A gel microthruster for spatial thrust regulation

Abstract

The application discloses a gel micro-propeller for space propulsion, which comprises an electrode plate, a sealing ring, a combustion chamber, a nozzle, a threaded connecting port, a feeding port, an anti-backfire channel and a thermal protection layer. The gel micro-propeller has a small volume; the required gel propellant is continuously supplied by an injection pump; the gel propellant is ignited after the electrode plate is electrified; the combustion rate of the gel propellant is regulated by changing the feeding flow of the gel propellant; and the propeller keeps stable work when the flow of the gel propellant is constant. In addition, there is no problem of current wiring in the gel micro-propeller, and the related circuit content is concentrated in a commercialized circuit board. Therefore, the gel micro-propeller is light in weight, convenient to carry, simple in structure and high in maneuverability, and the influence of the problems of a large volume of a previous propeller and complex lines during installation on space micro-nano satellites is eliminated, and the gel micro-propeller is mainly used for precise control of the propulsive force required for attitude adjustment and orbit deviation of space micro-nano satellites.

Description

Technical Field

[0001] This invention belongs to the field of space propulsion, and in particular to a gel micro-propulsion device with adjustable space thrust. Background Technology

[0002] In recent years, with the urgent need for space exploration among various countries, an increasing number of microsatellites and nanosatellites have been launched into space to complete high-standard space missions. This has placed higher demands on the maneuverability and sensitivity of microsatellites and nanosatellites, such as achieving formation flying, orbital deviation, and attitude adjustment technologies. Furthermore, the large number of microsatellites and nanosatellites in space significantly reduces their operational space and may lead to collisions and re-entry accidents due to overlapping orbits. Therefore, developing space propulsion technology is of great significance for space exploration.

[0003] Rocket engines and propellants are the primary power sources for weapons, missiles, manned rockets, and spacecraft. Solid rocket motors are simple in structure and technologically mature, but once ignited, they can only operate continuously until the propellant is completely burned off, and cannot be restarted multiple times. While liquid rocket motors can adjust thrust through throttle valves, their complex structure and high cost, coupled with the susceptibility of liquid propellants to leakage, significantly limit their application. Therefore, researching engines suitable for space propulsion and achieving thrust-adjustable propulsion technology has become one of the goals of space propulsion technology.

[0004] For space propulsion technology, developing small thrust engines and achieving re-ignitionable propellants are currently hot research topics. Propellant formulation design has been introduced in previous literature [Zhang Wei, Li Chuntian, Bao Lirong, et al. A hydroxylamine nitrate-based green pollution-free gel propellant and its preparation method, CN115650808A[P]]. However, there are few reports on small thrusters both domestically and internationally, with little description of the structural design and parameter optimization of micro-thrusters. The size effect and excessive heat loss caused by thruster miniaturization have not been adequately addressed. On the other hand, thruster miniaturization can reduce the payload mass of micro- and nano-satellites, thereby increasing the feasibility of micro- and nano-satellites achieving more functions. Therefore, conducting structural design and optimization of space micro-thrusters, exploring their performance characteristics and environmental adaptability are urgent challenges that need to be overcome in the field of space propulsion. Summary of the Invention

[0005] In view of the current state of research in space propulsion technology, the technical problem to be solved by this invention is to provide a space micro-thruster with precisely adjustable thrust and capable of repeated starts. Under energized conditions, the injection pump controls the flow rate of the gel propellant, thereby changing the propellant combustion rate and achieving adjustable thrust.

[0006] The technical solution to achieve the purpose of this invention is as follows:

[0007] A gel micro-thruster with adjustable spatial thrust is disclosed. The thruster comprises, sequentially arranged, an upper electrode plate, an upper sealing ring, a main body, a lower sealing ring, and a lower electrode plate. A combustion chamber is centrally located within the main body, and a heat protection layer is positioned on one side of the main body. A stainless steel nozzle is mounted outside the heat protection layer. A channel is provided on the heat protection layer, connecting the stainless steel nozzle to the combustion chamber. A backfire prevention channel is provided on the opposite side of the main body, with a feed inlet at its end. The backfire prevention channel in the micro-thruster design suppresses reverse combustion of the thruster within the combustion chamber.

[0008] The combustion chamber has a volume of 10mm × 12mm × 8mm.

[0009] The nozzle of the stainless steel nozzle is equipped with a convergence structure.

[0010] The convergent structure is a convergent nozzle with a convergence angle of 50°, which converges the combustion chamber pressure and increases thrust output.

[0011] The propellant used in the micro-thruster is a gel propellant. The gel propellant is fed using an injection pump; the thrust is precisely controlled by adjusting the volumetric flow rate of the gel propellant using the injection pump.

[0012] Both the upper and lower electrode plates are made of 304 stainless steel. The upper and lower electrode plates serve as the positive and negative electrodes of the micro-thruster, respectively. The electrode plates are used to connect to external current and form a circuit with the gel propellant inside the combustion chamber, causing the gel propellant to burn.

[0013] Both the upper and lower sealing rings are custom-made with Teflon material, which can improve the sealing performance of the gel micro-thruster and enhance its thrust performance.

[0014] The combustion chamber is made of zirconia ceramic, a high-temperature resistant material. By injecting gel propellant into the combustion chamber, the micro-thruster can maintain continuous ignition and output continuous thrust.

[0015] Each component has threaded holes and is tightly connected with fixing screws, allowing for repeated disassembly and reuse, reducing the raw materials consumed in making gel micro-propellers and lowering production costs.

[0016] The various components are fixed together by threads.

[0017] The combustion chamber has a structure of 10mm×12mm×8mm, ensuring that the volume of the combustion chamber is sufficient to generate thrust and that the propeller will not rupture due to excessive pressure.

[0018] The heat protection layer is made of Teflon material to prevent accidents such as cracking of the combustion chamber wall and nozzle due to excessive combustion temperature.

[0019] Compared with the prior art, the present invention has the following significant advantages:

[0020] (1) This invention is made of materials such as stainless steel, zirconium oxide ceramic, and Teflon, and has a simple structure and low cost.

[0021] (2) The present invention uses the propellant cover plate directly as the electrode plate, which increases the electrode area, enhances the combustion efficiency of the gel propellant, and eliminates problems such as internal current wiring.

[0022] (3) The present invention can be disassembled and recycled multiple times, achieving the effect of multiple recovery after one launch, thus improving the efficiency of micro-thrusters.

[0023] (4) The present invention optimizes the structure of the combustion chamber, the anti-backfire channel and the nozzle. The final micro-thruster has high mechanical strength, extends the service life of the micro-thruster, solves the problem of multiple backfires during propellant combustion and outputs reliable thrust.

[0024] (5) The present invention is lightweight and easy to carry, which greatly reduces the load on micro and nano satellites and enables them to perform more functions.

[0025] (6) The present invention can achieve functions such as precise thrust adjustment and repeated ignition.

[0026] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention applied to a space micro-thruster.

[0028] Figure 2 This is a schematic diagram of the electrode plate structure of the present invention applied to a space micro-thruster.

[0029] Figure 3 This is a schematic diagram of the insulation layer structure of the present invention applied to a space micro-thruster.

[0030] Figure 4 This is a schematic diagram of the nozzle structure of the present invention applied to a space micro-thruster.

[0031] Figure 5 This is a schematic diagram of the sealing ring structure of the present invention applied to a space micro-thruster.

[0032] Figure 6 This is a schematic diagram of the combustion chamber and AA cross-sectional structure of the present invention applied to a space micro-thruster.

[0033] Figure 7 This is a schematic diagram of the micro-thruster tested during the design process of this invention and its fracture condition.

[0034] Figure 8 This is a schematic diagram of the micro-thruster's operating state before and after the improvement, showing the backfire phenomenon of the micro-thruster (left) and the improved micro-thruster's operating state (right).

[0035] 1. Upper electrode plate; 2. Upper sealing ring; 3. Main body; 4. Thermal protection layer; 5. Stainless steel nozzle; 6. Fixing screw one; 7. Channel; 8. Lower electrode plate; 9. Lower sealing ring; 10. Combustion chamber; 11. Anti-backfire channel; 12. Fixing screw two; 13. Fixing screw three; 14. Nozzle; 15. Converging structure; 16. Feed inlet. Detailed Implementation

[0036] Combination Figures 1-6 :

[0037] like Figure 1 As shown, the present invention includes an upper electrode plate 1, a lower electrode plate 8, an upper sealing ring 2, a lower sealing ring 9, a combustion chamber 10, a nozzle 5, a feed inlet 16, a backfire prevention channel 11, a heat protection layer 4, and fixing screws 6, 12, and 13. The electrode plates 1 and 8 have four M3 threaded holes for micro-thruster encapsulation. The electrode plates are 40mm long and 36mm wide, with each threaded hole 5mm from both ends and 6mm from both sides. The electrode plates 1 and 8 are fused with Teflon sealing gaskets 2 and 9. The sealing rings are customized according to the position and number of threaded holes on the electrode plates and are machined to have the same shape and position as the combustion chamber. This is to prevent the gaskets from eroding during the combustion of the gel propellant and to connect the electrode plates to the gel propellant circuit within the combustion chamber. The main body 3 of the micro-thruster is made of high-temperature resistant zirconium oxide. This part has a front side, a rear side, an upper side, and a lower side. The front side has two M3×3 threaded holes, 8mm from both ends and 4mm from the upper surface, for connecting the front nozzle. The combustion chamber 10 has dimensions of 10mm × 12mm × 8mm. A converging nozzle with a convergence angle of 50° is designed at the front end of the combustion chamber. A feed inlet 16 and a backfire prevention channel 11 are designed on the rear side. The feed inlet has a diameter of 6mm and a length of 5mm. The backfire prevention channel has a diameter of 2.5mm and a length of 11mm. Four M3 threaded holes are located on the upper and lower sides for tight sealing.

[0038] The insulation layer 4 is made of custom Teflon and has two M3 threaded holes for connecting the combustion chamber and the nozzle, as well as for insulating both. The nozzle 6 is made of custom stainless steel and has a convergent structure with a convergence angle that matches the nozzle convergence angle, which enhances thrust output. It also has two M3 threaded holes for sealing.

[0039] The electrode plate, sealing ring, and combustion chamber are all installed using M3×8 internal hex bolts.

[0040] The nozzle, insulation layer, and combustion chamber are installed using M3×6 flat-head screws.

[0041] This invention utilizes two identical stainless steel electrodes 1 and 8 as cover plates for the micro-thruster, with M3 threaded holes for sealing. Teflon gaskets 2 and 9 are installed under the cover plates for sealing; the shape and size of the Teflon gaskets are customized according to the size of the combustion chamber and the thruster, and M3 threaded holes are also present on the sealing rings for sealing. The combustion chamber 10 is made of high-temperature resistant zirconium oxide, and the combustion chamber nozzle has a converging structure with M3 threaded holes on both sides for sealing. A Teflon insulation layer 7 is designed at the connection between the combustion chamber and the nozzle to prevent the combustion chamber from cracking due to overheating; the Teflon insulation layer also has M3 threaded holes for sealing. The nozzle 14 is made of 304 stainless steel and has a converging structure 15 with a convergence angle of 50° to enhance the thrust of the micro-thruster; M3 threaded holes are also present at the nozzle for sealing. A gel propellant inlet 16 is designed behind the combustion chamber; a backfire prevention channel 11 is designed between the inlet and the combustion chamber.

[0042] To improve the service life of this micro-thruster, its combustion chamber volume is 10mm × 12mm × 8mm. Extensive experiments have shown that when the combustion chamber volume of this micro-thruster is designed to be large, excessive propellant combustion pressure can easily lead to irreversible accidents such as combustion chamber rupture. To optimize the propellant combustion chamber structure, the structural parameters of the propellant combustion chamber used in the experiment are shown in Table 1.

[0043] To reduce the occurrence of backflow of combustion flames in the propeller, this invention specifically designs a backfire prevention channel. Experiments show that when the diameter of the backfire prevention channel is sufficiently small and the length sufficiently long, backfire in the propeller can be effectively prevented. The backfire prevention channel used in this invention has a diameter of 2.5 mm and a length of 11 mm. The structural parameters of the backfire prevention channel used in the experiment are shown in Table 1.

[0044] To enhance the thrust performance of the propulsion unit, a convergent nozzle was added at the combustion chamber port. The convergence angle of the nozzle has a coupling effect on thrust and combustion chamber pressure: if the convergence angle is too small, it can easily lead to excessive combustion chamber pressure and propulsion unit rupture; if the convergence angle is too large, it has no convergence effect on combustion chamber thrust, reducing the thrust performance of the propulsion unit. The optimized nozzle convergence angle of this invention is 50°, and the nozzle structural parameters used in the experiment are shown in Table 1.

[0045] The device operates as follows: After encapsulation, a commercially available circuit board is used as a current control switch to connect the power supply to the end caps of the micro-thruster. The gel propellant is fed by an injection pump at a specific volumetric flow rate. Once the gel propellant enters the combustion chamber, it forms a current loop with the electrode plates, igniting and burning the propellant. During combustion, the anti-backfire channel prevents the propellant from burning backwards into the supply pipe within the combustion chamber, increasing the combustion pressure. Additionally, the converging nozzle further compresses the thrust, both enhancing the thrust performance of the micro-thruster. Finally, the thrust is output through the nozzle. The entire process allows control of the micro-thruster's output thrust by changing the gel propellant's volumetric flow rate. When the micro-thruster stops working, the power is turned off, and the injection pump is shut down. The entire process is controllable in real-time and can be repeatedly ignited.

[0046] Table 1 Structural parameters affecting propulsion operation

[0047]

[0048] Finally, the above examples are merely specific instances of the present invention. Obviously, the present invention is not limited to the above embodiments, and all modifications that can be directly derived or conceived by those skilled in the art from the disclosure of the present invention are considered to be within the scope of protection of the present invention.

Claims

1. A gel micro-propulsion device with adjustable thrust in space, characterized in that: The propulsion unit includes an upper electrode plate, an upper sealing ring, a main body, a lower sealing ring, and a lower electrode plate arranged in sequence; the main body has a combustion chamber in the center, a heat protection layer on one side of the main body, and a stainless steel nozzle on the outside of the heat protection layer. A channel is provided on the heat protection layer to connect the stainless steel nozzle and the combustion chamber; An anti-backflow channel is provided on the opposite side of the main body, and the end of the anti-backflow channel is the feed inlet; The combustion chamber has a volume of 10mm × 12mm × 8mm.

2. The gel micro-thruster for adjustable space thrust according to claim 1, characterized in that: The nozzle of the stainless steel nozzle is equipped with a convergence structure.

3. A gel micro-propulsion device for adjustable space thrust according to claim 2, characterized in that, The convergent structure is a convergent nozzle with a convergence angle of 50°, which converges the combustion chamber pressure and increases thrust output.

4. The gel micro-thruster for adjustable space thrust according to claim 1, characterized in that: The propellant used in the micro-thruster is a gel propellant.

5. The gel micro-thruster for adjustable space thrust according to claim 1, characterized in that: The gel propellant is fed using an injection pump; the thrust is precisely controlled by adjusting the volumetric flow rate of the gel propellant using the injection pump.

6. A gel micro-propulsion device for adjustable space thrust according to claim 1, characterized in that: Both the upper and lower electrode plates are made of 304 stainless steel. The upper and lower electrode plates serve as the positive and negative electrodes of the micro-thruster, respectively. The electrode plates are used to connect to external current and form a circuit with the gel propellant inside the combustion chamber, causing the gel propellant to burn.

7. A gel micro-thruster for adjustable space thrust according to claim 1, characterized in that: Both the upper and lower sealing rings are custom-made with Teflon material, which can improve the sealing performance of the gel micro-thruster and enhance its thrust performance.

8. A gel micro-thruster for adjustable space thrust according to claim 1, characterized in that: The combustion chamber is made of zirconia ceramic, a high-temperature resistant material. By injecting gel propellant into the combustion chamber, the micro-thruster can maintain continuous ignition and output continuous thrust.

9. A gel micro-thruster for adjustable space thrust according to claim 1, characterized in that: The various components are fixed together by threads.

10. A gel micro-thruster for adjustable space thrust according to claim 9, characterized in that: Each component has threaded holes and is tightly connected with fixing screws, allowing for repeated disassembly and reuse, reducing the raw materials consumed in making gel micro-propellers and lowering production costs.

Images