A microwave field-based solid rocket engine thrust regulation system and method

Abstract

A kind of solid rocket engine thrust regulation system and method based on microwave field, including combustion chamber shell, annular heat insulating layer and annular grain are arranged around the inner wall of combustion chamber shell;Empty flow passage is formed in grain;Combustion chamber shell front end outside is connected with waveguide outlet, inside is connected with heat insulating layer and igniter;Igniter is installed in the inner wall of grain;Gas outlet end of combustion chamber shell is sequentially provided with nozzle convergent section, nozzle throat and nozzle divergent section respectively;Pressure sensor, temperature sensor and force sensor are distributed outside nozzle divergent section, and engine performance parameters collected by pressure sensor, temperature sensor and force sensor are transmitted to monitoring terminal by electric signal;Monitoring terminal changes microwave field intensity according to the need of working condition to output electric signal of impedance transformer and microwave power, and realizes the thrust regulation of solid rocket engine.The present application adjusts the size of microwave output according to working condition, and realizes the thrust regulation of solid rocket engine.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rocket engine technology, in particular to a solid rocket engine thrust regulation system and method based on microwave field. BACKGROUND

[0002] The size of the solid rocket engine thrust directly determines the acceleration ability and load capacity of the rocket, and has a key influence on the flight trajectory and flight speed of the rocket. The traditional solid rocket engine cannot stop the propellant combustion process once it is ignited, resulting in the inability to regulate the engine output thrust and limiting its flexibility.

[0003] Currently, the inference adjustment according to the working principle mainly has two ways:

[0004] 1. Change the throat area of the nozzle.

[0005] 2. Control the combustion process of the solid propellant. The way of changing the throat area will cause very serious ablation problem, and is only suitable for engines with low energy content, small size and short working time.

[0006] Therefore, a new technology capable of dynamically adjusting the propellant combustion process has become a research focus. SUMMARY

[0007] In order to overcome the defects existing in the above prior art, the present application provides a solid rocket engine thrust regulation system and method based on microwave field, which feeds microwave energy into the solid rocket engine combustion chamber, uses microwave energy to enhance the combustion of solid propellant, and collects the performance parameters of the solid rocket engine during operation through pressure sensors, temperature sensors and force sensors. The collected data is transmitted to the monitoring terminal, and the monitoring terminal adjusts the microwave output size according to the working condition, so as to realize the thrust regulation of the solid rocket engine. This method can effectively avoid the shortcomings of low combustion efficiency and unstable thrust output of the existing thrust regulation measures.

[0008] In order to achieve the above purpose, the technical scheme adopted by the present application is:

[0009] A solid rocket engine thrust regulation system based on microwave field, comprising a microwave generating device;

[0010] The propellant column of the solid rocket engine is in the form of a ring column with a hollow flow channel, the microwave field generating device is arranged at one end of the hollow flow channel, and the combustion chamber is connected to the other end; the microwave generating device generates microwaves and forms a microwave field in the hollow flow channel;

[0011] The combustion chamber is provided with sensors to monitor the working state of the solid rocket engine. When it is necessary to increase the engine thrust, the microwave field intensity is increased, and when it is necessary to reduce the engine thrust, the microwave field intensity is reduced.

[0012] The combustion chamber comprises a nozzle convergent section, a nozzle throat section and a nozzle divergent section arranged in sequence, and the sensor is arranged in the nozzle divergent section.

[0013] The sensor comprises a pressure sensor, a temperature sensor and a force sensor, and the higher the pressure and temperature and the greater the thrust generated by the engine, the three are interrelated, and the purpose of arranging the three sensors is to improve the detection accuracy and obtain more accurate engine performance.

[0014] The propellant grain is installed in the combustion chamber shell, a heat insulation layer is arranged on the inner wall of the combustion chamber shell, and the igniter is arranged at one end of the hollow flow channel away from the combustion chamber.

[0015] The igniter is arranged around the emission head of the microwave generating device.

[0016] The microwave generating device comprises a microwave power supply, a microwave generator, an impedance transformer and a waveguide; the microwave power supply is a current adjustable power supply, the impedance transformer is arranged at the emission end of the microwave generator, the waveguide is the emission head of the microwave generating device, and is installed at one end of the hollow flow channel away from the combustion chamber, so that the impedance matched microwave is sent into the hollow flow channel.

[0017] In the case of a circular propellant grain, the radius of the initial hollow flow channel is one tenth of the radius of the propellant grain, and other propellant grain types need to be designed according to the specific shape.

[0018] The inner side of the heat insulation layer is in close contact with the propellant grain; the propellant grain adopts a side-burning distribution, and the middle flow channel is distributed with a microwave field with adjustable intensity; the combustion chamber shell is ignited from the inside, and the middle flow channel is distributed with a microwave field with adjustable intensity from the inside to the combustion chamber shell.

[0019] The propellant grain contains aluminum.

[0020] The high-pressure and high-temperature gas generated after the propellant grain burns enters the nozzle throat section through the nozzle convergent section, and then is discharged to the atmosphere through the nozzle divergent section.

[0021] The angle of the divergent section of the nozzle divergent section is 6°-12°.

[0022] The microwave power supply is connected with the microwave generator, the microwave power generated by the magnetic flux tube in the microwave generator is controlled by controlling the output current of the microwave power supply; the microwave outlet of the microwave generator is connected with the inlet of the impedance transformer, and is cooled through a heat exchanger; the impedance transformer is responsible for matching the impedance of the microwave generator and the impedance of the solid rocket engine, so as to provide a wider microwave working range; the outlet of the impedance transformer is connected with the inlet of the waveguide, and the matched microwave enters the solid rocket engine through the waveguide and establishes a microwave field in the flow channel.

[0023] The waveguide is connected to the combustion chamber shell in the following manner:

[0024] If the combustion chamber shell is made of metal, a hole is opened at the connection site to allow the microwave to enter.

[0025] If the combustion chamber shell is made of composite material, no hole is needed.

[0026] Metal reflects microwaves, and composite material can transmit microwaves, so when using metal, a hole needs to be opened to allow the generated microwave plasma to enter the combustion chamber and establish a microwave field.

[0027] A method for regulating the thrust of a solid rocket engine based on a microwave field, comprising the following steps:

[0028] The establishment of the microwave field can be divided into cold start and hot start.

[0029] Cold start microwave field: Before the engine is ignited, the initial microwave field strength is determined according to the working condition requirements, the microwave power supply, microwave generator and impedance transformer are pre-set and started, the generated microwaves enter the engine through the waveguide and establish an initial microwave field in the flow channel; an external microwave source is used to discharge in the resonant cavity to form a suspended plasma, which is reflected by the metal and cannot penetrate the metal. The propellant grain contains aluminum, and a microwave field is established in the flow channel in the middle of the grain.

[0030] Then start the igniter to ignite the propellant grain, make it burn in the microwave field, and collect the real-time working condition of the engine through the pressure sensor, temperature sensor and force sensor and transmit it to the control terminal. The control terminal outputs an electric signal to change the working parameters of the microwave power supply and impedance transformer according to the required thrust change, and then changes the intensity of the microwave field in the engine, realizing the thrust regulation of the solid rocket engine. The output power and impedance of the microwave power supply can affect the intensity of the output microwave plasma, thereby changing the intensity of the microwave field in the flow channel. The greater the power and the smaller the impedance, the higher the intensity of the generated microwave field.

[0031] Hot start microwave field: After the engine is normally ignited and enters the working state, the working performance data of the engine is collected through the pressure sensor, temperature sensor and force sensor distributed on the nozzle expansion section. The collected data is transmitted to the control terminal in the form of an electric signal, and the control terminal sets the working parameters of the microwave power supply and impedance transformer according to the working condition requirements, and starts them through an electric signal. Under the excitation of the microwave power supply, the microwave generator and the heat exchanger enter the working state, the generated microwaves are matched by the impedance transformer and then fed into the working engine combustion chamber through the waveguide, establishing a microwave field. Subsequently, the intensity of the microwave field is adjusted according to the working condition requirements of the engine, realizing the thrust regulation of the solid rocket engine.

[0032] According to actual thrust demand, the microwave power source, the microwave generator, the impedance transformer and the waveguide assembly can be replaced to realize the microwave field in different working ranges.

[0033] The beneficial effects of the present application are:

[0034] The present application feeds microwave energy into the combustion chamber of the solid rocket engine, uses the microwave energy to enhance the combustion of the solid propellant, and collects the performance parameters of the solid rocket engine during operation through the pressure sensor, the temperature sensor and the force sensor, and transmits the collected data to the monitoring terminal, so that the monitoring terminal adjusts the microwave output according to the working condition, thereby realizing the thrust regulation and control of the solid rocket engine. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a schematic diagram of the system structure of the present application.

[0036] In the drawings: 1 - combustion chamber shell, 2 - heat insulation layer, 3 - igniter, 4 - propellant grain, 5 - convergent nozzle section, 6 - nozzle throat, 7 - divergent nozzle section, 8 - pressure sensor, 9 - temperature sensor, 10 - force sensor, 11 - waveguide, 12 - impedance transformer, 13 - heat exchanger, 14 - microwave generator, 15 - microwave power source, 16 - monitoring terminal. DETAILED DESCRIPTION

[0037] The present application will be further described in detail below in combination with the drawings.

[0038] As shown in the drawings, Figure 1 The present application is a solid rocket engine thrust regulation and control system and method based on microwave field. The system comprises a combustion chamber shell 1, a heat insulation layer 2, an igniter 3, a propellant grain 4, a convergent nozzle section 5, a nozzle throat 6, a divergent nozzle section 7, a pressure sensor 8, a temperature sensor 9, a force sensor 10, a waveguide 11, an impedance transformer 12, a heat exchanger 13, a microwave generator 14, a microwave power source 15 and a monitoring terminal 16.

[0039] The outer side of the front end of the combustion chamber shell 1 is connected with the outlet of the waveguide 11, and the inner side of the combustion chamber shell 1 is connected with the heat insulation layer 2 and the igniter 3; the inner side of the heat insulation layer 2 is in close contact with the grain 4; the grain 4 adopts side-burning distribution, and the middle flow passage is distributed with an adjustable intensity microwave field; the right side of the grain 4 is sequentially connected with the convergent nozzle section 5, the nozzle throat 6 and the divergent nozzle section 7. The structure of the grain 4 is a hollow cylinder in the middle, and the hollow part is the flow passage.

[0040] The pressure sensor 8, the temperature sensor 9 and the force sensor 10 distributed outside the nozzle expansion section 7 realize monitoring of the working state of the engine; the pressure sensor 8, the temperature sensor 9 and the force sensor 10 transmit the collected engine performance parameters to the monitoring terminal 16 through electric signals; after the monitoring terminal 16 obtains the current engine real-time working condition, the impedance transformer 12 and the microwave power supply 15 output electric signals according to the working condition requirement, the microwave field intensity is changed, and the thrust control of the solid rocket engine is realized.

[0041] The microwave power supply 15 is connected with the microwave generator 14, the microwave power generated by the magnetic flux tube in the microwave generator 14 is controlled by controlling the output current of the microwave power supply 15; the microwave outlet of the microwave generator 14 is connected with the inlet of the impedance transformer 12, and is cooled through the heat exchanger 13; the impedance transformer 12 is responsible for matching the impedance of the microwave generator 14 and the impedance of the solid rocket engine, so as to provide a wider microwave working range; the outlet of the impedance transformer 12 is connected with the inlet of the waveguide 11, the matched microwave enters the solid rocket engine through the waveguide 11, and the microwave field is established in the flow channel.

[0042] Implementation case one

[0043] In this embodiment, the microwave field is cold start. Firstly, the initial microwave field intensity is determined according to the engine working condition requirement, the microwave power supply 15, the microwave generator 14 and the impedance transformer 12 are pre-set according to the required microwave field intensity, after the setting is completed, the microwave power supply 15 and the impedance transformer 12 are started, so that the microwave generator 14 generates microwave, the heat exchanger 13 enters the working state along with the start of the microwave generator 14, the working temperature of the microwave generator 14 is ensured to be within the bearing range of the magnetic flux tube, the microwave generated by the microwave generator 14 enters the waveguide 11 after being matched and adjusted by the impedance transformer 12, the microwave enters the engine under the constraint of the waveguide 11, and the initial microwave field is established in the flow channel. Subsequently, the igniter 3 is started to ignite the propellant grain 4, the grain 4 starts to burn in the microwave field, the high-temperature and high-pressure gas generated by the burning flows through the nozzle convergent section 5, the nozzle throat 6 and the nozzle expansion section 7 in sequence, and finally is discharged from the engine.

[0044] The pressure, temperature and thrust of the engine exhaust are collected by the pressure sensor 8, the temperature sensor 9 and the force sensor 10 distributed on the nozzle expansion section 7, the obtained data are transmitted to the control terminal 16 in the form of electric signals to monitor the working state of the engine in real time, meanwhile, the control terminal 16 can output electric signals to the microwave power supply 15 and the impedance transformer 12 according to the required thrust change, so as to change the microwave power output by the microwave generator 14, finally the intensity of the microwave field in the engine is changed, and the thrust control of the solid rocket engine is realized.

[0045] Implementation case two

[0046] In this embodiment, the microwave field is hot-started. In this case, the microwave field is started when the engine is in operation. The process is as follows:

[0047] First, the igniter 3 is started, the propellant column 4 is ignited, and the solid rocket engine enters the working state. The high-temperature and high-pressure gas generated by the combustion of the propellant column 4 flows through the convergent section 5 of the nozzle, the throat 6 of the nozzle, and the divergent section 7 of the nozzle in sequence, and is finally discharged from the engine. The pressure sensor 8, the temperature sensor 9, and the force sensor 10 distributed on the divergent section 7 of the nozzle collect the working performance data of the engine, and transmit the collected data to the control terminal 16 through electrical signals. After obtaining the real-time data of the engine, the control terminal 16 sets the working parameters of the microwave power supply 15 and the impedance converter 12 according to the working conditions, and then starts the microwave power supply 15 and the impedance converter 12 through electrical signals. Under the excitation of the microwave power supply 15, the microwave generator 14 and the heat exchanger 13 enter the working state, generate microwaves, match the microwaves through the impedance converter 12, and feed the microwaves into the combustion chamber of the engine that is in operation through the waveguide 11. The fed microwaves interact with the propellant that is burning, promote the generation of free electrons in the balanced flame, make the flame combustion zone generate more plasma, improve the combustion efficiency of the solid propellant, and thus increase the thrust. The subsequent process is the same as that in Case 1, and thus will not be described in detail.

Claims

1. A microwave field-based solid rocket engine thrust regulation system, characterized by, The microwave generating device comprises a microwave power supply, a microwave generator, an impedance transformer and a waveguide. The solid rocket engine comprises a cylindrical grain (4) with a hollow flow channel, the microwave generating device is arranged at one end of the hollow flow channel, and the other end of the hollow flow channel is connected to a combustion chamber. The combustion chamber is provided with sensors to monitor the working state of the solid rocket engine, the microwave field intensity is increased when the engine thrust needs to be increased, and the microwave field intensity is decreased when the engine thrust needs to be decreased. The combustion chamber comprises a convergent nozzle section (5), a nozzle throat (6) and a divergent nozzle section (7) arranged in sequence, and the sensors are arranged in the divergent nozzle section (7). The sensors comprise a pressure sensor (8), a temperature sensor (9) and a force sensor (10), the higher the pressure and the higher the temperature, the greater the engine thrust. The cylindrical grain (4) is installed in a combustion chamber shell (1), a heat insulation layer (2) is arranged on the inner wall of the combustion chamber shell (1), and an igniter (3) is arranged at the end of the hollow flow channel away from the combustion chamber. The igniter (3) is arranged around the emission head of the microwave generating device. The microwave generating device comprises a microwave power supply (15), a microwave generator (14), an impedance transformer (12) and a waveguide (11), the microwave power supply (15) is a current adjustable power supply, the impedance transformer (12) is arranged at the emission end of the microwave generator (14), the waveguide (11) is the emission head of the microwave generating device, is installed at the end of the hollow flow channel away from the combustion chamber, and sends the microwave matched in impedance into the hollow flow channel. When the cylindrical grain (4) is a circular grain, the initial hollow flow channel has a radius of one tenth of the radius of the cylindrical grain (4). The microwave power supply (15) is connected with the microwave generator (14), the microwave power generated by the magnetic flux tube in the microwave generator (14) is controlled by controlling the output current of the microwave power supply (15), the microwave outlet of the microwave generator (14) is connected with the inlet of the impedance transformer (12), and is cooled through a heat exchanger (13), the impedance transformer (12) is responsible for matching the impedance of the microwave generator (14) and the impedance of the solid rocket engine, so as to provide a wider microwave working range, and the outlet of the impedance transformer (12) is connected with the inlet of the waveguide (11), the matched microwave enters the solid rocket engine through the waveguide (11), and a microwave field is established in the flow channel.

2. A microwave field based solid rocket motor thrust regulation system according to claim 1, characterized in that, The inner side of the heat insulation layer (2) is in close contact with the cylindrical grain (4), the cylindrical grain (4) adopts a side-burning distribution, and the middle flow channel is distributed with a microwave field with adjustable intensity. The cylindrical grain (4) contains aluminum. The high-pressure and high-temperature gas generated after the cylindrical grain (4) burns enters the nozzle throat (6) through the convergent nozzle section (5), and then is discharged to the atmosphere through the divergent nozzle section (7).

3. A microwave field based solid rocket motor thrust regulation system according to claim 1, wherein, The angle of the divergent section of the divergent nozzle section (7) is 6°-12°.

4. The microwave field-based solid rocket motor thrust regulation system of claim 1, wherein, The connection mode of the waveguide (11) and the combustion chamber shell (1) is: If the combustion chamber shell (1) is made of metal material, a hole is opened at the connection position to allow the microwave to enter; If the combustion chamber shell (1) is made of composite material, no hole needs to be opened.

5. The method of claim 1-4, wherein the method is a method of regulating the thrust of a solid rocket engine based on a microwave field, characterized in that, The method comprises the following steps: The establishment of microwave field can be divided into cold start and hot start; Cold start microwave field: before the engine is ignited, the initial microwave field intensity is determined according to the working condition requirements, the microwave power supply (15), the microwave generator (14) and the impedance transformer (12) are pre-set and started, the generated microwave enters the engine through the waveguide (11) to establish the initial microwave field in the flow channel; the external microwave source is used to discharge and form suspended plasma in the resonant cavity, the plasma enters the combustion chamber shell (1) and is reflected by the metal, and cannot penetrate the metal, the propellant grain (4) contains aluminum, and the microwave field is established in the flow channel in the middle of the propellant grain (4); Then, the igniter (3) is started to ignite the propellant grain (4), so that it burns in the microwave field, and the real-time working condition of the engine is collected through the pressure sensor (8), the temperature sensor (9) and the force sensor (10) and is transmitted to the control terminal (16), the control terminal (16) outputs an electric signal to change the working parameters of the microwave power supply (15) and the impedance transformer (12) according to the required thrust change, thereby changing the intensity of the microwave field in the engine, and realizing the thrust control of the solid rocket engine; Hot start microwave field: after the engine is normally ignited and enters the working state, the working performance data of the engine is collected through the pressure sensor (8), the temperature sensor (9) and the force sensor (10) distributed on the nozzle expansion section (7), the collected data is transmitted to the control terminal (16) in the form of electric signal, the control terminal (16) sets the working parameters of the microwave power supply (15) and the impedance transformer (12) according to the working condition requirements, and starts through the electric signal, the microwave generator (14) and the heat exchanger (13) enter the working state under the excitation of the microwave power supply (15), the generated microwave is matched through the impedance transformer (12), and then fed into the working engine combustion chamber through the waveguide (11) to establish the microwave field, and the intensity of the microwave field is adjusted according to the working condition requirements of the engine, thereby realizing the thrust control of the solid rocket engine.

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