HIGH-ALTITUDE HALL-EFFECT THRUSTER

专利摘要:
A Hall effect thruster (10) configured to be arranged inside or outside a spacecraft. The thruster has a concentrator (36) for collecting particles (P). The shape of this concentrator is defined by a continuous contour (C1) around the thrust axis and is such that over a major part of the contour, each section of the concentrator perpendicular to the contour is parabolic and has a focus ( F1) belonging to the contour (C1). The magnetic circuit (50) is further arranged to generate the magnetic field (B) near the contour (C1).
公开号:FR3038663A1
申请号:FR1556477
申请日:2015-07-08
公开日:2017-01-13
发明作者:Frederic Raphael Jean Marchandise；Stephan Zurbach
申请人:SNECMA SAS；
IPC主号:

专利说明:

FIELD OF THE INVENTION
The present invention relates to the field of atmospheric power Hall effect thrusters.
BACKGROUND
US2003 / 046921 discloses an atmospheric feed Hall effect propellant. Such a propellant uses the particles of the residual atmosphere in which it evolves to function.
Atmospheric-powered Hall effect thrusters are primarily used to propel observation satellites; these thrusters are particularly useful in low orbit. At this altitude, the residual atmosphere brakes the satellites, which limits their lifetime. Advantageously, atmospheric-powered Hall effect thrusters make it possible to compensate for this drag, and thus to increase the life of the satellites.
However, given the rarefaction of the atmosphere with the altitude, these thrusters can not operate beyond an altitude close to 100 km. They are therefore unusable at altitudes above this one, as for example to allow the transfer of satellites to higher orbits.
PRESENTATION OF THE INVENTION
The object of the invention is therefore to provide an atmospheric power Hall effect propeller capable of operating at a higher altitude than traditional Hall effect thrusters.
A first aspect of the invention relates first of all to Hall effect thrusters comprising an (internal) channel for particle acceleration.
According to this first aspect of the invention, the aforementioned objective is achieved by means of a Hall effect thruster for developing a thrust along a thrust axis, the thruster comprising: a channel for collecting, accelerating and accelerating the thrust. ejection of particles by the propellant when the latter is in operation, the channel being delimited radially by an inner wall and an outer wall; an electrical circuit comprising an anode, a cathode, and a voltage source for emitting electrons via the cathode and attracting electrons through the anode; a magnetic circuit for generating a magnetic field in the channel axially downstream of the anode, the magnetic field being directed in a substantially radial direction with respect to the thrust axis; the thruster being characterized in that the channel is open on an upstream side of the propellant and has a particle concentrator for collecting particles; the shape of the concentrator is defined by a continuous contour located in a plane perpendicular to the thrust axis and surrounding it; over a major part of the contour, namely at least 50% of the contour and preferably at least 75% of the contour, each section of the concentrator perpendicular to the contour is of parabolic shape and has a focus belonging to the contour; and the magnetic circuit is arranged to generate the magnetic field in the vicinity of the contour.
In a manner known per se, the cathode is placed downstream of the anode. In addition, the electrical circuit is arranged such that the electric field is generated in a generally axial direction (that of the thrust axis) between the anode and the cathode.
In general, downstream of the concentrator the channel further has a cylindrical or substantially cylindrical rear portion. By "cylindrical" rear part, is meant here a rear portion whose surface is generated by the displacement in a direction of a closed contour; here, this direction is the thrust axis. The rear part of the channel then serves to channel and direct the particles during their acceleration and ejection by the propellant.
This rear part generally extends directly from the downstream limit of the concentrator.
The channel is generally annular in shape; it therefore has an inner wall and an outer wall. In a preferred embodiment, the magnetic circuit comprises a plurality of connecting arms arranged to connect the inner wall and the outer wall of the channel.
The fact that the contour surrounds the thrust axis (naturally, in view along this axis), means that the contour is around this axis in view along the axis of thrust.
Moreover, the term 'voltage source' denotes in this document broadly a device capable of generating a voltage. This tension does not have to be constant or even periodic in time. As a result, a current source configured to provide a current of constant current constitutes a voltage source within the meaning of the present invention.
In one embodiment, the voltage source is controllable: it is configured so that the voltage it applies between the anode and the (or) cathode (s) can be inverted to order. In case of inversion, the roles of the anode and the cathode (or cathodes) in the electrical circuit are reversed.
This inversion makes it possible to reverse the direction of the force applied by the thruster, and to use it as a braking system, for example to brake a satellite during re-entry into the atmosphere. On the other hand, a second aspect of the invention relates to a specific thruster configuration, in which the particles are accelerated not inside the channel indicated above, in the heart of the thruster, but on the contrary outside of the here, around the wall. Despite this important difference, the operating principle of the Hall effect thruster remains however substantially identical to that of the earlier Hall effect thrusters.
According to this second aspect of the invention, the objective of the invention indicated above is achieved by means of a Hall effect thruster to develop a thrust along a thrust axis, the thruster comprising: a magnetic circuit for generating a field magnetic; an electrical circuit comprising an anode, a first cathode, and a voltage source for emitting electrons at least through the first cathode and attracting electrons through the anode; the thruster being characterized in that. the thruster is arranged inside a wall formed around the thrust axis; . the magnetic circuit and the electrical circuit are arranged to generate magnetic and electrical fields around the wall; and. in any section parallel to the thrust axis and perpendicular to the wall: the magnetic circuit has an upstream magnetic pole and a downstream magnetic pole, disposed substantially at the surface of the wall at a distance from one another, and the magnetic circuit is arranged such that the magnetic field is oriented in a direction substantially perpendicular to the surface of the wall to the right of the upstream magnetic pole; the anode and the first cathode are located on either side of the upstream magnetic pole; . the wall has a particle concentrator for concentrating particles; the shape of the concentrator being defined by a closed contour (or curve) located in a plane perpendicular to the thrust axis and around the wall; over a major part of the contour, namely at least 50% of the contour and preferably at least 75% of the contour, each section of the concentrator perpendicular to the contour being of parabolic shape and having a focus belonging to the contour; the magnetic circuit being arranged to generate the magnetic field in the vicinity of the contour.
The wall mentioned above is usually the outer wall of the crankcase of the spacecraft on which the thruster is mounted.
Downstream of the concentrator, this wall may further comprise a cylindrical or substantially cylindrical rear portion. This rear part is a shield used to protect the back of the satellite ions ejected by the propellant and other incident particles.
The characteristics stated above, whether with reference to the first or second aspect of the invention, allow the propellant advantageously to have a sufficient supply of particles and this even if the spacecraft is moving at high altitude.
Indeed, a good part of the particles that are in the trajectory of the spacecraft hit the concentrator. This one has a specific shape with its sections that have a parabolic shape (that is to say a form of parabola portion).
Because of this shape, the particles that hit the wall of the concentrator are all directed substantially in the same area, namely towards the focus of the dish.
As a result, the concentrator makes it possible to concentrate all the particles that it collects in a rather small volume. It follows that near this point, the particle density rises and clearly exceeds the particle density of the residual atmosphere.
It is thus possible advantageously in this zone to raise the density of particles to a sufficient value for the feed of the Hall effect propellant (of the order of 1020 particles per cubic meter).
It is understood that it is necessary to size the diameter and more generally the dimensions of the walls of the concentrator so as to ensure that this particle density is achieved, taking into account the altitude and speed at which it is planned to exploit the satellite.
Particles concentrated near the focus of the dish are used as propellant feed gas.
Due to the particular arrangement of its electrical circuit and its magnetic circuit, the thruster is designed to generate a cathode grid formed of electrons blocked by the magnetic field at or near the focus of these magnetic fields. parables.
The particles caught by the spacecraft are thus directed by the concentrator towards the focus of the parabola and thus towards the virtual cathode grid of the propellant. They then ionize and are accelerated towards the rear of the thruster under the effect of the electric field generated between the anode and the cathode of the electric circuit.
Thus, the arrangement of the propellant and in particular of its concentrator makes it possible to overcome the low density of particles at high altitude, by concentrating the particles found on the trajectory of the satellite in a reduced zone, in which they can be accelerated in a to generate a thrust for the spacecraft.
The thruster configured according to the second aspect of the invention may optionally comprise, as in the first aspect of the invention, a controllable voltage source whose poles can be inverted to allow the thruster to be used as a braking system.
Whether according to the first aspect or the second aspect, the invention can advantageously be implemented by integrating one or more of the following improvements: the contour from which the shape of the concentrator is defined can be in particular a circle, or an ellipse, or an oval; the anode may constitute a portion of the wall or one of said walls; the anode may be recessed in the wall or one of said walls.
Finally, the invention also relates to a spacecraft incorporating at least one Hall effect thruster as defined above. As such, it relates in particular to a spacecraft incorporating at least one Hall effect thruster according to the first aspect of the invention, the spacecraft being configured to carry a payload arranged radially inside the inner wall of the channel. thruster.
In one embodiment of such a spacecraft, the outline may be a circle, or an ellipse, or an oval.
In one embodiment of such a spacecraft, the anode may constitute a portion of one of the walls of the thruster channel.
BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and its advantages will appear better on reading the detailed description which follows, of embodiments shown by way of non-limiting examples. The description refers to the appended figures in which: - Figure 1 is a longitudinal section of a propellant for spacecraft, according to the first aspect of the invention; FIG. 2 is a perspective view of a satellite comprising the thruster of FIG. 1; - Figure 3 is a longitudinal section spacecraft comprising a propellant according to the second aspect of the invention; and FIG. 4 is a perspective view of the satellite of FIG.
DETAILED DESCRIPTION OF THE INVENTION
Two embodiments of the invention corresponding respectively to its first and second aspects will now be presented through the examples of two satellites 1 and 101, respectively comprising a thruster 10 and a thruster 110, both in accordance with the invention. .
These satellites 1 and 101 are satellites that are intended to evolve in the Earth's atmosphere by remaining between 100 and 300 km altitude.
Advantageously, this altitude is relatively low, which allows certain equipment (communication equipment, cameras, etc.) to have a relatively small size and therefore a relatively small mass. Conversely, at this altitude the Earth's atmosphere opposes a weak resistance, but not zero, to the passage of the satellite. It is therefore necessary to compensate for induced drag.
The function of the Hall effect thruster included in each of these satellites is to provide a thrust to the satellite, to maintain it in operation at the desired altitude.
It also allows for changes or corrections of orbits.
Advantageously, a thruster according to the invention, such as those on board these satellites, coupled with electrical energy supply means such as solar panels, is able to provide, over very long periods of time, the thrust required to maintain the altitude of the aircraft. satellite.
The first embodiment illustrates the first aspect of the invention in relation to FIGS. 1 and 2.
Figures 1 and 2 show the thruster 10 of the satellite 1 (an example of spacecraft), which is an atmospheric supply Hall effect thruster.
The thruster 10 generally has a shape of revolution about a thrust axis X. It is arranged inside a casing 20 of substantially cylindrical shape of X axis. The upstream end 22 of this casing is then open. that the other end 26 (downstream end) is partially closed by a substantially flat bottom 25 perpendicular to the X axis. However, the bottom 25 is traversed by an annular passage 28 for ejecting particles.
The bottom 25 has a general disc shape perpendicular to the axis X. Due to the presence of the passage 28, the bottom 25 is constituted by a disc 56, and by an annular ring 58 located radially around the annular passage 28. The crown 58 is integrally formed with the rest of the housing 20. Inside the housing 20, the thruster 10 comprises a channel 30 of generally annular shape about the axis X. More generally, this channel 30 may also be axisymmetric. However, non-axisymmetric shapes can alternatively be envisaged, for example, with an oval cross-section or racetrack.
The channel 30 is of generally annular shape and has a radially outer wall 34 and a radially inner wall 32, which are concentric about the X axis.
The channel 30 is essentially constituted by a particle concentrator 36, which opens on the upstream side (on the left in FIG. 1) of the satellite 1 and serves to collect the particles lying on the trajectory of the satellite.
On the downstream side, the concentrator 36 opens on the annular passage 28, which is itself open on the downstream side of the satellite 1 to allow the ejection of accelerated particles by the propellant 10.
According to the invention, the shape of the concentrator 36 is defined by a continuous contour C1. In this embodiment, this contour Cl is a circle, located in a plane perpendicular to the thrust axis. The circle C1 is centered on the X axis (and therefore it surrounds this axis).
In any plane perpendicular to the circle C1 (i.e., in this embodiment, in any meridian plane), the cross-section of the concentrator is that shown in FIG. 1: It has a parabolic shape S, whose focus Fl belongs to the circle Cl (Only a part of the parabola S serves to define the shape of the concentrator 36).
The circle C1 is positioned to be located axially at the annular passage 28.
On the upstream side, the thruster 10 further comprises connecting arms 24 which provide a mechanical connection between the inner and outer walls 32 and 34 of the channel 30. Between the arms 24 are formed four openings 25 through which particles P enter the chamber. channel 30.
The thruster 10 comprises a magnetic circuit 50 and an electrical circuit 60.
The magnetic circuit 50 comprises: the housing 20 itself, which is made of ferromagnetic material and thus forms an external magnetic core; the bottoms 24 and 25, made of ferromagnetic material; and a central magnetic core 54 in the shape of a shaft, which extends along the axis X. The disk 56 which constitutes part of the bottom 25 forms the downstream end of the shaft 54. The set of elements of the circuit Magnet 50 previously indicated are arranged to allow a lossless circulation of a magnetic field through the magnetic circuit.
To protect the downstream part of the channel from wear and to contain the electron cloud formed in the air gap of the magnetic circuit, the axially downstream portions of the walls 32 and 34 are formed by rings of ceramic material 82 and 84, positioned at the ring passage 28.
The magnetic circuit 50 further comprises an inner annular coil 70 and an outer annular coil 72, which serve to generate the magnetic field B necessary for the operation of the Hall effect thruster. These two coils are formed concentrically about the axis X. They are substantially cylindrical coils, each of which turns substantially a circle of axis X.
The coil 70 is formed around the shaft 54 inside (radially) of the wall 32 (i.e., between the shaft 54 and the wall 32). The coil 72 is formed on the inner face of the cylindrical housing 20, and more precisely between the inner face and the outer wall 34 of the channel 30. The coils 70 and 72 are powered by a source of electrical energy not shown.
In the magnetic circuit 50, the central magnetic core 54 and the external magnetic core (the housing 20) are arranged in such a way that their polarities are opposite.
The circuit 50 is arranged to generate a substantially radial magnetic field B in the annular passage 28, which thus constitutes the air gap of the circuit 50. Thus, the downstream part of the channel 30 passes or extends in the gap 28 of the circuit 50.
In the channel 30, the intensity of the magnetic field B is maximum at (axially) level of the annular passage 28. On the other hand, as previously indicated, the thruster 10 also comprises an electric circuit 60.
This circuit comprises an anode 62 located axially slightly upstream of the annular passage 28, a cathode 64 located for the most part downstream of the end 26 of the channel 30 (and therefore downstream of the passage 28), and a voltage source 68 connecting the anode 62 to the cathode 64.
In this embodiment, the voltage source 68 is controllable (although this is not shown in the figures): its voltage can be inverted to reverse the thrust of the thruster. The anode 62 forms part of the internal wall 34 of the channel 30: it is thus integrated with this channel, while being electrically isolated from it (and in particular from the wall 34).
In the vicinity of the anode 62, the magnetic field B generated by the magnetic circuit 50 is attenuated by internal and external magnetic screens 77 formed respectively on the inner surface of the housing 20 and on the outer surface of the shaft 54. These screens 77 are also used to mechanically support the coils 70 and 72.
The cathode 64 is located outside the open downstream end of the annular channel 28. In the embodiment of FIGS. 1 and 2, it is fixed on the disk 56, on the outer side, that is to say on the outside. downstream of the shaft 54. In Figure 2, the cathode 64 is shown in dashed lines.
In another embodiment, the cathode 64 can be fixed not on the disk 56, but rather on the outer surface (on the downstream or rear side) of the ring 58. The cathode can then have in particular an annular shape, and not the stud shape shown in FIG.
The cathode 64 is connected to the electrical voltage source 66 by a cable flowing inside the inner wall 32 of the channel 30, and more specifically, inside the shaft 54.
In the embodiment of FIGS. 1 and 2, the volume available inside (radially) of the wall 32 is arranged to receive a payload 35 of the satellite 1.
This is arranged radially inside the inner wall 32, as illustrated in FIGS. 1 and 2.
In another embodiment, the thruster may be specifically designed with a much larger interior volume inside the wall 32. A large part, or even the totality of the payload can then be arranged in this volume, at the inside the inner wall 32 of the thruster channel 30.
In this case, the thruster is arranged in practice in the form of an annular structure arranged around the payload of the satellite or more generally of the spacecraft.
The operation of the thruster 10 will now be described. This operation is globally identical to that of the thruster described in document US2003 / 0046921 A1.
When the satellite 1 moves at high speed in the atmosphere, the particles in its path are caught by the concentrator 36 and penetrate into it.
As shown in FIG. 1, when a particle P thus enters the concentrator 36, it most often strikes one of the walls 32 or 34 thereof.
However, it has been found that particles bounce almost specularly on the walls of satellites or spacecraft. In other words, the shocks between a particle and a wall of the satellite seem to be frictionless, that is to say that the angle of incidence and the ejection angle of the particle vis-à- Wall screws are equal.
Consequently, following this shock and because of the properties of the focus of a dish, a particle P striking a wall 32 or 34 of the concentrator 36 is returned to the focus Fl, that is to say towards a point of the circle Cl.
Thus, the concentrator advantageously makes it possible to direct the particles caught by the satellite 1 into a rather small area located in the vicinity of the circle C1.
This circle C1 is positioned so as to be situated at the place where the radial magnetic field B generated by the magnetic circuit is the most intense, that is to say at the level of the annular passage 28.
In addition, an electric voltage, typically of the order of 150 to 800 V is established between the cathode 64 downstream of the downstream end of the channel 30 and the anode 62. The cathode 64 thus emits electrons, which are in large part trapped in a 'magnetic enclosure' formed by the magnetic field B. This magnetic chamber is adapted to the desired performance and is typically of the order of 100 to 300 gauss. The electrons trapped in this magnetic chamber thus form a virtual cathode grid 65, substantially forming a ring along the circle C1 inside the channel 30.
An electric field E is thus generated in the channel 30, at the annular passage 28 (Fig.l) and upstream thereof to the anode 62, and in particular at the virtual cathode gate 65.
A small part of the electrons thus trapped, namely those which are the most energetic (typically 10 to 40 eV), however, escape the magnetic chamber and join the anode 62.
As indicated above, the particles P which are captured by the satellite 1 are concentrated by the concentrator 36 in the vicinity of the circle C1. They thus enter the virtual cathode grid 65 formed by the electrons trapped by the magnetic field B.
The impacts between these electrons and the particles P ionize them. Due to their electric charge, the ionized particles are then accelerated towards the downstream end 26 of the channel 30 by the electric field E. Since the mass of the ionized particles is several orders of magnitude higher than that of the electrons, the magnetic field does not confine these ions as it does for electrons. The thruster 10 thus generates a plasma jet which is ejected at an extremely high speed through the downstream end of the channel 30. The thruster 10 thus produces a thrust substantially aligned with the central axis X.
The second embodiment, which illustrates the second aspect of the invention, will now be presented in connection with FIGS. 3 and 4.
FIG. 3 represents a satellite 101 comprising a Hall effect thruster 110 according to the invention.
The satellite 101 is arranged in an outer protective casing 120 which generally has a shape of revolution about an axis X. The thruster 110 is arranged inside the outer wall 122 of the casing 120.
The thruster 110 has an axisymmetric structure about the X axis. The terms "upstream" and "downstream", in the present context, are defined with respect to the normal direction of circulation of the satellite and therefore of the thruster.
The wall 122 has two parts, namely a particle concentrator 136, which serves to concentrate the particles P in the path of the satellite 101 or in the vicinity thereof, and a rear portion 124 located downstream of the concentrator 136.
The shape of the concentrator 136 is defined by a continuous contour C2. As in the previous embodiment, the outline C2 is a circle. It is located in a plane perpendicular to the axis of thrust X and around the wall 120.
In section in any plane perpendicular to the contour C2, the concentrator 122 has a parabolic shape with a focus F2 belonging to the contour C2.
The concentrator 136 and the rear portion 124 meet at a ridge forming a circle C3 (Fig.4).
The rear portion 124 of the wall 120 is of cylindrical shape of axis X; its shape is that caused by the displacement of the circle C3 rearward along the direction of the axis X.
The thruster 110 comprises a magnetic circuit 150 and an electrical circuit 160.
The magnetic circuit 150 is arranged to create a substantially radial magnetic field at (axially, with reference to the X axis) of the upstream portion of the wall 122.
For this purpose, it comprises a plurality of identical elementary magnetic circuits 132 distributed axisymmetrically around X-axis.
Each circuit 132 has a soft iron core 134 which in an axial section is U-shaped. The core 134 has a long rod 136 which extends parallel to the X axis near the wall 122 (and at the inside of it). It also comprises two angled sections 138 which are bent in a radial plane towards the wall 122, so that the end of these sections is disposed just below the surface of the wall 122. Next to these sections 138, the housing 120 has rings 140 of non-magnetic material to allow the passage of the magnetic field. The rings 140 may for example be ceramic, polycrystalline cubic carbon (that is to say diamond) or alumina.
Each circuit 132 also comprises a coil 146 forming a solenoid arranged around the rod 136.
The terminals of the coils 146 of the circuits 132 are connected to those of a voltage source 144. This voltage source is chosen such that under the effect of the voltage applied to the coils 146, a stable magnetic field B can be created around the wall. A power source can also be used.
As a result, when a voltage is applied by the voltage source 144 to the coils 146, each magnetic circuit 132 generates a magnetic field B. This field is radiated by the circuit 132 outside the satellite 101 in the space in the vicinity of the satellite. The shaped field lines are shown in FIG. 3. As shown in this figure, the ends of the bent sections 138 thus form magnetic poles for the circuits 132, namely an upstream magnetic pole 170 and a downstream magnetic pole 172.
At the right of an upstream magnetic pole 170, the magnetic field B is oriented in a direction substantially perpendicular to the surface of the wall 122.
As can be seen in FIG. 4, the upstream magnetic poles 170 of two adjacent elementary magnetic circuits 132 are formed so as to be close to one another, or even possibly to be in contact. The same goes for the downstream magnetic poles 172. This allows the magnetic circuit to have an upstream magnetic pole and a downstream magnetic pole in any axial plane, which generate the magnetic field B. Thanks to this, the magnetic field B is generated substantially uniformly over the entire periphery of the wall 122.
The upstream magnetic poles 170 are formed at (axially) the contour C2. Thus, the magnetic circuit 150 is arranged in such a way that the magnetic field B generated at the right of the upstream magnetic pole is generated in the vicinity of the contour C2.
The thruster 110 also comprises an electrical circuit 160. This circuit comprises an anode 162, a first cathode 164, a second cathode 166, a third cathode 167 and a voltage source 168 connecting the anode 162 to the first, the second cathode and the third cathode 164, 166, 167. The anode 162 is located axially upstream of the upstream magnetic pole 170. The first cathode 64 is located downstream of the upstream magnetic pole 170 but in the immediate vicinity thereof and therefore at a distance upstream of the downstream magnetic pole 172.
The second cathode 166 is located between the upstream magnetic pole 170 and the downstream magnetic pole 172. It is therefore downstream of the upstream magnetic pole 170, and upstream of the downstream magnetic pole 172.
The third cathode 167 is located downstream of the downstream magnetic pole 172.
Each of the cathodes 166 and 167 is furthermore located near the downstream magnetic pole 172, and therefore at a distance downstream from the first cathode 164. The anode 162, as well as the first, second and third cathodes 164, 166, 167 are each in the form of a ring. Each of these rings extends over the entire circumference of the wall 122 generally in a plane perpendicular to the X axis (or more precisely, between two close planes perpendicular to the X axis). Each of these cathodes is flush with the surface of the wall 122 and thus constitutes a portion of this wall.
The thruster 110 operates in a similar manner to the thruster 10.
Like the voltage source 68 in the previous embodiment, the voltage source 168 is controllable: its voltage can be inverted to reverse the thrust of the thruster.
According to the direction given to the voltage by the voltage source 168, the force generated by the thruster 110 may be in one direction or the other, in the direction X; as the case may be, the thruster therefore acts either as a motor system or as a braking system.
The operating mode of the thruster described here is the motor mode:
When a voltage is applied by the voltage source 168 between the anode 162 and the cathodes 164, 166 and 167, an electric field E is formed in the space outside the satellite around the wall 122, essentially between the anode 162 and the first cathode 164. This field is oriented substantially in a direction parallel to the axis X.
In addition, under the effect of the voltage established between the cathodes 164, 166 and 167 downstream and the anode 162 upstream, the cathodes 164, 166 and 167 begin to emit electrons. These are largely trapped in a magnetic chamber formed by the magnetic field created by the magnetic circuit 150, adapted to the desired performance, and which can be typically of the order of 100 to 300 gauss. The electrons trapped in this magnetic chamber will thus form a virtual cathode grid 165. However, some high energy electrons (typically 10 to 40 eV) escape the magnetic chamber and join the anode 62.
Due to the relative displacement of the satellite 101 with respect to the atmosphere, at each moment particles enter the virtual cathode grid 165. The impacts between the electrons retained in this gate and the atoms of these particles cause the ionization of these particles. this. The ionized particles, under the effect of the electric field E created by the electrical circuit 160, are then accelerated towards the rear of the satellite. The thruster 110 thus generates a plasma jet which is ejected at an extremely high speed in the X direction towards the rear of the satellite, downstream of the wall 122. For reasons of symmetry, the thrust generated is substantially aligned with the central axis X.
When the thruster 110 is in operation, the second and third cathodes 166 and 167 provide electrons to the particles released downstream of the satellite 100, and thus ensure the electrical neutrality thereof. The use of the second cathode 166 is optional. It is mainly the third cathode 67, situated downstream of the downstream magnetic pole 52, which supplies the electrons necessary for the neutralization of the particles accelerated by the propellant 10.
Advantageously, the propellant according to the invention does not require a supply of propellant gas, unlike most Hall effect thrusters.
In addition, its arrangement on the outer wall of the satellite releases a large part of the interior space of the satellite, which allows to have a large payload.
Note also that the electric field E generated by the electrical circuit 160 is extremely low in the vicinity of the downstream magnetic pole 172. As a result, the force generated by the thruster 110 is created in the vicinity of the upstream magnetic pole 170; in the absence of an electric field E in the vicinity of the downstream magnetic pole 172, almost no reverse force is generated in the vicinity of the latter pole.
Advantageously according to the invention, it is not necessary for the concentrator to direct the particles which it concentrates precisely towards the focus of the parabola defined by its wall (in the case of the propellant 10) or by its walls (in the case of the thruster 110). As a virtual cathode grid is formed in a certain volume surrounding this focus, it is sufficient that the particles caught by the concentrator are directed within this volume. This gives some tolerance as to the shape of the wall or walls of the concentrator.

权利要求:
Claims (10)
[1" id="c-fr-0001]
A Hall effect thruster (10) for developing thrust along a thrust axis, the thruster comprising: a channel (30) for collecting, accelerating and ejecting particles by the thruster when the thruster is in operation, the channel (30) being delimited radially by an inner wall (32) and an outer wall (34); an electrical circuit (60) including an anode (62), a cathode (64), and a voltage source (68) for emitting electrons via the cathode (64) and attracting electrons through the anode (62); a magnetic circuit (50) for generating a magnetic field (B) in the channel (30) axially downstream of the anode, the magnetic field being directed in a substantially radial direction with respect to the thrust axis (X); the thruster being characterized in that the channel (30) is open on an upstream side of the propellant and has a particle concentrator (36) for collecting particles (P); the shape of the concentrator is defined by a continuous contour (C1) located in a plane perpendicular to the thrust axis and surrounding it; over a major part of the contour, each section of the concentrator perpendicular to the contour is parabolic and has a focus (F1) belonging to the contour (C1); and the magnetic circuit (50) is arranged to generate the magnetic field (B) in the vicinity of the contour (C1).
[2" id="c-fr-0002]
2. Propeller according to claim 1, wherein the magnetic circuit comprises a plurality of link arms (24) arranged to connect the inner wall (32) and the outer wall (34) of the channel, the channel having an annular shape. .
[3" id="c-fr-0003]
A Hall effect thruster (110) for developing a thrust along a thrust axis, the thruster comprising: a magnetic circuit (150) for generating a magnetic field (B); an electrical circuit (160) including an anode (162), a first cathode (164), and a voltage source (168) for emitting electrons at least via the first cathode (164) and attracting electrons via the anode (162); the thruster being characterized in that. the thruster (110) is arranged inside a wall (122) formed around the thrust axis (X); . the magnetic circuit (150) and the electrical circuit (160) are arranged to generate magnetic (B) and electrical (E) fields around the wall (122); and. in any section parallel to the thrust axis (X) and perpendicular to the wall (122): the magnetic circuit (150) has an upstream magnetic pole (170) and a downstream magnetic pole (172) disposed substantially on the surface of the wall at a distance from each other, and the magnetic circuit (150) is arranged such that the magnetic field is oriented in a direction substantially perpendicular to the surface of the wall to the right of the upstream magnetic pole (170). ); the anode (162) and the first cathode (164) are located on either side of the upstream magnetic pole (170); and in that : . the wall (120) has a particle concentrator (136) for concentrating particles (P); the shape of the concentrator being defined by a closed contour (C2) located in a plane perpendicular to the thrust axis and running around the wall; over a major part of the contour, each section of the concentrator perpendicular to the contour being of parabolic shape and having a focus (F2) belonging to the contour (C2); the magnetic circuit (150) being arranged to generate the magnetic field in the vicinity of the contour (C2).
[4" id="c-fr-0004]
4. Propeller according to any one of claims 1 to 3, wherein said contour (C1, C2) is a circle, or an ellipse, or an oval.
[5" id="c-fr-0005]
5. Propellant according to any one of claims 1 to 4, wherein the anode (62,162) constitutes a portion of the wall (122) or one of said inner and outer walls (32,34).
[6" id="c-fr-0006]
The thruster of any one of claims 1 to 5, wherein the anode (62,162) is recessed in the wall (122) or one of said inner and outer walls (32,34).
[7" id="c-fr-0007]
7. Spacecraft (1; 101) incorporating at least one Hall effect thruster (10; 110) according to any one of claims 1 to 6.
[8" id="c-fr-0008]
8. Spacecraft (1; 101) incorporating at least one Hall effect thruster (10; 110) according to claim 1 or 2, the spacecraft being configured to carry a payload disposed radially inside the inner wall. (32) of the channel (30).
[9" id="c-fr-0009]
9. Spacecraft according to claim 8, wherein said contour (Cl) is a circle, or an ellipse, or an oval.
[10" id="c-fr-0010]
Spacecraft according to claim 8 or 9, wherein the anode (62) constitutes a portion of one of said walls (32,34).

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同族专利:

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公开号 | 公开日

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IL256754D0|2018-03-29|

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BR112018000271A2|2018-12-18|

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CN107850055A|2018-03-27|

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US20180216606A1|2018-08-02|

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WO2017006056A1|2017-01-12|

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EP3320208B1|2019-08-28|

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US10662930B2|2020-05-26|

---

JP2018525557A|2018-09-06|

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EP3320208A1|2018-05-16|

---

CN107850055B|2020-02-21|

---

FR3038663B1|2019-09-13|

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JP6756814B2|2020-09-16|

---

IL256754A|2021-07-29|

引用文献:

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公开号 | 申请日 | 公开日 | 申请人 | 专利标题

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US20030046921A1|2001-06-21|2003-03-13|Vlad Hruby|Air breathing electrically powered hall effect thruster|

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US20050178919A1|2003-10-30|2005-08-18|Dressler Gordon A.|System and method for an ambient atmosphere ion thruster|

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US20080116808A1|2006-11-22|2008-05-22|Mcclure Paul D|Over-Wing Traveling-Wave Axial Flow Plasma Accelerator|FR3101383A1|2019-09-26|2021-04-02|Tarek Romain Imtital|Double-flow electrothermal thruster|US6145298A|1997-05-06|2000-11-14|Sky Station International, Inc.|Atmospheric fueled ion engine|

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FR2945842B1|2009-05-20|2011-07-01|Snecma|PLASMA PROPELLER WITH HALL EFFECT.|

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FR2950115B1|2009-09-17|2012-11-16|Snecma|PLASMIC PROPELLER WITH HALL EFFECT|

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FR2982914B1|2011-11-22|2014-01-17|Snecma|HALL EFFECTOR|

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CN102767497B|2012-05-22|2014-06-18|北京卫星环境工程研究所|Fuel-free spacecraft propelling system based on spatial atomic oxygen and propelling method|ES2733773B2|2018-05-31|2021-10-01|Univ Madrid Carlos Iii|U-Geometry Electrodeless Plasma Space Engine and Use of U Geometry|

---

EP3872341A1|2020-02-25|2021-09-01|Von Karman Institute For Fluid Dynamics|Adjustable intake-collector for the optimum propulsion efficiency of an air-breathing electric thruster|

法律状态:
2016-08-04| PLFP| Fee payment|Year of fee payment: 2 |

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2017-01-13| PLSC| Search report ready|Effective date: 20170113 |

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2017-05-02| PLFP| Fee payment|Year of fee payment: 3 |

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2018-06-21| PLFP| Fee payment|Year of fee payment: 4 |

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2019-06-21| PLFP| Fee payment|Year of fee payment: 5 |

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2020-04-10| CD| Change of name or company name|Owner name: SAFRAN AIRCRAFT ENGINES, FR Effective date: 20200304 |

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2020-06-23| PLFP| Fee payment|Year of fee payment: 6 |

优先权:

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申请号 | 申请日 | 专利标题

---

FR1556477A|FR3038663B1|2015-07-08|2015-07-08|HIGH-ALTITUDE HALL-EFFECT THRUSTER|

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FR1556477|2015-07-08|FR1556477A| FR3038663B1|2015-07-08|2015-07-08|HIGH-ALTITUDE HALL-EFFECT THRUSTER|

---

BR112018000271-2A| BR112018000271A2|2015-07-08|2016-07-06|hall effect thruster and space vehicle.|

---

US15/742,288| US10662930B2|2015-07-08|2016-07-06|Hall-effect thruster usable at high altitude|

---

JP2018500494A| JP6756814B2|2015-07-08|2016-07-06|Hall effect propulsion machine that can be used at high altitudes|

---

CN201680042275.9A| CN107850055B|2015-07-08|2016-07-06|Hall effect thruster for high altitude|

---

PCT/FR2016/051715| WO2017006056A1|2015-07-08|2016-07-06|Hall-effect thruster usable at high altitude|

---

EP16750927.2A| EP3320208B1|2015-07-08|2016-07-06|Hall-effect thruster usable at high altitude|

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IL256754A| IL256754A|2015-07-08|2018-01-07|Hall-effect thruster usable at high altitude|