A high-pressure visualized electrically-controlled solid propellant combustion characteristic measuring device

Abstract

The application discloses a kind of high-pressure visualization electric control solid propellant combustion characteristic measuring device, including combustion chamber, the first end of combustion chamber is connected with motor chamber;The second end of combustion chamber away from motor chamber is provided with electrode disc;Motor is installed in motor chamber, the output end of motor is towards electrode disc, and the output end of motor is provided with support rod, the other end of support rod is connected with lifting base;Lifting base extends into the inside of combustion chamber, and for installing electric control solid propellant;Insulating section is arranged between combustion chamber and motor chamber, and the dynamic seal of insulating section and support rod;The electric control solid propellant of the application is moved towards electrode disc by motor, can keep the burning surface of electric control solid propellant stable in the same position, so as to facilitate the observation of the combustion condition of electric control solid propellant by external high-speed camera, improve the measurement accuracy of electric control solid propellant.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electrically controlled solid propellant measurement, and particularly relates to a high-pressure visual electrically controlled solid propellant combustion characteristic measurement device. BACKGROUND

[0002] The electrically controlled solid propellant is a new type of solid propellant with electric response characteristics, can realize the combustion of powered propellant and the extinguishment of unpowered propellant, and can control the burning rate of the solid propellant by adjusting the electric field parameters; the electrically controlled solid propellant realizes the control of the combustion process of the solid propellant, and makes the solid rocket engine have the functions of multiple start and thrust adjustment; has broad prospects.

[0003] The electrically controlled solid propellant needs to apply a continuous voltage to the burning surface to maintain the electrolytic combustion of the propellant, and the existing electrically controlled solid propellant combustion characteristic measurement device usually uses a motor to drive the electrode to move in the direction of the retreating of the propellant burning surface at a certain speed, so that the continuous voltage on the propellant burning surface is maintained, and the combustion characteristics of the propellant are measured.

[0004] However, the existing device is only suitable for the measurement of the combustion characteristics of the electrically controlled solid propellant under normal pressure, and if the existing device is used for measurement under high pressure, the entire device needs to be placed in a sealed pressure container, and if the combustion characteristics such as ignition and extinguishment of the electrically controlled solid propellant are measured, the burning surface needs to be observed, and the common method is to design an observation window on the side wall of the pressure container; if the existing device is used for measurement, the position of the propellant burning surface will change constantly, so the observation window needs to have a larger area to cover the entire area of the changing propellant burning surface, but the high-pressure environment limits the area of the observation window to be not too large; at the same time, the position of the burning surface changes in a large area, and the measurement camera also needs to have a larger field of view, but generally a large field of view will result in a lower resolution of the burning surface area, affecting the measurement accuracy; therefore, the existing measurement device is not suitable for the measurement of the electrically controlled solid propellant under high pressure, and the accurate combustion characteristics of the electrically controlled solid propellant cannot be obtained. SUMMARY

[0005] The present application provides a high-pressure visual electrically controlled solid propellant combustion characteristic measurement device, which keeps the burning surface in continuous contact with the electrode and basically unchanged by moving the electrically controlled solid propellant, thereby improving the measurement accuracy of the electrically controlled solid propellant.

[0006] The present application adopts the following technical scheme: a high-pressure visual electrically controlled solid propellant combustion characteristic measurement device, characterized in that it comprises a combustion chamber, and the first end of the combustion chamber is connected with a motor chamber;

[0007] The second end of the combustion chamber away from the motor chamber is provided with an electrode disc;

[0008] A motor is installed in the motor chamber, the output end of the motor faces the electrode disc, and the output end of the motor is provided with a support rod, the other end of the support rod is connected with a lifting base; the lifting base extends into the combustion chamber, and is used for installing the electric control solid propellant;

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

[0010] Further, two target wires are arranged in the electric control solid propellant in an axial interval;

[0011] The two ends of each target wire are respectively connected to different terminal posts on the lifting base, and the terminal posts are connected to an external target wire power supply through an extension line.

[0012] Further, the two target wires intersect with each other.

[0013] Further, the part of the extension line located in the combustion chamber is a telescopic extension line.

[0014] Further, the electrode disc comprises a positive electrode disc and a negative electrode disc which do not contact each other;

[0015] The positive electrode disc extends a positive electrode strip towards the electric control solid propellant, the negative electrode disc extends a negative electrode strip towards the electric control solid propellant, and the electric contact points of the positive electrode strip and the negative electrode strip are located in the same plane and do not contact each other.

[0016] Further, the positive electrode disc and the negative electrode disc are fixedly connected to the second end of the combustion chamber through a fixing column.

[0017] Further, the fixing column is provided with an adjusting spring at both ends of the positive electrode disc / negative electrode disc.

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

[0019] Further, a first observation window is formed in the shell of the combustion chamber, and the first observation window and the positive electrode disc / negative electrode disc are located on the same section of the combustion chamber.

[0020] Further, the part of the positive electrode disc / negative electrode disc facing the first observation window has an opening.

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

[0022] The beneficial effects of the present application are: the electric control solid propellant is driven by the motor to move towards the electrode disc, the burning surface of the electric control solid propellant can be kept stable at the same position, so that the external high-speed camera can observe the burning condition of the electric control solid propellant, and the measurement accuracy of the electric control solid propellant is improved. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 A structure schematic diagram of a high-pressure visualized electrically controlled solid propellant combustion characteristic measuring device according to an embodiment of the present application;

[0024] Figure 2 A state schematic diagram of an electrically controlled solid propellant combustion process according to an embodiment of the present application;

[0025] Figure 3 A structure schematic diagram of an isolation section according to an embodiment of the present application;

[0026] Figure 4 A schematic diagram of a measured target line voltage change according to an embodiment of the present application.

[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 cylinder; 320. Gas source cylinder; 330. Pressure sensor;

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

[0031] 510. Electrode disc; 520. Fixing column; 530. Electrically controlled power supply;

[0032] 610. High-speed camera;

[0033] 710. Collector; 720. Processor;

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

[0035] The present application will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0036] The burning rate is one of the important combustion characteristics of the electrically controlled solid propellant, and the burning rate is defined as the distance of the burning surface of the electrically controlled solid propellant along the normal direction in unit time. The two main factors affecting the burning rate of the electrically controlled solid propellant are the electric field parameter and the environmental pressure. The electrically controlled solid propellant, like most solid propellants, has a burning rate that increases with the increase of the pressure. The relationship between the burning rate and the pressure can be represented by u=a·p n , wherein u is the burning rate, p is the pressure, a is a constant, and n is the pressure index.

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

[0038] As can be seen from the operating characteristics of electrically controlled solid propellants, their combustion characteristics also include ignition and quenching characteristics; similar to burning rate, these combustion characteristics vary under different ambient pressures. Since electrically controlled solid propellants operate in the high-pressure combustion chamber of an engine, obtaining accurate combustion characteristics requires measuring these characteristics under high pressure.

[0039] In this invention, high pressure is relative to atmospheric pressure, specifically referring to atmospheric pressure up to 10 MPa. When the combustion chamber pressure reaches a certain level, existing measurement methods require placing the entire device, along with the motor, in a sealed pressure vessel. This not only results in a very large pressure vessel, but also the high-temperature corrosive gases and small solid particles generated by propellant combustion can significantly impact the lifespan of the motor and moving parts.

[0040] This invention discloses a high-pressure visual electronically controlled solid propellant combustion characteristic measurement device, such as... Figure 1 As shown, the system includes a combustion chamber 110, with a motor chamber 120 connected to the first end of the combustion chamber 110; an electrode disk 510 is provided at the second end of the combustion chamber 110 away from the motor chamber 120; a motor 210 is installed inside the motor chamber 120, with the output end of the motor 210 facing the electrode disk 510, and a support rod 230 is provided at the output end of the motor 210, with the other end of the support rod 230 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 to the support rod 230.

[0041] The present invention uses a motor 210 to drive the electrically controlled solid propellant 800 to move toward the electrode disk 510, which can keep the combustion surface of the electrically controlled solid propellant 800 stable in the same position, thereby facilitating the observation of the combustion of the electrically controlled solid propellant 800 by an external high-speed camera and improving the measurement accuracy of the electrically controlled solid propellant.

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

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

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

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

[0046] In one embodiment, as shown in Figure 3 the center through-hole of the isolation section 130 has a diameter of 10 mm, and the support rod 230 passes through the through-hole, as shown in Figure 3 Y-shaped sealing ring 132 and O-shaped sealing ring 131 are embedded in the side wall of the through-hole from the motor chamber 120 to the combustion chamber 110 to achieve dynamic sealing. The dynamic sealing structure ensures the upward and downward movement of the motor support rod 230 while preventing high-temperature corrosive gas and solid particles from entering the motor chamber.

[0047] The dynamic sealing mainly relies on the Y-shaped sealing ring 132, and the O-shaped sealing ring 131 is more convenient to replace than the Y-shaped sealing ring 132, so the O-shaped sealing ring 131 is used to block the high-temperature combustion gas to protect the Y-shaped sealing ring 132, which is a consumable and needs to be 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, so that the high-temperature corrosive gas and solid particles generated by the combustion of the electrically-controlled solid propellant 800 cannot enter the motor chamber 120 to affect the operation and service life of the motor 210 while reducing the volume of the combustion chamber 110.

[0049] The lifting base 240 is used for fixing the electrically-controlled solid propellant 800 and the target wire 410, and is connected to the supporting rod 230, and is driven by the motor 210 to move towards the electrode disc 510 at a certain speed with the electrically-controlled solid propellant 800, so as to keep the continuous contact between the burning surface of the electrically-controlled solid propellant 800 and the electrode disc 510 during the combustion process of the electrically-controlled solid propellant 800.

[0050] The first observation window 140 is arranged on the shell of the combustion chamber 110, and the first observation window 140 and the positive electrode disc / negative electrode disc are located on the same section of the combustion chamber 110.

[0051] The movement of the electrically-controlled solid propellant replaces the movement of the electrode disc 510 in the application, so that the position of the burning surface is basically kept unchanged, and the combustion characteristics of the electrically-controlled solid propellant 800 can be observed through the fixed-position first observation window 140.

[0052] In the embodiment of the application, the second observation window 150 is also arranged on the shell of the combustion chamber 110 opposite to the first observation window 140, and the second observation window 150 can be used for observing the combustion characteristics of the electrically-controlled solid propellant 800, and can also provide a laser light source for optical diagnosis.

[0053] Specifically, the thickness of the lifting base 230 is 10 mm, the middle part is a 3-mm-high boss, the inside of the boss is hollowed out and the inner diameter is greater than the diameter of the electrically-controlled solid propellant 800, and the electrically-controlled solid propellant 800 is fixed in the boss (i.e. in the inside of the circular ring) by filling fireclay. Meanwhile, the electrically-controlled solid propellant 800 is selected as a cylindrical propellant with a diameter of 10 mm.

[0054] There are four terminal posts (used for connecting the target wire 410) around the circular boss, and adjacent two terminal posts are 90° apart, the terminal post is a threaded rod, and is fixed by two upper and lower nuts and the lifting base 240, and the terminal post and the lifting base 240 are insulated by using a polytetrafluoroethylene gasket.

[0055] The application also comprises two target wires 410 arranged axially and spaced apart in the electrically-controlled solid propellant 800; the two ends of each target wire 410 are connected to different terminal posts on the lifting base 240, and the terminal posts are connected to an external target wire power supply 440 through the extension line 420. The two target wires 410 cross each other.

[0056] The average burning rate of the electrically controlled solid propellant 800 under high pressure environment is measured by the target line method; the optical observation window is designed near the position of the propellant burning surface, and the optical diagnosis method is used to measure the ignition and extinguishment and other combustion characteristics of the electrically controlled solid propellant under high pressure environment.

[0057] The target line 410 is made of metal wire, preferably thin lead wire, and two metal target lines pass through the inside of the electrically controlled solid propellant 800, and the part of the target line 410 outside the electrically controlled solid propellant 800 is wrapped with soft plastic tube to prevent the target line 410 from being melted by the splashed propellant components before the burning surface retreats to the position of the target line 410.

[0058] The upper end of the target line 410 is fixed on the terminal post of the lifting base 230, and the two non-adjacent terminal posts of the same target line 410 are used to make the two target lines 410 form a 90° angle, so that when one target line 410 is melted, it will not fall on the other target line 410.

[0059] The lower end of the target line 410 is fixed on the terminal post of the lifting base 230, and the extension line 420 enters the combustion chamber 110 from the inner threaded post of the side wall of the lower cylinder segment of the combustion chamber 110, and a polytetrafluoroethylene plug is placed in the inner threaded post, and the extension line 420 passes through the polytetrafluoroethylene plug and is compressed by the bolt to make it deform to achieve the sealing effect.

[0060] The part of the extension line 420 inside the combustion chamber 110 is a telescopic extension line. Specifically, the part of the extension line 420 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 target line extension line 420 used in the application is not easy to break and easy to stretch, and the easy-to-break metal target line 410 is relatively static relative to the lifting base 230; the target line extension line 420 has a thick rubber protection to ensure that it will not be damaged by the high-temperature gas in the combustion chamber and the splashed propellant combustion products.

[0062] A certain size of voltage is applied to the target line 410 by the target line power supply 440, the voltage of the target line 410 becomes smaller after passing through the voltage dividing circuit 430 and enters the collector 710, and the change of the voltage 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 disc 510 comprises a positive electrode disc and a negative electrode disc which are not in contact with each other; the positive electrode disc extends a positive electrode strip towards the electrically-controlled solid propellant 800, the negative electrode disc extends a negative electrode strip towards the electrically-controlled solid propellant 800, and the contact points of the positive electrode strip and the negative electrode strip are located in the same plane and are not in contact with each other. The positive electrode disc and the negative electrode disc are fixedly connected to the second end of the combustion chamber 110 through the fixing column 520.

[0064] The electrode disc 510 is a composite structure of a circular annular polytetrafluoroethylene sheet and electrode sheets, wherein the positive and negative electrode strips are embedded in the two circular annular electrode sheets respectively, the electrode sheets are insulated by the polytetrafluoroethylene sheet, and there are a plurality of protruding contact points below the positive and negative electrode strips, which are staggered with each other and contact the propellant combustion surface, so as to form an electric field on the propellant combustion surface.

[0065] In order to better observe the combustion process of the electrically-controlled solid propellant, the portion of the positive electrode disc / negative electrode disc facing the first observation window 140 has an opening. That is, the electrode sheet and the polytetrafluoroethylene sheet are not complete circular annular, and there is an opening of 60° on the electrode disc 510 in the direction of the first observation window 140, and the electrode disc structure is connected by the electrode strips in the middle. The fixing column 520 is provided with an adjusting spring at both ends of the positive electrode disc / negative electrode disc; one end of the adjusting spring is fixed to the fixing column 520, and the other end abuts against the insulating layer of the positive electrode disc / negative electrode disc.

[0066] The electrode disc is suspended in the inner portion of the upper cylinder segment of the combustion chamber 110, and the distance between the electrode disc 510 and the top is 200 mm, which is greater than the flame height of the electrically-controlled solid propellant 800, so as to avoid affecting the combustion of the electrically-controlled solid propellant 800.

[0067] The electrode disc 510 is fixed through the four copper columns (i.e. one form of the fixing column 520) in the inner portion of the upper cylinder segment of the combustion chamber 110.

[0068] A spring with a certain elastic coefficient is fixed above each mounting hole of the electrode disc 510, so that the electrode disc 510 has a certain amount of free displacement, so that the deviation amount of the moving speed of the electrically-controlled solid propellant 800 and the burning rate will be compensated by the extension length of the spring, and the electrically-controlled solid propellant 800 can obtain the estimated maximum burning rate u max and the estimated minimum burning rate u min of the propellant through theoretical estimation before measurement. The stretching length of the spring under the action of the gravity of the electrode disc 510 is G, which should satisfy wherein L is the length of the electrically-controlled solid propellant 800. Specifically, in the present device, the gravity of the electrode disc 510 is 50 N, and the elastic coefficient of the spring is 1.1 N / mm, so the stretching length G is 55 mm.

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

[0070] In the actual measurement process, the motor 210 is set to the maximum estimated burning speed u max The movement, the theoretical estimated burning speed and the actual burning speed deviation u max The spring free displacement amount will be compensated to maintain the continuous contact between the propellant combustion surface and the electrode; and the force between the electrode disc 510 and the propellant combustion surface during the measurement process is equal to the difference between the weight of the electrode disc and the tension of the spring, so that the force acting on the combustion surface will not exceed the weight of the electrode disc 510, thereby avoiding excessive force between the electrode disc 510 and the propellant combustion surface.

[0071] The two fixed columns 520 (usually conductive metal columns) are also used for conducting electricity to the positive and negative electrodes of the electrode disc. The two fixed columns 520 extend to the outside of the upper cylinder segment, and are insulated and sealed with a polytetrafluoroethylene gasket. The two fixed columns are partially insulated by a polytetrafluoroethylene sleeve. The upper ends of the two fixed columns 520 are connected to the positive and negative electrodes of the power supply, and the lower ends of the two fixed columns 520 are connected to the positive and negative electrode discs by wires, so that the positive and negative electrode discs have the same electric field as the electric control burning power supply.

[0072] Because the electric control solid propellant 800 has different burning speed characteristics under different electric field conditions, the electric control burning power supply selects a high-power adjustable direct current power supply with an output voltage of 1-380 V and a maximum output current of 20 A, so as to apply different electric field conditions to the electric control solid propellant 800.

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

[0074] Two threaded interfaces are arranged on the sidewall of the upper cylinder segment of the combustion chamber 110, and are connected with the gas inlet pipeline and the gas outlet pipeline respectively; one end of the gas inlet pipeline is connected with a high-pressure nitrogen gas source bottle 320, a pressure reducing valve and a gas inlet electromagnetic valve in sequence, and is used for filling high-pressure nitrogen gas into the combustion chamber. The other end of the gas outlet pipeline is connected with a four-way joint. One channel of the four-way joint is connected with a gas outlet electromagnetic valve, which is used for remotely controlling the discharge of high-pressure gas in the combustion chamber after the test is completed; one channel of the four-way joint is connected with a pressure relief valve, which can automatically release pressure when the pressure in the combustion chamber 110 exceeds the maximum design pressure; one channel of the four-way joint is connected with a pressure stabilizing gas bottle 310, and the volume of the pressure stabilizing gas bottle 310 is 50L, which can ensure that the pressure in the combustion chamber 110 is relatively stable when the electrically controlled solid propellant burns. A high-pressure manual ball valve is arranged on the pressure stabilizing gas bottle 310, which is used for emergency pressure relief of the tester when the gas outlet electromagnetic 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, the pressure sensor 330 is installed on the sidewall of the lower cylinder segment of the combustion chamber 100.

[0075] A transparent observation window is arranged on the sidewall of the upper cylinder segment of the combustion chamber 110, and a pressure-resistant quartz glass is fixed by a circular flange pressure disc. The observation window is two circular windows with a diameter of 50mm, which are a first observation window 140 and a second observation window 150, and the positions of the two observation windows are 180°.

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

[0077] In order to facilitate the test, a tooling bench is also designed. The tooling bench is a platform with a circular hole in the middle. The diameter of the circular hole is 110mm, which is slightly larger than the diameter of the motor chamber 120 and smaller than the diameter of the combustion chamber 110. Therefore, the motor chamber 120 can pass through the circular hole and be placed below the bench, and the combustion chamber 110 will be placed above the bench. The design of the mounting bracket not only can fix the test device well, but also can make the test device at a height convenient for the operator to operate.

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

[0079] Compared with the prior art, the electrode plate 510 is driven to move instead of the electrode, the burning surface of the electrically-controlled solid propellant 800 is kept in contact with the electrode plate 510, and the burning surface position is kept at the pressure-resistant observation window, so that the burning characteristics of the electrically-controlled solid propellant can be studied by using the optical diagnosis method.

[0080] In addition, the electrode plate 510 is provided with a certain amount of free movement by the spring installed on the electrode plate 510, so as to compensate for the difference between the driving speed of the motor and the burning speed of the electrically-controlled solid propellant 510, to ensure that the two are in contact at all times, and the force of the electrode on the burning surface is not too large.

[0081] The notch on the electrode plate structure can ensure that the optical measurement equipment is not blocked to observe the combustion process of the electrically-controlled solid propellant.

[0082] In a specific embodiment, the burning speed of a certain electrically-controlled solid propellant 800 under a pressure of 1 MPa is measured, the electrically-controlled combustion voltage is 220 V, and the method comprises the following steps:

[0083] Step one: a cylindrical electrically-controlled solid propellant 800 with a diameter of 10 mm is selected as the object of the burning speed measurement, the length of the electrically-controlled solid propellant 800 is 60 mm, two lead wires that are easy to melt and conduct electricity are embedded in the propellant sample at 1 / 3 and 2 / 3 of the length of the propellant sample as target lines 410, so that the distance X between the target lines 410 is 20 mm, and the part of the lead wire outside the propellant that is wrapped with a soft plastic tube is used to prevent the lead wire from being melted by the splashed electrically-controlled solid propellant 800 before the burning surface retreats to the position of the lead wire.

[0084] Step two: the motor 210 is controlled to lower the lifting base 240 to the lowest position; the electrically-controlled solid propellant 800 is fixed in the circular boss of the lifting base 240 with fireproof mortar, so as to realize the movement of the propellant at a certain speed under the driving of the motor 210.

[0085] Step three: connect the target wire 410 embedded in the electrically controlled solid propellant 800 to the upper end of the corresponding four terminal posts on the lifting base 240, two of which are connected to the first target wire and the other two are connected to the second target wire; pass the extension wire 420 through the internal threaded post on the sidewall of the lower cylinder segment of the combustion chamber 110 and seal it by pressing the polytetrafluoroethylene plug with a bolt; connect the extension wire 420 to the lower end of the corresponding target wire terminal post on the lifting base 240, and connect the other end of the extension wire 420 to the target wire power supply 440 and the signal collector 710. Set the target wire power supply 440 to load 10V voltage on the two target wires 410, and the voltage on the two target wires 410 is divided by the voltage dividing circuit 430 and then 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 electrically controlled solid propellant 800 burns and retreats to the position of the target wire 410, the target wire 410 is melted and broken, and the voltage collected by the collector 710 will drop from 1V to 0V, so that the time when the electrically controlled solid propellant 800 retreats to the position of the target wire 410 can be obtained. The voltage recorded at the moment when the two target wires 410 are melted is shown in Figure 4 .

[0086] Step four: the electrode disc 510 has positive and negative electrode contacts distributed in the middle of the circular ring. The electrode disc electrode contacts are installed downward on the four fixed columns 520 (copper columns) in the upper cylinder segment of the combustion chamber 110; each fixed column has a spring with the same elastic coefficient above the electrode disc 510 installation hole; the positive and negative electrodes of the electrode disc 510 are connected to the positive and negative copper columns through wires, and the copper column extension part is connected to the electric power supply 530 through wires. In this embodiment, 220V direct current power supply is used.

[0087] Step five: after the electrically controlled solid propellant 800, the target wire 410 and the electrode disc 510 are installed, the upper and lower cylinder segments are connected through the flanges to form a sealed combustion chamber 110.

[0088] Step six: install the optical glass of the observation window of the upper cylinder segment of the combustion chamber 110, fix the pressure-bearing glass on the observation window of the upper cylinder segment through the flange, and paste an optical glass sheet on the inside of the pressure-bearing optical glass to protect the pressure-bearing from being contaminated by the splashed propellant combustion products. The next time, only the optical glass sheet needs to be replaced. 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: the pressure sensor 330 is screwed on the lower cylinder segment sidewall of the combustion chamber 110 to monitor the pressure in the combustion chamber 110 in real time; the inlet and exhaust pipelines are connected to the combustion chamber, and the inlet and exhaust electromagnetic valves are opened for a period of time to blow out the air in the tester; after the blowing is completed, the exhaust electromagnetic valve is closed, the inlet electromagnetic valve is opened to fill the combustion chamber with nitrogen at a certain pressure, in this embodiment, 1 MPa nitrogen is filled; and the pressure is released through the exhaust electromagnetic valve after the test is completed.

[0090] Step eight: the theoretical maximum burning rate u max of the electric control solid propellant 800 under the current test condition is 6.5 mm / s, and the theoretical minimum burning rate u min is 4 mm / s, so the stepping motor movement speed is set to 6.5 mm / s, and the difference between the actual burning rate of the propellant and the speed is compensated by the free movement amount of the electrode disc 510, and the maximum compensation amount is less than the spring stretching amount G=55 mm, which can ensure that the electrode and the propellant burning surface maintain good contact during the entire test process.

[0091] The electric control power supply 530 is turned on, as shown in Figure 2 , the stepping motor drives the electric control solid propellant 800 to move upwards at a set speed; Figure 2 (a) is a schematic view at the initial moment, Figure 2 (b) is a schematic view of the electric control solid propellant 800 just starting to contact the electrode disc 510, Figure 2 (c) is a schematic view of the state of the electric control solid propellant 800 after burning for a period of time.

[0092] The high-speed camera 610 is turned on to take pictures when the electric control solid propellant 800 is about to contact the electrode; the electric control 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 turn, as shown in Figure 2 , the voltage change moments of the first target line and the second target line are obtained in the collector 710.

[0093] Step nine: in this embodiment, the moment when the first target line is disconnected t1=35.56 s; the moment when the second target line is melted t2=39.11 s, and the distance between the two target lines x=20 mm, so the burning rate r of the electric control solid propellant 800 under the pressure of 1 MPa can be calculated by the formula .

[0094] The video taken by the high-speed camera 610 can be analyzed frame by frame to obtain the ignition and combustion characteristics of the electric control solid propellant 800. If the power is turned off before the electric control solid propellant 800 is completely burned out, the extinguishing characteristics of the electric control solid propellant 800 can be obtained.

Claims

1. A high pressure visualized electrically controlled solid propellant combustion characteristic measuring device, characterized by, The combustion chamber (110) is connected with a motor chamber (120) at a first end thereof; An electrode disc (510) is arranged at a second end of the combustion chamber (110) away from the motor chamber (120); A motor (210) is arranged in the motor chamber (120), and an output end of the motor (210) faces the electrode disc (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 with a lifting base (240); the lifting base (240) extends into the combustion chamber (110), and is used for mounting an electrically-controlled solid propellant (800); A partition section (130) is arranged between the combustion chamber (110) and the motor chamber (120), and the partition section (130) is dynamically sealed with the support rod (230).

2. A high pressure visualized electrically controlled solid propellant combustion characteristic measuring device according to claim 1, wherein Two target wires (410) are arranged in the electrically-controlled solid propellant (800) in an axial direction; Two ends of each of the target wires (410) are respectively connected to different terminal posts on the lifting base (240), and the terminal posts are connected to an external target wire power supply (440) through an extension line (420).

3. A high pressure visualized electrically controlled solid propellant combustion characteristic measuring device according to claim 2, wherein The two target wires (410) cross each other.

4. A high pressure visualized electrically controlled solid propellant combustion characteristic measuring device according to claim 2 or 3, characterized in that, The extension line (420) is a telescopic extension line in the combustion chamber (110).

5. A high pressure visualized electrically controlled solid propellant combustion characteristic measuring device according to claim 4, wherein The electrode disc (510) comprises a positive electrode disc and a negative electrode disc which are not in contact with each other; The positive electrode disc extends a positive electrode strip towards the electrically-controlled solid propellant (800), the negative electrode disc extends a negative electrode strip towards the electrically-controlled solid propellant (800), and the contact points of the positive electrode strip and the negative electrode strip are located in the same plane and are not in contact with each other.

6. A high pressure visualized electrically controlled solid propellant combustion characteristic measuring device according to claim 5, wherein The positive electrode disc and the negative electrode disc are fixedly connected to the second end of the combustion chamber (110) through a fixing column (520).

7. A high pressure visualized electrically controlled solid propellant combustion characteristic measuring device according to claim 6, wherein Adjusting springs are arranged on the fixing column (520) at both ends of the positive electrode disc / negative electrode disc. One end of the adjusting spring is fixed to the fixing column (520), and the other end of the adjusting spring abuts against an insulating layer of the positive electrode disc / negative electrode disc.

8. A high pressure visualized electrically controlled solid propellant combustion characteristic measuring device according to claim 7, wherein A first observation window (140) is arranged on a shell of the combustion chamber (110), and the first observation window (140) and the positive electrode disc / negative electrode disc are located on the same section of the combustion chamber (110).

9. A high pressure visualized electrically controlled solid propellant combustion characteristic measuring device according to claim 8, wherein The positive electrode disc / negative electrode disc has an opening towards the first observation window (140).

10. A high pressure visualized electrically controlled solid propellant combustion characteristics measuring device according to any one of claims 5 to 9, characterized in that, The combustion chamber (110) is connected with a pressure supply mechanism.

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