CN103835905B - Variable cross-section channel of multi-level tangential magnetic field plasma pusher - Google Patents

Abstract

The invention relates to a variable-section channel of a multi-stage cusp magnetic field plasma pusher, which belongs to the field of cusp magnetic field plasma pushers, and in particular relates to a variable-section channel of a cusp magnetic field plasma pusher. The invention aims to solve the problem that the gas working medium is prone to leakage on the wall surface of the straight channel of the conventional tangent magnetic field plasma pusher. The inner wall of the ceramic channel of the plasma pusher is embedded with n annular bosses along the axial direction of the ceramic channel, and the inner walls of the n bosses are all cylindrical, or the inner side of the axial section of the n bosses The walls are all arched, wherein n is a positive integer. The present invention changes the section by adding bosses inside the channel, so that the wall surface of the ceramic straight channel of the plasma pusher presents a form of variable section, which makes the gas working medium flow on the wall. The place can be fully ionized to prevent the wall gas from escaping, thereby eliminating the secondary plume that may exist at the outlet. The invention of the present invention is applicable to a tangent magnetic field plasma pusher.

Description

Variable cross-section channel of multi-level tangential magnetic field plasma pusher

technical field

The invention belongs to the field of tangent magnetic field plasma pushers, in particular to a variable-section channel of cusp magnetic field plasma pushers.

Background technique

The tangential magnetic field plasma thruster is a new type of electric propulsion concept emerging internationally. It is different from traditional electric propulsion devices. It mainly includes ceramic discharge channels and permanent magnets with opposite polarities. Approaching the helical movement of the anode, during this process, the anode releases the gas working fluid and collides with the electrons to ionize, and the ionized ions will be accelerated and ejected under the action of the axial electric field to form a thrust. Due to the magnetic confinement of the axial magnetic field and the magnetic mirror effect of the magnetic tip, the collision of electrons with the inner wall of the channel can be avoided, resulting in longer engine life, better performance such as thrust and efficiency. However, since it is difficult for electrons to reach the wall of the straight channel, the degree of ionization of the gas working medium at the wall is insufficient, and part of the gas working medium is discharged without being ionized, that is, the wall gas working medium escapes, resulting in insufficient ionization and gas When the utilization rate of the working medium decreases, when the gas working medium moves to the magnetic tip of the outlet, ionization may occur at the tip of the outlet, causing a secondary plume, resulting in an expansion of the divergence angle of the plume, resulting in a decrease in effective thrust and efficiency.

Contents of the invention

The present invention aims to solve the problem that the gas working medium escapes easily on the wall surface of the straight channel of the existing tangential magnetic field plasma pusher, and now provides a variable cross-section channel of the multi-stage cusp magnetic field plasma pusher.

The present invention provides variable cross-section channels of multi-stage tangential magnetic field plasma pushers with two structures, wherein:

The first structure: the variable cross-section channel of the multi-level tangential magnetic field plasma pusher, the inner wall of the ceramic channel of the plasma pusher is embedded with n circular bosses along the axial direction of the ceramic channel, and the n bosses The inner side walls of the n bosses are all cylindrical, the difference between the inner diameter and the outer diameter of the n bosses is between 2 mm and 10 mm, and the inner diameters of the n bosses gradually increase along the anode to the cathode of the ceramic channel, where n is positive integer.

The second structure: the variable cross-section channel of the multi-level tangent magnetic field plasma pusher, the interior of the ceramic channel of the plasma pusher is embedded with n circular bosses along the axial direction of the ceramic channel, and the n bosses The inner side walls of the axial section are all arched; the minimum inner diameter of the n bosses gradually increases along the anode to the cathode of the ceramic channel, and the inner walls of the n bosses are kept from intersecting the magnetic field lines generated by the plasma pusher; where n is a positive integer.

The variable-section channel of the multi-stage tangential magnetic field plasma pusher of the present invention changes the cross-section by adding bosses inside the channel, so that the wall surface of the ceramic straight channel of the plasma pusher presents a form of variable cross-section, which makes The gas working medium can be fully ionized at the wall surface to prevent gas leakage on the wall surface, thereby eliminating the possible secondary plume at the outlet, controlling the plume divergence angle, increasing the ionization efficiency by 10%, and increasing the thrust by 15%. Higher specific impulse and efficiency.

At the same time, due to the use of the boss, there is a large irregular change in the cross section at the magnetic tip, which will cause the gas to form a vortex here, which increases the flow resistance of the gas, thereby increasing the residence time of the gas at the magnetic tip. At the magnetic tip is the main ionization zone, which increases the ionization rate of the gas by 10%. In addition, the wavy curved inner wall can change the wall surface laminar flow into turbulent flow, and can also slow down the gas flow.

The variable cross-section channel of the multi-stage tangent magnetic field plasma pusher described in the present invention is applicable to the tangent magnetic field plasma pusher.

Description of drawings

Fig. 1 is a schematic structural view of the boss in the first embodiment.

Fig. 2 is the A-A view of Fig. 1 .

Fig. 3 is a cross-sectional view of the variable-section channel of the multi-stage tangent magnetic field plasma pusher described in Embodiment 2, and curve A represents the magnetic field lines.

FIG. 4 is a schematic structural view of the boss described in Embodiment 4. FIG.

Fig. 5 is a B-B view of Fig. 4 .

Fig. 6 is a cross-sectional view of the variable-section channel of the multi-stage tangent magnetic field plasma pusher described in Embodiment 4, and curve B represents the magnetic field lines.

detailed description

Specific Embodiment 1: Referring to Fig. 1, Fig. 2 and Fig. 3, this embodiment will be described in detail. In the variable cross-section channel of the multi-stage tangent magnetic field plasma pusher described in this embodiment, the inner wall of the ceramic channel of the plasma pusher is along the The axial direction of the ceramic channel is embedded with n annular bosses 1, the inner side walls of the n bosses 1 are all cylindrical surfaces, and the difference between the inner diameter and outer diameter of the n bosses 1 is between 2 mm and Between 10 mm, the inner diameters of the n bosses 1 gradually increase along the anode to the cathode of the ceramic channel, wherein n is a positive integer.

In this embodiment, if the difference between the inner diameter and the outer diameter of the boss is too large, it will affect the axial movement of ions, and if it is too small, the improvement of the wall gas leakage phenomenon will not be obvious, so it is optimal between 2mm and 10mm value.

Embodiment 2: This embodiment is a further description of the variable cross-section channel of the multi-stage tangential magnetic field plasma pusher described in Embodiment 1. In this embodiment, each boss 1 corresponds to the adjacent A magnetic tip between two poles.

The boss located at the magnetic tip of the ceramic channel can improve the ionization efficiency.

Embodiment 3: This embodiment is to further explain the variable cross-section channel of the multi-stage tangential magnetic field plasma pusher described in Embodiment 1. In this embodiment, the inner wall of the ceramic channel of the plasma pusher Wavy.

When the straight ring boss is used, the inner wall of the ceramic channel is made into a wave surface, which can make the wall gas flow into a turbulent flow and more fully ionize the wall gas.

Specific Embodiment Four: Referring to Fig. 4, Fig. 5 and Fig. 6, this embodiment will be described in detail. In the variable cross-section channel of the multi-stage tangent magnetic field plasma pusher described in this embodiment, the inside of the ceramic channel of the plasma pusher is along the ceramic There are n annular bosses 1 embedded in the axial direction of the channel, and the inner sidewalls of the axial sections of the n bosses 1 are arched; the minimum inner diameter of the n bosses 1 gradually increases from the anode to the cathode of the ceramic channel. increase, and keep the inner walls of the n bosses 1 not intersecting the magnetic field lines generated by the plasma pusher; where n is a positive integer.

In this embodiment, the minimum inner diameters of different bosses are different, and the radians and widths are also different; the minimum inner diameters of the n bosses gradually increase along the anode to the cathode of the ceramic channel, showing an expansion type, so as to reduce the impact of the bosses on the plasma. Especially ionic hindrance.

The inner curves of the bosses are parallel to the lines of magnetic force, so that the inner walls of the n bosses do not intersect with the lines of magnetic force generated by the plasma pusher, which can avoid excessive collision losses of electrons and the walls.

Embodiment 5: This embodiment is to further explain the variable cross-section channel of the multi-stage tangential magnetic field plasma pusher described in Embodiment 4. In this embodiment, each boss 1 corresponds to a first-stage permanent magnet the middle part.

In this embodiment, each boss corresponds to the middle part of the first-stage permanent magnet, which can avoid the larger ionization area at the magnetic tip, thereby expanding the ionization space of the magnetic tip ionization area and improving the ionization efficiency.

Embodiment 6: This embodiment is to further explain the variable cross-section channel of the multi-stage tangential magnetic field plasma pusher described in Embodiment 4. In this embodiment, the magnetic field inside the ceramic channel of the plasma pusher The tip is provided with a magnetizer.

Embodiment 7: This embodiment is a further description of the variable cross-section channel of the multi-stage tangential magnetic field plasma pusher described in Embodiment 6. In this embodiment, the material of the magnetizer is pure iron.

Embodiment 8: This embodiment is a further description of the variable cross-section channel of the multi-stage tangential magnetic field plasma pusher described in Embodiment 1 or 4. In this embodiment, the material of n bosses 1 is the same as ceramic The channel material is boron nitride.

Specific embodiment nine: This embodiment is to further explain the variable cross-section channel of the multi-stage tangential magnetic field plasma pusher described in specific embodiment one or four. In this embodiment, the n bosses 1 and ceramic The channels are integrated into a one-piece structure.

In order to ensure the safety and reliability of the engine, the boss and the ceramic channel of the engine are integrated, which can be realized by hot pressing and sintering, or high-temperature ceramic adhesive is used to bond the boss and the ceramic channel into one body. And the inner wall of the wavy surface can also be hot-pressed by making a corresponding mold.

Claims (4)

1. The variable cross-section channel of the multi-stage tangent magnetic field plasma pusher is characterized in that the inner wall of the ceramic channel of the plasma pusher is embedded with n circular bosses (1) along the axial direction of the ceramic channel, The inner side walls of the n bosses (1) are all cylindrical surfaces, the difference between the inner diameter and the outer diameter of the n bosses (1) is between 2 mm and 10 mm, and the inner diameters of the n bosses (1) are along the The anode of the ceramic channel increases gradually from the cathode, where n is a positive integer, and each boss (1) corresponds to a magnetic tip between two adjacent magnetic poles. 2 . The variable-section channel of the multi-stage tangent magnetic field plasma pusher according to claim 1 , wherein the inner wall of the ceramic channel of the plasma pusher is wavy. 3 . 3. The variable cross-section channel of the multi-stage tangent magnetic field plasma pusher according to claim 1, characterized in that the material of the n bosses (1) and the material of the ceramic channel are both boron nitride. 4. The variable cross-section channel of the multi-stage tangent magnetic field plasma pusher according to claim 1, characterized in that, the n bosses (1) are integrated with the ceramic channel.