CN112943571B - High specific impulse and high power space propeller based on compact ring plasma - Google Patents

Abstract

The invention relates to a high specific impulse and high power space thruster based on compact ring plasma, which adopts the compact ring plasma as a propellant to form a space thruster with a bell mouth shape. The compact ring plasma thruster has the characteristics of large thrust, high specific impulse, no plume, adjustable specific impulse and thrust and the like, and can be used as one of the technical paths of high specific impulse and high power plasma thrusters; the main machine device of the space thruster consists of a forming area and an accelerating area, wherein the forming area part consists of a solenoid coil, a metal cylindrical inner electrode and a metal cylindrical outer electrode; the accelerating area part is composed of a metal cylindrical outer electrode and a metal hollow conical inner electrode; the design that the shape of the accelerating area is similar to that of a bell mouth reduces the resistance of the compact ring plasma as propellant in the accelerating process, and is beneficial to reducing the conversion of the kinetic energy of the compact ring to the internal energy. The invention is beneficial to solving the problems of low acceleration efficiency, low specific impulse, low power and plume existing in the existing propeller.

Description

A High Specific Impulse and High Power Space Thruster Based on Compact Ring Plasma

technical field

The invention relates to the fields of deep space exploration and aerospace, in particular to a space thruster with high specific impulse and high power based on compact ring plasma.

Background technique

The "China's Science and Technology Development Roadmap to 2050" issued by the Chinese Academy of Sciences proposes to develop basic technologies such as "deep space ultra-high speed and autonomous navigation". The technological breakthrough of high-specific impulse and high-power space thrusters is one of the core technologies for increasing the speed of aircraft and carrying out deep space exploration. At present, the specific impulse range of the propeller is 200s-12000s, and the power range is 12KW-100KW.

The currently used Hall thrusters and ion thrusters have disadvantages such as low thrust, low specific impulse, and plume problems. The compact ring is a high-density self-organized plasmoid generated in the coaxial electrode and accelerated axially. The compact ring can withstand a large electromagnetic force and be accelerated to a high speed state by the electromagnetic force. The current highest speed record is 2500km /s. At present, high-power high-specific impulse plasma thrusters have become a necessary technology for deep space exploration and interstellar navigation.

Therefore, the study of space thrusters with high specific impulse and high power for compact annular plasmas will help to solve the problems of low thrust, low specific impulse, and plumes in existing thrusters.

Contents of the invention

The technical solution of the present invention is to overcome the deficiencies of the existing technology, apply the compact ring plasma technology to the field of deep space exploration technology, provide a high specific impulse and high power space thruster based on the compact ring plasma, and solve the problem of the current thruster Low specific impulse and low acceleration efficiency.

The technical solution of the present invention is as follows: a space thruster with high specific impulse and high power based on compact annular plasma, using compact annular plasma as a propellant to form a space thruster with a trumpet shape.

The space thruster includes a host device and a high-voltage pulse power supply; the host device includes a forming area and an accelerating area; the metal cylindrical inner electrode of the forming area is connected with the metal hollow conical inner electrode of the accelerating area to form a The inner electrode, the inner electrode of the metal cylinder in the formation area and the outer electrode of the metal cylinder are insulated and isolated by a polytetrafluoroethylene cylinder; the outer electrode of the same metal cylinder is used in the formation area and the acceleration area; the acceleration area is composed of a hollow conical inner electrode It is composed of a metal cylindrical outer electrode, and its shape is similar to that of a bell mouth. The hollow conical inner electrode is welded together with the metal cylindrical inner electrode in the forming area, and the metal cylindrical outer electrode is located at the outermost layer of the host device; The design reduces the resistance encountered by the compact ring plasma as a propellant during the acceleration process, and reduces the conversion of the kinetic energy of the compact ring plasma to the internal energy. The current used in the formation zone and the acceleration zone comes from the same high-voltage pulse power supply, so that the More energy is used to accelerate the propellant, improving energy conversion efficiency.

The ratio of the length of the formation zone to the length of the acceleration zone is designed to be 3/7, and the ratio of the radius of the metal hollow conical inner electrode to the end of the metal cylindrical outer electrode is designed to be 1/5, and the acceleration efficiency of the space propeller with the above characteristics is close to 50%, which is beneficial to solve the problem of low acceleration efficiency of existing thrusters.

The specific impulse and power of the space thruster are as follows: the specific impulse is 10,000-50,000s, and the power is 5,000KW-25,000KW, which solves the problems of low specific impulse and low power of current thrusters. Neutral, solves the plume problem that current propellers have.

The forming area includes: solenoid coil, metal ring cover plate, metal cylinder inner electrode, metal ring plate flange, polytetrafluoroethylene cylinder, metal cylinder outer electrode and gas injection window; inside the solenoid coil It is a cylinder made of insulating material, and the coil is wound on the outside; the insulating material of the solenoid coil and the metal ring cover are fixed together, and the metal ring cover and the metal ring plate flange are fixed with screws, and the metal ring The inner electrode of the metal cylinder is welded on the ring cover plate, and the insulated metal ring plate flange at the lower end is covered on the inner electrode of the metal cylinder. One end of the metal ring plate flange is fixed by the polytetrafluoroethylene cylinder and the metal cylinder cover plate. The other end of the ring plate flange is fixed together with the metal ring outer electrode welding plate with screws, and the metal cylindrical outer electrode is welded on the metal ring outer electrode welding plate, and there are several radially distributed electrodes on the metal cylindrical outer electrode The gas injection window, the neutral gas injected through the window will diffuse between the inner electrode of the metal cylinder and the outer electrode of the metal cylinder, and through the ionization and acceleration of the high-voltage pulse power supply, the injected neutral gas will form a dense compact ring plasma.

In the acceleration zone, a metal ring plate flange is welded to the end of the metal cylinder outer electrode, and the metal ring plate flange is used to connect with the test platform or the drift tube during the experimental test.

磁通与主机装置的金属圆柱内电极、金属圆柱外电极之间间距的关系式为

这里

是磁通，B是磁感应强度，R是线圈半径，I_f是形成紧凑环等离子体的成型电流，λ是螺旋度本征值，δ是形成区金属圆柱内、外电极之间的间距。The solenoid coil is insulated from the metal cylinder inner electrode and the metal cylinder outer electrode of the host device, and the length, number of turns, and winding size of the solenoid coil can be determined according to the required magnetic flux and the forming requirements of the compact ring , the relationship between the magnetic flux and the plasma radius of the compact ring is

The relationship between the magnetic flux and the distance between the metal cylinder inner electrode and the metal cylinder outer electrode of the host device is

here

is the magnetic flux, B is the magnetic induction intensity, R is the radius of the coil, I _f is the forming current for forming a compact ring plasma, λ is the eigenvalue of the helicity, and δ is the distance between the inner and outer electrodes of the metal cylinder in the formation area.

A single discharge of the high-voltage pulse power supply satisfies the formation and acceleration of the compact ring plasma in the host device, that is, a single discharge of a single high-voltage pulse power supply can realize the formation and acceleration of the compact ring plasma as a propellant. The adjustment of the power supply voltage realizes the adjustable specific impulse and thrust of the space thruster.

The airtightness of the host device is good, and the host device needs to be evacuated to above 10 ^-4 Pa when in use, and the gas injected into the gas injection window is a high-pressure gas with a purity higher than 99.999% and a pressure range of 0.2-8.0 MPa.

The working principle of the high specific impulse and high power space thruster based on compact ring plasma is as follows:

(a) Firstly, the solenoid coil is energized to generate a poloidal magnetic field, and the gas is injected from the gas injection window between the inner electrode of the metal cylinder and the outer electrode of the metal cylinder;

(b) secondly, trigger the high-voltage pulse power supply, and the high-voltage pulse power supply breaks down between the inner electrode of the metal cylinder and the outer electrode of the metal cylinder and ionizes the gas into a neutral plasma;

(c) The plasma passing through the formation area of the host device becomes a compact ring plasma, which is accelerated by electromagnetic force in the acceleration area, and finally ejected from the bell mouth.

The advantages of the present invention compared with prior art have:

(1) The acceleration zone of the host device of the high-specific impulse and high-power space thruster based on the compact ring plasma of the present invention is composed of a metal hollow conical inner electrode and a metal cylindrical outer electrode, and its shape is similar to that of a bell mouth. The design of this bell mouth shape reduces the resistance encountered by the compact ring plasma as a propellant during the acceleration process, thereby helping to reduce the conversion of the kinetic energy of the compact ring into internal energy, so that more energy can be obtained from the power source It is used to accelerate the propellant and improve the energy conversion efficiency.

(2) The ratio of the formation area to the length of the acceleration area of the host device of the high specific impulse high-power space thruster based on the compact ring plasma of the present invention is 3/7, and the longer design of the acceleration area improves the efficiency of the compact ring as a propellant Accelerate efficiency.

(3) The high-specific impulse and high-power space thruster based on the compact ring plasma of the present invention uses a single discharge of a high-voltage pulse power supply to generate and accelerate the compact ring plasma, thereby increasing the power of the thruster.

(4) The high specific impulse and high power space thruster based on the compact ring plasma of the present invention has the following advantages: (a) large average thrust (>1N); (b) high energy conversion efficiency (>50%); (c) The propellant is quasi-neutral (no plume); (d) the specific impulse is high (10000-50000s).

(5) The high-specific impulse and high-power space thruster based on the compact ring plasma of the present invention can realize the adjustable specific impulse and thrust of the thruster through the adjustment of the high-voltage pulse power supply.

Description of drawings

Fig. 1 is a schematic diagram of the overall structural concept design of the present invention;

2 is a schematic diagram of the overall structure of the host device of the present invention,

FIG. 3 is a schematic cross-sectional structure diagram of the host device of the present invention.

Among them, 1 is the forming area, 2 is the outer electrode of the metal cylinder, 3 is the inner electrode of the metal cylinder, 4 is the solenoid coil, 5 is the filling magnetic field generated by the solenoid coil, 6 is the gas injection window, and 7 is the high-voltage pulse power supply , 8 is the acceleration zone, 9 is the inner electrode of the metal hollow cone, 10 is the poloidal magnetic field of the compact annular plasma, 11 is the annular magnetic field of the compact annular plasma, 12 is the compact annular plasma, and 13 is the metal ring cover 14 is a metal ring plate flange, 15 is a polytetrafluoroethylene cylinder, 16 is a metal cylindrical cover plate, 17 is a metal ring outer electrode welding plate, and 18 is a metal ring plate flange.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

可得到需要外部电源提供160A的电流给螺线管线圈，从而产生

的磁通。同时这种基于紧凑环等离子体设计的具有喇叭口形状的空间推进器比冲在10000～50000s，功率在5000KW-25000KW，解决了当前推进器的比冲低、功率低的问题。此外由于紧凑环等离子体作为推进剂呈准中性，可以解决当前推进器存在的羽流问题。此外，本发明首次将紧凑环等离子体作为大功率等离子体推进器的技术路径之一来解决现有推进器推力小、比冲低、存在羽流的问题。The acceleration region of the host device of the present invention is designed in the shape of a bell mouth to reduce the dissipation of the kinetic energy of the compact ring plasma, so that more energy obtained from the power supply is used to accelerate the compact ring plasma, improving the energy conversion efficiency, The design of this bell mouth shape reduces the resistance encountered by the compact ring plasma as a propellant during the acceleration process, thereby helping to reduce the conversion of kinetic energy of the compact ring plasma into internal energy, so that the energy obtained from the power supply More are used to accelerate the compact ring plasma, thereby improving the energy conversion efficiency. The ratio of the length of the formation zone of the host device to the length of the acceleration zone is designed to be 3/7, the ratio of the radius of the end of the metal hollow cone inner electrode to the metal cylinder outer electrode is designed to be 1/5, and the hollow cone inner electrode and the metal cylinder outer electrode are designed to be 1/5. The acceleration area of the host device composed of electrodes is designed in the shape of a bell mouth. The simulation calculation results show that the acceleration efficiency of the space thruster with the above characteristics is close to 50%, which is beneficial to solve the problem of low acceleration efficiency of the existing thrusters. The solenoid coil is insulated from the metal cylinder inner electrode and the metal cylinder outer electrode of the host device. The designed solenoid coil of the host device has a length of 0.25m and a radius of 0.04m, and is wound with a copper wire with a diameter of 2mm. On the solenoid, it needs to be wound 125 times, and the winding density is: n=500/m. According to the magnetic induction intensity generated by the solenoid coil is 0.1T, using the relationship between the magnetic induction intensity of the solenoid coil and the current:

It can be obtained that an external power supply is required to provide a current of 160A to the solenoid coil, thereby generating

of magnetic flux. At the same time, the trumpet-shaped space thruster based on the compact ring plasma design has a specific impulse of 10,000-50,000s and a power of 5,000KW-25,000KW, which solves the problems of low specific impulse and low power of the current thrusters. In addition, because the compact ring plasma is quasi-neutral as a propellant, it can solve the plume problem existing in current thrusters. In addition, the present invention for the first time uses compact ring plasma as one of the technical paths of high-power plasma thrusters to solve the problems of low thrust, low specific impulse, and plume in existing thrusters.

As shown in Figures 1 and 2, a high-specific-impact high-power space thruster based on a compact ring plasma of the present invention includes two parts, a formation zone 1 and an acceleration zone 8, and a solenoid coil 4 is an insulating material Made into a cylinder with coils wound around the outside. Fix the insulating material of the solenoid coil 4 and the metal ring cover plate 13 together, the metal ring cover plate 13 and the metal ring plate flange 14 are fixed with screws, and the metal ring cover plate 13 is welded with the inner electrode of the metal cylinder 2. The insulated metal ring plate flange 14 at the lower end is covered on the inner electrode 3 of the metal cylinder. One end of the metal ring plate flange 14 is fixed by a polytetrafluoroethylene cylinder 15 and a metal cylinder cover plate 16, and the other end is fixed with a screw. The metal ring outer electrode welding plate 17 is fixed together, and the metal cylinder outer electrode 2 is welded on the metal ring outer electrode welding plate 17, and several radially distributed gas injection windows 6 are opened on the metal cylinder outer electrode 2. The acceleration zone of the host device, which is composed of the metal hollow conical inner electrode 9 and the metal cylindrical outer electrode 2, is similar to the shape of a bell mouth. The metal hollow conical inner electrode 9 in the acceleration area is welded together with the metal cylindrical inner electrode 3 in the formation area, and the metal cylindrical outer electrode 2 is located at the outermost layer of the host device.

The working implementation of the high specific impulse and high power space thruster based on the compact ring plasma of the present invention is as follows:

(1) First, the solenoid coil 4 is energized to generate a filling magnetic field 5 (polar magnetic field), and the gas is injected from the gas injection window 6 between the inner electrode 3 of the metal cylinder and the outer electrode 2 of the metal cylinder;

(2) Next, trigger the high-voltage pulse power supply 7, and the high-voltage pulse power supply 7 breaks down between the metal cylinder inner electrode 3 and the metal cylinder outer electrode 2 and ionizes the gas into a neutral plasma;

(3) The plasma passing through the forming area 1 of the host device becomes a compact ring plasma 12, which is accelerated in the acceleration area 8 under the action of a high-voltage pulse power supply, and finally ejected from the bell mouth.

As shown in Figure 2, the metal ring cover plate 13 and the metal ring plate flange 14 are fixed together by screws, and one end of the metal ring plate flange 14 is fixed to the metal cylindrical cover plate 16 through a polytetrafluoroethylene cylinder 15 , the other end is fixed together with the metal ring outer electrode welding plate 17 by screws, the metal cylinder outer electrode 2 is welded on the metal ring outer electrode welding plate 17, and there are several radially distributed injection holes on the metal cylinder outer electrode 2. Air window6.

As shown in Figure 3, the host device has a solenoid coil 4, the solenoid coil 4 is insulated from the metal cylinder inner electrode 3 and the metal cylinder outer electrode 2, and the solenoid coil 4 and the metal ring are insulated by insulating materials. The cover plate 13 is fixed, and the metal ring cover plate 13 and the metal ring plate flange 14 insulated at the lower end are fixed with screws, the metal cylinder inner electrode 3, and one end of the metal ring plate flange 14 passes through the polytetrafluoroethylene cylinder 15 and the metal ring plate flange 14. The cylindrical cover plate 16 is fixed, and the other end is fixed together with the metal ring outer electrode welding plate 17 by screws. The metal ring outer electrode welding plate 17 is welded with the metal cylindrical outer electrode 2, and there are several Radially distributed gas injection windows 6 . The metal hollow conical inner electrode 9 in the acceleration area is welded together with the metal cylindrical inner electrode 3 in the formation area, and the metal cylindrical outer electrode 2 is located at the outermost layer of the host device. A metal ring plate flange 18 is welded to the end of the metal cylindrical outer electrode 2, and the metal ring plate flange 18 can be used to connect with a test platform or a drift tube during experimental testing, and can also be removed in practical application.

The detailed description of the high-specific-impact high-power space thruster based on compact ring plasma with reference to the above-mentioned embodiments is illustrative rather than restrictive, so changes and modifications without departing from the general concept of the present invention should be Belong to within the protection scope of the present invention.

Claims (8)

1. A space thruster with high specific impulse and high power based on compact annular plasma, characterized in that: compact annular plasma is used as a propellant to form a space thruster with a bell mouth shape; The space thruster includes a host device and a high-voltage pulse power supply; the host device includes a forming area and an accelerating area; the metal cylindrical inner electrode of the forming area is connected with the metal hollow conical inner electrode of the accelerating area to form the The inner electrode, the inner electrode of the metal cylinder in the formation area and the outer electrode of the metal cylinder are insulated and isolated by a polytetrafluoroethylene cylinder; the outer electrode of the same metal cylinder is used in the formation area and the acceleration area; the acceleration area is composed of a hollow conical inner electrode It is composed of metal cylindrical outer electrode, the shape is similar to the shape of the bell mouth, the hollow conical inner electrode is welded together with the metal cylindrical inner electrode in the forming area, and the metal cylindrical outer electrode is located in the outermost layer of the host device, used in the forming area and the accelerating area The current comes from the same high voltage pulsed power supply. 2. The high specific impulse and high power space thruster based on compact ring plasma according to claim 1, characterized in that: the ratio of the length of the formation zone to the length of the acceleration zone is designed to be 3/7, and the metal hollow cone The ratio of the radius of the electrode to the end of the metal cylinder outer electrode is designed to be 1/5, and the acceleration efficiency of the space thruster with the above characteristics is close to 50%. 3. The space thruster with high specific impulse and high power based on compact annular plasma according to claim 1, characterized in that: the specific impulse and power of the space thruster are: the specific impulse is 10000-50000s, and the power is 5000KW -25000KW. 4. The space thruster with high specific impulse and high power based on compact ring plasma according to claim 1, characterized in that: the formation area includes: a solenoid coil, a metal ring cover plate, a metal cylinder inner electrode, Metal ring plate flange, polytetrafluoroethylene cylinder, metal cylinder outer electrode and gas injection window; the inside of the solenoid coil is a cylinder made of insulating material, and the coil is wound outside; the insulating material of the solenoid coil It is fixed together with the metal ring cover plate, the metal ring cover plate and the metal ring plate flange are fixed by screws, the metal ring cover plate is welded with the inner electrode of the metal cylinder, and the metal ring plate flange insulated at the lower end is covered on the metal ring plate flange. On the inner electrode of the cylinder, one end of the flange of the metal ring plate is fixed with the metal cylindrical cover plate through a polytetrafluoroethylene cylinder, and the other end of the flange of the metal ring plate is fixed with the welding plate of the outer electrode of the metal ring by screws. A metal cylinder outer electrode is welded on the metal ring outer electrode welding plate. There are several radially distributed gas injection windows on the metal cylinder outer electrode. Diffusion between the outer electrodes of the cylinder, through the ionization and acceleration of the high-voltage pulse power supply, the injected neutral gas will form a dense compact ring plasma. 5. The high specific impulse and high power space thruster based on compact ring plasma according to claim 1, characterized in that: in the acceleration zone, a metal ring plate flange is welded to the end of the metal cylinder outer electrode, the metal The ring plate flange is used to connect with the test platform or drift tube during the experimental test. 6. The high specific impulse and high power space thruster based on compact ring plasma according to claim 4, characterized in that: between the solenoid coil and the metal cylinder inner electrode and the metal cylinder outer electrode of the host device Insulation, the length, number of turns, and winding size of the solenoid coil are determined according to the required magnetic flux and the forming requirements of the compact toroidal plasma, and the relationship between the magnetic flux and the radius of the compact toroidal plasma is:

The relationship between the magnetic flux and the distance between the metal cylinder inner electrode and the metal cylinder outer electrode of the host device is

is the magnetic flux, B is the magnetic induction intensity, R is the radius of the coil, I _f is the formation current of the compact ring plasma, λ is the eigenvalue of the helicity, and δ is the distance between the inner and outer electrodes of the metal cylinder in the formation area. 7. The high-specific impulse and high-power space thruster based on compact ring plasma according to claim 1, characterized in that: a single discharge of the high-voltage pulse power supply can meet the requirements for the formation of compact ring plasma in the host device. Acceleration, that is, a single discharge of a single high-voltage pulse power supply can realize the formation and acceleration of a compact ring plasma as a propellant. In addition, the specific impulse and thrust of the space thruster can be adjusted by adjusting the voltage of the high-voltage pulse power supply. 8. The space thruster with high specific impulse and high power based on compact annular plasma according to claim 1, characterized in that: when the host device is activated, the host device is evacuated to above 10 ^-4 Pa, and the gas injection window injects The gas used is a high-pressure gas with a purity higher than 99.999% and a pressure range of 0.2 to 8.0 MPa.

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