Integrated electrospray thruster transmitting module based on 3D printing technology

Abstract

The invention discloses an integrated electrospray thruster transmitting module based on a 3D printing technology, and belongs to the technical field of spaceflight. The integrated electrospray thruster transmitting module is an integrated component which is integrally formed through a micro three-dimensional photoetching 3D printing technology, and a continuous fluid transmission channel from a liquid supply connector at the bottom end to a transmitting nozzle at the top end is arranged in the integrated electrospray thruster transmitting module; in the fluid flowing direction, the integrated electrospray thruster transmitting module sequentially comprises a liquid supply interface layer, a multi-layer flow channel structure and a transmitting layer from bottom to top. Integrated forming and high integration of the complex micro-channel structure are achieved, the array liquid supply uniformity is improved through the forked micro-channel structure, the size of sprayed liquid drops and the single-hole flow are reduced, and therefore emitter miniaturization is achieved, and the overall emission performance and working stability of the electrospray thruster are improved.

Description

Technical Field

[0001] This invention relates to the field of aerospace technology, specifically to an integrated electro-spray thruster launch module based on 3D printing. The module achieves structural integration and miniaturization through microscale flow channel integral forming, thereby improving launch performance. Background Technology

[0002] Electrospray thrusters are miniature electric propulsion devices that utilize a strong electric field to form a Taylor cone of conductive or ionic liquid at the jet end, further generating charged droplets or ion beams to obtain reaction thrust. These thrusters offer advantages such as compact structure, low power consumption, high specific impulse, and the ability to achieve precise thrust adjustment at the micro-Newton to millinewton level, making them promising candidates for applications in attitude control and orbit maintenance of micro- and nano-satellites.

[0003] Existing electrospray thrusters typically consist of a fluid supply system, a launcher assembly, an electrode system, and a packaging structure. Among these, the launcher assembly is responsible for uniformly delivering the working fluid to multiple micro-scale injection units and achieving stable injection under the influence of a high electric field. Its structural design directly affects the thruster's injection stability, thrust consistency, and overall performance.

[0004] However, existing electro-spray thruster launcher assemblies mostly adopt a split-structure design. Their microchannel layer, launch array layer, and liquid supply interface layer typically need to be machined separately before assembly. This not only involves complex manufacturing processes and high assembly precision requirements, but also easily introduces positional deviations during the alignment of the multi-layer structure, thus affecting the consistency and stability of the array spray. Furthermore, the split-structure design is limited by the machining precision of traditional micromachining processes, making it difficult to meet the dimensions of the launcher nozzle and internal micro-scale channels for practical applications. This can easily lead to excessive liquid supply and excessively large launch droplets, thereby reducing spray performance and affecting the overall working effect of the thruster.

[0005] Meanwhile, in multi-nozzle array structures, it is difficult to ensure the uniformity of the working fluid distribution among different launch units, which can easily lead to localized flow unevenness or unstable jetting, thereby reducing the overall thrust output consistency and operational reliability. Therefore, there is an urgent need for an electro-spray thruster launch module that can achieve integrated molding of complex microchannel structures, improve array fluid supply uniformity, and balance structural integration and manufacturing feasibility. Summary of the Invention

[0006] The technical problem to be solved by this invention is as follows: Existing electro-spray thruster launch modules suffer from problems such as a split structure, complex manufacturing and assembly, limitations in micro-scale flow channel and nozzle dimensions due to traditional processing techniques, uneven liquid supply, large droplet size and flow rate, and insufficient jetting stability in multi-nozzle arrays. This invention provides an integrated electro-spray thruster launch module based on 3D printing technology. This module achieves integrated molding and high integration of complex micro-flow channel structures, and improves the uniformity of liquid supply to the array through a bifurcated micro-flow channel structure, reducing the size of jet droplets and the flow rate per orifice. This results in miniaturization of the launcher and enhances the overall launch performance and operational stability of the electro-spray thruster.

[0007] The objective of this invention is achieved through the following technical solution: According to one aspect of the present invention, an integrated electrospray thruster launching module based on 3D printing technology is provided. The integrated electrospray thruster launching module is an integral component formed by micro-stereolithography 3D printing technology. The integrated electrospray thruster launching module has a continuous fluid transmission path from the bottom liquid supply interface to the top launching nozzle. According to the fluid flow direction, the integrated electrospray thruster launching module includes, from bottom to top, a liquid supply interface layer 7, a multi-layer flow channel structure, and a launching layer 1.

[0008] Furthermore, the integrated electro-spray thruster launching module has an overall cuboid structure, and the four side edges in the thickness direction are provided with rounded corners 9 for transition.

[0009] The launching layer 1 is located at the top of the integrated electro-spray thruster launching module. It includes launching units arranged in an array in the central area of ​​the top surface. Each launching unit includes a recessed launching protection hole 8 and a launching nozzle 10 located at the center of the bottom surface of the launching protection hole 8 and extending upward.

[0010] Furthermore, the emission nozzle 10 has a conical frustum structure, with a first connecting channel 4 forming along the entire length of the emission axis at its center, for communicating with the multi-layer channel structure below.

[0011] The multi-layer flow channel structure is located inside the integrated electro-spray thruster launch module and includes a branched flow channel layer 3 and a hydraulic resistance layer 2 from bottom to top along the launch axis. The branched flow channel layer 3 is used to distribute the working fluid entering the main flow channel 15 in a hierarchical and uniform manner, and the hydraulic resistance layer 2 is used to provide the hydraulic resistance required for launch in each branch after distribution and to achieve micro-fluid supply.

[0012] Furthermore, the hydraulic resistance layer 2 is located below the emission layer 1, and includes m structurally identical and independently arranged high-resistance microchannel units 14, which are symmetrically distributed in two columns. Each high-resistance microchannel unit 14 is further divided into 2n independent and uniformly long-range tortuous branch channels, thereby forming 2n parallel liquid outlets 16 in each unit, resulting in a total of 2n×m branch channels and liquid outlets 16 in the entire layer; the number of branch channels and liquid outlets 16 is consistent with the number of emission units in the emission layer 1. The liquid outlets 16 at the ends of each branch channel are combined to form a 2 / m×4n array distribution, and are all connected to the emission nozzles 10 in the emission layer 1 through the first connecting channel 4.

[0013] Furthermore, the bifurcation channel layer 3 is located below the hydraulic resistance layer 2. The bifurcation channel layer 3 constitutes a symmetrical, hierarchical bifurcation microchannel network, including a main channel 15 and multiple levels of sub-channels formed by progressively splitting from the main channel 15 to both sides. Sub-channels at each bifurcation node are generated in pairs and arranged symmetrically about the central axis of their corresponding parent channel. In each bifurcation level, the cross-sectional area of ​​each sub-channel is set to half the cross-sectional area of ​​its corresponding parent channel, ensuring that the total cross-sectional area of ​​the two sub-channels in the same bifurcation level is consistent with that of the parent channel. By repeating the above symmetrical, equal-section bifurcation structure, the final bifurcation forms end sub-channels that are connected to the high-resistance microchannel units 14 in the hydraulic resistance layer 2 via the second connecting channel 5.

[0014] The liquid supply interface layer 7 is located at the bottom of the integrated electro-spray thruster launch module. It has a circular interface countersunk hole 12 at its center. A third connecting flow channel 6 is opened at the center of the circular interface countersunk hole 12. The upper end of the third connecting flow channel 6 is connected to the inlet of the main flow channel 15 of the branch flow channel layer 3, and the lower end is used for the access of the external liquid supply pipeline.

[0015] Furthermore, the edge of the circular interface countersunk hole 12 is chamfered 11.

[0016] Furthermore, the transition parts of each of the above flow channels are provided with rounded corner transition structures 13 to reduce local flow resistance and abrupt changes in the flow field, thereby improving the continuity and stability of fluid transmission.

[0017] Compared with the prior art, the advantages of the present invention are as follows: (1) The present invention adopts an integrated molding method based on 3D printing to integrate the launch nozzle, multi-layer microchannel and liquid supply structure into a whole, effectively avoiding the coaxiality error and sealing failure caused by traditional split assembly, and realizing the miniaturization and high integration of the integrated electro-spray thruster launch module.

[0018] (2) By constructing a hierarchical branched microchannel network and a high-resistance microchannel structure inside the transmitter, the working fluid is uniformly distributed in multiple stages before entering each transmitter nozzle, which significantly improves the consistency of liquid supply between array units and reduces the flow deviation of a single nozzle.

[0019] (3) The high-resistance microchannel plays a precise role in limiting the flow rate, which can effectively reduce the single-hole jet flow rate and droplet size, thereby improving the stability and specific impulse of electrospray launch and improving thrust accuracy.

[0020] (4) Complex three-dimensional microscale flow channel structures can be printed in one step, breaking through the limitations of traditional micromachining processes in terms of channel size and structural complexity, realizing flow channel processing at a minimum of 40 μm, and improving the freedom of structural design. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of the integrated electro-spray thruster launch module; Figure 2 Top view of the integrated electro-spray thruster launch module; Figure 3 A bottom view of the integrated electro-spray thruster launch module; Figure 4 A schematic diagram of the internal flow channel of the integrated electro-spray thruster launch module; Figure 5 This is a schematic diagram of the hydraulic resistance layer; Figure 6 This is a schematic diagram of the bifurcation channel layer; In the diagram: 1. Emission layer; 2. Hydraulic resistance layer; 3. Branching flow channel layer; 4. First connecting flow channel; 5. Second connecting flow channel; 6. Third connecting flow channel; 7. Liquid supply interface layer; 8. Emission protection hole; 9. Rounded corner; 10. Emission nozzle; 11. Chamfer; 12. Circular interface countersunk hole; 13. Rounded corner transition structure; 14. High resistance microchannel unit; 15. Main flow channel; 16. Liquid outlet. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0024] like Figure 1-6 As shown, a preferred embodiment of the present invention provides an integrated electro-spray thruster launching module based on 3D printing technology. According to the fluid flow direction, the integrated electro-spray thruster launching module mainly includes, from bottom to top: a liquid supply interface layer 7, a multi-layer flow channel structure, and a launching layer 1.

[0025] In one specific embodiment of the present invention, such as Figure 1 As shown, the integrated electrospray thruster launching module is integrally formed using micro-stereolithography 3D printing technology, with HTL high-temperature resistant photosensitive resin selected as the forming material. The integrated electrospray thruster launching module is fabricated using additive manufacturing, employing the Mofang Technology S130 micro-nano 3D printing system. Its minimum forming feature size can reach tens of micrometers, enabling one-time forming of the microscale flow channel structure inside the launcher, meeting the design requirements of the electrospray launcher for microchannel dimensional accuracy and structural consistency.

[0026] In one specific embodiment of the present invention, the integrated electro-spray thruster launching module has an overall cuboid structure with external dimensions of 30 mm × 30 mm × 3 mm, and has rounded corners 9 on the four side edges in the thickness direction to reduce assembly interference and improve assembly consistency and positioning accuracy.

[0027] In a specific embodiment of the present invention, as shown in FIG2, the launching layer 1 is located at the top of the launching module of the integrated electro-spray thruster, and includes 64 launching units uniformly arranged in an 8×8 array in the central region of the top surface. Each launching unit includes a launching protection hole 8 and a launching nozzle 10 disposed at the center of the bottom surface of the launching protection hole 8 and extending upward along the launching direction. The diameter of the launching protection hole 8 is 2 mm, the depth is 0.5 mm, and the center-to-center distance between adjacent launching protection holes 8 is 2.5 mm. The launching nozzle 10 has a conical frustum structure with a bottom diameter of 0.24 mm, a top diameter of 0.06 mm, and a height of 0.4 mm, such that the top of the launching nozzle 10 is recessed by about 0.1 mm relative to the opening of the launching protection hole 8. Through the above structural design, the emission protection hole 8 provides physical shielding for the emission nozzle 10, which can effectively prevent the nozzle tip from being accidentally hit or worn during assembly and use. At the same time, the emission protection hole 8 can form a local electric field enhancement area when working, which is beneficial to stabilizing the electrospray emission process and improving the overall structural strength of the emission layer 1.

[0028] In a specific embodiment of the present invention, as shown in Figures 4 and 5, the plane of the hydraulic resistance layer 2 is parallel to the upper surface of the integrated electro-spray thruster launching module and is located 1 mm below the upper surface of the integrated electro-spray thruster launching module along the launching axis. The hydraulic resistance layer 2 includes 16 high-resistance microchannel units 14 with identical structures and independently arranged, and the 16 high-resistance microchannel units 14 are symmetrically distributed in two columns. Each high-resistance microchannel unit 14 is further divided into 4 independent long-range tortuous branch channels of equal length, thereby forming 4 parallel liquid outlets 16 in each unit, forming a total of 64 branch channels and corresponding liquid outlets 16 in the entire layer. The diameter of each branch channel is 40 μm and the length is 15 mm. The liquid outlets 16 at the end of each branch channel are combined to form an 8×8 array distribution, and are respectively connected to the launching nozzles 10 in the launching layer 1 through the first connecting channel 4. During transmitter operation, the ionic liquid needs to be stably delivered to each emission nozzle 10 at an extremely low flow rate to achieve electrospray emission. To this end, the branch channels provide the required high hydraulic resistance through a small diameter and a long-range tortuous structure, thereby precisely limiting and stably controlling the single-channel liquid supply flow rate to meet the low-flow requirements of electrospray emission. Simultaneously, the 16 high-resistance microchannel units 14 are arranged symmetrically from left to right and combined with a long-range tortuous channel structure to achieve high-resistance compact integration within a limited module space, which is beneficial for the overall miniaturization design of the transmitter. The consistent length of each branch channel ensures that each emission nozzle 10 receives uniform liquid supply conditions, improving the stability and consistency of array emission.

[0029] In a specific embodiment of the present invention, the first connecting flow channel 4 passes through each emission nozzle 10 along the emission axis direction and is distributed in an 8×8 array corresponding to each emission nozzle 10. Its diameter is 40 μm and is consistent with the branch flow channel of the hydraulic resistance layer 2. It is used to connect the emission layer 1 with the multi-layer flow channel structure below.

[0030] In one specific embodiment of the present invention, such as Figure 4 , Figure 6The plane of the bifurcation channel layer 3 is parallel to the plane of the hydraulic resistance layer 2, and is located 1 mm below the plane of the hydraulic resistance layer 2 along the launch axis. The bifurcation channel layer 3 is configured as a symmetrical hierarchical bifurcation microchannel network, including a main channel 15 and multiple sub-channels formed by the main channel 15 branching outwards from both sides. Sub-channels at each bifurcation node are generated in pairs and arranged symmetrically about the central axis of their corresponding parent channel. In each bifurcation level, the cross-sectional area of ​​each sub-channel is set to half the cross-sectional area of ​​its corresponding parent channel, ensuring that the total cross-sectional area of ​​the two sub-channels in the same bifurcation level is consistent with that of the parent channel. By repeating the above symmetrical equal-section bifurcation structure four times, the terminal sub-channels of the fourth bifurcation are connected to the high-resistance microchannel units 14 in the hydraulic resistance layer 2 via the second connecting channel 5. The equivalent diameter of the terminal sub-channels formed by the fourth bifurcation is... The cross-sectional area of ​​the branch flow channel 3 is approximately twice that of the hydraulic resistance layer 2. This allows the working fluid, after entering the hydraulic resistance layer 2 via the second connecting flow channel 5, to be further divided into two equally spaced branch flow channels with a diameter of 40 μm. This achieves cross-sectional area matching and continuous flow transition between the branch flow channel layer 3 and the hydraulic resistance layer 2. Through this multi-stage, symmetrically branched structure with equal cross-sectional area, the working fluid is uniformly distributed step-by-step before entering the high-resistance microchannel unit 14, effectively improving the array's fluid supply consistency and overall emission stability.

[0031] In one specific embodiment of the present invention, the second connecting channel 5 is located between the hydraulic resistance layer 2 and the bifurcated channel layer 3, and a total of 32 channels are symmetrically arranged along the left and right sides of the module, with a diameter of [missing information]. μm is used to introduce the fourth-level end sub-channel of the bifurcation channel layer 3 into the corresponding high-resistance microchannel unit 14, so as to realize continuous fluid coupling between the bifurcation channel layer 3 and the hydraulic resistance layer 2.

[0032] In one specific embodiment of the present invention, the liquid supply interface layer 7 is located at the bottom of the integrated electro-spray thruster launch module, and a circular countersunk hole 12 is provided at its center. The countersunk hole has a diameter of 9.0 mm and a depth of 0.4 mm. The orifice has a 0.2 mm, 45° chamfer 11 around its circumference for positioning and assembling the external liquid supply pipeline and reducing assembly interference. A third connecting flow channel 6 is provided at the center of the countersunk hole. The third connecting flow channel 6 has a diameter of 0.4 mm. Its lower end is used to communicate with the external liquid supply pipeline, and its upper end is connected to the inlet of the main flow channel 15 of the branched flow channel layer 3, realizing the introduction of working fluid from the external liquid supply system into the internal flow channel structure of the module.

[0033] In one specific embodiment of the present invention, the transition parts of each of the above flow channels are provided with rounded corner transition structures 13 to reduce local flow resistance and flow field abrupt changes, and improve the continuity and stability of fluid transmission.

[0034] Based on the above structural configuration, the transmission path of the working fluid during the transmitter's operation is as follows: During the transmitter's operation, the working fluid first enters the main channel 15 inlet of the branching channel layer 3 through the third connecting channel 6 at the center of the external supply pipeline 7 via the external supply pipeline. Within the branching channel layer 3, it is distributed to multiple terminal sub-channels through a four-stage symmetrical equal-section integral branching structure. Each terminal sub-channel is connected to a high-resistance microchannel unit 14 in the hydraulic resistance layer 2 via the second connecting channel 5. The working fluid then enters the long-range tortuous branch channels within each high-resistance microchannel unit 14, where it is restricted to a small, stable flow rate under high hydraulic resistance. The working fluid, regulated by the hydraulic resistance layer 2, is further transported to the corresponding launch nozzle 10 in the launch layer 1 via the first connecting channel 4, ultimately achieving array electrospray launch under the influence of a strong electric field.

[0035] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An integrated electro-spray thruster launching module based on 3D printing technology, characterized in that, The integrated electro-spray thruster launching module is an integral component formed by micro-stereolithography 3D printing technology. The integrated electro-spray thruster launching module has a continuous fluid transmission path from the bottom liquid supply interface to the top launching nozzle. According to the fluid flow direction, the integrated electro-spray thruster launching module includes, from bottom to top: a liquid supply interface layer (7), a multi-layer flow channel structure, and a launching layer (1). The launching layer (1) is located at the top of the integrated electro-spray thruster launching module. It includes launching units arranged in an array in the central area of ​​the top surface. Each launching unit includes a recessed launching protection hole (8) and a launching nozzle (10) located at the center of the bottom surface of the launching protection hole (8) and extending upward. The multi-layer flow channel structure is set inside the integrated electro-spray thruster launch module, and includes a bifurcation flow channel layer (3) and a hydraulic resistance layer (2) from bottom to top along the launch axis. The bifurcation flow channel layer (3) is used to distribute the working fluid entering the main flow channel (15) in a hierarchical and uniform manner, and the hydraulic resistance layer (2) is used to provide the hydraulic resistance required for launch in each branch after distribution and to realize micro-fluid supply. The liquid supply interface layer (7) is located at the bottom of the integrated electro-spray thruster launch module. It has a circular interface countersunk hole (12) in the center. The circular interface countersunk hole (12) has a third connecting channel (6) in the center. The upper end of the third connecting channel (6) is connected to the inlet of the main channel (15) of the branch channel layer (3), and the lower end is used for the access of the external liquid supply pipeline.

2. The integrated electro-spray thruster launching module based on 3D printing technology according to claim 1, characterized in that, The integrated electro-spray thruster launch module has a rectangular parallelepiped structure and rounded corners (9) on the four side edges in the thickness direction.

3. The integrated electro-spray thruster launching module based on 3D printing technology according to claim 1, characterized in that, The emission nozzle (10) has a cone-shaped frustum structure, and a first connecting channel (4) that runs through the entire length is formed at its center along the emission axis, which is used to connect with the multi-layer channel structure below.

4. The integrated electro-spray thruster launching module based on 3D printing technology according to claim 1, characterized in that, The hydraulic resistance layer (2) is located below the emission layer (1). It includes m high-resistance microchannel units (14) with the same structure and independently arranged. The m high-resistance microchannel units (14) are symmetrically distributed in two columns. Each high-resistance microchannel unit (14) is further divided into 2n independent long-distance tortuous branch channels with the same length, thereby forming 2n parallel liquid outlets (16) in each unit. The entire layer forms a total of 2n×m branch channels and liquid outlets (16). The number of branch channels and liquid outlets (16) is the same as the number of emission units in the emission layer (1). The liquid outlets (16) at the end of each branch channel are combined to form a 2 / m×4n array distribution, and are all connected to the emission nozzles (10) in the emission layer (1) one by one through the first connecting channel (4).

5. The integrated electro-spray thruster launching module based on 3D printing technology according to claim 1, characterized in that, The bifurcation channel layer (3) is located below the hydraulic resistance layer (2). The bifurcation channel layer (3) is a hierarchical bifurcation microchannel network with symmetrical sides, including a main channel (15) and multi-level sub-channels formed by the main channel (15) splitting into both sides. The sub-channels at each bifurcation node are generated in pairs and arranged symmetrically about the central axis of their corresponding parent channel. In each bifurcation, the cross-sectional area of ​​each sub-channel is set to 1 / 2 of the cross-sectional area of ​​its corresponding parent channel, so that the total cross-sectional area of ​​the two sub-channels in the same bifurcation is consistent with the parent channel. By repeating the above symmetrical equal cross-section bifurcation structure, the last bifurcation forms the end sub-channels that are connected to the high-resistance microchannel unit (14) in the hydraulic resistance layer (2) through the second connecting channel (5).

6. The integrated electro-spray thruster launching module based on 3D printing technology according to claim 1, characterized in that, The edge of the circular interface countersunk hole (12) is chamfered (11).

7. The integrated electro-spray thruster launching module based on 3D printing technology according to claim 1, characterized in that, All the transition points of the above flow channels are provided with rounded corner transition structures (13) to reduce local flow resistance and flow field abrupt changes, and improve the continuity and stability of fluid transmission.

Images