A device and method for measuring grain deformation during solid propellant pressurized curing processes

Abstract

The application discloses a solid propellant pressurization and solidification process grain deformation variable measuring device, and belongs to the technical field of aerospace power; the application establishes a set of measuring device which can directly measure the deformation variable of a grain in a pressurization process, can spray random speckles on the surface of a film through digital image correlation technology (DIC technology), records the images of the film before and after deformation by using a miniature high-speed camera, displays the speckle information in the form of gray scale, matches the feature points on the deformation picture by using a specific search method and a correlation function, finally obtains corresponding strain values and position values, and then completes the deformation variable measurement of the grain; in addition, the temperature and pressure data can be measured by a pressure sensor and a temperature thermocouple arranged in the device, data support is provided for studying the volume change of the grain in the simulation of the pressurization and solidification process of the solid engine charge, and the device is simple in structure, practical and reliable, and high in safety.

Description

Technical Field

[0001] This invention relates to the field of aerospace propulsion technology, specifically to a device and method for measuring the deformation of a propellant column during the pressurization and solidification process of a solid propellant. Background Technology

[0002] As the fill ratio of solid rocket motors continues to increase, the thermal stress generated by the curing and cooling of the propellant grains after molding also increases, significantly affecting the structural safety and interfacial bonding performance of the engine. To reduce the increased thermal stress of the propellant grains caused by high fill ratios and improve the molding quality of the propellant grains and various bonding interfaces, a pressure-curing molding process is adopted for high-fill propellant grain molding. The basic process mainly includes: casting the propellant slurry; applying pressure to the propellant slurry to cause the composite material shell to expand and deform under internal pressure; after the slurry has cured at a constant temperature and pressure, the propellant grains are cooled and depressurized in a certain way; after the pressure is removed, the composite material shell rebounds and shrinks due to unloading, which can both offset some of the deformation caused by the shrinkage of the propellant grains due to curing and cooling, and also form a certain compressive preload at the bonding interfaces between the insulation layer, liner, and propellant grains to improve interfacial bonding performance. With the increasing demands for high fill ratios and structural safety in aerospace and military solid rocket motors, the improvement of solid propellant pressure-curing technology is particularly important.

[0003] During pressurized curing, high-pressure gas typically comes into direct contact with the propellant slurry through the inlet pipe. This not only increases the risk of accidents but also negatively impacts the structural integrity of the propellant grain. Furthermore, the synergy between temperature and pressure during pressurized curing is crucial for successfully completing the test and producing higher-performance propellant grains. Since curing is an exothermic process, the heat generated by the propellant slurry also affects its own curing process. Therefore, studying the self-generated heat of the propellant slurry is essential for achieving temperature-pressure synergy in pressurized curing. To improve the structural integrity of solid propellant grains, enhance the safety of pressurized curing tests, and meet the need to study the impact of the propellant slurry's self-generated heat on curing, it is necessary to design and manufacture a safe pressurized curing device and method that avoids direct contact between the propellant grain and high-pressure gas and allows for direct measurement of the grain's internal temperature.

[0004] Existing pressure curing devices typically involve direct contact between high-pressure gas and the propellant slurry for pressurization, making it difficult to measure the deformation of the propellant grain during the pressure curing process. To improve the structural integrity of solid propellant grains, enhance the safety of pressure curing experiments, and meet the needs of studying deformation during the pressure curing process, it is necessary to design and manufacture a measuring device and method that can directly measure the deformation of the propellant grain during the pressure curing process while avoiding direct contact between the propellant grain and high-pressure gas. Summary of the Invention

[0005] 1. The technical problem to be solved by the present invention

[0006] The purpose of this invention is to provide a device for measuring the deformation of a solid propellant column during the pressurization and solidification process to solve the problems mentioned in the background art.

[0007] 2. Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] This invention improves upon traditional solid propellant pressurization and curing measurement devices by using a thin film to non-contactly pressurize high-pressure gas and propellant slurry; it measures the internal temperature of the device cavity in real time using a temperature thermocouple and monitors the internal pressure of the cavity in real time using a pressure sensor; and it uses digital image correlation (DIC) technology to record images of the thin film before and after deformation using a miniature high-speed camera, ultimately achieving the measurement of deformation during the pressurization and curing process of the propellant grain. Furthermore, it constructs a simple, safe, and reliable experimental device and proposes a device and method for measuring the deformation of propellant grains during the pressurization and curing process of solid propellants; specifically, it includes the following:

[0010] A device for measuring the column deformation of a solid propellant during pressurized curing process includes a gas supply system, a curing system, and a data acquisition system, wherein:

[0011] The gas supply system includes a metal hose A, a hose connector, a gas delivery cylinder, a high-pressure nitrogen cylinder, a pressure reducing valve, a metal hose B, and a manual valve. The high-pressure nitrogen cylinder is fixed to a cylinder rack to prevent tipping and is threadedly connected to the pressure reducing valve. Adjusting the pressure reducing valve lowers the pressure inside the cylinder, allowing the required high-pressure gas to flow to the curing system. The metal hose connects the high-pressure nitrogen cylinder to the curing system via a threaded connection, serving as the curing system's inlet pipe. The metal hose B is threadedly connected to the metal hose A via a tee, and the manual valve is fixed to the port of the metal hose B via the threaded connection.

[0012] The curing system includes an insulation box, a pressure tank cover, an upper flange, a pressure tank cavity, a cylinder flange, a cylinder, a cylinder base plate, a lower flange, a pressure sensor base, a wire threading cap, sealing silicone, a wire threading base, a diaphragm, a slurry, and a pressure tank base plate. The pressure tank cover is connected to a metal hose A via a hose connector, allowing high-pressure nitrogen to enter the pressure tank smoothly and stably. The pressure tank cavity is bolted to the pressure tank via an upper flange and to the pressure tank base plate via a lower flange. The cylinder is bolted to the cylinder flange and the cylinder base plate. The wire threading cap and the wire threading base are threaded together and sealed with sealing silicone. The pressure tank cover and the sealing silicone have small holes for a temperature thermocouple to pass through the cover into the cavity. The pressure sensor base is used to connect a pressure sensor for real-time pressure measurement. The diaphragm is fixed between the lower surface of the cylinder flange and the upper surface of the cylinder via the cylinder flange.

[0013] The data acquisition system includes a pressure data transmission line, a temperature data transmission line, a pressure sensor, a miniature camera, a temperature thermocouple, and a data acquisition instrument. The pressure sensor is connected to the pressure sensor base via threads to measure the pressure inside the pressurization chamber in real time, and transmits the measurement data to the data acquisition instrument via the pressure data transmission line. The temperature thermocouple passes through a threaded cap, sealing silicone, a threaded base, and a small hole in the pressure tank cover to measure the temperature inside the pressure tank cavity, and transmits the measurement data to the data acquisition instrument via the temperature data transmission line. The miniature camera is fixed below the cover via a threaded connection, with its head aligned with the diaphragm to capture real-time images of the diaphragm deformation.

[0014] Preferably, the pressure tank cover and the upper flange are provided with positioning grooves, a cross-shaped sealing gasket is installed in the positioning groove, an annular sealing ring is fixedly installed on the outside of the cross-shaped sealing gasket, and a secondary sealing gasket is sleeved on the outside of the cross-shaped sealing gasket. The secondary sealing gasket is installed between the pressure tank cover and the upper flange.

[0015] Preferably, bolt holes are evenly provided on the upper cover and upper flange of the pressure tank, and a pressure groove is provided on the upper side of the bolt holes. A pressure ring is slidably installed in the pressure groove, and a pressure plate is provided on the lower circumference of the pressure ring. An arc-shaped extrusion surface is provided on the side of the pressure plate near the pressure ring, and an arc-shaped extrusion surface is also provided below the pressure ring. The pressure plate is slidably installed in the bolt holes for the bolts to evenly extrude the sealing gasket.

[0016] Preferably, the film is made of butyl rubber, which has high elasticity and high toughness properties, to prevent excessive deformation of the drug column during the pressurization and curing process, which could lead to film expansion and damage, resulting in dangerous situations such as drug leakage.

[0017] Preferably, the cylinder body should be tightly connected to the cylinder body flange and the cylinder body bottom plate to prevent leakage of medicine, which could cause the medicine slurry to enter between the cylinder body flange and the upper surface of the cylinder body, causing compression of the medicine slurry and resulting in unnecessary danger; the pressure tank cavity should be tightly connected to the pressure tank top cover and the pressure tank bottom plate to prevent air leakage.

[0018] Preferably, the camera head of the miniature camera should be aligned with the film to achieve real-time imaging of the entire surface of the film, and the camera head should be lower than the front end of the temperature thermocouple to prevent the temperature thermocouple from obstructing the camera; the entire fixed position of the miniature camera should be as far away from the air duct as possible to avoid interference or even damage to the miniature camera by high-pressure gas during air intake and exhaust.

[0019] Preferably, the slurry is separated from the high-pressure nitrogen gas by a thin film, which reduces the danger of the pressure curing experiment.

[0020] Preferably, the cylinder body should be tightly connected to the cylinder body flange and the cylinder body bottom plate to prevent leakage of medicine, which could cause the medicine slurry to enter between the cylinder body flange and the upper surface of the cylinder body, causing compression of the medicine slurry and resulting in unnecessary danger; the pressure tank cavity should be tightly connected to the pressure tank top cover and the pressure tank bottom plate to prevent air leakage.

[0021] A method for measuring the column deformation of solid propellant during pressurized solidification includes the following steps:

[0022] S1. Assembly test device: Connect the pressure tank cavity to the pressure tank cover with the upper flange bolts, and connect it to the pressure tank bottom plate with the lower flange bolts, and check the airtightness.

[0023] S2. Gas source installation and securing. Install the high-pressure nitrogen cylinder on the anti-tipping cylinder stand;

[0024] S3. Installation and fixing of gas supply pipeline, various sensors and data transmission lines: Connect the high-pressure nitrogen cylinder to the curing system via the metal hose A through the threaded connection, which serves as the gas supply pipeline for the curing system; connect the pressure sensor and the pressure sensor base through the threaded connection; pass the temperature thermocouple through the wire threading cap, sealing silicone, wire threading base and the small hole left on the top cover of the pressure tank, respectively; transmit the measurement data to the data acquisition instrument through the pressure data transmission line and the temperature data transmission line; turn on the data acquisition instrument and perform initial signal detection;

[0025] S4. Vacuum casting method is used to pour the slurry into the cylinder and then the device is sealed.

[0026] S5. Turn on the high-pressure nitrogen cylinder to supply gas and adjust the working status of the pressure reducing valve;

[0027] S6. Conduct a pressure curing test and collect data in real time;

[0028] S7. After the test is completed, close the pressure reducing valve, open the manual valve, and discharge the gas from the metal hose B.

[0029] 3. Beneficial effects

[0030] (1) Simple structure and safe and reliable: The test device of the present invention has only a dozen main components, which are closely matched and tightly connected, and the overall device works reliably and is highly safe.

[0031] (2) Modular components: The main components of the test device of the present invention can be easily disassembled, especially the film and the cylinder can be disassembled to facilitate timely replacement of the film and removal of residual drugs or residues inside the cylinder so as to carry out the next test as soon as possible;

[0032] (3) Multiple data can be measured: The present invention has installed a miniature camera, a temperature thermocouple and a pressure sensor in the device to measure the deformation of the drug column, the temperature and pressure rise in the device, the heat preservation and pressure holding and the temperature and pressure drop in real time throughout the entire process of pressurization and curing.

[0033] (4) Reusability and cost saving: In the test device of the present invention, except for the nitrogen cylinder that needs to be replaced, all parts, as well as miniature camera, temperature thermocouple, pressure sensor, etc., can be reused, thereby saving test costs.

[0034] (5) Quantification of drug column deformation: This invention uses digital image correlation technology (DIC technology) to spray randomly distributed speckles on the surface of the film. A miniature high-speed camera is used to record images of the film before and after deformation. The speckle information is displayed in grayscale. A specific search method and correlation function are used to match the feature points on the deformation image. Finally, based on the obtained strain value and position value, the deformation of the drug column is measured.

[0035] (6) Temperature and pressure co-visualization: Through real-time measurement by temperature thermocouples and pressure sensors, the heating and pressurization, heat preservation and pressure preservation, and cooling and pressurization processes in the experiment are clearly visible on the data acquisition instrument. Attached Figure Description

[0036] Figure 1 This is a schematic cross-sectional view (front view) of the main structure of the device for measuring the deformation of a solid propellant column during the pressurization and solidification process proposed in this invention;

[0037] Figure 2 This is a schematic diagram (top view) of the macroscopic layout of a device for measuring the deformation of a solid propellant column during the pressurization and solidification process proposed in this invention;

[0038] Figure 3 This is an exploded view of the pressure tank cover and upper flange of the present invention;

[0039] Figure 4 For the present invention Figure 3 Enlarged view of point A in the middle;

[0040] Figure 5 This is a schematic diagram of the DIC principle mentioned in Embodiment 1 of the present invention.

[0041] In the diagram: 1. Metal hose A; 2. Insulation box; 3. Hose connector; 4. Top cover; 5. Upper flange; 6. Air guide tube; 7. Pressurized tank cavity; 8. Cylinder flange; 9. Cylinder; 10. Lower flange; 11. Cylinder base plate; 12. Pressure data transmission line; 13. Temperature data transmission line; 14. Pressure sensor; 15. Pressure sensor base; 16. Wire threading cap; 17. Sealing silicone; 18. Wire threading base; 19. Miniature camera; 20. Temperature thermocouple; 21. Membrane; 22. Medicine syrup; 23. Pressurized tank base plate; 24. High-pressure nitrogen cylinder; 25. Pressure reducing valve; 26. Metal hose B; 27. Hand valve; 28. Data acquisition instrument; 41. Secondary sealing gasket; 42. Cross-shaped sealing gasket; 43. Positioning groove; 51. Pressure ring; 52. Pressure groove; 53. Arc-shaped pressure block; 54. Return spring; 55. Pressure plate. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Example 1:

[0044] Please see Figure 1-5 This invention proposes a device for measuring the column deformation of solid propellant during the pressurized solidification process, which includes a gas supply system, a solidification system, and a data acquisition system;

[0045] The gas supply system includes a metal hose A1, a hose connector 3, a gas delivery cylinder 6, a high-pressure nitrogen cylinder 24, a pressure reducing valve 25, a metal hose B 26, and a hand valve 27. The high-pressure nitrogen cylinder 24 is fixed to a cylinder rack to prevent tipping and is threadedly connected to the pressure reducing valve 25. By adjusting the pressure reducing valve 25, the pressure inside the cylinder is reduced, allowing the required high-pressure gas to flow to the curing system. The metal hose B 26 connects the high-pressure nitrogen cylinder 24 to the curing system via a threaded connection, serving as the inlet pipe for the curing system. The metal hose B 26 is threadedly connected to the metal hose A1 via a tee, and the hand valve 27 is fixed to the port of the metal hose B 26 via the threaded connection.

[0046] The curing system includes an insulation box 2, a pressure tank cover 4, an upper flange 5, a pressure tank cavity 7, a cylinder flange 8, a cylinder 9, a cylinder bottom plate 11, a lower flange 10, a pressure sensor base 15, a wire threading cap 16, sealing silicone 17, a wire threading base 18, a membrane 21, a slurry 22, and a pressure tank bottom plate 23. The pressure tank cover 4 is connected to a metal hose A1 via a hose connector 3, allowing high-pressure nitrogen to enter the pressure tank smoothly and stably. The pressure tank cavity 7 is bolted to the pressure tank cover 4 via the upper flange 5 and to the pressure tank bottom plate. 23 is bolted to the lower flange 10; the cylinder body 9 is bolted to the cylinder flange 8 and the cylinder base plate 11; the wire thread cap 16 is threaded to the wire thread base 18 and sealed with silicone sealant 17; the pressure tank cover 4 and the silicone sealant 17 have small holes for the temperature thermocouple 20 to pass through the pressure tank cover 4 and enter the cavity; the pressure sensor base 15 is used to connect the pressure sensor 14 to realize real-time pressure measurement; the diaphragm 21 is fixed between the lower surface of the cylinder flange 8 and the upper surface of the cylinder body 9 through the cylinder flange 8.

[0047] Positioning grooves 43 are provided on the upper cover 4 and upper flange 5 of the pressure tank. A cross-shaped sealing gasket 42 is installed in the positioning groove 43. An annular sealing ring is fixedly installed on the outside of the cross-shaped sealing gasket 42. A secondary sealing gasket 41 is sleeved on the outside of the cross-shaped sealing gasket 42. The secondary sealing gasket 41 is installed between the upper cover 4 and the upper flange 5 of the pressure tank.

[0048] In this design, the cross-shaped sealing gasket 42 ensures a full seal when the pressure tank cover 4 and upper flange 5 are sealed. A ring-shaped sealing ring is fixedly installed on the outside of the cross-shaped sealing gasket 42 to provide a secondary seal on the outside of the pressure tank cover 4 and upper flange 5. To prevent damage to the gasket, a secondary sealing gasket 41 is added to the outside of the cross-shaped sealing gasket 42. This secondary sealing gasket 41 provides a secondary seal on the pressure tank cover 4 and upper flange 5, reducing pressure leakage caused by gasket damage. Both the cross-shaped sealing gasket 42 and the secondary sealing gasket 41 are made of highly elastic, high-temperature corrosion-resistant materials.

[0049] Bolt holes are evenly provided on the upper cover 4 and upper flange 5 of the pressure tank, and a pressure groove 52 is provided on the upper side of the bolt holes. A pressure ring 51 is slidably installed in the pressure groove 52. A pressure plate 55 is provided on the circumference below the pressure ring 51. An arc-shaped extrusion surface is provided on the side of the pressure plate 55 near the pressure ring 51. An arc-shaped extrusion surface is also provided below the pressure ring 51. The pressure plate 55 is slidably installed in the bolt holes for the bolts to evenly extrude the sealing gasket.

[0050] The tightening of the bolts can compress the pressure ring 51. At this time, the tightening of the bolts can directly cause the lower surface of the pressure ring 51 to be squeezed against the upper surface of the pressure plate 55, which in turn causes the pressure plate 55 to squeeze the bolt surface. This can prevent uneven compression of the gasket when the bolts are tightened on the upper cover 4 and upper flange 5 of the pressure tank, thereby reducing the damage to the gasket caused by the uneven tightening of the bolts and reducing the service life of the gasket.

[0051] The data acquisition system includes a pressure data transmission line 12, a temperature data transmission line 13, a pressure sensor 14, a miniature camera 19, a temperature thermocouple 20, and a data acquisition instrument 28. The pressure sensor 14 is connected to the pressure sensor base 15 by threads to measure the pressure in the pressurization chamber in real time, and transmits the measurement data to the data acquisition instrument 28 through the pressure data transmission line 12. The temperature thermocouple 20 passes through the wire-threading cap 16, the sealing silicone 17, the wire-threading base 18, and the small hole left on the top cover of the pressurization tank to measure the temperature inside the pressurization tank cavity 7, and transmits the measurement data to the data acquisition instrument 28 through the temperature data transmission line 13. The miniature camera 19 is fixed below the top cover 4 by threads, with the camera head aligned with the diaphragm 21 to capture real-time images of the deformation of the diaphragm 21.

[0052] The film 21 is made of butyl rubber, which has high elasticity and high toughness properties. This prevents the film 21 from expanding and breaking during the pressure curing process of the drug column, which could lead to dangerous situations such as drug leakage.

[0053] The temperature thermocouple 20 passes through the wire threading cap 16, the sealing silicone 17, the wire threading base 18, and the small holes left on the pressure tank cover 4 to directly measure the temperature inside the slurry 22. The diameter of the temperature thermocouple 20 should match the three small holes to prevent air leakage.

[0054] The camera head of the miniature camera 19 should be aligned with the film 21 to achieve real-time imaging of the entire surface of the film 21. The camera head should be lower than the front end of the temperature thermocouple 20 to prevent the temperature thermocouple 20 from obstructing the camera. The entire fixed position of the miniature camera 19 should be as far away from the air duct 6 as possible to avoid interference or even damage to the miniature camera 19 when the air is inlet or outlet.

[0055] The slurry 22 avoids direct contact with high-pressure nitrogen gas through the membrane 21, reducing the danger of the pressure curing experiment;

[0056] The cylinder body 9 should be tightly connected to the cylinder flange 8 and the cylinder bottom plate 11 to prevent leakage of medicine, which would cause the medicine slurry 22 to enter between the cylinder flange 8 and the upper surface of the cylinder body 9, causing compression of the medicine slurry 22 and resulting in unnecessary danger; the pressure tank cavity 7 should be tightly connected to the pressure tank cover 4 and the pressure tank bottom plate 23 to prevent air leakage.

[0057] This invention further proposes a method for measuring the column deformation of solid propellants during the pressurization and solidification process, comprising the following steps:

[0058] Assembly test device: Connect the pressure tank cavity 7 to the pressure tank cover 4 with the upper flange 5 bolts, and connect it to the pressure tank bottom plate 23 with the lower flange 10 bolts, and check the airtightness;

[0059] Gas source installation and securing: Install the high-pressure nitrogen cylinder 24 on the anti-tipping cylinder rack;

[0060] Gas supply line, sensors, and data transmission lines are installed and fixed: The high-pressure nitrogen cylinder 24 is connected to the curing system via a threaded connection using a metal hose A1, serving as the gas supply line for the curing system. The pressure sensor 14 and pressure sensor base 15 are connected via threads. The temperature thermocouple 20 passes through the wire thread cap 16, sealing silicone 17, wire thread base 18, and the small hole left on the pressure tank cover 4, respectively. The measurement data is transmitted to the data acquisition instrument 28 via the pressure data transmission line 12 and the temperature data transmission line 13. The data acquisition instrument 28 is turned on and a preliminary signal check is performed.

[0061] The slurry 22 was poured into the cylinder 9 using a vacuum casting method, and the device was then sealed.

[0062] Turn on the high-pressure nitrogen cylinder 24 to supply gas, and adjust the working status of the pressure reducing valve 25;

[0063] A pressure curing test was conducted, and data was collected in real time. A schematic diagram of the DIC technology principle is shown below. Figure 3 ;

[0064] After the test is completed, close the pressure reducing valve 25, open the hand valve 27, and release the gas from the metal hose B 26.

[0065] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concept, should be covered within the scope of protection of the present invention.

Claims

1. A device for measuring the column deformation during the pressurized solidification process of a solid propellant, characterized in that, The device includes a gas supply system, a curing system, and a data acquisition system, wherein: The gas supply system includes a high-pressure nitrogen cylinder (24), which is fixed on a cylinder rack and equipped with a pressure reducing valve (25). The pressure reducing valve (25) is used to adjust the pressure inside the high-pressure nitrogen cylinder (24). A metal hose A (1) is connected to the pressure reducing valve (25). The end of the metal hose A (1) away from the pressure reducing valve (25) is connected to the curing system, which serves as the air inlet pipe of the curing system. A metal hose B (26) is connected to the metal hose A (1) through a three-way pipe. A hand valve (27) is fixedly installed at the opening of the metal hose B (26). The top of the curing system is connected to a data transmission line, and the end of the data transmission line away from the curing system is connected to the data acquisition instrument (28) of the data acquisition system; The curing system includes an insulation box (2), with a pressure tank bottom plate (23) at the bottom of the insulation box (2). A pressure tank cavity (7) is placed on the pressure tank bottom plate (23), and the bottom of the pressure tank cavity (7) is fixed to the pressure tank bottom plate (23) by a lower flange (10). A pressure tank top cover (4) is provided above the pressure tank cavity (7), and the pressure tank top cover (4) is fixed to the top of the pressure tank cavity (7) by an upper flange (5). 4) A hose connector (3) and a pressure sensor base (15) are installed on the hose. The end of the metal hose A (1) away from the high-pressure nitrogen cylinder (24) is fixedly connected to the hose connector (3). A gas guide tube (6) is fixedly connected to the bottom of the hose connector (3). The gas guide tube (6) is located inside the pressurized tank cavity (7). A pressure sensor (14) is installed on the pressure sensor base (15). A pressure data transmission line (12) is connected to the pressure sensor (14). The curing system also includes a cylinder (9), which is located inside the pressure tank cavity (7). The cylinder (9) contains a slurry (22), and a cylinder flange (8) is provided at the top of the cylinder (9). A film (21) is fixedly connected to the bottom surface of the cylinder flange (8). The miniature camera (19) is installed inside the pressure tank cavity (7) near the membrane (21) to monitor the deformation of the membrane (21) in real time.

2. The device for measuring the column deformation during the pressurized solidification process of solid propellant as described in claim 1, characterized in that, The pressure tank cover (4) and the upper flange (5) are both provided with positioning grooves (43). A cross-shaped sealing gasket (42) is installed in the positioning groove (43). An annular sealing ring is fixedly installed on the outside of the cross-shaped sealing gasket (42). A secondary sealing gasket (41) is sleeved on the outside of the cross-shaped sealing gasket (42). The secondary sealing gasket (41) is installed between the pressure tank cover (4) and the upper flange (5).

3. The device for measuring the column deformation during the pressurized solidification process of solid propellant as described in claim 2, characterized in that, Bolt holes are evenly provided on the upper cover (4) and upper flange (5) of the pressurizing tank, and a pressure groove (52) is provided on the upper side of the bolt holes. A pressure ring (51) is slidably installed in the pressure groove (52). A pressure plate (55) is provided on the circumference below the pressure ring (51). An arc-shaped extrusion surface is provided on the side of the pressure plate (55) near the pressure ring (51). An arc-shaped extrusion surface is also provided below the pressure ring (51). The pressure plate (55) is slidably installed in the bolt hole for the bolt to evenly extrude the sealing gasket.

4. The device for measuring the column deformation during the pressurized solidification process of solid propellant as described in claim 1, characterized in that, A wire-threading base (18) is provided at the center of the top surface of the pressure tank cover (4). A wire-threading cap (16) is connected to the wire-threading base (18). A sealing silicone (17) is provided between the wire-threading cap (16) and the wire-threading base (18). A fine hole is provided on the wire-threading base (18), the wire-threading cap (16), the sealing silicone (17), and the pressure tank cover (4). A temperature thermocouple (20) is installed through the fine hole to measure the temperature inside the pressure tank cavity (7). A temperature data transmission line (13) is connected to the top of the temperature thermocouple (20).

5. The device for measuring the column deformation during the pressurized solidification process of solid propellant as described in claim 1, characterized in that, The data acquisition system includes a pressure data transmission line (12), a temperature data transmission line (13), a pressure sensor (14), a miniature camera (19), a temperature thermocouple (20), and a data acquisition instrument (28). The pressure sensor (14) is connected to the data acquisition instrument (28) through the pressure data transmission line (12), and the temperature thermocouple (20) is connected to the data acquisition instrument (28) through the temperature data transmission line (13).

6. A device for measuring the column deformation during the pressurized solidification process of a solid propellant as described in claim 4 or 5, characterized in that, The film (21) is made of butyl rubber and has high elasticity and high toughness properties, which are used to prevent the film (21) from expanding and breaking.

7. The device for measuring the column deformation during the pressurized solidification process of solid propellant as described in claim 4, characterized in that, The inner diameter of the fine hole is matched with the diameter of the temperature thermocouple (20) to avoid air leakage.

8. The device for measuring the column deformation during the pressurized solidification process of solid propellant as described in claim 6, characterized in that, By setting up a thin film (21) to prevent the slurry (22) from coming into direct contact with high-pressure nitrogen, the danger of the pressure curing experiment is reduced.

9. The device for measuring the column deformation during the pressurized solidification process of solid propellant as described in claim 4, characterized in that, The cylinder body (9) is tightly connected to the cylinder flange (8) and the cylinder bottom plate (11) to prevent leakage of medicine, so that the medicine slurry (22) enters between the cylinder flange (8) and the upper surface of the cylinder body (9) and squeezes the medicine slurry (22); the pressure tank cavity (7) is tightly connected to the pressure tank cover (4) and the pressure tank bottom plate (23) to prevent air leakage.

10. A method for measuring the column deformation of solid propellant during the pressurization and solidification process based on the apparatus described in any one of claims 1-9, characterized in that, By using digital image correlation technology, randomly distributed speckles are sprayed onto the surface of the thin film. Images of the thin film before and after deformation are recorded using a miniature camera (19). The speckle information is displayed in grayscale. The feature points on the deformation image are matched using image feature search methods and correlation functions. Finally, based on the obtained strain and position values, the deformation of the propellant column is measured. Specifically, the following steps are included: S1. Assembly test device: The pressure tank cavity (7) is fixedly connected to the pressure tank cover (4) through the upper flange (5), and fixedly connected to the pressure tank bottom plate (23) through the lower flange (10) to check the air tightness; S2. Gas source installation and fixing: Install the high-pressure nitrogen cylinder (24) on the anti-tipping cylinder rack; S3. Installation and fixing of gas supply pipeline, various sensors and data transmission lines: Connect the high-pressure nitrogen cylinder (24) to the curing system through the threaded connection of the metal hose A (1) as the gas supply pipeline of the curing system; connect the pressure sensor (14) and the pressure sensor base (15) through the threaded connection, and pass the temperature thermocouple (20) through the wire thread cap (16), the sealing silicone (17), the wire thread base (18), and the small hole left on the pressure tank cover (4) respectively. Transmit the measurement data to the data acquisition instrument (28) through the pressure data transmission line (12) and the temperature data transmission line (13), turn on the data acquisition instrument (28) and perform initial signal detection; S4. The slurry (22) is poured into the cylinder (9) using a vacuum casting method and the device is sealed. S5. Open the high-pressure nitrogen cylinder (24) to supply gas, and adjust the working status of the pressure reducing valve (25); S6. Conduct a pressure curing test and collect data in real time; S7. After the test is completed, close the pressure reducing valve (25), open the hand valve (27), and discharge the gas from the metal hose B (26).

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