Pulse plasma thruster based on tooth-shaped propellant

Abstract

The invention relates to a pulse plasma thruster based on a tooth-shaped propellant. The pulse plasma thruster comprises an electrode cathode; the electrode anode is arranged opposite to the electrode cathode; the spark plug is arranged on the electrode cathode; the propellant is positioned between the electrode cathode and the electrode anode; the propellant has a surface facing the electrode cathode and the electrode anode, on which a plurality of notches are formed inside the propellant perpendicular to the surface. According to the thruster, on the premise that the thrust effect of the thruster and the mechanical strength of the propellant are not affected, carbon deposited on the surface of the propellant is cut off by breaking through the notches, short circuit in the thruster is avoided, and therefore the working life is remarkably prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of micro electric thrusters, and in particular relates to a pulsed plasma thruster based on toothed propellant. Background Art

[0002] With the development of modern miniaturized satellite technology, it has become possible to develop smaller and smaller satellites. Micro-nano satellites below 50kg, represented by cubic satellites, have received high attention and have become an important part of the aerospace industry, especially commercial aerospace.

[0003] For micro-nano satellites, a matching miniaturized and highly efficient propulsion system is an important component to extend their lifespan, and can provide power support for tasks such as drag compensation, attitude control, orbit maintenance, and formation flying. As the first electric propulsion system used in orbit, the pulsed plasma thruster is a relatively mature micro-propulsion technology that can be used for micro-nano satellites. Summary of the invention

[0004] However, the applicant has found that the existing pulsed plasma thrusters are prone to carbon deposition on the surface of the propellant after long-term operation, which may lead to ignition failure and end of life, and thus cannot meet the high total impulse requirements. To solve the above problems, the present invention provides the following solutions:

[0005] A pulsed plasma thruster based on toothed propellant, comprising:

[0006] electrode cathode;

[0007] An electrode anode, arranged opposite to the electrode cathode;

[0008] A spark plug, disposed on the electrode cathode;

[0009] a propellant disposed between the electrode cathode and the electrode anode;

[0010] The propellant has a surface facing the electrode cathode and the electrode anode, and a plurality of notches are formed on the surface and inside the propellant perpendicularly to the surface.

[0011] According to one aspect of the present invention, it further includes a charge chamber, wherein the propellant is located in the charge chamber.

[0012] According to one aspect of the present invention, a positioning portion is provided on the electrode anode, and the positioning portion is in contact with the surface of the propellant.

[0013] According to one aspect of the present invention, a spring is further included. The spring is located on a side of the propellant facing away from the surface and applies a force to the propellant toward the cathode of the electrode.

[0014] According to one aspect of the present invention, the propellant comprises tetrafluoroethylene.

[0015] According to one aspect of the present invention, the number of the notches is 2-5.

[0016] According to one aspect of the present invention, the area of ​​all the notches on the plane where the surface is located is less than 10% or 5% of the area of ​​the entire right side surface.

[0017] According to one aspect of the invention, the dimension of each notch in the direction of the propellant perpendicular to the surface is greater than 40%, 50% or 60% of the dimension of the propellant in the dimension perpendicular to the surface.

[0018] According to one aspect of the invention, the dimension of each notch in the direction of the propellant perpendicular to the surface is smaller than 90% or 80% of the dimension of the propellant in the dimension perpendicular to the surface.

[0019] According to one aspect of the invention, the spring is a constant force spring.

[0020] As can be seen from the above, the thruster according to the present invention can significantly improve the service life by opening the slot to cut off the carbon deposited on the surface of the propellant without affecting the thrust effect of the thruster and the mechanical strength of the propellant, thereby avoiding short circuit inside the thruster. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 Schematic diagram of the working principle of pulsed plasma thruster.

[0023] Figure 2 Schematic diagram of carbon deposition in pulsed plasma thruster.

[0024] Figure 3 A three-dimensional view of a pulsed plasma thruster based on toothed propellant of the present invention.

[0025] Figure 4 It is a front cross-sectional view of a pulsed plasma thruster based on toothed propellant of the present invention.

[0026] Figure 5 Schematic diagram of carbon deposition in the pulsed plasma thruster based on toothed propellant of the present invention.

[0027] Figure 6 Schematic diagram of carbon deposition in a pulsed plasma thruster with only a single slot.

[0028] Figure 7 Schematic diagram of carbon deposition in a pulsed plasma thruster with a slot length that is too short.

[0029] Figure 8 Schematic diagram of carbon deposition in a pulsed plasma thruster with an excessively long slot length. DETAILED DESCRIPTION

[0030] In order to better illustrate the purpose and advantages of the present invention, the invention is further described below with reference to the accompanying drawings and examples.

[0031] Figure 1 Figure 1 is a schematic diagram of the working principle of the pulsed plasma thruster. Figure 1 As shown, the cathode and the anode are arranged opposite to each other, and a propellant is arranged between the two. A spark plug is arranged on the cathode. In addition, a spring is arranged to apply a thrust to the propellant in the direction of the cathode and the anode. The cathode and the anode are respectively connected to the positive and negative poles of a DC power supply DC. In addition, an energy storage capacitor is also connected to two poles of the DC power supply.

[0032] Before ignition, there is a high voltage between the electrode cathode and the electrode anode, and the vacuum between the two is not broken down. The spark plug ignites after receiving the pulse ignition signal, generating a small amount of charged particles. The charged particles accelerate toward the two plates under the action of the strong electric field and collide with the surface of the propellant to generate new charged particles. The newly generated charged particles will continue to accelerate toward the two plates under the action of the strong electric field, continue to collide to generate new charged particles, and so on, until there is a large amount of plasma in the discharge area between the two plates, and the two plates of the pulse plasma thruster are broken down, the energy storage capacitor is discharged, and a large current arc discharge is generated along the surface of the propellant. The discharge arc will burn off a very thin layer of the propellant surface and ionize it into plasma. These generated plasmas are ejected outward under the action of the self-induced magnetic field and aerodynamic heat to generate pulse thrust.

[0033] The applicant found that as the thruster works, carbon atoms are generated when the propellant decomposes. Some carbon atoms cannot be ionized and accelerated due to the end of discharge, resulting in carbon deposition on the surface of the propellant. Figure 2 As shown, the carbon atoms that fail to ionize and accelerate will be deposited at the position I shown in the figure. After research and analysis, it was found that the carbon atoms that fail to ionize and accelerate will be deposited at the position I shown in the figure, and the deposited carbon atoms have good conductivity and connect the cathode plate and the anode plate, causing the thruster to short-circuit and fail to work normally, thus affecting its service life.

[0034] To this end, the applicant proposes a pulsed plasma thruster based on toothed propellant of the present invention. Figure 3 A three-dimensional view of a pulsed plasma thruster based on toothed propellant of the present invention. Figure 4 It is a front cross-sectional view of a pulsed plasma thruster based on toothed propellant of the present invention.

[0035] like Figure 3 As shown, the pulsed plasma thruster includes an electrode cathode 1, a spark plug 2, a charge chamber 3, a spring 4, a propellant 5, and an electrode anode 6. The electrode cathode 1 and the motor anode 2 are arranged at a certain distance from each other, and the spark plug 2 is arranged on the electrode cathode 1 as an ignition device. The charge chamber 3 is provided with a propellant 5. The main component of the propellant 5 is tetrafluoroethylene, which can be decomposed to generate plasma. The charge chamber 3 plays a fixing role, and the propellant 5 can be embedded in its internal groove.

[0036] In addition, preferably, a positioning portion or a stopper is also provided on the anode 6, so that the propellant 5 can abut against the stopper or positioning portion with its right side under the thrust of the spring 4, which is preferably a constant force spring. The stopper or positioning portion can be a step portion.

[0037] Figure 4 1 is a front cross-sectional view of a pulsed plasma thruster based on toothed propellant according to the present invention. Figure 4 It can be clearly seen that the propellant 5 is a toothed propellant, that is, it is divided into a plurality of tooth-like parts by at least one notch at one end. This is similar to the teeth in a gear or the teeth in a comb. The toothed propellant is an integral part without a notch at the other end.

[0038] Figure 5 Schematic diagram of carbon deposition in the pulsed plasma thruster based on toothed propellant of the present invention. Figure 3 and Figure 4 It can be seen that, as a preferred example, the number of slots is 3. Figure 5 In the diagram, they are represented by A, B and C respectively. Figure 5 The letter "I" is also used to indicate the location of carbon deposition. When the structure of the present invention is adopted, since the propellant is isolated at the three notches A, B, and C, and the isolation is in a vacuum state, it can be regarded as that the pulse plasma thruster forms a circuit break between the notches A and C, so that the deposited carbon will not affect the next ignition of the pulse plasma thruster, thereby achieving the effect of extending the life of the thruster.

[0039] The applicant has also studied other possible structures of the toothed propellant. Specifically, Figures 6 to 8 As shown, Figure 6Schematic diagram of carbon deposition in a pulsed plasma thruster with only a single slot. Figure 7 Schematic diagram of carbon deposition in a pulsed plasma thruster with a slot length that is too short. Figure 8 Schematic diagram of carbon deposition in a pulsed plasma thruster with an excessively long slot length.

[0040] See also Figure 6 After research, it was found that if the propellant only has one notch at the center of the right surface, the carbon atoms that fail to be ionized and accelerated will be deposited at position I shown in the figure. The deposited carbon atoms have good conductivity, so that the potential of the upper surface of the notch (position A shown in the figure) is the same as that of the cathode plate, and the potential of the lower surface of the notch (position B shown in the figure) is the same as that of the anode plate. Before the spark plug receives the pulse ignition signal, a high voltage exists between the cathode plate and the anode plate, which makes the potential of the upper and lower surfaces of the notch vary greatly, which may cause the vacuum between AB shown in the figure to be broken down, affecting the normal operation of the thruster and thus affecting its service life.

[0041] See also Figure 7 If the length of the slot on the right surface of the propellant is short (3mm in length is used as an example in the figure), a small part of the right surface of the propellant will be burned when the thruster is working, causing the slot length to gradually shorten with the increase in the number of working times, and eventually the length approaches zero. That is, after the thruster works a few times, the propellant is worn flat, causing the thruster to short-circuit in a short time, unable to work normally, and affecting its service life.

[0042] See also Figure 8 If the length of the slot on the right surface of the propellant is long (9.5 mm is used as an example in the figure), the part of the propellant connecting the slots is too thin. Due to the physical effects such as vibration generated by the thruster itself when it is working, the connection may be broken, changing the thrust effect of the constant force spring on the left side of the propellant. It is impossible to ensure that the right side of the propellant can be kept at the electrode anode positioning step of the thruster body, resulting in the thruster not being able to work normally and affecting its service life.

[0043] Based on the above-mentioned multiple embodiments, the present invention proposes that although the specific sizes of each propellant and other working parameters of the propellant may be different, under the basic concept of forming a circuit break by setting a notch as proposed in the present invention, those skilled in the art can set a suitable number and size of the notches according to other conditions recognized by the applicant, such as avoiding affecting the overall structure of the propellant.

[0044] Preferably, the number of the notches may be 2 to 5, preferably 3. In addition, the height of the notches should not be too high, so as to prevent the height of the plurality of notches from affecting the area of ​​the right side surface, i.e., the working surface, of the propellant. For example, the area of ​​all the notches on the plane where the right side surface is located is less than 10% of the area of ​​the entire right side surface, preferably less than 5%.

[0045] In addition, as described above, the dimension of each notch between the left and right surfaces of the propellant is greater than 40%, preferably greater than 50%, preferably greater than 60%, but less than 90%, preferably less than 80% of the dimension between the left and right surfaces of the propellant.

[0046] The above description is merely an exemplary embodiment of the spirit and principle of the present invention. It will be appreciated by those skilled in the art that various changes may be made to the described examples without departing from the spirit and principle, and these changes and their various equivalents are all anticipated by the inventors and fall within the scope defined by the claims of the present invention.

Claims

1. A pulsed plasma thruster based on toothed propellant, comprising: Electrode cathode (1); An electrode anode (6) is arranged opposite to the electrode cathode (1); A spark plug (2) is arranged on the electrode cathode (1); A propellant (5) is located between the electrode cathode (1) and the electrode anode (6); It is characterized in that The propellant has a surface facing the electrode cathode (1) and the electrode anode (6), and a plurality of notches are formed on the surface perpendicularly to the surface inside the propellant.

2. A pulsed plasma thruster based on toothed propellant according to claim 1, characterized in that: It also comprises a charge chamber (3), wherein the propellant is located in the charge chamber.

3. A pulsed plasma thruster based on toothed propellant according to claim 1, characterized in that: The electrode anode (6) is provided with a positioning portion, and the positioning portion is in contact with the surface of the propellant.

4. A pulsed plasma thruster based on toothed propellant according to any one of claims 1 to 3, characterized in that: Also included is a spring (4), which is located on the side of the propellant facing away from the surface and applies a force to the propellant toward the cathode of the electrode.

5. A pulsed plasma thruster based on toothed propellant according to any one of claims 1 to 3, characterized in that: The propellant includes tetrafluoroethylene.

6. A pulsed plasma thruster based on toothed propellant according to any one of claims 1 to 3, characterized in that: The number of the notches is 2-5.

7. A pulsed plasma thruster based on toothed propellant according to any one of claims 1 to 3, characterized in that: The area of ​​all the notches on the plane where the surface is located is less than 10% or 5% of the area of ​​the entire right side surface.

8. A pulsed plasma thruster based on toothed propellant according to any one of claims 1 to 3, characterized in that: Each notch has a dimension of the propellant in a direction perpendicular to the surface that is greater than 40%, 50% or 60% of a dimension of the propellant in a dimension perpendicular to the surface.

9. A pulsed plasma thruster based on toothed propellant according to claim 8, characterized in that: The dimension of each notch in the direction of the propellant perpendicular to the surface is less than 90% or 80% of the dimension of the propellant in the dimension perpendicular to the surface.

10. A pulsed plasma thruster based on toothed propellant according to claim 4, characterized in that: The spring is a constant force spring.

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