A gas distributor for enhancing ionization efficiency of a radio frequency ion thruster

Abstract

A gas distributor for improving ionization efficiency of a radio frequency ion thruster, comprising a gas supply pipeline, a cavity, a flow guide ball, radial rotational flow holes, axial diffusion holes and a flow guide ball limiter, the gas supply pipeline and the cavity are integrally formed, the radial rotational flow holes and the axial diffusion holes are dispersedly arranged in the cavity, the flow guide ball is filled into the cavity through the gas supply pipeline, the flow guide ball limiter is arranged in the cavity to prevent relative movement of the flow guide ball in the cavity, and the gas distributor composed of the gas supply pipeline, the cavity, the flow guide ball, the radial rotational flow holes, the axial diffusion holes and the flow guide ball limiter is arranged at the bottom of a discharge chamber of the thruster.

Description

Technical Field

[0001] This invention relates to a gas distributor for improving the ionization efficiency of a radio frequency ion thruster, belonging to the field of electric propulsion technology. Background Technology

[0002] Radio-frequency ion thrusters (RITs) are mature electric propulsion devices already in orbit. Continuously improving their performance remains a core concern for researchers worldwide. The structure of a radio-frequency ion thruster (RIT) is as follows: Figure 1 As shown, a radio frequency (RF) power supply is used to provide RF power at a certain frequency to the RF coil wound outside the insulating ionization chamber. Under the action of RF, a magnetic field along the axial direction and an angular vortex electric field are generated in the ionization chamber. Then, an ignition voltage is applied to the accelerating grid, introducing electrons emitted by the neutralizer into the ionization chamber. These electrons move in the induced vortex electric field and gain energy, and collide with the working gas in the ionization chamber to ionize it, while generating more free electrons. When the absorbed power and lost power reach equilibrium, a stable discharge plasma is formed. Finally, the ions are focused, accelerated, and extracted by the grid assembly. At the same time, the cathode neutralizer emits electrons to neutralize the ions in the thruster plume region, thereby maintaining the satellite's electrical neutrality.

[0003] The primary function of the gas distributor is to uniformly distribute the neutral working gas entering the thruster's discharge chamber from the gas supply line, ensuring a sufficiently high ionization efficiency and thus enabling the thruster to achieve optimal performance. However, numerous studies have shown that most current radio frequency ion thrusters use a direct-flow gas distributor, meaning the working gas is supplied directly to the discharge chamber after entering the distributor. This presents two significant problems during actual operation: first, uneven distribution of the working gas within the discharge chamber; and second, the working gas often moves axially out of the chamber, resulting in a short residence time. Consequently, this leads to low gas ionization efficiency and poor performance parameters during thruster operation. Furthermore, backfire occurs in the gas supply line, which can erode the non-metallic supply hoses, ultimately causing thruster failure. Summary of the Invention

[0004] The technical problem solved by this invention is that, in the existing technology, most direct-flow gas distributors are prone to uneven distribution of working gas in the discharge chamber or the working gas will move directly along the axial direction and leave the discharge chamber, resulting in a short residence time in the discharge chamber. Therefore, this invention proposes a gas distributor for improving the ionization efficiency of radio frequency ion thrusters.

[0005] The present invention solves the above-mentioned technical problem through the following technical solution:

[0006] A gas distributor for improving the ionization efficiency of a radio frequency ion thruster includes a gas supply line, a cavity, a guide ball, radial swirling holes, axial diffusion holes, and a guide ball limiter. The gas supply line and the cavity are integrally formed. The radial swirling holes and axial diffusion holes are dispersed within the cavity. The guide ball is injected into the cavity through the gas supply line. The guide ball limiter is disposed within the cavity to prevent relative movement of the guide ball within the cavity. The gas distributor, consisting of the gas supply line, cavity, guide ball, radial swirling holes, axial diffusion holes, and guide ball limiter, is disposed at the bottom of the discharge chamber of the thruster.

[0007] The neutral gas output from the thruster enters the cavity through the gas supply pipeline. After passing through the guide ball, the axial velocity of the neutral gas is reduced once. After passing through the radial swirling hole and the axial diffusion hole, the neutral gas is evenly distributed by the combined action of the radial swirling hole and the axial diffusion hole to ensure that the gas pressure is balanced throughout the discharge chamber. The axial velocity of the neutral gas is reduced a second time in the discharge chamber to prolong the residence time of the neutral gas in the discharge chamber.

[0008] The radial swirling orifice transforms the axial motion component of the neutral gas into a radial motion component to achieve swirling gas supply, while the axial diffusion orifice amplifies the radial motion component of the neutral gas; the swirling gas supply is achieved through the oblique hole design of the radial swirling orifice.

[0009] The number of guide balls is adjusted and distributed according to the flow rate of neutral gas output by the thruster.

[0010] The axial velocity of the neutral gas is adjusted by the angle of the radial swirling orifice, which is between 30° and 60°. The radial swirling orifice and the axial diffusion orifice have different sizes, and the aperture ratio is determined according to the size ratio of the gas distributor and the discharge chamber.

[0011] The axial length of the cavity is determined according to the working performance parameters of the thruster, and the range of the axial length is 1 / 3 to 1 / 2 of the axial length of the discharge chamber of the gas distributor.

[0012] The guide ball limiter is located at the connection between the cavity and the gas supply pipeline to prevent the guide ball from moving relative to the neutral gas output direction.

[0013] The size of the guide ball is larger than that of the radial swirling hole and the axial diffusion hole, and it is an irregular sphere.

[0014] All components of the gas distributor are made of non-magnetic stainless steel, and the gas distributor can operate continuously for no more than 8 hours at a time.

[0015] The number of radial swirling holes and axial diffusion holes is determined according to the performance parameters and working requirements of the thruster, and the molding scheme is preset in advance and integrally formed with the air supply pipeline and the cavity.

[0016] The advantages of this invention compared to the prior art are:

[0017] This invention provides a gas distributor for improving the ionization efficiency of a radio frequency ion thruster. It employs a multi-dimensional swirling gas supply method, resulting in a more uniform distribution of the working gas within the discharge chamber. The swirling gas supply alters the macroscopic flow velocity, superimposing the originally axially flowing neutral gas flow with a circumferential rotating flow. This converts the axially distributed kinetic energy into both axial and circumferential kinetic energy, thereby reducing the axial velocity of the working gas, extending its residence time within the discharge chamber, and improving the thruster's ionization efficiency. Furthermore, this complex structural design effectively avoids the discharge backfire phenomenon present in straight-through gas distributors, demonstrating broad prospects for applications in radio frequency ion thrusters. Attached Figure Description

[0018] Figure 1 A schematic diagram of the radio frequency ion thruster structure provided for the invention;

[0019] Figure 2 A cross-sectional view of the gas distributor structure provided for the invention;

[0020] Figure 3 A schematic diagram of the radial swirl hole angle provided for the invention; Detailed Implementation

[0021] A gas distributor for improving the ionization efficiency of a radio frequency ion thruster employs a multi-dimensional swirling gas supply method, resulting in a more uniform distribution of the working gas within the discharge chamber. By altering the macroscopic flow velocity of the gas, the neutral gas initially flowing axially within the channel is superimposed with circumferential rotational flow. This converts the axially distributed kinetic energy into both axial and circumferential kinetic energy, thereby reducing the axial velocity of the working gas, extending its residence time within the discharge chamber, and ultimately improving the thruster's ionization efficiency. Furthermore, this complex structural design effectively avoids the discharge backfire phenomenon present in straight-through gas distributors, demonstrating broad application prospects in radio frequency ion thrusters. The specific structure is as follows:

[0022] The device includes a gas supply line 1, a cavity 2, a guide ball 3, a radial swirling hole 4, an axial diffusion hole 5, and a guide ball limiter 6. The gas supply line and the cavity are integrally formed. The radial swirling hole and the axial diffusion hole are dispersedly arranged in the cavity. The guide ball is injected into the cavity through the gas supply line. The guide ball limiter is set in the cavity to prevent relative movement of the guide ball in the cavity. The gas distributor, which consists of the gas supply line, the cavity, the guide ball, the radial swirling hole, the axial diffusion hole, and the guide ball limiter, is set at the bottom of the discharge chamber of the thruster.

[0023] The neutral gas output from the thruster enters the cavity through the gas supply pipeline. After passing through the guide ball, the axial velocity of the neutral gas is reduced once. After passing through the radial swirling hole and the axial diffusion hole, the neutral gas is evenly distributed by the combined action of the radial swirling hole and the axial diffusion hole to ensure that the gas pressure is balanced throughout the discharge chamber. The axial velocity of the neutral gas is reduced a second time in the discharge chamber to prolong the residence time of the neutral gas in the discharge chamber.

[0024] The following description, in conjunction with the accompanying drawings and preferred embodiments, provides further details:

[0025] In the current embodiment, the radio frequency ion thruster is as follows: Figure 1 As shown, Figure 2 As shown, the gas distributor uses a guide ball 3 to achieve primary deceleration and uniform distribution of neutral gas in the cavity 2, and uses radial swirling holes 4 and axial diffusion holes 5 to achieve secondary deceleration and uniform distribution of neutral gas in the discharge chamber of the radio frequency ion thruster, thereby improving the ionization rate of the neutral gas working fluid and the thrust of the radio frequency ion thruster and other performance parameters. The guide ball limiter 6 can ensure that the guide ball 3 does not move relative to the cavity 2. The test results show that the invented gas distributor increases the ionization rate of neutral gas by more than 15%.

[0026] The radial swirling orifice converts the axial motion component of the neutral gas into a radial motion component to achieve swirling gas supply, while the axial diffusion orifice amplifies the radial motion component of the neutral gas; the swirling gas supply is achieved through the oblique hole design of the radial swirling orifice.

[0027] The number of guide balls is adjusted and distributed according to the neutral gas flow rate output by the thruster;

[0028] The gas distributor uses a combination of lateral swirling holes 4 and axial diffusion holes 5. The lateral swirling holes and axial diffusion holes have different sizes, and their aperture ratio depends on the size ratio of the gas distributor to the discharge chamber.

[0029] The size of the guide ball is larger than that of the lateral swirling hole 4 and the axial diffusion hole 5, and it is an irregular sphere;

[0030] The axial length of the gas distributor is 1 / 3 to 1 / 2 of the axial length of the discharge chamber, which improves the uniformity of gas reaching the outlet of the gas distributor.

[0031] The guide ball limiter is located at the connection between the cavity and the gas supply line to prevent the guide ball from moving relative to the neutral gas output direction;

[0032] The gas distributor's continuous working time is no more than 8 hours, and all components inside the gas distributor are made of non-magnetic stainless steel.

[0033] The number of radial swirling holes and axial diffuser holes is determined based on the thruster's performance parameters and operational requirements. The molding scheme is pre-set and integrally molded with the air supply pipeline and cavity.

[0034] The gas distributor has technical advantages such as extending the residence time of neutral gas in the discharge chamber, improving the uniformity of neutral gas distribution in the discharge chamber, and eliminating backfire in the gas supply line. It can be used to improve the ionization rate of neutral gas and the electrical efficiency of radio frequency ion thrusters.

[0035] Example 1:

[0036] This embodiment describes a gas distributor for improving the ionization efficiency of a radio frequency ion thruster. It comprises a gas supply line 1, a cavity 2, a guide ball 3, a radial swirling orifice 4, an axial diffusion orifice 5, and a guide ball limiter 6. The gas supply line 1, cavity 2, radial swirling orifice 4, and axial diffusion orifice 5 are integrally machined. The guide ball 3 is supplied to the cavity 2 via the gas supply line 1. The guide ball limiter 6 is installed in a designated position to prevent relative movement of the guide ball 3 within the cavity 2. The gas distributor is made of non-magnetic stainless steel. In actual installation, the gas distributor is installed at the bottom of the thruster's discharge chamber. Neutral gas enters cavity 2 through gas supply pipe 1. After passing through guide ball 3, the axial velocity of the neutral gas decreases once and is evenly distributed to radial swirling hole 4 and axial diffusion hole 5. Radial swirling hole 4 converts the axial motion component of the neutral gas into a radial motion component and achieves swirling gas supply through 45° inclined hole. Axial diffusion hole 5 increases the radial motion component of the neutral gas. Under the combined action of radial swirling hole 4 and axial diffusion hole 5, the neutral gas is evenly distributed, ensuring the gas pressure is balanced throughout the discharge chamber. At the same time, the axial velocity component of the neutral gas decreases a second time, further extending the residence time of the neutral gas in the discharge chamber, significantly increasing the collision frequency of neutral gas atoms and electrons, and ultimately improving the ionization efficiency of the neutral gas and enhancing the working performance of the thruster.

[0037] Example 2:

[0038] This embodiment describes a gas distributor for improving the ionization efficiency of a radio frequency ion thruster. It comprises a gas supply line 1, a cavity 2, a flow guide ball 3, a radial swirling orifice 4, an axial diffusion orifice 5, and a flow guide ball limiter 6. By appropriately increasing the number of flow guide balls, the velocity of neutral gas atoms in the gas distributor can be reduced, while simultaneously improving the uniformity of the working gas distribution, enhancing the uniformity and frequency of collisions between neutral gas atoms and electrons, and ultimately improving the ionization efficiency and performance of the thruster.

[0039] Example 3:

[0040] This embodiment describes a gas distributor for improving the ionization efficiency of a radio frequency ion thruster. It comprises a gas supply pipe 1, a cavity 2, a guide ball 3, a radial swirling orifice 4, an axial diffusion orifice 5, and a guide ball limiter 6. By appropriately changing the angle of the radial swirling orifice, the axial velocity of neutral gas atoms exiting the gas distributor can be reduced, increasing the collision frequency between neutral gas atoms and electrons, thereby improving the ionization efficiency and performance of the thruster. For example... Figure 3 As shown, the angle α of the radial swirling orifice is generally between 30 and 60°.

[0041] Example 4:

[0042] This embodiment describes a gas distributor for improving the ionization efficiency of a radio frequency ion thruster. It consists of a gas supply line 1, a cavity 2, a guide ball 3, a radial swirling orifice 4, an axial diffusion orifice 5, and a guide ball limiter 6. Currently, the axial length of the gas distributor is 30 mm. The ionization efficiency and performance of the thruster can be improved by appropriately increasing the axial length of the gas distributor. However, the axial length of the gas distributor should not be too long, generally it should be 1 / 3 to 1 / 2 of the axial length of the discharge chamber.

[0043] Example 5:

[0044] The gas distributor of the present invention for radio frequency ion thruster has completed 10 radio frequency ion thruster ignition tests, with the longest working time of a single test being 8 hours. Compared with the direct-flow gas distributor, the gas distributor of the invention increases the neutral gas ionization rate by 15%.

[0045] The gas distributor proposed in the above embodiments solves the problems existing in the gas distributors of radio frequency ion thrusters, such as uneven distribution of neutral gas working fluid in the discharge chamber, short residence time of gas in the discharge chamber, and backfire in the gas supply pipeline. It can effectively improve the ionization rate of neutral gas and improve the working performance of radio frequency ion thrusters.

[0046] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

[0047] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A gas distributor for improving ionization efficiency of a radio frequency ion thruster, characterized in that: it comprises a gas supply pipeline, a cavity, a flow guide ball, a radial rotational flow hole, an axial diffusion hole, and a flow guide ball limiter, the gas supply pipeline and the cavity are integrally formed, the radial rotational flow hole and the axial diffusion hole are dispersedly arranged in the cavity, the flow guide ball is added to the cavity through the gas supply pipeline, the flow guide ball limiter is arranged in the cavity to prevent the relative movement of the flow guide ball in the cavity, and the gas distributor composed of the gas supply pipeline, the cavity, the flow guide ball, the radial rotational flow hole, the axial diffusion hole, and the flow guide ball limiter is arranged at the bottom of a discharge chamber of the thruster. The radial rotational flow hole converts the axial movement component of the neutral gas into a radial movement component to realize rotational flow gas supply, and the rotational flow gas supply is realized through the inclined hole design of the radial rotational flow hole.

2. The gas distributor for improving ionization efficiency of a radio frequency ion thruster according to claim 1, characterized in that: the input neutral gas enters the cavity through the gas supply pipeline, the axial velocity of the neutral gas is reduced after passing through the flow guide ball, and the neutral gas is uniformly distributed under the joint action of the radial rotational flow hole and the axial diffusion hole to ensure the balance of gas pressure at all places in the discharge chamber and to reduce the axial velocity of the neutral gas in the discharge chamber for a second time to prolong the residence time of the neutral gas in the discharge chamber.

3. The gas distributor for improving ionization efficiency of a radio frequency ion thruster according to claim 1, characterized in that: the number of the flow guide balls is adjusted and distributed according to the neutral gas flow output by the thruster.

4. The gas distributor for improving ionization efficiency of a radio frequency ion thruster according to claim 3, characterized in that: the axial length of the cavity is determined according to the working performance parameters of the thruster, and the axial length ranges from 1 / 3 to 1 / 2 of the axial length of the discharge chamber where the gas distributor is arranged.

5. The gas distributor for improving ionization efficiency of a radio frequency ion thruster according to claim 1, characterized in that: the size of the flow guide ball is larger than the size of the radial rotational flow hole and the axial diffusion hole, and the flow guide ball is an irregular ball.

6. The gas distributor for improving ionization efficiency of a radio frequency ion thruster according to claim 1, characterized in that: all the components in the gas distributor are made of non-magnetic stainless steel.

7. The gas distributor for improving ionization efficiency of a radio frequency ion thruster according to claim 1, characterized in that: the number of the radial rotational flow hole and the axial diffusion hole is determined according to the performance parameters of the thruster and the working requirements of the thruster. ​ ​ ​ ​ ​ ​ ​

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