Single-component micro-thruster based on MEMS

Abstract

The utility model relates to the technical field of micro-thrusters, in particular to a single-component micro-thruster based on an MEMS (micro-electromechanical system), which comprises an air inlet layer body, a spray pipe layer body, a heating layer body and a shell, an air injection through hole is formed in the shell, and the spray pipe layer body, the heating layer body and the air inlet layer body are sequentially stacked in the shell in the direction away from the air injection through hole; the spray pipe layer body is provided with a Laval spray pipe channel, the Laval spray pipe channel penetrates through the two ends of the spray pipe layer body, the Laval spray pipe channel is aligned with and communicated with the air injection through hole, and the axial length of the Laval spray pipe channel is larger than the maximum diameter length of the Laval spray pipe channel. The air inlet layer body is provided with an air inlet flow channel, the air inlet end of the air inlet flow channel is communicated with an air inlet, and the air outlet end of the air inlet flow channel is communicated with the Laval nozzle channel; the heating layer body is used for heating inlet air of the air inlet flow channel to generate jet air, when fluid flows in the Laval nozzle channel, friction and energy loss in the fluid flowing process can be effectively reduced, and the thrust efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of micro-thrusters, in particular to a single-component micro-thruster based on MEMS. Background Art

[0002] With the continuous advancement of aerospace technology, the requirements for spacecraft performance are getting higher and higher, especially the demand for miniaturization of spacecraft. As one of the key technologies to achieve this goal, the development of micro-propulsion system has received widespread attention. The development of micro-electromechanical system (MEMS) technology has provided new possibilities for the design and manufacture of micro-propulsion systems, enabling thrusters to have the advantages of low cost, light weight, small size and high integration.

[0003] In the prior art, the structure of MEMS monocomponent micro-thrusters is mostly planar, resulting in a relatively flat tube-shaped nozzle structure. From the perspective of fluid mechanics, the performance is not as good as a cylindrical tube. Specifically, there is more friction and energy loss when the fluid flows in the nozzle, which makes it difficult to meet applications with high requirements for thrust efficiency.

[0004] Therefore, it is of practical value to study a MEMS monocomponent microthruster with less friction and energy loss when the fluid flows in the nozzle. Utility Model Content

[0005] The utility model aims to provide a single-component micro-thruster based on MEMS to solve the problems of high friction and energy loss when the existing fluid flows in the nozzle.

[0006] In order to solve the above technical problems, the utility model provides a MEMS-based single-component micro-thruster, comprising an air intake layer body, a nozzle layer body, a heating layer body and an outer shell; the outer shell is provided with an air jet through hole, and the nozzle layer body, the heating layer body and the air intake layer body are stacked and arranged in sequence in the outer shell in a direction away from the air jet through hole; the nozzle layer body is provided with a Laval nozzle channel, the Laval nozzle channel runs through both ends of the nozzle layer body, the Laval nozzle channel is aligned with and connected to the air jet through hole, and the axial length of the Laval nozzle channel is greater than the maximum diameter length of the Laval nozzle channel; the air intake layer body is provided with an air intake flow channel, the air intake end of the air intake flow channel is connected to an air inlet, and the air outlet end of the air intake flow channel is connected to the Laval nozzle channel; the heating layer body is used to heat the air intake of the air intake flow channel to generate a jet.

[0007] In one of the embodiments, the Laval nozzle channel includes a convergent pipe section and an expandable pipe section that are interconnected; the convergent pipe section and the expandable pipe section are arranged in sequence along the direction adjacent to the jet through hole; along the direction adjacent to the jet through hole, the diameter length of the convergent pipe section gradually decreases, and the diameter length of the expandable pipe section gradually increases.

[0008] In one of the embodiments, the jet inlet wall surface of the contraction duct section is transitionally connected to the outlet end wall surface of the inlet flow channel.

[0009] In one of the embodiments, the ratio of the maximum diameter of the contraction duct segment, the minimum diameter of the contraction duct segment, and the axial length of the contraction duct segment is 1:0.18:0.77 to 1:0.2:0.8.

[0010] In one embodiment, the axial length of the expansion pipe segment is greater than the maximum diameter length of the expansion pipe segment.

[0011] In one embodiment, the ratio of the maximum diameter of the expansion pipe segment, the minimum diameter of the expansion pipe segment and the axial length of the expansion pipe segment is 1.8:0.18:2.23 to 2:0.2:2.25.

[0012] In one embodiment, the maximum diameter of the contracting pipe section is smaller than the maximum diameter of the expanding pipe section.

[0013] In one of the embodiments, the intake air passage is a symmetrical air passage, and an inner wall of the intake air passage is coated with an iridium layer.

[0014] In one of the embodiments, the monopropellant micro-thruster further includes a heat insulation layer; the heat insulation layer is disposed between the air intake layer and the outer shell.

[0015] In one of the embodiments, the monopropellant micro-thruster further includes a sealing ring; the outer shell includes a first shell and a second shell; the first shell is threadedly connected to the second shell, and the second shell is provided with the jet through hole; the sealing ring is clamped between the second shell and the nozzle layer.

[0016] The beneficial effects of the utility model are as follows:

[0017] Since the nozzle layer is provided with a Laval nozzle channel, the Laval nozzle channel runs through both ends of the nozzle layer, the Laval nozzle channel is aligned with and connected to the jet through hole, the axial length of the Laval nozzle channel is greater than the maximum diameter length of the Laval nozzle channel, and the outlet end of the inlet flow channel is connected to the Laval nozzle channel, so when it is used, the gas in the inlet flow channel flows to the Laval nozzle channel after being heated. Since the axial length of the Laval nozzle channel is greater than the maximum diameter length of the Laval nozzle channel, when the fluid flows in the Laval nozzle channel, the friction and energy loss in the fluid flow can be effectively reduced, thereby improving the thrust efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of the overall structure provided by the preferred embodiment of the utility model;

[0020] Figure 2 It is an exploded schematic diagram of the overall structure provided by the preferred embodiment of the utility model;

[0021] Figure 3 This is a schematic diagram of the overall structure provided by the preferred embodiment of the utility model. Figure 1 ;

[0022] Figure 4 This is a schematic diagram of the overall structure provided by the preferred embodiment of the utility model. Figure 2 ;

[0023] Figure 5 It is a schematic cross-sectional view of the air intake layer provided in the preferred embodiment of the utility model.

[0024] The reference numerals are as follows:

[0025] 1. air intake layer; 10. air intake channel; 2. nozzle layer; 20. Laval nozzle channel; 200. contraction pipeline section; 201. expansion pipeline section; 3. heating layer; 4. heat insulation layer; 5. shell; 50. first shell; 500. air intake port; 51. second shell; 510. jet through hole; 6. sealing ring; DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0027] In order to solve the above problems, this scheme proposes a single-component micro-thruster based on MEMS, please refer to Figures 1 to 5 , comprising an air intake layer 1, a nozzle layer 2, a heating layer 3 and a shell 5; the shell 5 is provided with an air jet through hole 510, and in the direction away from the air jet through hole 510, the nozzle layer 2, the heating layer 3 and the air intake layer 1 are stacked in sequence in the shell 5; the nozzle layer 2 is provided with a Laval nozzle channel 20, the Laval nozzle channel 20 runs through both ends of the nozzle layer 2, the Laval nozzle channel 20 is aligned with and connected to the air jet through hole 510, and the axial length of the Laval nozzle channel 20 is greater than the maximum diameter length of the Laval nozzle channel 20; the air intake layer 1 is provided with an air intake flow channel 1 0, the air inlet end of the air inlet flow channel 10 is connected to the air inlet port 500, and the air outlet end of the air inlet flow channel 10 is connected to the Laval nozzle channel 20; the heating layer 3 is used to heat the air in the air inlet flow channel 10 to generate a jet. When used, nitrous oxide (N2O) is used as a propellant, which can be decomposed under the action of a catalyst and high temperature, and the reaction is exothermic and self-sustaining decomposition, thereby achieving specific impulse and thrust enhancement and saving energy. The nitrous oxide gas enters the air inlet flow channel 10 from the air inlet port 500, is heated by the reaction of the heating layer 3, and is finally ejected through the Laval nozzle channel 20.

[0028] After adopting this setting, since the axial length of the Laval nozzle channel 20 is greater than the maximum diameter length of the Laval nozzle channel 20, when the fluid flows in the Laval nozzle channel 20, the friction and energy loss in the fluid flow can be effectively reduced, thereby improving the thrust efficiency; and the MEMS process enables the thruster to have the advantages of low cost, light weight, small size and high integration.

[0029] Regarding the above-mentioned nozzle layer 2, as Figure 3 and Figure 4 As shown, a Laval nozzle channel 20 passing through both ends is provided in the nozzle layer 2, and the Laval nozzle channel 20 includes a convergent pipe section 200 and an expandable pipe section 201 which are interconnected; the convergent pipe section 200 and the expandable pipe section 201 are arranged in sequence along the direction adjacent to the jet through hole 510; along the direction adjacent to the jet through hole 510, the diameter length of the convergent pipe section 200 gradually decreases, and the diameter length of the expandable pipe section 201 gradually increases. After adopting this arrangement, the Laval nozzle channel 20 which first contracts and then expands can achieve supersonic fluid.

[0030] Furthermore, in order to reduce friction or interference with the airflow, e.g. Figure 3 and Figure 4As shown, the maximum diameter of the contraction pipe section 200 is smaller than the maximum diameter of the expansion pipe section 201. After adopting this setting, the airflow enters the contraction pipe section 200 and is continuously accelerated. The airflow is ejected backward when passing through the narrow throat. When the maximum diameter of the expansion pipe section 201 is larger than the maximum diameter of the contraction pipe section 200, the friction or interference of the ejected airflow is greatly reduced.

[0031] For the contraction duct section 200, if Figure 3 and Figure 4 As shown, the jet inlet wall of the contraction duct section 200 is transitionally connected to the outlet end wall surface of the inlet flow channel 10. After adopting this setting, the gas flowing out of the inlet flow channel 10 can enter the jet inlet of the contraction duct section 200 with minimal loss, avoiding obstruction or interference of the wall to the gas.

[0032] Furthermore, the ratio of the maximum diameter of the contraction pipe section 200, the minimum diameter of the contraction pipe section 200, and the axial length of the contraction pipe section 200 is 1:0.18:0.77 to 1:0.2:0.8.

[0033] Preferably, the ratio of the maximum diameter of the contraction duct segment 200, the minimum diameter of the contraction duct segment 200, and the axial length of the contraction duct segment 200 is 1:0.18:0.77.

[0034] Exemplarily, the maximum diameter of the contraction duct segment 200 is 1 mm, the minimum diameter of the contraction duct segment 200 is 0.18 mm, and the axial length of the contraction duct segment 200 is 0.77 mm.

[0035] For the expansion pipe section 201, if Figure 3 and Figure 4 As shown, the axial length of the expansion pipe section 201 is greater than the maximum diameter length of the expansion pipe section 201. After adopting this setting, the expansion pipe section 201 can reduce the friction and energy loss of the fluid during flow and improve the thrust efficiency.

[0036] Furthermore, the ratio of the maximum diameter of the expansion pipe segment 201, the minimum diameter of the expansion pipe segment 201, and the axial length of the expansion pipe segment 201 is 1.8:0.18:2.23 to 2:0.2:2.25.

[0037] Preferably, the ratio of the maximum diameter of the expansion pipe segment 201, the minimum diameter of the expansion pipe segment 201 and the axial length of the expansion pipe segment 201 is 1.8:0.18:2.23.

[0038] Exemplarily, the maximum diameter of the expansion tube segment 201 is 1.8 mm, the minimum diameter of the expansion tube segment 201 is 0.18 mm, and the axial length of the expansion tube segment 201 is 2.23 mm.

[0039] Regarding the above-mentioned air intake layer 1, Figure 1 , Figure 2 and Figure 5 As shown, an inlet flow channel 10 is provided in the inlet layer 1, the inlet end of the inlet flow channel 10 is connected to the inlet port 500 on the outer shell 5, and the outlet end of the inlet flow channel 10 is connected to the Laval nozzle channel 20. When used, the gas in the inlet flow channel 10 can be heated to achieve the final injection.

[0040] For the intake flow passage 10, if Figure 5 As shown, the expanded intake flow channel 10 is a symmetrical flow channel, that is, the intake end and the outlet end are arranged on the same axis, and the flow channel is symmetrically arranged relative to the axis. The inner wall of the intake flow channel 10 is coated with an iridium layer used as a catalyst. When in use, the intake flow channel 10 is connected to a nitrous oxide (N2O) device, which can be decomposed under the action of the catalyst and high temperature. The reaction is exothermic and self-sustaining decomposition, thereby achieving an increase in specific impulse and thrust and saving energy.

[0041] Exemplarily, the flow channel is formed by bonding two silicon wafers, one of which is 0.5 mm thick and has a 0.3 mm flow channel etched on the surface, and the shape of the flow channel is symmetrical; the other is 0.2 mm thick and has a 1 mm through hole etched in the center.

[0042] Regarding the above-mentioned heating layer 3, as Figure 2 As shown, the heating layer 3 is a heating wire, which is deposited on the circular surface of the air intake layer 1 , and voltage is applied to both ends of the heating wire, so that the heating wire can provide heat to the air intake passage 10 .

[0043] To prevent heat from escaping, Figure 2 , Figure 3 and Figure 4 As shown, the monocomponent micro-thruster also includes an insulating layer 4; the insulating layer 4 is arranged between the air intake layer 1 and the inner end surface of the outer shell 5. After adopting this arrangement, the heat of the air intake layer 1 heated by the heating layer 3 is isolated by the insulating layer 4, and the heat cannot be transferred to the bottom of the outer shell 5 and cannot overflow to affect other electronic equipment.

[0044] Preferably, the thermal insulation layer 4 includes but is not limited to an aerogel body, and the size of the aerogel body is 9 mm in diameter and 1 mm in thickness.

[0045] Regarding the above-mentioned housing 5, as Figures 1 to 4As shown, the shell 5 includes a first shell 50 and a second shell 51; the first shell 50 is threadedly connected with the second shell 51, the first shell 50 is provided with an air inlet 500 connected with the inlet flow channel 10, and electrode step holes on both sides for connecting the heating wire, and the second shell 51 is provided with an air injection hole 510; the sealing ring 6 is clamped between the second shell 51 and the nozzle layer 2. After adopting this setting method, when the second shell 51 is threadedly connected to the first shell 50, the sealing degree of the sealing ring 6 can be adjusted by adjusting the depth of the threading.

[0046] In order to achieve a more compact layout, such as Figure 1 As shown, the size of the entire thruster is approximately 13 mm in diameter and 7 mm in height, that is, the overall configuration of the thruster is a vertical configuration, making the layout more compact.

[0047] Specifically, a mounting groove with a depth of 0.8 mm and a width of 1 mm is provided on the circumference of the nozzle layer 2 , and the sealing ring 6 is installed in the mounting groove. When the first shell 50 is screwed with the second shell 51 , the sealing ring 6 is clamped and sealed by the second shell 51 and the nozzle layer 2 .

[0048] Exemplarily, there are 4 M1 threaded holes on the first shell 50, which are equally spaced apart, and the holes pass through the outer shell 5 for connection with the satellite substrate; there are two symmetrically distributed step holes on the side wall of the first shell 50, with diameters of 2 mm and 1 mm respectively; there is also a 1 mm diameter air inlet 500 on the side wall of the first shell 50, which is perpendicular to the straight line where the axes of the two step holes are located, and an injection hole 510 is opened on the second shell 51, and the second shell 51 is also provided with corresponding threaded holes, and the cover of the second shell 51 is 1 mm thick.

[0049] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the protection scope of the present invention.

Claims

1. A single-component micro-thruster based on MEMS, characterized in that: It includes an air intake layer body, a nozzle layer body, a heating layer body and an outer shell; The shell is provided with an air jet through hole, and the nozzle layer body, the heating layer body and the air intake layer body are sequentially stacked and arranged in the shell in a direction away from the air jet through hole; The nozzle layer is provided with a Laval nozzle channel, the Laval nozzle channel runs through both ends of the nozzle layer, the Laval nozzle channel is aligned with and connected to the jet through hole, and the axial length of the Laval nozzle channel is greater than the maximum diameter length of the Laval nozzle channel; The air intake layer body is provided with an air intake channel, the air intake end of the air intake channel is connected with an air inlet, and the air outlet end of the air intake channel is connected with the Laval nozzle channel; The heating layer is used to heat the intake air of the intake flow passage to generate the jet.

2. The monopropellant micro-thruster according to claim 1, characterized in that: The Laval nozzle channel includes a convergent pipe section and an expanded pipe section that are interconnected; The contraction pipeline section and the expansion pipeline section are arranged in sequence along a direction adjacent to the air injection through hole; Along the direction adjacent to the air injection through hole, the diameter length of the contraction pipeline section gradually decreases, and the diameter length of the expansion pipeline section gradually increases.

3. The monopropellant micro-thruster according to claim 2, characterized in that: The jet inlet wall surface of the contraction duct section is transitionally connected to the outlet end wall surface of the inlet flow channel.

4. The monopropellant micro-thruster according to claim 2, characterized in that: The ratio of the maximum diameter of the contraction pipe section, the minimum diameter of the contraction pipe section and the axial length of the contraction pipe section is 1:0.18:0.77 to 1:0.2:0.

8.

5. The monopropellant micro-thruster according to claim 2, characterized in that: The axial length of the expansion pipe section is greater than the maximum diameter length of the expansion pipe section.

6. The monopropellant micro-thruster according to claim 5, characterized in that: The ratio of the maximum diameter of the expansion pipe section, the minimum diameter of the expansion pipe section and the axial length of the expansion pipe section is 1.8:0.18:2.23 to 2:0.2:2.

25.

7. The monopropellant micro-thruster according to claim 2, characterized in that: The maximum diameter of the contracting conduit segment is smaller than the maximum diameter of the expanding conduit segment.

8. The monopropellant micro-thruster according to claim 1, characterized in that: The inlet flow channel is a symmetrical flow channel, and an iridium layer is coated on the inner wall of the inlet flow channel.

9. The monopropellant micro-thruster according to claim 1, characterized in that: The monopropellant micro-thruster further comprises a heat insulation layer; The heat insulation layer is arranged between the air intake layer and the outer shell.

10. The monopropellant micro-thruster according to claim 1, characterized in that: The monocomponent micro-thruster also includes a sealing ring; The housing comprises a first shell and a second shell; The first shell is threadedly connected to the second shell, and the second shell is provided with the air injection hole; The sealing ring is clamped between the second shell and the nozzle layer.

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