High-pressure visual electronic control solid propellant combustion characteristic measuring device

Abstract

The invention discloses a high-pressure visual electronic control solid propellant combustion characteristic measuring device which comprises a combustion chamber, and the first end of the combustion chamber is connected with a motor chamber; an electrode disc is arranged at the second end of the combustion chamber away from the motor chamber; a motor is installed in the motor chamber, the output end of the motor faces the electrode disc, a supporting rod is arranged at the output end of the motor, and the other end of the supporting rod is connected with a lifting base. The lifting base extends into the combustion chamber and is used for mounting an electric control solid propellant; an isolation section is arranged between the combustion chamber and the motor chamber and is in dynamic seal with the supporting rod; according to the invention, the electric control solid propellant is driven by the motor to move towards the electrode disc, and the burning surface of the electric control solid propellant can be kept stable at the same position, so that an external high-speed camera can observe the burning condition of the electric control solid propellant conveniently, and the measurement precision of the electric control solid propellant is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of electronically controlled solid propellant measurement, and in particular relates to a high-voltage visualized electronically controlled solid propellant combustion characteristic measurement device. Background Art

[0002] Electronically controlled solid propellant is a new type of solid propellant with electrical response characteristics. It can make the propellant burn when the power is on and extinguish when the power is off. The burning rate of the solid propellant can also be controlled by adjusting the electric field parameters. Electronically controlled solid propellant realizes the control of the solid propellant combustion process, so that the solid rocket engine has multiple start-up and adjustable thrust functions. It has broad prospects.

[0003] Electronically controlled solid propellants require continuous voltage to be applied to the combustion surface to maintain the electrolytic combustion of the propellant. Existing electronically controlled solid propellant combustion characteristics measurement devices usually use a motor to drive the electrode to move at a certain speed along the direction of the propellant combustion surface to maintain a continuous voltage on the propellant combustion surface, thereby measuring the combustion characteristics of the propellant.

[0004] However, the existing device is only suitable for measuring the combustion characteristics of electronically controlled solid propellants under normal pressure. If the existing device is used for measurement under high pressure, the entire device needs to be placed in a closed pressure vessel. In addition, in order to measure the combustion characteristics such as ignition and extinction of electronically controlled solid propellants, it is necessary to be able to observe the combustion surface. A common practice is to design an observation window on the side wall of the pressure vessel. If the existing device is used for measurement, the position of the propellant combustion surface will change continuously, so the observation window needs to have a large area to cover the entire area where the propellant combustion surface changes, but the high-pressure environment limits the area of ​​the observation window from being too large. At the same time, the area where the combustion surface position changes is large, and the measuring camera is also required to have a large field of view. However, under normal circumstances, a large field of view will result in a low resolution of the combustion surface area, affecting the measurement accuracy. Therefore, the existing measurement device is not suitable for measuring electronically controlled solid propellants under high pressure, and cannot obtain accurate combustion characteristics of electronically controlled solid propellants. Summary of the invention

[0005] The present invention provides a high-voltage visualized electronically controlled solid propellant combustion characteristic measuring device, which improves the measurement accuracy of the electronically controlled solid propellant by moving the electronically controlled solid propellant to keep the burning surface in continuous contact with the electrode and keep the position of the burning surface basically unchanged.

[0006] The present invention adopts the following technical solution: a high-voltage visual electronically controlled solid propellant combustion characteristic measuring device, characterized in that it comprises a combustion chamber, a first end of which is connected to a motor chamber;

[0007] An electrode disk is disposed at a second end of the combustion chamber away from the motor chamber;

[0008] A motor is installed in the motor chamber, the output end of the motor faces the electrode disk, and a support rod is provided at the output end of the motor, and the other end of the support rod is connected to a lifting base; the lifting base extends into the combustion chamber and is used to install the electronically controlled solid propellant;

[0009] An isolation section is arranged between the combustion chamber and the motor chamber, and the isolation section is dynamically sealed with the support rod.

[0010] Further, it also includes two target wires axially spaced apart and arranged in the electrically controlled solid propellant;

[0011] Both ends of each target line are connected to different terminals on the lifting base, and the terminals are also connected to an external target line power supply through an extension line.

[0012] Furthermore, the directions of the two target lines intersect each other.

[0013] Furthermore, the portion of the extension line located inside the combustion chamber is a retractable extension line.

[0014] Further, the electrode disk includes a positive electrode disk and a negative electrode disk that do not contact each other;

[0015] The positive electrode disc extends a positive electrode strip toward the electrically controlled solid propellant, and the negative electrode disc extends a negative electrode strip toward the electrically controlled solid propellant, and the contacts of the positive electrode strip and the negative electrode strip are located in the same plane and do not contact each other.

[0016] Furthermore, the positive electrode disk and the negative electrode disk are both fixedly connected to the second end of the combustion chamber via a fixing column.

[0017] Furthermore, adjustment springs are provided at both ends of the fixing column located at the positive electrode disk / negative electrode disk;

[0018] One end of the adjusting spring is fixed to the fixing column, and the other end is pressed against the insulating layer of the positive electrode disk / negative electrode disk.

[0019] Furthermore, a first observation window is provided on the shell of the combustion chamber, and the first observation window and the positive electrode disk / negative electrode disk are both located on the same cross section of the combustion chamber.

[0020] Further, a portion of the positive electrode disk / negative electrode disk facing the first observation window has a notch.

[0021] Further, the combustion chamber is connected to a pressure supply mechanism.

[0022] The beneficial effect of the present invention is that the present invention drives the electronically controlled solid propellant to move toward the electrode disk through a motor, so that the combustion surface of the electronically controlled solid propellant can be kept stable at the same position, thereby facilitating an external high-speed camera to observe the combustion of the electronically controlled solid propellant and improving the measurement accuracy of the electronically controlled solid propellant. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic structural diagram of a high-voltage visual electronically controlled solid propellant combustion characteristic measuring device according to an embodiment of the present invention;

[0024] Figure 2 Schematic diagram of the state of the electronically controlled solid propellant combustion process in an embodiment of the present invention;

[0025] Figure 3 It is a structural schematic diagram of an isolation section in an embodiment of the present invention;

[0026] Figure 4 Schematic diagram of target line voltage variation measured in an embodiment of the present invention.

[0027] Wherein: 110. combustion chamber; 120. motor chamber; 130. isolation section; 131. O-shaped sealing ring; 132. Y-shaped sealing ring; 140. first observation window; 150. second observation window;

[0028] 210. Motor; 220. Motor controller; 230. Support rod; 240. Lifting base;

[0029] 310. Pressure-stabilizing gas cylinder; 320. Gas source cylinder; 330. Pressure sensor;

[0030] 410. Target line; 420. Extension line; 430. Voltage divider circuit; 440. Target line power supply;

[0031] 510. electrode disk; 520. fixing column; 530. electric control power supply;

[0032] 610. High-speed camera;

[0033] 710. Collector; 720. Processor;

[0034] 800.Electrically controlled solid propellant. DETAILED DESCRIPTION

[0035] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Burning rate is one of the important combustion characteristics of electronically controlled solid propellants. Burning rate is defined as the distance that the burning surface of the electronically controlled solid propellant moves in the normal direction per unit time. The two main factors affecting the burning rate of electronically controlled solid propellants are the electric field parameters and the ambient pressure. Like most solid propellants, the burning rate of electronically controlled solid propellants increases with the increase of pressure. The relationship between burning rate and pressure can usually be expressed as u=a·p n It is represented by , where u is the burning rate, p is the pressure, a is a constant, and n is the pressure exponent.

[0037] The target wire method is a commonly used method for measuring the burning rate of solid propellants. The target wire is a fusible and conductive metal wire. It is embedded in the solid propellant sample at a certain interval. When the burning surface of the solid propellant retreats to the target wire position, the target wire melts. By recording the time intervals of different target wire melting, the burning rate of the solid propellant can be obtained.

[0038] From the working characteristics of the electronically controlled solid propellant, it can be known that the combustion characteristics of the electronically controlled solid propellant also include ignition and extinction characteristics, etc. Like the burning rate, these combustion characteristics will also be different under different ambient pressures. The electronically controlled solid propellant works in an engine combustion chamber with a relatively high pressure. Therefore, in order to obtain the accurate combustion characteristics of the electronically controlled solid propellant, it is necessary to measure the combustion characteristics of the electronically controlled solid propellant under high pressure.

[0039] In the present invention, high pressure is relative to normal pressure, specifically normal pressure to 10MPa. When the combustion chamber pressure reaches a certain level, the existing measurement method requires the entire device together with the motor to be placed in a closed pressure vessel, which not only results in a large volume of the pressure vessel, but also the high-temperature corrosive gas and small solid particles generated by the combustion of the propellant will have a great impact on the life of the motor and moving parts.

[0040] The present invention discloses a high-voltage visual electronically controlled solid propellant combustion characteristic measuring device. Figure 1 As shown, it includes a combustion chamber 110, and the first end of the combustion chamber 110 is connected to the motor chamber 120; the second end of the combustion chamber 110 away from the motor chamber 120 is provided with an electrode disk 510; a motor 210 is installed in the motor chamber 120, the output end of the motor 210 faces the electrode disk 510, and the output end of the motor 210 is provided with a support rod 230, and the other end of the support rod 230 is connected to a lifting base 240; the lifting base 240 extends into the interior of the combustion chamber 110, and is used to install the electronically controlled solid propellant 800; an isolation section 130 is provided between the combustion chamber 110 and the motor chamber 120, and the isolation section 130 is dynamically sealed with the support rod 230.

[0041] The present invention drives the electric-controlled solid propellant 800 to move toward the electrode disk 510 through the motor 210, which can keep the burning surface of the electric-controlled solid propellant 800 stable at the same position, thereby facilitating an external high-speed camera to observe the combustion of the electric-controlled solid propellant 800 and improving the measurement accuracy of the electric-controlled solid propellant.

[0042] In one embodiment, the combustion chamber 110 is a thick-walled cylindrical barrel section structure with a diameter of 300 mm; the combustion chamber 110 is composed of an upper barrel section and a lower barrel section, so as to facilitate the installation of the internal electronically controlled solid propellant 800, the target wire 400 and the electrode disk 510, and the upper barrel section and the lower barrel section are connected and sealed by a flange and an O-ring. The length of the upper barrel section is 300 mm, and the length of the lower barrel section is 110 mm. The combustion chamber 110 is made of 45 steel, with a wall thickness of 15 mm, a designed pressure of 10 MPa, and the first and fourth strength theories are used for strength verification.

[0043] In one embodiment, the motor chamber 210 is located at the bottom of the device and is a thick-walled cylindrical barrel section structure with a diameter of 100 mm and a length of 300 mm. Its upper end is connected to the high-pressure combustion chamber 110 through the isolation section 130. A high-thrust stepping screw motor is fixed inside the motor chamber 120. The motor has a maximum thrust of 5000N, an adjustable screw movement speed of 1-50mm / s, and a maximum movement distance of 200mm. The motor 210 is installed through the flange at the bottom of the motor.

[0044] The motor control line is led out from the side wall and connected to the motor controller 220 at a distance through an extension line; the screw motor is connected to the stainless steel support rod 230, and the support rod 230 can be controlled to rise or fall at a certain speed by rotating the motor 210; the support rod 230 passes through the isolation section 130 to reach the high-pressure combustion chamber 110; the support rod head 230 is a threaded structure and is connected to the lifting base 240.

[0045] The function of the isolation section 130 is to prevent the high-temperature corrosive gas and small solid particles generated by the combustion of the electronically controlled solid propellant from affecting the operation of the stepper motor. The isolation section 130 is a flange structure with a hole in the middle, and its upper end surface is connected to the bottom of the high-pressure combustion chamber 110, and its lower end surface is connected to the top of the motor chamber 120.

[0046] In one embodiment, Figure 3 As shown, the diameter of the central through hole of the isolation segment 130 is 10 mm, and the support rod 230 passes through the through hole. Figure 3 As shown, a Y-shaped sealing ring 132 and an O-shaped sealing ring 131 are sequentially embedded in the side wall of the through hole from the motor chamber 120 to the combustion chamber 110 to realize dynamic sealing. The dynamic sealing structure ensures that the motor support rod 230 moves up and down while ensuring that the high-temperature corrosive gas and solid particles in the combustion chamber do not enter the motor chamber.

[0047] The dynamic seal mainly relies on the Y-shaped sealing ring 132. The O-shaped sealing ring 131 is easier to replace than the Y-shaped sealing ring 132, so the O-shaped sealing ring 131 is used to block the high-temperature gas to protect the Y-shaped sealing ring 132, which is a consumable and is replaced after each test.

[0048] The motor 210 is separated from the combustion chamber 110 by the dynamic sealing effect of the isolation section 130, which reduces the volume of the combustion chamber 110 while ensuring that the high-temperature corrosive combustion gas and solid particles generated by the combustion of the electronically controlled solid propellant 800 will not enter the motor chamber 120 and affect the operation and service life of the motor 210.

[0049] The lifting base 240 is used to fix the electrically controlled solid propellant 800 and the target wire 410, and is connected to the support rod 230. Driven by the motor 210, the lifting base 240 moves the electrically controlled solid propellant 800 toward the electrode disk 510 at a certain speed to maintain continuous contact between the burning surface of the electrically controlled solid propellant 800 and the electrode disk 510 during the combustion process.

[0050] A first observation window 140 is provided on the shell of the combustion chamber 110 . The first observation window 140 and the positive electrode disk / negative electrode disk are located on the same cross section of the combustion chamber 110 .

[0051] The present invention replaces the movement of the electrode disk 510 with the movement of the electrically controlled solid propellant, so that the position of the combustion surface remains basically unchanged, so as to facilitate observation of the combustion characteristics of the electrically controlled solid propellant 800 through the first observation window 140 at a fixed position.

[0052] In the embodiment of the present invention, a second observation window 150 is provided on the shell of the combustion chamber 110 opposite to the first observation window 140. The second observation window 150 can be used to observe the combustion characteristics of the electronically controlled solid propellant 800, and can also provide a laser light source for optical diagnosis.

[0053] Specifically, the lifting base 230 has a thickness of 10 mm, a 3 mm high boss in the middle, the boss is hollowed out and the inner diameter is larger than the diameter of the electric-controlled solid propellant 800, and the electric-controlled solid propellant 800 is fixed inside the boss (i.e. inside the ring) by filling fireproof mud. At the same time, the electric-controlled solid propellant 800 selects a cylindrical medicine strip with a diameter of 10 mm.

[0054] There are four terminals (used to connect the target line 410) around the circular boss, and the angle between two adjacent terminals is 90 degrees. The terminals are threaded rods and are fixed to the lifting base 240 by two upper and lower nuts. The terminals and the lifting base 240 are insulated with polytetrafluoroethylene gaskets.

[0055] The present invention also includes two target wires 410 axially spaced apart and arranged in the electric-controlled solid propellant 800; the two ends of each target wire 410 are respectively connected to different terminals on the lifting base 240, and the terminals are further connected to an external target wire power supply 440 through an extension wire 420. The directions of the two target wires 410 intersect each other.

[0056] The target line method is used to measure the average burning rate of 800 electronically controlled solid propellants under high pressure. An optical observation window is designed near the burning surface of the propellant, and optical diagnostic methods are used to measure other combustion characteristics such as ignition and extinction of electronically controlled solid propellants under high pressure.

[0057] The target wire 410 is made of metal wire, and preferably, the metal target wire is made of thin lead wire. Two metal target wires pass through the inside of the electric-controlled solid propellant 800, and a soft plastic wire tube is used to wrap the portion of the target wire 410 that remains outside the electric-controlled solid propellant 800 to prevent the target wire 410 from being melted by the splashing propellant component before the burning surface retreats to the position of the target wire 410.

[0058] The target wire 410 is fixed to the upper end of the terminal of the lifting base 230; the two non-adjacent terminals used by the same target wire 410 make the two target wires 410 form a 90° angle to prevent one target wire 410 from falling onto another target wire 410 when it is melted.

[0059] An extension line 420 of the target line 410 is fixed to the lower end of the terminal post of the lifting base 230. The extension line 420 enters the combustion chamber 110 from the internal thread column on the side wall of the lower barrel section of the combustion chamber 110. A polytetrafluoroethylene plug is placed inside the internal thread column. The extension line 420 passes through the polytetrafluoroethylene plug, and then the polytetrafluoroethylene plug is tightened by bolts to cause it to deform to achieve a sealing effect.

[0060] The portion of the extension line 420 located inside the combustion chamber 110 is a retractable extension line. Specifically, the portion of the extension line 420 located inside the combustion chamber 110 is a stretchable spiral line, and the fully stretched length is greater than the length of the combustion chamber 110.

[0061] The present invention uses a target wire extension wire 420 that is not easy to break and is easy to stretch to move with the lifting base 230, while the easily broken metal target wire 410 is stationary relative to the lifting base 230; the target wire extension wire 420 is protected by a thicker rubber to ensure that it will not be damaged by the high-temperature combustion gas in the combustion chamber and the splashing propellant combustion products.

[0062] A certain voltage is applied to the target line 410 through the target line power supply 440. The voltage of the target line 410 is converted into a smaller voltage after passing through the voltage divider circuit 430 and enters the collector 710. The voltage change is recorded by the collector 710. When the target line 410 is disconnected, the voltage recorded by the collector 710 will become 0.

[0063] The electrode disk 510 includes a positive electrode disk and a negative electrode disk that do not contact each other; the positive electrode disk extends a positive electrode strip toward the electric-controlled solid propellant 800, and the negative electrode disk extends a negative electrode strip toward the electric-controlled solid propellant 800, and the contacts of the positive electrode strip and the negative electrode strip are located in the same plane and do not contact each other. The positive electrode disk and the negative electrode disk are both fixedly connected to the second end of the combustion chamber 110 through a fixing column 520.

[0064] The electrode disk 510 is a composite structure of a circular polytetrafluoroethylene sheet and an electrode sheet, wherein the positive and negative electrode strips are respectively embedded in two circular electrode sheets, and the electrode sheets are insulated by polytetrafluoroethylene sheets. There are many protruding contacts under the positive and negative electrode strips, and these contacts are interlaced with each other to contact the propellant combustion surface, forming an electric field on the propellant combustion surface.

[0065] In order to better observe the combustion process of the electrically controlled solid propellant, the part of the positive electrode disk / negative electrode disk facing the first observation window 140 has a notch. In other words, the electrode sheet and the polytetrafluoroethylene sheet are not complete rings. In the direction of the first observation window 140, there is a 60° opening on the electrode disk 510, and the electrode disk structure is connected by the electrode strip in the middle. Adjustment springs are provided at both ends of the positive electrode disk / negative electrode disk on the fixing column 520; one end of the adjustment spring is fixed to the fixing column 520, and the other end is pressed against the insulating layer of the positive electrode disk / negative electrode disk.

[0066] The electrode disk is suspended inside the upper cylinder section of the combustion chamber 110 . The electrode disk 510 is 200 mm away from the top, which is greater than the flame height of the electronically controlled solid propellant 800 , so as to avoid affecting the combustion of the electronically controlled solid propellant 800 .

[0067] The electrode disk 510 is fixed by four copper pillars (i.e., a form of the fixing pillars 520 ) inside the upper barrel section of the combustion chamber 110 .

[0068] A spring with a certain elastic coefficient is fixed above each mounting hole of the electrode disk 510, so that the electrode disk 510 has a certain amount of free displacement, so that the deviation between the moving speed and the burning speed of the electronically controlled solid propellant 800 will be compensated by the spring expansion amount. The estimated maximum burning speed u of the electronically controlled solid propellant 800 can be obtained by theoretical estimation before measurement. max and the estimated minimum burning rate u min , the stretching length of the spring when subjected to the gravity of the electrode disk 510 is G, which should satisfy Wherein, L is the length of the electronically controlled solid propellant 800. Specifically, in the present device, the electrode disk 510 has a gravity of 50 N and a spring elastic coefficient of 1.1 N / mm, so the stretching length G=55 mm.

[0069] In the design, the maximum movement distance of the motor 210 is 200mm, and the maximum distance between the lifting base and the electrode disk 510 is 200mm. The maximum length of the electronically controlled solid propellant 800 is determined to be 200mm; according to the movement speed of the motor ≤50mm / s, the maximum burning rate of the electronically controlled solid propellant 800 is determined to be 50mm / s; in order to ensure the accuracy of the target line method, the length of the electronically controlled solid propellant 800 should be adjusted according to its estimated burning rate to ensure that the burning time between the two target lines is ≥2s.

[0070] In the actual measurement process, the motor 210 is set to the maximum estimated combustion rate u max Movement, deviation between theoretical estimated burning rate and actual burning rate u max -u will be compensated by the free displacement of the spring to maintain continuous contact between the propellant burning surface and the electrode; and during the measurement process, the force between the electrode disk 510 and the propellant burning surface is equal to the difference between the gravity of the electrode disk and the spring tension, and the force on the burning surface will not exceed the gravity of the electrode disk 510, avoiding excessive force between the electrode disk 510 and the propellant burning surface.

[0071] The two fixing posts 520 (usually conductive metal posts) are also used to conduct electricity to the positive and negative electrodes of the electrode disk. The two fixing posts 520 extend all the way to the outside of the upper cylinder section and are insulated and sealed from the upper cylinder section by a polytetrafluoroethylene gasket. The two fixing posts are insulated from the part that passes through the hole of the electrode disk by a polytetrafluoroethylene sleeve. The parts extending from the upper ends of the two fixing posts 520 are connected to the positive and negative electrodes of the power supply, and then the lower ends of the two fixing posts 520 are connected to the positive electrode disk and the negative electrode disk respectively by wires, so that the connection between the positive electrode disk and the negative electrode disk has the same electric field as the electronically controlled combustion power supply.

[0072] Since the electronically controlled solid propellant 800 has different burning rate characteristics under different electric field conditions, the electronically controlled combustion power supply uses a high-power adjustable DC power supply with an adjustable output voltage of 1 to 380V and a maximum output current of 20A, so as to achieve different electric field conditions for the electronically controlled solid propellant 800.

[0073] In the present invention, the combustion chamber 110 is connected to a pressure supply mechanism. The pressure supply system provides a stable pressure environment of ≤10MPa for the high-pressure combustion chamber, and is composed of an air intake and exhaust device and a pressure-stabilizing gas cylinder.

[0074] There are two threaded interfaces on the side wall of the upper barrel section of the combustion chamber 110, which are connected to the air intake pipeline and the exhaust pipeline respectively; one end of the air intake pipeline is connected to the gas source bottle 320 of high-pressure nitrogen, the pressure reducing valve and the air intake solenoid valve in sequence, which are used to fill the combustion chamber with high-pressure nitrogen. The other end of the exhaust pipeline is connected to the four-way. One channel is connected to the exhaust solenoid valve, which is used to remotely control the discharge of high-pressure gas in the combustion chamber after the test; one channel is connected to the pressure relief valve, which can automatically release pressure when the pressure in the combustion chamber 110 exceeds the maximum design pressure; one channel is connected to the pressure-stabilizing gas cylinder 310, which has a volume of 50L and can ensure that the pressure in the combustion chamber 110 is relatively stable when the electronically controlled solid propellant is burning. The pressure-stabilizing gas cylinder 310 is also designed with a high-pressure manual ball valve for emergency pressure relief of the tester when the exhaust solenoid valve fails. In addition, a pressure sensor 330 is used to monitor the pressure in the combustion chamber 110 in real time. In order to avoid the influence of high-temperature gas on the pressure sensor 330 as much as possible, the pressure sensor 330 is installed on the side wall of the lower barrel section of the combustion chamber 100.

[0075] A transparent observation window is designed on the side wall of the upper cylinder section of the combustion chamber 110, and the pressure-resistant quartz glass is fixed by a circular flange pressure plate. The observation windows are two circular windows with a diameter of 50 mm, namely the first observation window 140 and the second observation window 150, and the two observation windows are located at 180 degrees.

[0076] The center height of the observation window is located near the hanging position of the electrode disk 510, that is, near the burning surface of the propellant. Through the setting of the observation window, the high-speed camera 610 can be used to record the ignition and extinguishing process of the electric-controlled solid propellant 800, and the ignition and extinguishing characteristics of the electric-controlled solid propellant 800 can be analyzed. In addition, the temperature of the burning surface of the electric-controlled solid propellant 800 can also be measured by using a spectral camera through the optical observation window.

[0077] In order to conduct the test more conveniently, a tooling stand is also designed. The tooling stand is a platform with a round hole in the middle. The diameter of the round hole is 110 mm, which is slightly larger than the diameter of the motor room 120 and smaller than the diameter of the combustion chamber 110. Therefore, the motor room 120 can be placed below the table through the round hole, and the combustion chamber 110 will be placed above the table. The design of this mounting frame can not only fix the test device well, but also put the test device at a height that is convenient for the test personnel to operate.

[0078] The measuring device of the present invention can measure the combustion characteristics of the electric-controlled solid propellant 800 under different pressures and voltages. The average burning rate of the electric-controlled solid propellant 800 under high pressure environment can be measured by the target line method; and other combustion characteristics such as ignition and extinction of the electric-controlled solid propellant 800 under high pressure environment can be measured by the optical diagnosis method.

[0079] Compared with the existing electronically controlled propellant combustion characteristic measuring device, the present invention uses the driving electronically controlled solid propellant 800 to replace the movement of the electrode. While ensuring that the burning surface of the electronically controlled solid propellant is in contact with the electrode disk 510, the position of the burning surface is maintained at the pressure-resistant observation window, and the combustion characteristics of the electronically controlled solid propellant can be studied using optical diagnostic methods.

[0080] In addition, the spring installed on the electrode disk 510 allows the electrode disk 510 to have a certain amount of free movement, thereby compensating for the difference between the motor drive speed and the burning speed of the electronically controlled solid propellant 510, ensuring that the two are in contact at all times and that the force exerted by the electrode on the burning surface is not too large.

[0081] The gap in the electrode disk structure ensures that the optical measurement equipment can observe the electronically controlled propellant combustion process without obstruction.

[0082] In a specific implementation example, the burning rate of a certain electronically controlled solid propellant 800 is measured under a pressure environment of 1 MPa, wherein the electronically controlled combustion voltage is 220 V, and the following steps are included:

[0083] Step 1: A cylindrical electrically controlled solid propellant 800 with a diameter of 10 mm is selected as the object for burning rate measurement. The length of the electrically controlled solid propellant 800 is selected to be 60 mm. Two fusible and conductive lead wires are respectively punched and embedded at the positions of 1 / 3 and 2 / 3 of the propellant sample as target wires 410. It can be seen that the distance between the target wires 410 is X=20 mm. A soft plastic wire tube is used to wrap the part of the lead wire remaining outside the propellant to prevent the lead wire from being melted by the splashing electrically controlled solid propellant 800 component before the burning surface retreats to the lead wire position.

[0084] Step 2: Control the motor 210 to lower the lifting base 240 to the lowest position; fix the electrically controlled solid propellant 800 in the circular boss of the lifting base 240 with fireproof mud to achieve the movement of the propellant at a certain speed driven by the motor 210.

[0085] Step 3: Connect the target wire 410 embedded in the electric-controlled solid propellant 800 to the upper ends of the corresponding four terminals on the lifting base 240, two of which are connected to the first target wire, and the other two terminals are connected to the second target wire; insert the extension wire 420 from the internal threaded column on the side wall of the lower barrel section of the combustion chamber 110, and use bolts to squeeze the polytetrafluoroethylene plug to deform and achieve sealing; connect the extension wire 420 to the lower end of the corresponding target wire terminal on the lifting base 240, and the other end of the extension wire 420 is connected to the target wire power supply 440 and the signal collector 710. Set the target wire power supply 440 to load a voltage of 10V on the two target wires 410 respectively, and the voltage on the two target wires 410 is divided by the voltage divider circuit 430 and enters the collector 710, and the collector 710 is connected to the processor 720. At this time, the voltage collected by the collector 710 is 1V; when the burning surface of the electric-controlled solid propellant 800 retreats to the position of the target line 410, the target line 410 is fused, and the voltage collected by the collector 710 will drop from 1V to 0V, thereby obtaining the time when the electric-controlled solid propellant 800 retreats to the burning surface of the target line 410. The voltage recorded at the time when the two target lines 410 are fused is as follows: Figure 4 shown.

[0086] Step 4: The positive and negative contacts are staggered in the middle of the circular ring of the electrode disk 510. The electrode contacts of the electrode disk are facing downward and installed on the four fixed columns 520 (copper columns) in the upper barrel section of the combustion chamber 110. A spring with the same elastic coefficient is fixed above each installation hole of the electrode disk 510. The positive and negative electrodes of the electrode disk 510 are connected to the positive and negative copper columns through wires, and the extended part of the copper column is connected to the electronically controlled power supply 530 through wires. In this embodiment, 220V DC power supply is used.

[0087] Step 5: After installing the electronically controlled solid propellant 800 , the target wire 410 and the electrode disk 510 , the upper and lower barrel sections are connected by flanges to form a closed combustion chamber 110 .

[0088] Step 6: Install the optical glass of the upper barrel section observation window of the combustion chamber 110, fix the pressure-bearing glass to the upper barrel section observation window through the flange, and paste an optical glass sheet on the inner side of the pressure-bearing optical glass to protect the pressure-bearing glass from being contaminated by the splashing propellant combustion products. Only the optical glass sheet needs to be replaced for the next test. Place the high-speed camera 610 outside the observation window and adjust the appropriate focal length, aperture, exposure time and sampling rate.

[0089] Step seven: Connect the pressure sensor 330 to the side wall of the lower barrel section of the combustion chamber 110 through threads to monitor the pressure in the combustion chamber 110 in real time; connect the intake and exhaust pipes to the combustion chamber, and open the intake solenoid valve and the exhaust solenoid valve for a period of time at the same time, in order to blow out the air in the tester first; after the blowing is completed, close the exhaust solenoid valve, open the intake solenoid valve to fill the combustion chamber with nitrogen of a certain pressure, in this embodiment, 1MPa nitrogen is filled; after the test, release the pressure through the exhaust solenoid valve.

[0090] Step 8: Theoretically estimate the maximum burning rate u of the electronically controlled solid propellant 800 under the current test conditions max =6.5mm / s, theoretically estimated minimum burning speed u min =4mm / s, so the stepper motor movement speed is set to 6.5mm / s, and the difference between the actual burning speed of the propellant and this speed will be compensated by the free movement of the electrode disk 510. The maximum compensation required is Less than the spring stretch G = 55mm, it can ensure that the electrode maintains good contact with the propellant burning surface during the entire test process.

[0091] Turn on the electronic control power supply 530, such as Figure 2 As shown, the stepper motor is controlled to drive the electronically controlled solid propellant 800 to move upward at a set speed; Figure 2 (a) is a schematic diagram of the initial moment. Figure 2 (b) is a schematic diagram of the initial contact between the electronically controlled solid propellant 800 and the electrode disk 510. Figure 2 (c) is a schematic diagram of the state of the electronically controlled solid propellant 800 after burning for a period of time.

[0092] Furthermore, when the electric-controlled solid propellant 800 is about to contact the electrode, the high-speed camera 610 is turned on to take a picture; the electric-controlled solid propellant 800 starts to burn after contacting the electrode contact point, and the burning surface passes through the first target line and the second target line in sequence, such as Figure 2 As shown, the voltage change moments of the first target line and the second target line are obtained in the collector 710 .

[0093] Step 9: In this embodiment, the time when the first target line is disconnected is t1 = 35.56s; the time when the second target line is fused is t2 = 39.11s. It is known that the distance between the two target lines is x = 20mm, then the formula The calculated burning rate of the electronically controlled solid propellant 800 at a pressure of 1 MPa is r = 5.63 mm / s.

[0094] By analyzing the video captured by the high-speed camera 610 frame by frame, the ignition and combustion characteristics of the electronically controlled solid propellant 800 can be obtained. If the power supply is disconnected before the electronically controlled solid propellant 800 is completely burned out, the extinction characteristics of the electronically controlled solid propellant 800 can be obtained.

Claims

1. A high-voltage visual electronically controlled solid propellant combustion characteristics measuring device, characterized in that: It comprises a combustion chamber (110), wherein a first end of the combustion chamber (110) is connected to a motor chamber (120); An electrode disk (510) is disposed at a second end of the combustion chamber (110) away from the motor chamber (120); A motor (210) is installed in the motor chamber (120), the output end of the motor (210) faces the electrode disk (510), and a support rod (230) is provided at the output end of the motor (210), and the other end of the support rod (230) is connected to a lifting base (240); the lifting base (240) extends into the combustion chamber (110) and is used to install an electronically controlled solid propellant (800); An isolation section (130) is provided between the combustion chamber (110) and the motor chamber (120), and the isolation section (130) is dynamically sealed with the support rod (230).

2. A high-voltage visual electronically controlled solid propellant combustion characteristic measuring device as claimed in claim 1, characterized in that: Also included are two target wires (410) axially spaced apart and arranged in the electrically controlled solid propellant (800); Both ends of each target line (410) are respectively connected to different connecting posts on the lifting base (240), and the connecting posts are also connected to an external target line power supply (440) via an extension line (420).

3. A high-voltage visual electronically controlled solid propellant combustion characteristic measuring device as claimed in claim 2, characterized in that: The two target lines (410) run in a direction that intersects with each other.

4. A high-voltage visual electronically controlled solid propellant combustion characteristic measuring device as claimed in claim 2 or 3, characterized in that: The portion of the extension line (410) located inside the combustion chamber (110) is a retractable extension line.

5. A high-voltage visual electronically controlled solid propellant combustion characteristic measuring device as claimed in claim 4, characterized in that: The electrode disk (510) comprises a positive electrode disk and a negative electrode disk that are not in contact with each other; The positive electrode disk extends a positive electrode strip toward the electrically controlled solid propellant (800), and the negative electrode disk extends a negative electrode strip toward the electrically controlled solid propellant (800), and the contacts of the positive electrode strip and the negative electrode strip are located in the same plane and do not contact each other.

6. A high-voltage visual electronically controlled solid propellant combustion characteristic measuring device as claimed in claim 5, characterized in that: The positive electrode disk and the negative electrode disk are both fixedly connected to the second end of the combustion chamber (110) via a fixing column (520).

7. A high-voltage visual electronically controlled solid propellant combustion characteristic measuring device as claimed in claim 6, characterized in that: Adjustment springs are arranged on both ends of the positive electrode disk / negative electrode disk on the fixing column (520); One end of the adjustment spring is fixed to the fixing column (520), and the other end is pressed against the insulating layer of the positive electrode disk / negative electrode disk.

8. A high-voltage visual electronically controlled solid propellant combustion characteristic measuring device as claimed in claim 7, characterized in that: A first observation window (140) is provided on the shell of the combustion chamber (110), and the first observation window (140) and the positive electrode disk / negative electrode disk are both located on the same cross section of the combustion chamber (110).

9. A high-voltage visual electronically controlled solid propellant combustion characteristic measuring device as claimed in claim 8, characterized in that: A portion of the positive electrode disk / negative electrode disk facing the first observation window (140) has a notch.

10. A high-voltage visual electronically controlled solid propellant combustion characteristic measuring device according to any one of claims 5 to 9, characterized in that: The combustion chamber (110) is connected to a pressure supply mechanism.

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