Impulse propulsion system
The propulsion system addresses inefficiencies in current space propulsion by converting translational motion into rotational motion within viscous fluids, achieving high-thrust propulsion without fuel consumption, thereby reducing travel time and extending satellite lifespan.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2021-12-28
- Publication Date
- 2026-03-27
AI Technical Summary
Current space propulsion systems face inefficiencies in specific impulse, leading to long mission times and high fuel consumption, with electric propulsion systems having low thrust and chemical systems requiring excessive propellant, while satellite orbit changes are not feasible due to fuel constraints, and low Earth orbit lifespans are limited by fuel depletion and debris avoidance maneuvers.
A propulsion system utilizing counter-rotating longitudinal tubes with projectiles that convert translational motion into rotational motion within a viscous fluid, dissipating heat and generating momentum without conserving overall momentum, allowing for high-thrust propulsion without fuel consumption.
The system enables reduced travel time to reach orbits, decreased fuel mass, and increased satellite lifespan by leveraging non-isolated momentum conservation principles, enhancing propulsion efficiency and reducing debris-related maneuvers.
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Abstract
Description
Title of the invention: Impulse propulsion system Technical field of the invention
[0001] The invention relates to a propulsion system, and more specifically to an impulse propulsion system.
[0002] The invention is particularly intended for application in the space field, to equip a space vehicle such as a satellite. Previous technique
[0003] Space propulsion, to date, is based on the principle of action and reaction. Schematically, in terms of propulsion, this translates to the conservation of momentum in an isolated system. Typically, if gases are ejected from a spacecraft with a certain momentum, a momentum of the same magnitude and opposite direction to that of the gases is imparted to the spacecraft. In such a case, matter must be consumed to move forward, since momentum must be ejected from the spacecraft. The efficiency of a propulsion system is measured by a quantity called specific impulse, the unit of which is the second. However, this quantity does not tell the whole story.Currently, placing a six-tonne telecommunications satellite from a geostationary transfer orbit (GTO) to a geostationary orbit (GEO) using chemical propulsion with a specific engine impulse of 320 seconds requires eight days and three tonnes of propellant. With electric propulsion, where the engine specific impulse is 1500 seconds, eight months are required, but only 400 kg of propellant (usually xenon) are needed, reducing the satellite's mass to less than four tonnes.
[0004] In other words, current electric propulsion systems have a high specific impulse, but a low thrust, which results in very long mission times and lower launch costs, because the mass of fuel, for a given mission, is much lower than for chemical propulsion systems.
[0005] Furthermore, once a satellite, whatever its type, is in orbit, its orbit describes a plane. A change of plane is not currently feasible due to excessive fuel consumption.
[0006] On the other hand, a satellite in polar orbit, therefore in low Earth orbit, has overall a Lifespan of five years, corresponding to the time it takes to consume the fuel on board.
[0007] Finally, as space debris becomes more numerous, the number of avoidance maneuvers increases and, as a result, the lifespan of satellites in low Earth orbit potentially decreases. Presentation of the invention
[0008] The present invention aims to remedy the aforementioned drawbacks.
[0009] To this end, the present invention proposes a propulsion system comprising a motor having a pair of parallel longitudinal tubes, each longitudinal tube having a first end and a second end, and delimiting an internal volume filled with a fluid. Each longitudinal tube comprises: - a projectile, configured to move longitudinally within the internal volume, and fixedly attached to a propeller, - a mechanism for launching the projectile into the internal volume, from the first end of said longitudinal tube, the propeller being arranged to transform a translational movement of the projectile into a rotational movement, - a device for braking the rotation of the projectile within the internal volume, located at the second end of the longitudinal tube, - a device for returning the projectile from the second end to the first end of the longitudinal tube, - a heat dissipation device.
[0010] Said projectile launching mechanism and said projectile recall device being powered by at least one power source.
[0011] The said helices of the two longitudinal tubes are counter-rotating. Thus, when the helices are in rotation, two identical but opposite angular momenta will be created and will substantially cancel each other out.
[0012] Such a propulsion system is a pulse-thrust propulsion system. Each time the projectile is launched in its longitudinal tube by the launching mechanism, the projectile acquires momentum towards the other end of the longitudinal tube. During the impulse, the longitudinal tubes, and therefore the propulsion system, acquire momentum in the opposite direction, in accordance with the principle of action and reaction described above.
[0013] The propulsion system according to the invention advantageously allows the translational motion of the projectile to be partially converted into rotational motion, thanks to the viscosity of the fluid. Part of the rotational motion will be transformed into heat, due to the viscosity of the fluid, and another part will be transformed, depending on the nature of the braking device, either into heat or electrical energy. Thus, the part transformed into rotation does not affect the balance of the total longitudinal momentum of the system.
[0014] At a given instant, the projectile has a non-zero translational velocity towards the second end. It will therefore encounter fluid molecules, and the propeller will transform some of the translational energy into rotational energy of the projectile. At the end of its trajectory, at the second end of the longitudinal tube, the projectile potentially no longer has a translational velocity, but a rotational velocity. If we applied the principle of conservation of momentum, angular momentum should also be conserved. However, it is the fluid contained within the internal volume of the longitudinal tube, and not the longitudinal tube itself, that sets the propeller and the projectile in motion. We would therefore have a system with conservation of translational momentum, that is to say, stationary, but with non-zero angular momentum.The principle of conservation of momentum in an isolated system therefore does not apply in our case, because the system is not isolated.
[0015] Furthermore, in each longitudinal tube, the heat generated during the projectile's trajectory within the internal volume is dissipated by means of the heat dissipation device. The use of a heat dissipation device demonstrates that the propulsion system does not operate as an isolated system.
[0016] The longitudinal tubes (volume, length), the mass of the projectile and the impulse given to the projectile are dimensioned so that, in each longitudinal tube, the translational displacement of the projectile stops at the level of the second end of the longitudinal tube.
[0017] The projectile retrieval device advantageously allows the projectile to be brought back from the second end to the first end of the longitudinal tube so that it can be relaunched there.
[0018] In particular embodiments, the invention further meets the following characteristics, implemented separately or in each of their technically operative combinations.
[0019] In particular embodiments of the invention, to avoid contact between the projectile and the longitudinal tube, each longitudinal tube includes a device for holding the projectile in the internal volume.
[0020] In particular embodiments of the invention, the projectile retention device comprises at least one connecting arm extending between the projectile and the longitudinal tube.
[0021] In particular embodiments of the invention, so as not to impede the rotation of the projectile during its course in the longitudinal tube, the device of The support and the projectile are connected by a pivot joint.
[0022] In particular embodiments of the invention, to direct the projectile, each longitudinal tube includes a device for guiding the projectile in translation within the internal volume.
[0023] In particular embodiments of the invention, the projectile translational guidance device cooperates with the projectile retention device.
[0024] In particular embodiments of the invention, the same power supply is configured to power said projectile launching mechanism and said projectile recall device from at least one longitudinal tube.
[0025] In particular embodiments of the invention, the propulsion system comprises a tilting device configured to independently rotate each of the two longitudinal tubes around a respective parallel pivot axis, preferably of approximately 90°, in opposite directions. This tilting device is activated only once the projectile has reached the second end of the longitudinal tube, to accelerate the projectile's return, via the projectile retrieval device, to the first end of the longitudinal tube.
[0026] In particular embodiment configurations, to increase the thrust of the propulsion system in the same direction, said propulsion system comprises a plurality of pairs of parallel longitudinal tubes, the pairs being arranged parallel to each other.
[0027] The invention also relates to a vehicle, in particular a space vehicle, comprising a propulsion system conforming to at least one of its embodiments. A space vehicle equipped with such a propulsion system would have a reduced travel time to reach a given orbit, compared to a space vehicle equipped with conventional chemical or electric propulsion systems, without fuel consumption. Brief description of the figures
[0028] The invention will be better understood upon reading the following description, given by way of non-limiting example, and made with reference to the figures:
[0029] [Fig. 1] illustrates a propulsion system comprising a motor including a pair of longitudinal tubes, according to an embodiment of the invention,
[0030] [Fig.2] illustrates a variant of the embodiment of a projectile in a longitudinal tube.
[0031] In these figures, for reasons of clarity, the drawings are not to scale unless otherwise stated. Description of the implementation methods
[0032] The present invention relates to a propulsion system.
[0033] This propulsion system can, in general, be fitted to any means of transport, in particular those in the aeronautical, space, rail, automotive or maritime fields, without this being restrictive of the invention.
[0034] The invention is described in the particular context of one of its preferred fields of application in which the propulsion system is intended to be installed in a space vehicle, such as a satellite. However, nothing precludes the propulsion system from being installed in any other type of vehicle.
[0035] Fig. 1 schematically illustrates a propulsion system according to a preferred embodiment of the invention.
[0036] The propulsion system includes a motor 500. Said motor comprises at least one pair of longitudinal tubes 100.
[0037] In the following description, the propulsion system will be described in the preferred case where the engine comprises a pair of longitudinal tubes, as illustrated in [Fig.1].
[0038] The two longitudinal tubes 100 are advantageously arranged parallel to each other.
[0039] Preferably, the two longitudinal tubes 100 are similar and independent of each other.
[0040] Each longitudinal tube 100 has two longitudinal ends, called first end 10 and second end 11. Each longitudinal tube 100 is hermetically sealed, watertight and closed at its two longitudinal ends.
[0041] The two longitudinal tubes 100 are advantageously positioned in the same direction, with their first ends 11 arranged on the same side.
[0042] In the example of [Fig.1], the first ends 11 of the longitudinal tubes 100 are located on the left of [Fig.1].
[0043] Each longitudinal tube 100 preferably has a circular cross-section, as illustrated in [Fig.1], but may also have any other cross-sectional shape, for example square, rectangular, elliptical..., without this being a limitation of the invention.
[0044] Each longitudinal tube 100 is preferably made of a carbon material.
[0045] Each longitudinal tube 100 delimits a hollow internal volume 12, in which a fluid evolves.
[0046] Preferably, the fluid is a viscous fluid.
[0047] In a preferred embodiment, the fluid is a gas, such as air.
[0048] In other embodiments, the fluid may be a Newtonian fluid or a non-Newtonian fluid. As a reminder, a fluid is said to be Newtonian when its behavior does not change under the effect of mechanical stresses.
[0049] In other embodiments, the fluid may be a fluid whose viscosity changes under the action of a magnetic or electric field. These fluids are called res- specifically magnetorheological fluid or electrorheological fluid.
[0050] Each longitudinal tube 100 has, in its internal volume 12, a projectile 200. Said projectile is intended to and configured to move longitudinally in the longitudinal tube 100.
[0051] The projectiles 200 of each longitudinal tube 100 are preferably identical.
[0052] In a first embodiment, as illustrated in [Fig. 1], each projectile 200 may, for example, be in the form of a closed cylinder, hollow or solid. Each projectile 200 may have, for example, a circular, square, rectangular, elliptical, etc., cross-section, without this being a limitation of the invention. The projectile has a length much shorter than the length of the longitudinal tube.
[0053] In one embodiment, as illustrated in [Fig.1], the longitudinal tube 100 and its projectile 200 have the same cross-section.
[0054] In a second embodiment of the projectile, as illustrated in [Fig.2], when the longitudinal tubes 100 have a circular cross-section, each projectile 200 can be in the form of a hollow annular cylinder, open at its ends, the wall of which is located near an internal face 13 of the longitudinal tube 100. The mass of the projectile 100 is thus distributed near the periphery of the longitudinal tube 100.
[0055] Each projectile 200 is advantageously fixedly attached to a propeller 201.
[0056] By fixedly fixed, it is meant that there is no degree of freedom between the projectile 200 and the propeller 201. In other words, when the propeller 201 rotates, it causes the projectile to rotate.
[0057] Each projectile 200 and its propeller 201 are arranged in a longitudinal tube 100 such that an axis of rotation 202 of the propeller, and consequently an axis of rotation of the projectile, is parallel or coincident with an axis of revolution 14 of said longitudinal tube 100. Preferably, the axis of rotation 202 of the propeller 201 coincides with the axis of revolution 14 of said longitudinal tube 100, as illustrated in [Fig. 1].
[0058] In one embodiment, for projectiles according to the first embodiment variant, as illustrated in [Fig.1], the helices 201 of the projectiles 200 are located at one end of the projectile, on the same side, in their respective longitudinal tubes 100.
[0059] Preferably, as illustrated in [Fig.1], in each longitudinal tube 100, the projectile 200 faces the first end 10 of said longitudinal tube 100 and the propeller 201 faces the second end 11 of said longitudinal tube 100.
[0060] In another embodiment, for projectiles according to the second variant of the embodiment, as illustrated in [Fig. 2], the helices 201 of the projectiles are located inside the cylinder forming the projectiles, in their respective longitudinal tubes 100. Thus, the projectiles 100 disturb the flow less.
[0061] Advantageously, the propellers 201 of the projectiles 200 located in the longitudinal tubes 100 of the pair of longitudinal tubes are counter-rotating, that is, they rotate in opposite directions. Thus, when the propellers 201 rotate, two identical but opposite angular momenta will be simultaneously created, the sum of which is approximately zero. Therefore, a spacecraft equipped with a propulsion system with an even number of longitudinal tubes 100 and the propeller arrangement described will not be destabilized during thrust.
[0062] The efficiency of the propeller 201, that is to say its ability to transform the translational movement of the projectile 200 into a rotational movement, depends in particular on the fluid contained in the longitudinal tube and on the pressure in the internal volume of said longitudinal tube.
[0063] In non-limiting examples of the invention, a propeller 201 may be an aircraft propeller type propeller, an aircraft engine low pressure compressor type propeller, or a centrifugal compressor type propeller.
[0064] In an improved embodiment, the propeller is a variable-pitch propeller. Preferably, an electronic or mechanical device is configured to adjust the pitch, in particular by changing the pitch angle of the propeller blades.
[0065] Each longitudinal tube 100 preferably includes a projectile retention device 300 within the internal volume 12 of said longitudinal tube. Such a retention device 300 advantageously maintains the positioning of the projectile 200 at a distance from the internal face 13 of the longitudinal tube 100, so that the projectile 200, and / or its propeller 201, does not touch said internal face during engine operation.
[0066] Preferably, the projectile retention device 300 is identical for both tubes of the pair of longitudinal tubes 100.
[0067] In an example of an embodiment of a holding device 300, said holding device comprises at least one connecting arm 301, preferably, a plurality of connecting arms 301. Each connecting arm 301 is rigid and extends between the projectile 200 and the longitudinal tube 100. Each connecting arm 301 has a first end 302 arranged on the side of the projectile 200 and a second end 303 arranged on the side of the longitudinal tube 100.
[0068] Preferably, when the retaining device 300 comprises a plurality of connecting arms 301, these are arranged in the same plane.
[0069] In the non-limiting embodiment described in [Fig. 1], the retaining device 300 comprises three connecting arms 301 arranged at 120° to each other. Such a number and arrangement of connecting arms is particularly suitable when the The longitudinal tube has a circular cross-section, for example.
[0070] In another embodiment, not shown in the figures, the retaining device comprises four connecting arms arranged at 90° to each other. Such a number and arrangement of connecting arms is particularly suitable when the longitudinal tube has a square or rectangular cross-section, for example.
[0071] The holding device 300 is preferably connected to the projectile 200 in such a way that it does not prevent the projectile 200 from rotating about its axis of rotation. In other words, the holding device and the projectile are connected by a single-degree-of-freedom joint. This single degree of freedom is a rotational degree of freedom, allowing the projectile to rotate about its axis of rotation. The joint is a pivot joint.
[0072] In one embodiment, the holding device is connected to the projectile via at least one bearing (not shown).
[0073] In one embodiment, when the holding device 300 comprises a plurality of connecting arms 301 arranged in the same plane, each first end 302 of connecting arm is connected to the projectile 200 via a single bearing.
[0074] Each longitudinal tube 100 preferably includes a translational guidance device 400 for the projectile. Such a translational guidance device 400 advantageously ensures the longitudinal movement of the projectile 200 within the longitudinal tube 100 between the two longitudinal ends 10, 11. Said translational guidance device 400 advantageously cooperates with the projectile retention device 300.
[0075] Preferably, the translational guidance device 400 is identical for both tubes of the pair of longitudinal tubes 100.
[0076] In an example of an embodiment of a translational guide device 400, as illustrated in the figure, the translational guide device 400 includes at least one longitudinal groove 401, formed in the longitudinal tube 100, from the inner face 13.
[0077] The longitudinal tube 100 preferably has as many longitudinal grooves 401 as connecting arms 301. The second end 303 of each connecting arm 301 is configured to slide, slide or roll in an associated longitudinal groove 401.
[0078] Each longitudinal tube 100 includes a projectile launching mechanism (not shown in the figure). This projectile launching mechanism is configured to exert a thrust on the projectile 200 so as to set it in motion and launch it into the longitudinal tube 100.
[0079] The projectile launching mechanism is preferably located at the first end 10 of the longitudinal tube 100. The projectile 200 thus moves in the longitudinal tube 100 from the first end 10 to the second end 20.
[0080] Preferably, the projectile launching mechanism is identical for both tubes of the pair of longitudinal tubes 100.
[0081] In one embodiment, the projectile launching mechanism may include an electromagnet.
[0082] In another embodiment, the projectile launching mechanism may include a mechanical system of the catapult type or compression spring.
[0083] In the embodiment where the projectile launching mechanism is a compression spring, the projectile is launched into the longitudinal tube by the release of said compression spring which has previously been compressed.
[0084] Preferably, at least one power source (not shown in the figure), electrical, is configured to activate the projectile launch mechanism in each longitudinal tube 100. Said at least one power source is advantageously connected to the solar panels installed on the space vehicle or to the batteries on board said space vehicle.
[0085] Thus, at each longitudinal tube 100, the projectile launching mechanism is advantageously configured to impart an initial impulse to the projectile 100 at a predetermined speed. The projectile is then transferred momentum, or kinetic energy, towards the second end 11 of the longitudinal tube 100. At the moment of this impulse, the longitudinal tube 100 itself receives an equal amount of momentum in the opposite direction. During the advance of the projectile 200 within the longitudinal tube 100, the propeller blades 201 experience drag, which slows the projectile 200, and lift, which causes the propeller 201, and therefore the projectile 200, to rotate. Thanks to the propeller 201, the translational motion of the projectile 200 within the longitudinal tube 100 is thus progressively transformed into rotational motion.This rotational movement of projectile 200 will cause a progressive braking of the translational movement of projectile 200 in the longitudinal tube 100, while also generating heat.
[0086] Each blade of the propeller 201 will have form drag and friction drag. The friction drag, related to the viscosity of the fluid, will enable movement according to the well-known laws of fluid mechanics. In a particular embodiment, the propeller blades will be designed to maximize friction drag. It is this friction that will generate heat, and, since this heat is rejected to the outside, the system is not insulated, hence there is no conservation of overall momentum.
[0087] In the embodiment where the propeller is a variable-pitch propeller, the associated electronic, or mechanical, device is configured to adjust the pitch during the descent placement of the projectile in its longitudinal tube, allowing to maximize friction.
[0088] In other words, at each longitudinal tube 100, the initial translational kinetic energy of the projectile 200 is partially transformed into rotational kinetic energy and heat. It is this portion of rotational kinetic energy, created "naturally," that will be obtained, essentially, as the equivalent momentum transmitted to the spacecraft at the end of the projectile's movement through the longitudinal tube.
[0089] The longitudinal tubes 100 are dimensioned in length so that the translational displacement of the projectile 200 stops near the second end 11 of the longitudinal tube 100, as close as possible to said second end, without the projectile 200 or the propeller 201 of the projectile 200 touching said second end 11.
[0090] The length of a longitudinal tube 100 depends in particular on the mass of the projectile, the impulse imparted to the projectile 200 by the projectile launching mechanism, the efficiency of the propeller in the fluid environment in which the projectile moves, and the viscosity of the fluid, which viscosity can depend on parameters such as temperature or on externally regulated parameters such as an electromagnetic, electric, or magnetic field, depending on the nature of the fluid. Calculating this length is within the capabilities of a person skilled in the art.
[0091] In one embodiment, each longitudinal tube may have a length of approximately 4 m and a diameter of approximately 50 cm, with a projectile mass of approximately one kilogram. The projectile's launch speed is approximately 400 to 500 km / h.
[0092] As described previously, for each longitudinal tube 100, following the impulse given to the projectile 200, heat is created in said longitudinal tube during the movement of the projectile, due to fluid friction.
[0093] Each longitudinal tube 100 advantageously includes a heat dissipation device (not shown in the figure).
[0094] Preferably, the heat dissipation device is identical for both tubes of the pair of longitudinal tubes 100.
[0095] In one embodiment, the heat dissipation device is a finned type radiator.
[0096] In the preferred application where the propulsion system is fitted to a spacecraft, for each longitudinal tube 100, the associated heat dissipation device can only exchange heat with empty space via blackbody radiation. The heat dissipation device is therefore advantageously configured to emit photons, these photons having momentum.
[0097] The heat dissipation device of each longitudinal tube 100 is advantageous carefully arranged so that the emission of photons occurs in a direction that favors increasing the momentum of the propulsion system, and therefore of the spacecraft.
[0098] This emission of photons advantageously ensures that the propulsion system cannot therefore be considered as an isolated system.
[0099] As described previously, for each longitudinal tube 100, after the launch of the projectile 200, the translational course of the projectile 200 stops at the level of the second end 11 of the longitudinal tube 100. The projectile 200 is, at the level of this second end 11, only in rotation and rotates on itself at a certain speed.
[0100] Each longitudinal tube 100 advantageously includes a device for braking the rotation of the projectile (not shown in the figure).
[0101] Preferably, the braking device is identical for both tubes of the pair of longitudinal tubes 100.
[0102] In some embodiments, the braking device includes an electromagnetic brake or a mechanical brake.
[0103] Braking the rotation of the projectile in each longitudinal tube will create a parasitic angular momentum of opposite rotation. However, since the propulsion system's engine comprises a pair of longitudinal tubes, inside which the projectiles with their propellers rotate in a counter-rotating manner, the braking, to a first approximation, will have no effect on the propulsion system and therefore on the spacecraft, because the angular momentum of rotation will essentially cancel each other out.
[0104] As described previously, for each longitudinal tube 100, after the launch of the projectile 200, the translational course of the projectile 200 stops at the level of the second end 11 of the longitudinal tube 100 and then the projectile 200 is slowed in rotation.
[0105] Each longitudinal tube 100 advantageously includes a projectile return device (not shown in [Fig.1]) towards the first end 10 of said longitudinal tube 100.
[0106] Preferably, the projectile return device is identical for both tubes of the pair of longitudinal tubes 100.
[0107] This projectile recall device is configured to bring the projectile 200 located at the second end 11 back to the first end 10 of the longitudinal tube 100 in order to be relaunched there if necessary, via the projectile launching mechanism.
[0108] The projectile retrieval device is preferably configured to return the projectile 200 to a constant speed, lower than the projectile's launch speed in the transverse tube. The return of the projectile 200 to the first end 10 at a constant speed advantageously avoids creating any parasitic momentum in the propulsion system, and therefore in the spacecraft.
[0109] In exemplary embodiments, the projectile return device may include an electromagnet or a worm gear.
[0110] In one embodiment, to accelerate the return of the projectile 200 to the first end 10 of the longitudinal tube 100, the propulsion system may include a tilting device (not shown in [Fig. 1]). Such a tilting device is configured to independently rotate each of the two longitudinal tubes 100 around a respective parallel pivot axis by an angle of approximately 90°, but in opposite directions. The projectiles 200 from each longitudinal tube 100 are then returned to the first end 10 of the associated longitudinal tube 100, thus in the opposite direction, by the associated return device described above.The return of each projectile 200 to the first end 10 of the associated longitudinal tube 100 can be achieved more quickly because, on the one hand, the quantities of momentum created cancel each other out, and on the other hand, the quantities of momentum created do not interfere with the quantity of momentum imparted to the projectile along the axis of revolution of the longitudinal tube during the impulse, and therefore with the inverse quantity of momentum transmitted to the longitudinal tube during the impulse, and consequently to the propulsion system.
[0111] Preferably, at least one power supply (not shown in the figure), electrical, configured to activate the projectile retrieval device in each longitudinal tube.
[0112] Said at least one power supply source is connected to the solar panels installed on the space vehicle or to the batteries on board said space vehicle.
[0113] In one embodiment, a common electrical power supply is configured to activate the projectile launching mechanism and to activate the projectile recall device of a longitudinal tube.
[0114] The propulsion system according to the invention as described is therefore a pulse-thrust propulsion system and not a continuous thrust propulsion system.
[0115] At each launch of the projectiles 200 in the two longitudinal tubes 100, the longitudinal tubes, and therefore the propulsion system, are given a quantity of motion equal, but opposite, to the quantity of motion given to the projectile.
[0116] Preferably, to avoid an imbalance of the spacecraft, the launches of the projectiles 200 in the two longitudinal tubes 100 are carried out in a syn- chronicled.
[0117] Depending on the frequency of the pulses, i.e. depending on the frequency of launching the projectiles 200 in each longitudinal tube 100, the average thrust per unit time of the propulsion system will depend.
[0118] The pulse frequency depends in particular on the time taken by the projectile 200 in each longitudinal tube 100 to return, with the return device, from the second end 11 of the longitudinal tube 100 to the first end 10, the type of return device chosen to return the projectile 200.
[0119] The thrust of the propulsion system, in the same direction, can also be increased by increasing the number of pairs of longitudinal tubes 100, each pair of longitudinal tubes being arranged parallel to each other, with all the longitudinal tubes in the same direction.
[0120] In particular embodiments, not shown in the figure, to improve in particular the efficiency of the propellers 201, each longitudinal tube 100 may include a device for modifying the fluid viscosity and / or a device for modifying the fluid temperature and / or a device for modifying the fluid pressure.
[0121] In one embodiment, to perform thrusts in all directions, at least one pair of longitudinal tubes is mounted on a multi-axis system configured to orient said at least one pair of longitudinal tubes in a direction opposite to the desired thrust direction.
[0122] In embodiments, the projectile rotation braking devices 200 in the longitudinal tubes create parasitic angular momenta, the space vehicle comprising the propulsion system may include inertia wheels configured to create an onboard angular momenta intended to balance the space vehicle.
[0123] In a propulsion system comprising a given number of pairs of longitudinal tubes arranged in parallel, the propulsion system can therefore be configured in two ways: a. If all 200 projectiles from all pairs of longitudinal tubes 100 are launched synchronously, the thrust will be increased. The pulse frequency depends in particular on the time taken by the projectile in each longitudinal tube to travel from the first end to the second end of the longitudinal tube, and to return, with the return device, from the second end to the first end of the longitudinal tube. b. If the 200 projectiles from each pair of longitudinal tubes 100 are launched successively: in this case, the thrust will be less than if all the projectiles Projectiles from all pairs of longitudinal tubes are launched in a synchronized manner, but the pulse frequency will be increased.
[0124] The chosen configuration may depend on the vehicle in which the propulsion system will be used, and in particular on the maneuvers carried out by the vehicle.
[0125] In the case of the use of the propulsion system in a preferred application in the space domain, the space vehicle equipped with such a propulsion system can use the high-thrust configuration (configuration a)) for certain maneuvers, such as for example the orbit circularization maneuver, and the lower but more frequent thrust configuration (configuration b)), for other maneuvers, such as for example maneuvers in "disturbed" environments (planets with atmospheres to promote aerocapture, gravitational acceleration in the vicinity of asymmetric planets, etc.).
Claims
1.
2.
3.
4. Demands Propulsion system comprising an engine having a pair of parallel longitudinal tubes (100), each longitudinal tube (100) having a first end (10) and a second end (11), and delimiting an internal volume (12) filled with a fluid, each longitudinal tube (100) comprising: - a projectile (200), configured to move longitudinally within the internal volume (12), and fixedly attached to a propeller (201), with no degrees of freedom between the projectile and the propeller, - a projectile launching mechanism within the internal volume (12), from the first end (10) of said longitudinal tube (100), the propeller (201) being arranged to transform a translational movement of the projectile (200) into a rotational movement, - a device for braking the rotation of the projectile (200) in the internal volume (12), located at the second end (11) of the longitudinal tube (100), - a device for returning the projectile (200) from the second end (11) to the first end (10) of the longitudinal tube, - a heat dissipation device, said projectile launching mechanism (200) and said projectile retrieval device (200) being powered by at least one power source, said helices (201) of the projectiles located in the two longitudinal tubes (100) being counter-rotating. Propulsion system according to claim 1 in which each longitudinal tube (100) includes a device for holding (300) the projectile in the internal volume (12). Propulsion system according to claim 2 in which the projectile retention device (300) comprises at least one connecting arm (301) extending between the projectile (200) and the longitudinal tube (100). Propulsion system according to claim 2 or 3 wherein The retaining device (300) and the projectile (200) are connected by a pivot joint.
5. Propulsion system according to any one of the preceding claims in which each longitudinal tube (100) includes a translational guidance device (400) for the projectile in the internal volume (12).
6. Propulsion system according to claim 5 and any one of claims 2 to 4 wherein the translational guidance device (400) of the projectile (200) cooperates with the projectile retention device (300).
7. Propulsion system according to any one of the preceding claims wherein a single power source is configured to power said projectile launching mechanism (200) and said projectile recall device (200) from at least one longitudinal tube (100).
8. Propulsion system according to any one of the preceding claims comprising a tilting device configured to independently rotate each of the two longitudinal tubes (100) around a respective parallel pivot axis.
9. Propulsion system according to any one of the preceding claims comprising a plurality of pairs of parallel longitudinal tubes (100), the pairs being arranged parallel to each other.
10. Space vehicle comprising a propulsion system according to one of the preceding claims.