindrical section at the center of the cavity.

[0013] The permanent magnet is fixed inside the projectile and corresponds to the position of the cylindrical section of the second iron core.

[0014] After the second coil of the electromagnetic compensation structure is energized, the electromagnetic force generated interacts with the permanent magnet to form a gas-magnetic coupling ejection feedback loop. According to the direction of the energizing current, when the magnetic field lines generated by the electromagnetic compensation structure are opposite to the magnetic field lines of the permanent magnet itself in the interaction region, a repulsive force is generated to increase the velocity of the projectile; when the magnetic field lines generated by the electromagnetic compensation structure are the same as the magnetic field lines of the permanent magnet itself in the interaction region, an attractive force is generated to decrease the velocity of the projectile.

[0015] Further, the second iron core is made of soft magnetic material.

[0016] Further, the ejection mechanism includes a quick connector, a cylinder, an ejection rack, a velocity sensor, and an electromagnetic locking structure.

[0017] There are N piston holes evenly distributed at equal intervals inside the cylinder. The piston holes cooperate with the piston rod to form a piston. The lower end of the piston rod is fixed to the upper end face of the ejection rack; there is an air inlet groove inside the cylinder, and the air inlet groove communicates with the tops of the N piston holes. The quick connector communicates with the piston holes through the air inlet groove. When the air inlet groove is ventilated, the piston rod moves downward, driving the ejection rack to move downward; N≥1.

[0018] An electromagnetic locking structure is connected to the middle position of the lower end face of the ejection rack. The electromagnetic locking structure generates an electromagnetic force to adsorb the projectile and locks the projectile below the ejection rack; at the same time as the air inlet groove is ventilated, the electromagnetic locking structure is powered off, and the adsorption effect on the projectile disappears, completing the unlocking and release of the projectile; the velocity sensor measures the actual velocity value during the process of launching the projectile.

[0019] Further, the air-magnetic coupling compensation mathematical model is obtained through ground calibration. The specific process is as follows: Given the required value of the set speed and the ejection pressure of the set cylinder;

[0020] Use the set ejection pressure to drive the piston rod to move downward, driving the ejection frame to move downward; When the ejection frame passes through the fiber optic sensor, the speed is measured to obtain the actual speed value;

[0021] The electromagnetic compensation structure is powered on, keeping the set ejection pressure unchanged, and adjusting the current of the second coil until the actual speed value is equal to the required speed value;

[0022] Perform ground calibration multiple times, record the required speed value, ejection pressure, and current data required for the electromagnetic compensation structure to compensate the current speed error each time. Through polynomial fitting, establish the corresponding relationship between the speed error and the compensation current under the current set ejection pressure.

[0023] Further, the ejection mechanism uses a speed sensor to measure the actual speed value of the ejection frame, and the measurement point is set on the plane where the ejection frame is located when the piston rod moves to the middle position of the piston hole.

[0024] Further, the speed sensor includes a fiber optic sensor.

[0025] Further, a wind tunnel test air-magnetic coupling launch test method is provided, including the following steps:

[0026] S1. The air outlet groove of the cylinder is ventilated, and the ejection frame is retracted;

[0027] S2. The electromagnetic locking structure is powered on, the projectile is loaded into the ejection frame, and the projectile is locked by electromagnetic force;

[0028] S3. Start the wind tunnel. After the flow field is stable, the air inlet groove is ventilated, and the ejection pressure of the cylinder is set to make the piston rod move downward, driving the ejection frame to move downward;

[0029] S4. The locking electromagnetic structure is powered off, and the projectile continues to move downward synchronously with the ejection frame under the thrust provided by the ejection pressure;

[0030] S5 The speed sensor measures the speed to obtain the actual speed value of the ejection frame;

[0031] S6. Input the actual speed value of the ejection frame into the electromagnetic coupling compensation mathematical model, calculate the compensation current, and set the compensation current;

[0032] S7. The electromagnetic compensation structure is powered on and interacts with the permanent magnet in the projectile to correct the actual speed value with the set compensation current;

[0033] S8. Determine whether the corrected actual speed value is equal to the required speed value. If they are equal, power off the electromagnetic compensation structure, start shooting the trajectory of the projectile, and the test ends. If they are not equal and the piston rod can continue to move downward, repeat steps S5 - S8.

[0034] The beneficial effects of the present invention compared with the prior art are as follows:

[0035] (1). Since the present invention uses a cylinder as the main power source for launching to provide the initial launching speed, a fiber optic sensor is introduced during the launching process to monitor the launching parameters. At the same time, the interaction of the electromagnetic field between the electromagnetic compensation structure and the permanent magnet is used to compensate the speed of the projectile, forming an air - magnetic coupling ejection feedback loop, realizing the closed - loop feedback control during the launching process, and improving the accuracy of the initial launching parameters during the launching process of the launched object.

[0036] (2). The present invention obtains the required speed value, ejection pressure, and compensation current data required to overcome the speed error through multiple ground calibration tests, and establishes an air - magnetic coupling compensation mathematical model by means of polynomial fitting, obtaining a definite corresponding relationship between the speed error and the compensation current under the set ejection pressure, making the reliability of the closed - loop feedback control high. And the air - magnetic coupling compensation mathematical model is input into the air - magnetic coupling ejection control system, and real - time calculations are performed by the air - magnetic coupling ejection control system, improving the operating speed and having good real - time performance. Description of the Drawings

[0037] Figure 1 It is a flowchart of a wind tunnel test air - magnetic coupling launching test method according to an embodiment of the present invention;

[0038] Figure 2 It is a schematic diagram of an air - magnetic coupling test system for a high - speed wind tunnel launching test according to an embodiment of the present invention;

[0039] Figure 3 It is an assembly schematic diagram of an ejection mechanism and an electromagnetic compensation structure according to an embodiment of the present invention;

[0040] Figure 4 It is a schematic diagram of the air circuit of a cylinder according to an embodiment of the present invention;

[0041] Figure 5 It is a schematic diagram of an electromagnetic locking structure and an electromagnetic compensation structure according to an embodiment of the present invention. Detailed Embodiments

[0042] The following further describes the specific implementation of the present invention in detail according to the drawings.

[0043] As Figure 2As shown in the figure, the wind tunnel test gas-magnetic coupling ejection test system used in the present invention includes: a test section 1, an ejection mechanism 2, an electromagnetic compensation structure 9, a high-speed camera 11, a gas-magnetic coupling ejection control system 15, a gas-magnetic coupling compensation mathematical model computer 14, a wind tunnel measurement and control system 13, an aircraft model 16, and an angle of attack mechanism 17.

[0044] The electromagnetic compensation structure 9 is installed in the ejection mechanism 2, the ejection mechanism 2 is installed on the aircraft model 16, and the aircraft model 16 is installed inside the test section 1 through the angle of attack mechanism 17. The flow field inside the test section is controlled by the wind tunnel measurement and control system 13. The gas-magnetic coupling compensation mathematical model computer 14 is connected to the gas-magnetic coupling ejection control system 15 through a signal line, and the gas-magnetic coupling ejection control system 15 is connected to the ejection mechanism 2 through a signal line and an air path. The high-speed camera 11 is connected to the gas-magnetic coupling compensation mathematical model computer 14 through a signal line.

[0045] As Figure 3 shown, the ejection mechanism 2 includes a quick connector 21, a cylinder 20, a base 18, a bottom plate 19, an ejection frame 7, an optical fiber sensor 12, and an electromagnetic locking structure 8.

[0046] The bottom plate 19 is fixedly installed on the base, the cylinder 20 is fixedly installed on the upper surface of the bottom plate 19, and three piston holes are equidistantly arranged inside the cylinder 20 for installing the piston rod 4; the piston holes and the piston rod 4 cooperate to form a piston. The lower end of the piston rod 4 is provided with an opening for fixing the piston rod 4 on the upper end surface of the ejection frame 10. There is an air inlet groove 5 inside the cylinder 20, and the air inlet groove 5 communicates with the tops of the three piston holes. The quick connector 21 communicates with the piston holes through the air inlet groove 5; when the quick connector 21 intakes air, the cylinder 20 acts, the piston rod 4 moves downward, driving the ejection frame 7 to move downward and pushing the projectile 3 out.

[0047] The middle position of the lower end surface of the ejection frame 7 is connected to the electromagnetic locking structure 8. When the electromagnetic locking structure 8 is energized, it generates an electromagnetic force to adsorb the projectile 3, and unlocks the projectile 3 when powered off.

[0048] Both ends of the lower end surface of the ejection frame 7 are connected to two electromagnetic compensation structures 9. One electromagnetic compensation structure 9 is arranged on each side of the electromagnetic locking structure 8, and is used to generate an electromagnetic force after being energized to interact with the permanent magnet 10 to form a gas-magnetic coupling ejection feedback loop to compensate for the speed of the projectile 3.

[0049] The optical fiber sensor 12 is installed at the lower end of the base 18, on the plane where the ejection frame 7 is located when the piston rod moves to the middle position of the piston hole, and is used to measure the speed of the ejection frame 7.

[0050] As Figure 5As shown, the electromagnetic locking structure 8 includes an aluminum alloy backing plate, a first iron core 8-2, and two first coils 8-1. The aluminum alloy backing plate is fixedly connected to the lower end surface of the ejection rack 7; the first iron core 8-2 is installed on the lower end surface of the aluminum alloy backing plate. The first iron core 8-2 is of an inverted U-shaped structure, with cylindrical structures at both left and right ends and a square structure in the middle, and is made of soft magnetic material. The two first coils 8-1 are arranged on the cylindrical structures at the left and right ends of the first iron core 8-2, and have opposite winding directions. After being energized, they cooperate with the projectile 3 to complete the locking of the projectile 3.

[0051] The mating section of the projectile 3 and the electromagnetic locking structure 8 is made of soft magnetic material, and the materials of the front and rear sections of the projectile are not limited.

[0052] The electromagnetic compensation structure 9 includes a second iron core 9-2, a second coil 9-1, and a permanent magnet 10. The second iron core 9-2 is of a cylindrical structure with a base, and is made of soft magnetic material; its base is connected to the lower end surface of the ejection rack 7. The inside of the second iron core 9-2 is a hollow cylindrical cavity with a cylindrical section in the middle. There is an opening at the bottom of the second iron core 9-2 for the second coil 9-1 to route wires. The second coil 9-1 is placed inside the second iron core 9-2 and assembled onto the cylindrical section. The second coil 9-1 is wound in the same direction on the cylindrical section at the center of the cavity. The two permanent magnets 10 are fixed inside the projectile 3 at the projection positions of the cylindrical section, and there is a certain gap from the cylindrical section.

[0053] After the second coil 9-1 of the electromagnetic compensation structure is energized, an electromagnetic force is generated and interacts with the permanent magnet 10 to form an air-magnetic coupling ejection feedback loop. According to the direction of the energizing current, when the magnetic field lines generated by the electromagnetic compensation structure and the magnetic field lines of the permanent magnet 10 are opposite in direction in the interaction region, a repulsive force is generated to increase the speed of the projectile 3; when the magnetic field lines generated by the electromagnetic compensation structure and the magnetic field lines of the permanent magnet 10 are in the same direction in the interaction region, an attractive force is generated to reduce the speed of the projectile 3.

[0054] In this embodiment, the base 18 is of a cuboid structure with a concave structure in the middle for installing the bottom plate 19; there is a slot penetrating the bottom surface of the base 18 in the middle of the concave structure, and the shape of the slot is adapted to the shape of the ejection rack 7; there are an optical fiber sensor installation groove and an optical fiber sensor wire routing hole at the bottom of the base 18.

[0055] As Figure 4As shown in the figure, there are three piston holes, two intake slots 5, and an exhaust slot 6 inside the cylinder 20. An exhaust connection is provided on the side wall of the cylinder 20. Among them, the two intake slots 5 are symmetrically distributed with the central axis of the middle piston hole as the axis of symmetry. Each intake slot 5 communicates with two adjacent piston holes. The quick connector 21 is arranged in the center of the two intake slots 5 and communicates with one end of the two intake slots 5. A first plug 27 is provided at the other end of the two exhaust slots 5 that is not connected to the quick connector 21. The exhaust slot 6 communicates with the bottoms of the three piston holes and is in an inverted U shape, communicating from both sides of the bottom of the middle piston hole to the upper part of the cylinder 20; second plugs are provided at both ends of the exhaust slot 6 in the upper part of the cylinder 20. An opening is made on the side wall of the cylinder 20, and the exhaust connection is installed at the opening and communicates with the exhaust slot 6.

[0056] The magnetic coupling ejection control system 15 of this embodiment can control the charging and discharging of the air circuit of the ejection mechanism 2, the magnitude of the air pressure, the start and stop of the high-speed camera 11, the on-off of the electromagnetic coil current, and the magnitude of the current. At the same time, it can collect the speed signal measured by the fiber optic sensor 12. On the one hand, the magnetic coupling ejection control system 15 is connected to the cylinder 20 of the ejection mechanism 2 through the air circuit, controls the air pressure of the ejection mechanism 2 by controlling the opening degree of the cylinder pressure regulating valve, and controls the charging and discharging of the air circuit of the ejection mechanism 2; on the other hand, it is connected to the fiber optic sensor 12 to obtain the speed value of the ejection rack 7. According to the cylinder pressure and the speed of the ejection rack 7 collected at the same moment, the compensation current is obtained by using the magnetic coupling compensation mathematical model, and the magnitude of the electromagnetic coil compensation current of the electromagnetic compensation structure 9 is set through the current controller inside the magnetic coupling ejection control system 15.

[0057] Among them, under the control of the magnetic coupling ejection control system 15, when the intake slot 5 intakes air, the exhaust slot 6 exhausts air, and when the exhaust slot 6 intakes air, the intake slot 5 exhausts air.

[0058] The magnetic coupling compensation mathematical model computer 14 realizes the establishment of the magnetic coupling compensation mathematical model. The magnetic coupling compensation mathematical model is obtained through ground calibration. The specific process is as follows:

[0059] (1) Given the required speed value and set the ejection pressure of the cylinder 20;

[0060] (2) Use the set ejection pressure to drive the piston rod to move downward, driving the ejection rack 7 to move downward; when the ejection rack 7 passes through the fiber optic sensor 12, the speed is measured to obtain the actual speed value;

[0061] (3) The electromagnetic compensation structure 9 is energized, keeping the set ejection pressure unchanged, and adjusting the current of the second coil 9-1 until the actual speed value is equal to the required speed value;

[0062] (4) Conduct ground calibration multiple times. The gas-magnetic coupling compensation mathematical model computer 14 receives the required speed value, ejection pressure, and current data required for the electromagnetic compensation structure 9 to compensate for the current speed error for each calibration.

[0063] (5) The gas-magnetic coupling compensation mathematical model computer 14 establishes the corresponding relationship between the speed error and the compensation current under the currently set ejection pressure by means of polynomial fitting.

[0064] Furthermore, the gas-magnetic coupling compensation mathematical model computer 14 can input the gas-magnetic coupling compensation mathematical model into the gas-magnetic coupling ejection control system 15, and the gas-magnetic coupling ejection control system 15 performs real-time calculation of the compensation current to improve the operating speed.

[0065] The gas-magnetic coupling ejection control system 15 sets the electromagnetic coil current of the electromagnetic compensation structure 9 with the calculated compensation current to drive the electromagnetic compensation structure 9. The electromagnetic compensation structure 9 utilizes the magnetic force change generated by the current magnitude to complete the compensation of the projectile release speed.

[0066] As Figure 1 shown, based on the wind tunnel test gas-magnetic coupling release test system of the present invention, a wind tunnel test gas-magnetic coupling release test method is provided, including the steps:

[0067] S1. At the start of the test, the air outlet groove 6 of the cylinder 20 is ventilated, and the ejection rack 7 retracts.

[0068] S2. The electromagnetic locking structure 8 is energized, the projectile 3 is loaded into the ejection rack 7, and the projectile 3 is locked by electromagnetic force.

[0069] S3. Start the wind tunnel. After the flow field is stable, the air inlet groove 5 is ventilated, and the ejection pressure of the cylinder is set to make the piston rod move downward rapidly; the piston 4 moves downward, driving the ejection rack 7 to move downward.

[0070] S4. The locking electromagnetic structure 8 is powered off, and the projectile 3 continues to move downward synchronously with the ejection rack 7 under the thrust provided by the ejection pressure.

[0071] S5. The fiber optic sensor 12 measures the speed to obtain the actual speed value of the ejection rack.

[0072] S6. Input the actual speed value of the ejection rack into the electromagnetic coupling compensation mathematical model, calculate the compensation current, and set the compensation current.

[0073] S7. The electromagnetic compensation structure 9 is energized to interact with the permanent magnet 10 on the projectile to correct the actual speed value with the set compensation current.

[0074] S8. Determine whether the actual speed value is equal to the required speed value. If they are equal, the electromagnetic compensation structure 9 is powered off, and the high-speed camera 11 is started to capture the trajectory of the projectile 3, and the test ends. If they are not equal and the piston rod can continue to move downward, steps S5 to S8 are repeated.

[0075] Although the present invention is disclosed above in preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be defined by the scope defined in the claims of the present invention.

[0076] The content not described in detail in the specification of the present invention belongs to the well-known technology of those skilled in the art.

Claims

1. A wind tunnel test gas-magnetic coupling release test system, comprising a test section (1), an ejection mechanism (2), an aircraft model (16), an angle of attack mechanism (17), and a wind tunnel measurement and control system (13); the internal flow field of the test section (1) is controlled by the wind tunnel measurement and control system (13), one end of the angle of attack mechanism (17) is fixed inside the test section (1), the other end is connected to the aircraft model (16), and the ejection mechanism (2) is installed on the aircraft model (16); characterized in that, It also includes a pneumatic-magnetic coupling ejection control system (15) and an electromagnetic compensation structure (9); An ejection mechanism (2) that uses pneumatic work to generate thrust and launch a projectile (3), where the launch speed is proportional to the air pressure; and measures the actual speed value of the projectile (3); A pneumatic-magnetic coupling ejection control system (15) that controls the air pressure of the ejection mechanism (2), sets the ejection pressure of the ejection mechanism (2) according to the required speed value; receives the actual speed value of the projectile (3) under the action of the ejection pressure, obtains a compensation current using a pneumatic-magnetic coupling compensation mathematical model based on the error between the required speed value and the actual speed value, and drives the electromagnetic compensation structure (9) according to the compensation current; The pneumatic-magnetic coupling compensation mathematical model characterizes the corresponding relationship between the speed error and the compensation current under the currently set ejection pressure; An electromagnetic compensation structure (9) that generates an electromagnetic field after being energized, and changes the direction of the electromagnetic force by changing the direction of the energizing current to form an attractive or repulsive force; applies a compensation current to the electromagnetic compensation structure (9) to correct the actual speed value of the launched projectile (3).

2. The aeromagnetic coupling dropping test system for wind tunnel test according to claim 1, wherein There are M electromagnetic compensation structures (9), where M is an even number greater than 0; each electromagnetic compensation structure (9) includes a second iron core (9-2), a second coil (9-1), and a permanent magnet (10); The second iron core (9-2) is a cylindrical structure with a base, and its base is connected to the lower end face of the ejection frame (7). The inside of the second iron core (9-2) is a coaxial cylindrical cavity, and a cylindrical section is provided at the center of the cavity; The second coil (9-1) is wound in the same direction on the cylindrical section at the center of the cavity; The permanent magnet (10) is fixed inside the projectile (3) and corresponds to the cylindrical section of the second iron core (9-2); After the second coil (9-1) of the electromagnetic compensation structure is energized, an electromagnetic force is generated and interacts with the permanent magnet (10) to form a pneumatic-magnetic coupling ejection feedback loop. According to the direction of the energizing current, when the magnetic field lines generated by the electromagnetic compensation structure are opposite to the magnetic field lines of the permanent magnet (10) itself in the interaction region, a repulsive force is generated to increase the speed of the projectile (3); when the magnetic field lines generated by the electromagnetic compensation structure are the same as the magnetic field lines of the permanent magnet (10) itself in the interaction region, an attractive force is generated to decrease the speed of the projectile (3).

3. The aeromagnetic coupling dropping test system for wind tunnel test according to claim 2, wherein The second iron core (9-2) is made of soft magnetic material.

4. A wind tunnel test gas-magnetic coupling delivery test system according to claim 2, characterized in that, The ejection mechanism (2) includes a quick connector (21), a cylinder (20), an ejection frame (7), a speed sensor, and an electromagnetic locking structure (8); There are N piston holes evenly distributed at equal intervals inside the cylinder (20). The piston holes cooperate with the piston rod (4), and the lower end of the piston rod is fixed to the upper end face of the ejection frame (7); there is an air intake groove (5) inside the cylinder (20), and the air intake groove (5) communicates with the tops of the N piston holes. The quick connector (21) communicates with the piston holes through the air intake groove (5). When the air intake groove (5) is ventilated, the piston rod (4) moves downward, driving the ejection frame (7) to move downward; N≥1; An electromagnetic locking structure is connected to the middle position of the lower end face of the ejection rack (7). When the electromagnetic locking structure is powered on, it generates an electromagnetic force to adsorb the projectile (3), and locks the projectile (3) below the ejection rack (7). After the air inlet groove (5) is ventilated, the electromagnetic locking structure (8) is powered off, and the adsorption effect on the projectile (3) disappears, completing the unlocking and release of the projectile (3). The speed sensor measures the actual speed value during the process of launching the projectile.

5. The aeromagnetic coupling drop test system for wind tunnel test according to claim 4, characterized in that The air-magnetic coupling compensation mathematical model is obtained through ground calibration. The specific process is as follows: A required speed value is given, and the ejection pressure of the air cylinder (20) is set. The set ejection pressure is used to drive the piston rod to move downward, driving the ejection rack (7) to move downward. When the ejection rack (7) passes through the fiber optic sensor (12), the speed is measured to obtain the actual speed value. The electromagnetic compensation structure (9) is powered on, and the set ejection pressure remains unchanged. The current of the second coil (9-1) is adjusted until the actual speed value is equal to the required speed value. Ground calibration is carried out multiple times, and the required speed value, ejection pressure, and current data required for the electromagnetic compensation structure (9) to compensate the current speed error are recorded each time. Through polynomial fitting, the corresponding relationship between the speed error and the compensation current is established under the current set ejection pressure.

6. The aeromagnetic coupling dropping test system for wind tunnel test according to claim 5, characterized in that, The ejection mechanism (2) uses a speed sensor to measure the actual speed value of the ejection rack (7), and the measurement point is set on the plane where the ejection rack (7) is located when the piston rod moves to the middle position of the piston hole.

7. The aeromagnetic coupling release test system for wind tunnel test according to claim 6, characterized in that The speed sensor includes a fiber optic sensor.

8. The test method of an aeromagnetic coupling release test system according to claim 4, characterized in that It includes the following steps: S1. The air outlet groove (6) of the air cylinder is ventilated, and the ejection rack (7) retracts. S2. The electromagnetic locking structure (8) is powered on, the projectile (3) is loaded into the ejection rack (7), and the electromagnetic force is used to lock the projectile (3). S3. The wind tunnel is started. After the flow field is stable, the air inlet groove (5) is ventilated, and the ejection pressure of the air cylinder is set to make the piston rod move downward, driving the ejection rack (7) to move downward. S4. The electromagnetic locking structure (8) is powered off, and the projectile (3) continues to move downward synchronously with the ejection rack (7) under the thrust provided by the ejection pressure. S5. The speed sensor measures the speed to obtain the actual speed value of the ejection rack. S6. The actual speed value of the ejection rack is input into the air-magnetic coupling compensation mathematical model, the compensation current is calculated, and the compensation current is set. S7. The electromagnetic compensation structure (9) is powered on and interacts with the permanent magnet (10) in the projectile to correct the actual speed value with the set compensation current. S8. It is judged whether the corrected actual speed value is equal to the required speed value. If it is equal, the electromagnetic compensation structure (9) is powered off, the trajectory of the projectile (3) is photographed, and the test ends; if it is not equal, steps S5 to S8 are repeated.

Images