Device for regulating the rate of flow of propellant fluid for an electric thruster
Device ( 52 ) for regulating the rate of flow of propellant fluid for an electric thruster, of the thermo-capillary device type comprising at least one capillary duct that is electrically conductive and capable of regulating the rate of flow of propellant fluid under the action of a change in temperature of the duct, characterized in that said at least one capillary duct comprises a nickel-based alloy.
1. A thermo-capillary device for regulating a flow rate of a propellant fluid for an electric thruster, the thermo-capillary device consisting of at least one capillary duct that is electrically conductive and regulates the flow rate of the propellant fluid under the action of a change in temperature of the at least one capillary duct,
wherein said at least one capillary duct comprises a nickel-based alloy configured to avoid oxidation of the at least one capillary duct and maintain the flow rate for a service life of the thermocapillary device,
wherein the thermo-capillary device comprises Xenon or Krypton as said propellant fluid,
wherein the at least capillary duct of the thermo-capillary device is configured to be connected to a source of electric current such that an electric current passing through the at least one capillary duct provides heating of said at least one capillary duct by Joule effect, and
wherein said at least one capillary duct is connected to an electric current source.
2. The device according to claim 1 , wherein said at least one capillary duct consists of the nickel-based alloy.
3. The device according to claim 1 , wherein the nickel-based alloy comprises at least one element selected from chromium, iron, manganese, copper, niobium and molybdenum.
4. The device according to claim 3 , wherein the nickel-based alloy comprises iron.
5. The device according to claim 4 , wherein an iron content is less than or equal to 10% of the weight of the alloy.
6. The device according to claim 4 , wherein the nickel-based alloy comprises iron and chromium.
7. The device according to claim 6 , wherein the nickel-based alloy is selected from a) an alloy comprising at least 72% by weight of nickel, from 14 to 17% by weight of chromium and from 6 to 10% by weight of iron, b) an alloy comprising at least 58% by weight of nickel, from 20 to 23% by weight of chromium and the iron content less than or equal to 5% by weight, and c) an alloy comprising from 50 to 55% by weight of nickel and from 17 to 21% by weight of chromium.
8. The device according to claim 1 , wherein the nickel-based alloy comprises, as a percentage by weight, from 24 to 26% of chromium, from 0.15 to 0.25% of carbon, from 1.8 to 2.4% by aluminium, from 0.1 to 0.2% of titanium, from 0.05 to 0.12% of yttrium, from 0.01 to 0.10% of zirconium, at most 0.15% of manganese, at most 0.5% of silicon, at most 0.1% of copper, from 8 to 11% of iron, the remainder being nickel.
9. The device according to claim 1 , wherein the nickel-based alloy comprises, as a percentage by weight, 16% of chromium, 4.5% of aluminium, 3% of iron, at most 2% of cobalt, at most 0.5% of manganese, at most 0.5% of molybdenum, at most 0.5% of titanium, at most 0.5% of tungsten, at most 0.15% of niobium, at most 0.2% of silicon, at most 0.1% of zirconium, 0.04% of carbon, at most 0.01% of boron, 0.01% of yttrium, the remainder being nickel.
10. The device according to claim 1 , wherein the nickel-based alloy comprises, as a percentage by weight, 22% of chromium, 14% of tungsten, 2% of molybdenum, at most 3% of iron, at most 5% of cobalt, 0.5% of manganese, 0.4% of silicon, at most 0.5% of niobium, 0.3% of aluminium, at most 0.1% of titanium, 0.1% of carbon, 0.02% of lanthanum, at most 0.015% of boron, the remainder being nickel.
11. An electric thruster comprising a thermo-capillary device according claim 1 .
12. The electric thruster according to claim 11 , wherein said electric thruster is a Hall effect plasma thruster.
13. A satellite comprising an electric thruster according to claim 11 .
14. The device according to claim 1 , wherein the nickel-based alloy comprises at least 50% by weight of nickel.
15. The electric thruster according to claim 11 , wherein the electric thruster comprises:
a central hub extending about a main longitudinal axis,
a central magnetic winding surrounding the central hub,
an annular inner wall surrounding the central winding,
an annular outer wall surrounding the annular inner wall, wherein the annular inner wall and the annular outer wall delimiting an annular discharge channel extending about the main longitudinal axis,
a several peripheral magnetic windings having an axis parallel to the main longitudinal axis and the several peripheral magnetic windings are arranged all around the annular outer wall,
an anode configured to be used as a distributor for the injection of gas molecules in the annular discharge channel,
a cathode arranged at an outside of the several peripheral magnetic windings,
a supply system having a low-pressure buffer tank and a high-pressure tank of ionisable gas connected to the low-pressure buffer tank, wherein the supply system comprises, downstream from the low-pressure buffer tank, the thermo-capillary device configured to a fine adjustment of the flow rate of the propellant fluid towards the anode and the cathode respectively.
16. The electric thruster according to claim 15 , wherein the annular inner wall and the annular outer wall form an integral ceramic part.
17. A thermo-capillary device for regulating a flow rate of a propellant fluid for an electric thruster, the thermo-capillary device consisting of at least one capillary duct that is electrically conductive and regulates the flow rate of the propellant fluid under the action of a change in temperature of the at least one capillary duct,
wherein said at least one capillary duct consists of a nickel-based alloy configured to avoid oxidation of the at least one capillary duct and maintain the flow rate for a service life of the thermocapillary device, wherein the nickel-based alloy comprises at least 50% by weight of nickel,
wherein the thermo-capillary device comprises Xenon or Krypton as said propellant fluid,
wherein the at least capillary duct of the thermo-capillary device is configured to be connected to a source of electric current such that an electric current passing through the at least one capillary duct provides heating of said at least one capillary duct by Joule effect, and
wherein said at least one capillary duct is connected to an electric current source.
18. The thermo-capillary duct according to claim 1 , wherein a viscosity of the propellant fluid which circulates into the at least one capillary duct being heated, is changed and as soon as a flow conditions of the propellant fluid in the at least one capillary duct are also changed, such that the thermo-capillary device is configured to adjust a desired flow rate of propellant fluid according to the electric current applied on the at least one capillary duct.