An experimental system of microwave plasma assisted combustion composite solid propellant

Abstract

A kind of microwave plasma combustion-supporting composite solid propellant experimental system, the inlet and outlet of upper cavity of main combustion chamber pass through inlet and outlet pneumatic ball valve respectively, inlet and outlet solenoid valve are connected with first gas source;The main combustion chamber cavity is divided into two cavities, the upper cavity is ignition chamber, two ignition electrodes are connected with 24V DC power supply through wire respectively;The lower cavity is combustion chamber;A layer of cover plate is placed between the upper and lower two cavities to isolate;Microwave inlet is provided on the main combustion chamber cavity and connected with microwave source;The main combustion chamber cavity of the present application can be compatible with high pressure, microwave environment and ignition, the energy deposition of microwave plasma can greatly improve the effect of solid propellant burning rate, and the burning rate of solid propellant can be controlled in real time by real-time control of microwave source, compared with the existing solid propellant burning rate improvement method in structure has remarkable effect, real-time control and other incomparable advantages.

Description

Technical Field

[0001] The present invention relates to the technical field of solid rocket engines, and in particular to a microwave plasma combustion-assisted composite solid propellant experimental system for solid propellants under normal pressure and high pressure. Background Art

[0002] Solid rocket engines, as the primary power source for modern rockets and missiles, have a wide range of applications. Unlike liquid rocket engines, solid rocket engines use a pre-loaded solid propellant within the combustion chamber. Therefore, the performance of the propellant significantly impacts the performance of the rocket or missile. Furthermore, countries around the world have developed a wide variety of air defense missiles to counter missile attacks. Therefore, how to overcome interception by increasingly sophisticated air defense systems and ensure missile survivability have become challenges in rocket and missile development.

[0003] Microwave plasma can inject energy into composite solid propellants, ultimately forming energy deposition. Therefore, under the same conditions, microwave plasma-assisted combustion of composite solid propellants can significantly increase the burning rate, thereby significantly increasing the instantaneous pressure in the combustion chamber. If this technology is applied to corresponding solid motors, the instantaneous thrust generated by the tail nozzle will also be greatly enhanced, thus showing a promising future in missile penetration. However, there is currently very little research in China on the combustion-assisted effects of microwave plasma on solid propellants. Most current research on solid propellant combustion both domestically and internationally considers using physical or chemical methods to achieve this goal. These methods are generally ineffective and cannot achieve real-time control of the solid propellant's burning rate. For example, patent application publication number CN111440073A discloses a method for synthesizing and applying a burning rate regulator, a method for regulating the burning rate of propellants using energetic materials. However, this method suffers from the drawbacks of uncontrollable regulation and the inability to regulate in real time. Summary of the Invention

[0004] In order to overcome the defects of the above-mentioned prior art, the purpose of the present invention is to provide a microwave plasma combustion-assisted composite solid propellant experimental system, in which the main combustion chamber cavity is compatible with high pressure, microwave environment and ignition, and can explore the combustion enhancement effect of microwave plasma on composite solid propellant, and fill the gap in this research direction in China.

[0005] In order to achieve the above object, the purpose of the present invention is achieved through the following technical solutions:

[0006] A microwave plasma combustion-assisted composite solid propellant experimental system includes a main combustion chamber cavity 1, an air inlet and an air outlet on the main combustion chamber cavity 1 are respectively connected to an air inlet pneumatic ball valve 9 and an air outlet pneumatic ball valve 11; the A\B ports on the air inlet pneumatic ball valve 9 and the air outlet pneumatic ball valve 11 are respectively connected to the corresponding A\B ports on the air inlet solenoid valve 10 and the air outlet solenoid valve 12;

[0007] The P ports on the air inlet solenoid valve 10 and the air outlet solenoid valve 12 are connected to the first air source 5-1 and the second air source 5-2 respectively through the first pressure reducing valve 8-1 and the second pressure reducing valve 8-2;

[0008] The inlet of the air intake pneumatic ball valve 9 is connected to the third air source 5-3 through the supercharger 6 and the third pressure reducing valve 8-3 in sequence; the driving air inlet on the supercharger 6 is connected to the outlet of the air compressor 7;

[0009] The main combustion chamber cavity 1 is divided into two cavities, the upper cavity is the ignition chamber, and the two ignition electrodes are connected to the two terminals of the 24V DC power supply 2 through wires; the lower cavity is the combustion chamber; a cover plate covered with small holes is placed between the upper and lower cavities to isolate them;

[0010] The main combustion chamber cavity 1 is provided with a pressure measuring hole and is connected to a pressure sensor 13. The pressure sensor 13 is connected to a data acquisition port on a Dewesoft data acquisition instrument 14 via a data acquisition line; the signal output end of the Dewesoft data acquisition instrument 14 is connected to a computer 15.

[0011] The main combustion chamber cavity 1 is provided with a microwave inlet connected to the microwave source 3; the cooling water circulation channel on the microwave source 3 is connected to the cooling water inlet and outlet of the chiller 4 through a water pipe; the signal input port on the microwave source 3 is connected to the computer 15.

[0012] The power of the microwave source 3 can be infinitely regulated within the range of 0-3000W.

[0013] The air outlet pneumatic ball valve 11 and the air inlet pneumatic ball valve 9 are normally closed valves.

[0014] The air outlet solenoid valve 12 and the air inlet solenoid valve 10 are two-position five-way reversing valves.

[0015] The pressure sensor 13 is of model Da9420, with an output signal of 1-5V and a measurement range of 0-10MPa.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The method of the present invention uses microwaves to adjust the burning rate of composite solid propellants. The microwaves can be adjusted in real time through a microwave source, and the real-time microwave power and microwave action mode can be adjusted according to different needs. Therefore, it has the advantages of significant control effect and easy real-time adjustment.

[0018] 2. The present invention separates the main combustion cavity into an ignition chamber and a combustion chamber, thereby perfectly solving the problem of the heating wire igniting after microwave injection, thereby affecting normal ignition.

[0019] 3. The present invention is designed with control valves on key gas paths. For example, there is a pressure reducing valve at the gas source interface, and pneumatic ball valves at the air inlet and outlet. Therefore, the on / off of each path can be controlled by a valve, which greatly increases the safety of the experiment. At the same time, when problems occur in the experiment, they can be quickly located and iterated.

[0020] In summary, the present invention significantly increases the burning rate of solid propellants through energy deposition from microwave plasma. This can be controlled in real time by controlling the microwave source, such as by varying microwave power or operating mode. The main combustion chamber cavity of the present invention is compatible with high pressure, microwave environments, and ignition, offering significant innovations in both design and structure. Compared to existing methods for increasing the burning rate of solid propellants, this method offers unparalleled advantages, including significant results and real-time control. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a system principle diagram of the present invention. DETAILED DESCRIPTION

[0022] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that the embodiments of the present disclosure and the features therein can be combined with each other unless they conflict.

[0023] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0024] like Figure 1The microwave plasma combustion-assisted composite solid propellant experimental system includes a main combustion chamber cavity 1, an air inlet and an air outlet on the main combustion chamber cavity 1, which are respectively connected to an air inlet pneumatic ball valve 9 and an air outlet pneumatic ball valve 11. The air inlet pneumatic ball valve 9 and the air outlet pneumatic ball valve 11 are both normally closed valves. When pressurizing the combustion chamber cavity before the experiment, the air inlet pneumatic ball valve 9 is opened, and the air outlet pneumatic ball valve 11 does not operate and remains normally closed. When exhaust gas in the combustion chamber needs to be discharged after the experiment, the air outlet pneumatic ball valve 11 is opened, and the air inlet pneumatic ball valve 9 does not operate and remains normally closed.

[0025] The A\B ports on the air inlet pneumatic ball valve 9 and the air outlet pneumatic ball valve 11 are respectively connected to the corresponding A\B ports on the air inlet solenoid valve 10 and the air outlet solenoid valve 12. When the air inlet solenoid valve 10 and the air outlet solenoid valve 12 are powered on, the gas flows through the A port to the air inlet pneumatic ball valve 9 and the air outlet pneumatic ball valve 11 connected thereto, and pushes the internal ball valve to rotate, thereby opening the gas channel, and then flows out from the B port; when the air inlet solenoid valve 10 and the air outlet solenoid valve 12 are not powered on, the gas is blocked in front of the solenoid valve, and the ball valve inside the air inlet pneumatic ball valve 9 and the air outlet pneumatic ball valve 11 automatically resets and closes the gas channel under the action of spring tension; the P ports on the air inlet solenoid valve 10 and the air outlet solenoid valve 12 are respectively connected to the first air source 5-1 and the second air source 5-2 through the first pressure reducing valve 8-1 and the second pressure reducing valve 8-2. Because the solenoid valve needs to be actuated multiple times and the gas required is only the driving gas, the pressure reducing valve 8 controls the flow of low-pressure gas to the inlet solenoid valve 10 and the outlet solenoid valve 12, which can prevent the solenoid valve from being subjected to excessive impact and extend its service life;

[0026] The inlet of the air intake pneumatic ball valve 9 is connected to the third air source 5-3 through the booster 6 and the third pressure reducing valve 8-3 in sequence. The pressure range required in the experiment is 0~7MPa. Although the air source can be barely supplied when it is sufficient, it is difficult to meet such high-pressure conditions after multiple experiments. Therefore, a booster 6 is connected in series between the air source 5 and the air intake pneumatic ball valve 9. When the initial low-pressure air source enters from the inlet of the booster 6, it is compressed and pressurized by the internal pump, and then flows from the outlet to the inlet of the air intake pneumatic ball valve 9; the three pressure reducing valves are connected to the three air sources respectively; the purpose of this is mainly to reduce the gas pressure and prevent the high-pressure gas directly ejected from the air source 5 from damaging the air intake solenoid valve 10 and the air outlet solenoid valve 12, and it is also for the safety of the experiment;

[0027] The driving air inlet on the supercharger 6 is connected to the outlet of the air compressor 7. The pump inside the supercharger 6 needs to provide a certain driving pressure, so the air compressor 7 compresses the external air to form 0.6MPa driving air to drive the supercharger 6;

[0028] The two ignition electrodes on the main combustion chamber cavity 1 are connected to the two terminals of the 24V DC power supply 2 via wires. One end of the two wires is connected to the two electrodes, and the other end is connected to the two terminals of the 24V DC power supply. When the power is turned on, the heating wire wrapped around the two electrodes inside the combustion chamber cavity will rapidly heat up, igniting the propellant spline connected to it, thus achieving the ignition function.

[0029] The main combustion chamber body 1 is provided with a pressure measuring hole connected to a pressure sensor 13. The burning of the ignited propellant spline within the combustion chamber inevitably causes the pressure within the combustion chamber to rise. Once the spline combustion is complete, the pressure within the combustion chamber will drop again. Therefore, the voltage and current output values ​​of the pressure-sensitive material of the pressure sensor 13 can reflect the pressure changes within the entire combustion chamber, and the combustion time of the propellant spline can be obtained from the time from the pressure rise point to the pressure drop point. The pressure sensor 13 is connected to the data acquisition port of a Dewesoft data acquisition instrument 14 via a data acquisition line. The Dewesoft data acquisition instrument 14 can convert the real-time voltage and current signals of the pressure sensor 13 into a visual pressure image. The signal output terminal of the Dewesoft data acquisition instrument 14 is connected to a computer 15.

[0030] The main combustion chamber cavity 1 is provided with a microwave inlet connected to a microwave source 3. The microwave source can generate microwaves of a specific frequency and power, which are fed into the main combustion chamber cavity 1 via a waveguide, thereby achieving the effect of microwave combustion-supporting propellant. The cooling water circulation channel on the microwave source 3 is connected to the cooling water inlet and outlet of the chiller 4 via a water pipe. The microwave source 3 generates a large amount of heat when in operation. To prevent the microwave source 3 from burning out, a chiller 4 is provided to continuously absorb heat from the microwave source 3, thereby ensuring its normal operation. The signal input port on the microwave source 3 is connected to the computer 15.

[0031] The main combustion chamber cavity 1 is divided into two cavities, the upper cavity is the ignition chamber, used to ignite the solid propellant; the lower cavity is the combustion chamber, used for burning the solid propellant and feeding microwaves; a cover plate covered with small holes is placed between the two cavities to isolate them, and the lower cavity has windows on three sides. The rear window is used for lighting, the front window is used for shooting, and the right window matches the size of the microwave source 3 outlet and is used as the microwave entrance.

[0032] The power of the microwave source 3 can be infinitely regulated within the range of 0-3000W; in addition, it can be regulated to realize two working modes: continuous triggering and pulse triggering.

[0033] The air outlet pneumatic ball valve 11 and the air inlet pneumatic ball valve 9 are normally closed valves.

[0034] The air outlet solenoid valve 12 and the air inlet solenoid valve 10 are two-position five-way reversing valves.

[0035] The pressure sensor 13 is model Da9420, with an output signal of 1-5V and a measurement range of 0-10Mpa.

[0036] The working principle of the present invention is:

[0037] (1) Preliminary propellant loading: Open the upper end cover of the main combustion chamber cavity 1, pass the heating wire through the propellant and wrap it around the two ignition electrodes, use a special polytetrafluoroethylene clamp to clamp the bottom of the propellant on the suspended polytetrafluoroethylene clamping plate and fix it, then close the upper end cover, and finally tighten it with screws to ensure the combustion chamber is sealed.

[0038] (2) Inject gas to simulate a high-pressure environment: Connect the air intake solenoid valve 10 to a 24V DC power supply. After power is turned on, the low-pressure gas reduced by the first pressure reducing valve 8-1 pushes the ball valve inside the air intake pneumatic ball valve 9 to rotate, so that the air intake channel is opened. During this period, the air outlet pneumatic ball valve 11 is kept closed. Then, the air compressor 7 is operated to provide low-pressure driving gas for the supercharger 6. Then, the outlet pressure of the supercharger (that is, the pressure inside the combustion chamber) is set. Wait for the supercharger to continue working so that the entire combustion chamber is filled with high-pressure gas. Finally, the power supply of the air intake solenoid valve 10 is disconnected, the ball valve inside the air intake pneumatic ball valve 9 is reset, and the air intake channel is closed.

[0039] (3) Feeding the microwave environment: First, turn on the chiller 4 to make it work continuously, then turn on the microwave source 3, adjust the three pins on the microwave source to adjust the reflected power of the microwave so that it does not exceed 50% and is as low as possible, wait for the microwave source to work stably, and finally successfully feed the microwave into the main combustion chamber cavity 1.

[0040] (4) Ignition: Under high-voltage and microwave conditions, the propellant needs to be ignited and burned. One end of the two wires is connected to the electrode on the upper end cover of the combustion chamber, and the other end is connected to a 24V DC power supply. After the power is turned on, the heating wire inside the combustion chamber heats up and ignites the propellant spline. At the same time, the pressure measurement curve on the Devesoft is observed, and it is found that the pressure inside the combustion chamber begins to rise.

[0041] (5) Exhaust: Observe the pressure measurement curve. When the pressure curve stops rising and tends to be stable, it indicates that the propellant spline combustion has ended. At this time, connect the outlet solenoid valve 12 to the 24V DC power supply. After power is turned on, the low-pressure gas reduced by the second pressure reducing valve 8-2 pushes the ball valve in the outlet pneumatic ball valve 11 to rotate, so that the outlet channel is opened. During this period, the inlet pneumatic ball valve 9 is kept closed. After the combustion exhaust gas in the combustion chamber is exhausted, one experimental cycle ends.

[0042] This study employs a uniquely designed microwave plasma composite solid propellant combustion-enhancing experimental system. By feeding microwaves into the combustion chamber, microwaves enhance the combustion of composite solid propellants. Compared to traditional methods that influence the propellant's burning rate through various physical and chemical means, microwave combustion-enhancing technology allows for real-time burning rate control by enabling microwaves to be activated at any time. Furthermore, it allows for infinite burning rate control by adjusting the microwave power. This provides a more effective means of propellant combustion enhancement and a novel strategy for missile penetration.

[0043] The embodiments described above are only preferred specific implementations of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A microwave plasma combustion-assisted composite solid propellant experimental system, comprising a main combustion chamber cavity (1), characterized in that: The air inlet and the air outlet on the main combustion chamber cavity (1) are respectively connected to the air inlet pneumatic ball valve (9) and the air outlet pneumatic ball valve (11); the A\B ports on the air inlet pneumatic ball valve (9) and the air outlet pneumatic ball valve (11) are respectively connected to the corresponding A\B ports on the air inlet solenoid valve (10) and the air outlet solenoid valve (12); The respective P ports on the air inlet solenoid valve (10) and the air outlet solenoid valve (12) are connected to the first air source (5-1) and the second air source (5-2) through the first pressure reducing valve (8-1) and the second pressure reducing valve (8-2); The inlet of the air intake pneumatic ball valve (9) is connected to the third air source (5-3) through the supercharger (6) and the third pressure reducing valve (8-3) in sequence; the driving air inlet on the supercharger (6) is connected to the outlet of the air compressor (7); The main combustion chamber cavity (1) is divided into two cavities, the upper cavity being an ignition chamber used for igniting solid propellant, and the two ignition electrodes being connected to the two terminals of a 24V DC power supply (2) via wires; the lower cavity being a combustion chamber used for burning the solid propellant and feeding microwaves; A cover plate covered with small holes is placed between the upper and lower cavities to isolate them. The lower cavity has windows on three sides. The rear window is used for lighting, the front window is used for shooting, and the right window matches the size of the microwave source (3) outlet and is used as a microwave entrance. The main combustion chamber cavity (1) is provided with a pressure measuring hole and is connected to a pressure sensor (13); the pressure sensor (13) is connected to a data acquisition port on a Dewesoft data acquisition instrument (14) via a data acquisition line; the signal output end on the Dewesoft data acquisition instrument (14) is connected to a computer (15); The cooling water circulation channel on the microwave source (3) is connected to the cooling water inlet and outlet on the chiller (4) through a water pipe; and the signal input port on the microwave source (3) is connected to the computer (15).

2. A microwave plasma combustion-assisted composite solid propellant experimental system according to claim 1, characterized in that: The power of the microwave source (3) can be infinitely regulated within the range of 0-3000W.

3. The microwave plasma combustion-assisted composite solid propellant experimental system according to claim 1, characterized in that: The air outlet pneumatic ball valve (11) and the air inlet pneumatic ball valve (9) are normally closed valves.

4. The microwave plasma combustion-assisted composite solid propellant experimental system according to claim 1, characterized in that: The air outlet solenoid valve (12) and the air inlet solenoid valve (10) are two-position five-way reversing valves.

5. The microwave plasma combustion-assisted composite solid propellant experimental system according to claim 1, characterized in that: The pressure sensor (13) is of model Da9420, with an output signal of 1-5V and a measurement range of 0-10MPa.

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