Hybrid autonomous phage rocket motor

Abstract

The present invention relates to a jet propulsion system with a hybrid rocket engine, and more specifically to the storage of fuel before it is introduced into the combustion chamber. The propulsion system is made up of a combustion chamber (1) closed by a cap (2) and a valve (3). A solid propellant (4) serves as a tank for a liquid propellant (5). These two propellants are introduced into the chamber (1) to be combusted. The gases produced by this combustion are discharged through a nozzle (6) to provide thrust. The system is autocannibalistic in that it combusts its own structure to launch. The propulsion system described by the present invention is particularly intended for propelling spacecraft and launch vehicles.

Description

[Technical Field]

[0001] The present invention relates to a jet propulsion system, particularly for space launch vehicles, that includes a hybrid rocket motor, and more particularly to the storage of propellants before they are inserted into the combustion chamber. Jet chemical rocket motors expel a fluid resulting from a reaction between several propellants through a nozzle to generate thrust that enables the movement of the propulsion system and its payload. In hybrid rocket motors, at least one propellant is solid and at least one propellant is fluid. [Background technology]

[0002] In the current prior art, the storage of propellants for rocket motors depends on the type of propellant: solid propellants are stored directly in the combustion chamber, while fluid propellants are stored in tanks with a fixed geometry.

[0003] As a propulsion system flies, the fluid propellant tanks become empty, becoming a burden that gradually reduces the overall system's performance level. Empty tanks can also be removed from the propulsion system, in which case they become space junk and gradually clog space. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention proposes a solution to increase the performance level of propulsion systems, freeing them from the constraints associated with their tanks. To do so, the invention proposes replacing a propulsion system with a tank with a propulsion system with an automatic phage reservoir. More specifically, the invention comprises a hybrid rocket motor as set out in the appended claims.

[0005] The following detailed description and accompanying drawings will provide a better understanding of the nature and advantages of the present invention. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a schematic diagram of a hybrid autonomous phage rocket motor according to the present invention; FIG. [Figure 2] 1 illustrates an exemplary embodiment of the present invention in which hollow solid propellants, specifically particles of solid propellants, are conveyed to a combustion chamber by a lead screw system. DETAILED DESCRIPTION OF THE INVENTION

[0007] The present invention relates to a hybrid rocket motor for installation in a jet propulsion system. A hybrid rocket motor is a rocket motor that uses at least one liquid propellant and at least one solid propellant.

[0008] According to the present invention, a hybrid rocket motor includes a combustion chamber supplied with a hollow solid propellant and a fluid propellant, the hollow solid propellant having a cavity closed by an end cap and a valve, and the fluid propellant stored in the cavity of the hollow solid propellant. Furthermore, the hollow solid propellant may include a first portion inserted into the combustion chamber to be combusted in the combustion chamber together with the fluid propellant injected into the combustion chamber through the valve. The combustion generates hot gases, which are discharged through a nozzle to generate thrust. In particular, the first portion may have an inner surface facing the combustion space to be combusted. The hollow solid propellant remains in the combustion chamber until both the hollow solid propellant and the fluid propellant are inserted into the combustion chamber. It may further include a second portion extending outwardly and containing a fluid propellant.

[0009] Yet another aspect of the present invention relates to a hybrid rocket motor in which a pressurized combustion chamber closed by an end cap and a valve contains a hollow solid propellant, the inner surface of which combusts with a fluid propellant injected through the end cap to generate hot gases that are discharged through a nozzle to create thrust for the rocket. A portion of the hollow solid propellant travels around the end cap outside the combustion chamber and beyond the end cap to contain the fluid propellant until both the hollow solid propellant and the fluid propellant are inserted into the combustion chamber. In other words, the portion of the hollow solid propellant defined by the end cap functions as a container for the fluid propellant until both the hollow solid propellant and the fluid propellant are inserted into the combustion chamber.

[0010] Thus, by using a hollow solid propellant as a hollow structure in the form of any hollow cylinder that allows for the storage of a fluid propellant, the present invention allows the propulsion system to be freed from the constraints associated with tanks and allows for an increase in its performance levels.

[0011] In particular, hollow solid propellants are particles of solid propellant formed from solid propellant and having a hollow structure. Thus, hollow solid propellants have a rigid hollow structure, forming a tank whose walls are formed by the solid propellant itself.

[0012] In particular, the hollow solid propellant comprises a cavity that contains a fluid propellant and is closed by an end cap and a valve.

[0013] The hollow solid propellant may be formed, for example, by a homogeneous structure of solid propellant. The hollow solid propellant may also be formed predominantly by solid propellant or may contain additives or other components (e.g., ammonium perchlorate). The solid propellant is not, in particular, a high-energy propellant such as polyethylene or ABS (acrylonitrile butadiene styrene).

[0014] The hollow solid propellant is used to contain a fluid propellant intended to be burned in a combustion chamber. In other words, the cavity formed within the hollow structure of the hollow solid propellant serves as a container for the fluid propellant.

[0015] The fluid propellant may be an oxidizer, for example, a liquid cryogenic oxidizer.

[0016] According to one embodiment, no container or tank or additional structure is required to contain the hollow solid propellant, and therefore no rigid sealed container such as a rigid tank is required to seal the hollow solid propellant.

[0017] However, a coating may cover the hollow solid propellant to increase its rigidity.

[0018] The cavity formed in the hollow solid propellant is closed by an end cap and a valve, and the end cap may be provided with a valve.

[0019] The cavity may, for example, comprise a constant and unchanging diameter of a tubular shape, and the end cap may have a diameter corresponding to the diameter of the cavity.

[0020] According to one embodiment, the end caps and valves are not located at the ends of the hollow solid propellant, but instead are located inside the hollow solid propellant to close off the cavity at a given depth. In other words, the end cap and valve close the cavity to form a first hollow solid propellant portion downstream of the end cap. The downstream portion of the end cap is the portion located outside the cavity closed by the end cap. This downstream portion of the hollow solid propellant is inserted into the combustion chamber for combustion therein. A second hollow solid propellant portion located upstream of the end cap and valve serves as a container for the fluid propellant. The second propellant portion specifically extends outside the combustion chamber.

[0021] In particular, the end cap may serve to define a hollow solid propellant portion intended to contain a fluid propellant of the hollow solid propellant portion intended to be combusted in the combustion chamber.

[0022] The cavity formed in the hollow solid propellant may be, for example, any cylindrical shape.

[0023] According to the invention, the hollow solid propellant forming the tank of fluid propellant contains the solid propellant that is used during combustion to generate thrust in the combustion chamber.

[0024] The hollow solid propellant may be in the form of a straight cylinder having a base, a straight prism, or any other simple or complex shape, provided with a cavity with an opening suitable for being closed by an end cap.

[0025] The end cap may also include an injector downstream of the valve for introducing a fluid propellant contained within a cavity within the combustion chamber.

[0026] According to a particular embodiment, the hollow solid propellant may be coated, in particular on its outer surface, with a coating that makes it possible to improve the sliding of the hollow solid propellant inside the wall(s) of the combustion chamber. The coating may be, for example, polytetrafluoroethylene.

[0027] The hollow solid propellant may further include one or more additives, such as polytetrafluoroethylene, to improve the chemical compatibility of the solid propellant with the fluid propellant or to improve the regression rate during combustion.

[0028] Additionally, the rigidity imparted to hollow solid propellants, particularly solid propellant grains, serves to transfer thrust from the nozzle of the propulsion system to the payload.

[0029] According to one embodiment, the hollow solid propellant, in particular the solid propellant grain, has an end cap equipped with a valve and, for example, an injector, which serves to separate the solid propellant, in particular the solid propellant grain intended to contain the fluid propellant, from the hollow solid propellant, in particular the hollow solid propellant, intended to be burned in a combustion chamber. The combustion chamber is a pressurized space in which the combustion of the two propellants occurs together. The combustion is a chemical reaction of the two propellants, producing hot combustion gases that are expelled by a nozzle in a direction opposite to the displacement direction desired for the propulsion system's payload.

[0030] According to one aspect of the present invention, the combustion chamber is closed by an end cap and a valve and contains a hollow solid propellant, the inner surface of which burns with a fluid propellant injected through the end cap. The chamber may be further closed by a hollow solid propellant inserted into the combustion chamber.

[0031] The inner surface of the hollow solid propellant is specifically the surface of the hollow solid propellant that is located within the combustion chamber downstream of the end cap.

[0032] Furthermore, the nozzle is an opening in the combustion chamber that allows the hot gases produced during the combustion of the propellant to exit so as to propel the payload of the propulsion system.

[0033] The propulsion chamber may include walls having a shape complementary to that of the hollow solid propellant, such that the hollow solid propellant is inserted into the combustion chamber and slides along the chamber walls during combustion of the hollow solid propellant. In this manner, the combustion chamber walls form a container for receiving a first portion of the hollow solid propellant, and a second portion of the hollow solid propellant containing the fluid propellant extends outside the combustion chamber until both the hollow solid propellant and the fluid propellant are inserted into the combustion chamber.

[0034] According to one embodiment, the combustion chamber is defined in part by a first portion of hollow solid propellant and an end cap.

[0035] Additionally, the end cap may hermetically close a cavity formed in the hollow solid propellant, and the valve functions to circulate the fluid propellant in the cavity toward the combustion chamber.

[0036] The rocket motor may comprise one or more insertion systems for the propellant, which allow hollow solid propellants, in particular grains of solid propellant, to be inserted into the combustion chamber and allow the end caps to be moved while the hollow solid propellants, in particular grains of solid propellant, having a shape that may be cylindrical, are burned.

[0037] The propulsion system according to the invention is an autophagy system in the sense that it consumes the structure of the system itself, since the hollow solid propellant is gradually introduced inside the combustion chamber during consumption of the hollow solid propellant.

[0038] When the hollow solid propellant is introduced into the combustion chamber, the storage volume of the fluid propellant decreases. This is because the propellant insertion system displaces the hollow solid propellant within the combustion chamber during combustion, reducing the cavity for storing the fluid propellant closed by the end cap. Therefore, as a result of the compression of the end cap within the cavity for storing the fluid propellant, the fluid propellant is also forced into the combustion chamber through the valve. A single propellant insertion system may be sufficient to force two propellants into the chamber.

[0039] According to a particular embodiment, the rocket motor further comprises connection means for connecting at least one wall of the combustion chamber to the end cap, for mechanically connecting the end cap to the combustion chamber.

[0040] The mechanical connection can hold the end cap in a specific position relative to the combustion chamber while allowing movement, e.g., rotational movement, of the end cap. Alternatively, the end cap may be held in a fixed position within the rocket motor by the connection means.

[0041] The connecting means may comprise at least one knife mechanically connecting at least one wall of the combustion chamber to the end cap, the mechanical connection being a knife in the sense that a first portion of the hollow solid propellant inserted into the combustion chamber is at least partially pierced by the at least one knife during insertion.

[0042] In particular, the hollow solid propellant is subjected to a large internal pressure during insertion into the combustion chamber, so that the particles of the solid propellant can be easily penetrated by the blade while entering the combustion chamber. This is because the knife cuts the particles of the solid propellant, especially in the direction of insertion of the particles of the solid propellant. The knife that penetrates the hollow solid propellant also prevents the rotational movement of the hollow solid propellant. In other words, the connecting means further has the purpose of stopping the hollow solid propellant from rotating.

[0043] The knife mechanically connects the end cap to the wall of the combustion chamber and severs the hollow solid propellant at the rate of introduction of the hollow solid propellant into the combustion chamber.

[0044] When the end cap is mechanically connected to the combustion chamber wall by multiple knives, they can have different lengths, since the blades can mechanically connect the end cap to the combustion chamber wall at different heights within the combustion chamber. According to another embodiment, the knives can have the same length.

[0045] The rocket motor may further comprise a propellant insertion system that controls the insertion of solid propellant particles into the combustion chamber and the introduction of fluid propellant into the combustion chamber.

[0046] The insertion system may comprise means for generating a translational movement of the hollow solid propellant charge to insert it into the combustion chamber during combustion. The insertion system for the propellant charge may be connected to the end cap. According to another embodiment, the end cap may comprise the insertion system for the propellant charge.

[0047] The means for generating translational motion of the hollow solid propellant is suitable for generating translational motion of the hollow solid propellant relative to the wall and / or end cap of the combustion chamber.

[0048] For example, a propellant insertion system may be arranged in the area of ​​the end cap, which may be mechanically connected to the chamber, thereby allowing (or not allowing) the hollow solid propellant, in particular the particles of solid propellant, to move at the same speed inside. For example, the end cap and the combustion chamber may be connected by a certain number of knives. If necessary, the hollow solid propellant, in particular the particles of solid propellant, already under strong internal pressure, can be easily cut by the knives while being introduced into the chamber.

[0049] In particular, the means for generating a translational movement of the hollow solid propellant may be implemented, for example, by a lead screw type system. The means for generating a translational movement of the hollow solid propellant may comprise a screw adapted to be rotated by a thread forming a surface of the hollow solid propellant so as to apply a force for inserting the hollow solid propellant into the combustion chamber. The thread forming the surface of the hollow solid propellant may in particular form an inner surface of the hollow solid propellant.

[0050] For example, the hollow solid propellant may have a thread on the inner wall of the cavity that connects with a screw formed around the end cap. The thread may be obtained, for example, by tapping. The end cap closing the cavity may have a thread that complements the thread disposed on the inner wall of the cavity. According to another embodiment, a screw is connected to the end cap, but rotation of the screw does not cause rotational movement of the end cap.

[0051] The mechanical insertion system for the particles may consist, for example, of a lead screw system, where the hollow solid propellant, in particular the solid propellant particles, are provided with threads that interlock with threads around the end cap.

[0052] According to certain embodiments, the hollow solid propellant may be coated with a coating that reduces thread friction when interlocking with the threads forming the surface of the hollow solid propellant, and the coating may be, for example, polytetrafluoroethylene.

[0053] The rocket motor may further comprise a mechanical rotation system, such as an electric motor powered by a battery, a fuel cell, a gas generator or any other power source that allows the screw to rotate, thereby moving the hollow solid propellant, in particular the solid propellant particles, in translation.

[0054] A turbine or any other system using combustion gases may also be considered to drive the threaded screw or end cap. Thus, the propellant insertion system allows for the supply of hollow solid propellant to the combustion chamber, and the compression of the end cap in the cavity caused by the displacement of the hollow solid propellant allows for the introduction of fluid propellant into the combustion chamber via the valve.

[0055] In this particular embodiment based on a lead screw system, the propellant insertion system controls the rotation of the screw relative to the hollow solid propellant. This lead screw system allows the rotational movement of the screw to be converted into a translational movement of the hollow solid propellant, which displaces the hollow solid propellant within the combustion chamber. The hollow solid propellant also moves in a translational sense relative to the end cap.

[0056] This translational movement of the hollow solid propellant is accompanied by a reduction in the size of the cavity within the combustion chamber since the end caps are not subjected to such translational movement, and therefore the pressure on the fluid propellant increases within the cavity enclosed by the end caps.

[0057] According to another embodiment, the lead screw system is transposed between the hollow solid propellant and the end cap, i.e., the hollow solid propellant may include a screw, and the nut may be formed by the combustion chamber or the end cap.

[0058] The rotational movement of the particles can be stopped within the lead screw system using the aforementioned knives or any other system for stopping rotation.

[0059] The system for rotating the screw may also be advantageous for driving a pump used to increase the pressure of the fluid propellant between the tank and the combustion chamber.

[0060] This is because in this case the pump driven by the rotary system is able to increase the pressure of the fluid propellant contained in the cavity with a view to introducing it into the combustion chamber.

[0061] The properties of the solid particles may be tailored using coatings, additives, or specific microstructures. For example, a layer of polytetrafluoroethylene may be applied to hollow solid propellant particles, particularly solid propellant particles, to improve chemical compatibility with the fluid propellant, improve sealing of the threads, and reduce friction against the screw or combustion chamber walls. Hollow solid propellant particles, particularly solid propellant particles, may also be composed of several materials, and the outer shell of the hollow solid propellant particles, particularly solid propellant particles, may be composed of a thermally ablative material that releases low-temperature gases as it pyrolyzes, insulating the walls of the combustion chamber and nozzle. It is also conceivable to use composite materials as hollow solid propellant particles, particularly solid propellant particles, or to implement the use of composite materials using additive manufacturing processes.

[0062] FIG. 1 illustrates an embodiment of the present invention in the context of a hybrid rocket motor.

[0063] According to one embodiment, the propellants used by the hybrid rocket motor are a liquid cryogenic oxidizer and a solid fuel, respectively, at ambient temperatures, although the present invention is directed to other combinations of propellants. Figure 1(a) shows a hybrid rocket motor that includes hollow solid propellant, particularly solid propellant particles, and fluid propellant that must be consumed to provide the thrust required to displace the payload of the propulsion system, while Figure 1(b) shows a hybrid rocket motor in which the majority of the hollow solid propellant, particularly solid propellant particles, and fluid propellant have been consumed to illustrate the autophagy aspect of the propulsion system.

[0064] The combustion chamber 1 is capable of withstanding the pressure inside it and is closed by an end cap 2 and a valve 3 which delimit two parts: an area intended for the combustion of hollow solid propellants, in particular particles of solid propellant 4, in the combustion chamber 1, and an area intended for storing fluid propellant 5.

[0065] The combustion chamber 1 is notably defined by a wall 1a connected to a nozzle 6 for discharging the combustion gases and enabling the propulsion of a payload by thrust of the propulsion system.

[0066] The combustion chamber also comprises, opposite the nozzle, an opening suitable for receiving a hollow solid propellant, in particular a portion of a particle of solid propellant 4, with a storage cavity for fluid propellant 5. This opening is closed by an end cap and a valve.

[0067] As shown, the plug and valve also serve to close the cavity of the hollow solid propellant 4. The end cap may also be provided with a valve.

[0068] The cavity comprises a constant and unchanging diameter, such as a tube, and the end cap has a diameter corresponding to the diameter of the cavity.

[0069] In the illustrated embodiment, the outer surface of the hollow solid propellant 4 has a shape that complements the wall 1a of the combustion chamber 1, for being introduced into the chamber 1 during consumption of the solid and fluid propellants.

[0070] Fluid propellant 5 can be introduced into the combustion chamber by valve 3, for example, when pressure is applied to the fluid propellant within the cavity of the hollow solid propellant by the end cap.

[0071] As shown in Figure 1, the portion of the hollow solid propellant located between the end cap and the combustion chamber wall 1a is used for combustion, and the portion of the solid propellant located above the combustion chamber serves as a container for the fluid propellant until both the hollow solid propellant and the fluid propellant are introduced into the combustion chamber 1.

[0072] Therefore, during use of the hollow solid propellant and the fluid propellant disposed in the combustion chamber, the two propellants disposed upstream of the combustion chamber are inserted into the combustion chamber to be consumed, thereby reducing the size of the propulsion system until most of the hollow solid propellant and the fluid propellant are consumed, as shown in Figure 1(b). Combustion is carried out by combusting the hollow solid propellant located in the combustion chamber and the fluid propellant 5 introduced into the combustion chamber.

[0073] By being introduced into the combustion chamber 1 and combusting with particles of hollow solid propellants, in particular solid propellant 4, the fluid propellant 5 generates combustion gases which are then ejected by a nozzle 6, enabling the propulsion of the system by reaction. Combustion is the chemical reaction of two propellants to generate gases used for thrust.

[0074] The portion of the hollow solid propellant located within the combustion chamber 1 may include a reduced thickness, as shown in Figure 1. In other words, the surface of the propellant being burned, i.e., the inner surface of the hollow solid propellant, may be approximately conical.

[0075] Figure 2 shows an exemplary embodiment of the hybrid rocket motor of the present invention, in which hollow solid propellants are delivered to the combustion chamber by a propellant insertion system. The propellant insertion system shown in Figure 2 is based on a lead screw system. Figure 2(a) shows a hybrid rocket motor including hollow solid propellants and fluid propellants that must be consumed, while Figure 2(b) shows a hybrid rocket motor in which most of the hollow solid propellants, particularly the solid propellant particles and fluid propellants, have been consumed to demonstrate the autophagy aspect of the propulsion system.

[0076] As shown in Figure 2(a), the inner surface, i.e., cavity, of the hollow solid propellant 4 is provided with threads 9. According to certain embodiments, the threads 9 are provided on all or part of the surface of the cavity of the hollow solid propellant.

[0077] In the illustrated embodiment, the threads 9 present on the hollow solid propellant cavity function as a nut.

[0078] According to the embodiment shown in Figure 2, the end cap 2 is provided on its outer surface with a screw 8 of an insertion system for the propellant, suitable for being rotated within a thread 9 forming the inner surface, i.e. the cavity, of the hollow solid propellant 4, applying a force for its insertion into the combustion chamber. This lead screw system makes it possible to convert the rotational movement of the screw into a translational movement of the hollow solid propellant, thereby displacing it in the combustion chamber.

[0079] Alternatively, the lead screw system is transposed between the hollow solid propellant and the end cap.

[0080] The end cap may be provided with a thread. However, the thread may be different from the end cap. The rocket motor shown in FIG. 2 may be provided with a connecting means 7 for connecting at least one wall of the combustion chamber 1 to the end cap 2. The connecting means shown is formed by a knife 7. The knife may be of different dimensions, in particular may have different lengths.

[0081] According to the embodiment shown, the end cap 2 is mechanically connected to the combustion chamber 1 by a knife 7 which absorbs the internal pressure. The knife 7 penetrates the grains of the solid propellant 4.

[0082] When the rocket motor is operating, the screw 8 rotates, causing the hollow solid propellant, in particular the grains of solid propellant 4, to translate towards the inside of the combustion chamber 1 by translating the internal threads 9 within the hollow solid propellant.

[0083] According to a particular embodiment, the particles of hollow solid propellant, in particular solid propellant 4, cannot rotate relative to the combustion chamber as they are prevented from rotating by the knife 7 and are therefore forced to move axially into the combustion chamber 1.

[0084] As the end cap 2 advances into the hollow solid propellant, particularly into the grains of solid propellant 4, the volume of the contained fluid propellant 5 decreases. This is because the hollow solid propellant 4 undergoes translational motion relative to the end cap 2, and the volume of the cavity of the hollow solid propellant 4 that contains the fluid propellant 5 decreases during combustion.

[0085] This reduction in volume forces the fluid propellant 5 through the valve 3 and into the combustion chamber 1. The rotational speed of the screw 8 therefore affects the mass flow rate that is introduced into the combustion chamber.

[0086] As the hollow solid propellant, in particular the particles of solid propellant, advances into the chamber during combustion, the inner surface of the hollow solid propellant, in particular the particles of solid propellant 4, present in the combustion chamber, assumes a conical shape within the chamber 1, and the shape of this surface does not change during combustion at a constant rotation speed of the screw 8.

[0087] The substantially constant regression rate along the chamber results in a generally conical shape of the hollow solid propellant exiting the combustion chamber.

[0088] Industrial Applications This type of propulsion is particularly suitable for space launch vehicles. At the end of the burn, the rocket motor consumes most of the hollow solid propellant, especially the solid propellant particles. Therefore, the remaining mass of a space launch vehicle using this propulsion system is very small at the end of the burn.

[0089] declaration A hybrid rocket motor in which a pressurized combustion chamber (1) closed by an end cap (2) and a valve (3) contains a hollow solid propellant (4), the inner surface of which burns with a fluid propellant (5) injected through the end cap (2) to generate hot gases (6) that are discharged through a nozzle (6) to generate thrust for the rocket, wherein the portion of the hollow solid propellant (4) defined by the end cap (2) serves as a container for the fluid propellant (5) until both the hollow solid propellant and the fluid propellant are inserted into the combustion chamber (1).

[0090] A hybrid rocket motor in which a pressurized combustion chamber (1) closed by an end cap (2) and a valve (3) contains a hollow solid propellant (4), the inner surface of which burns with a fluid propellant (5) injected through the end cap (2) to generate hot gases (6) that are discharged through a nozzle (6) to generate thrust for the rocket, wherein a portion of the hollow solid propellant (4) moves around the end cap (2) beyond the combustion chamber (1) and outside the combustion chamber (1) to contain the fluid propellant (5) until both the hollow solid propellant and the fluid propellant are inserted into the combustion chamber (1).

[0091] A rocket motor according to the preceding declaration, characterized in that a certain number of knives (7) connect the combustion chamber (1) to the end cap (2), the exterior of which is a screw (8) that rotates within a thread (9) that forms the interior surface of the hollow solid propellant (4) so ​​as to apply a force to insert the hollow solid propellant (4) into the chamber.

[0092] A rocket motor according to the preceding declaration, characterized in that the rotation of the screw (8) also drives a pump that allows further pressurization of the fluid propellant (5) between the interior of the solid propellant (4) and the combustion chamber (1).

[0093] A rocket motor according to the preceding declaration, characterized in that the screw (8) is rotated by an electric motor powered by an energy source such as a battery, a fuel cell or a gas generator.

[0094] A rocket motor according to any one of the preceding statements, characterized in that the screw (8) is rotated by a turbine driven by gases produced by combustion.

[0095] Any of the preceding claims, characterized in that a thermal ablative layer is disposed on the outside of the solid propellant (4) and emits a cryogenic gas to insulate the walls of the chamber (1) and the nozzle (6). The rocket motor according to any one of claims 1 to 4.

[0096] A rocket motor according to any one of the preceding statements, characterized in that the solid propellant (4) is a composite material.

[0097] A rocket motor according to any one of the preceding statements, characterized in that the solid propellant (4) is manufactured by additive manufacturing.

[0098] A rocket motor according to any one of the preceding statements, characterized in that the hollow solid propellant contains additives to enable improvement of the density, mechanical strength, thermal conductivity, regression rate during combustion, radial distribution of temperature of exhaust gases, chemical compatibility, average molar mass of exhaust gases, frictional properties or any other physical properties of the solid propellant and combustion products of the solid propellant (4) and the fluid propellant (5).

Claims

1. A hybrid rocket motor comprising a combustion chamber supplied by a hollow solid propellant (4) and a fluid propellant (5), the hollow solid propellant having a cavity closed by a plug and a valve, the fluid propellant being stored within the cavity of the hollow solid propellant.

2. The hollow solid propellant is a first portion inserted into the combustion chamber to be combusted in the combustion chamber together with a fluid propellant (5) injected into the combustion chamber through the valve; a second portion (4) extending outside the combustion chamber (1) and containing the fluid propellant (5) until both the hollow solid propellant and the fluid propellant are inserted into the combustion chamber (1); 10. The rocket motor of claim 1, comprising:

3. 3. A rocket motor according to claim 1 or 2, further comprising connecting means for connecting at least one wall of the combustion chamber (1) with an end cap (2).

4. 4. The rocket motor according to claim 3, wherein the connecting means comprises at least one knife (7) for mechanically connecting the at least one wall of the combustion chamber to the end cap, and the first portion of the hollow solid propellant is pierced by the at least one knife during insertion of the hollow solid propellant into the combustion chamber.

5. 5. A rocket motor according to claim 3 or 4, characterized in that the connecting means comprises a plurality of knives that mechanically connect the at least one wall of the combustion chamber to the end cap at different heights within the combustion chamber.

6. 6. A rocket motor according to claim 1, further comprising an insertion system for the propellant in the combustion chamber.

7. The rocket motor of claim 6, wherein the end cap comprises the insertion system for the propellant.

8. 8. A rocket motor according to claim 6 or 7, characterized in that the insertion system for the propellant comprises means for generating a translational movement of the hollow solid propellant to insert the hollow solid propellant into the combustion chamber.

9. 9. A rocket motor according to claim 8, characterized in that the means for generating a translational movement of the hollow solid propellant comprise a screw (8) suitable for being rotated on a thread (9) forming a face of the hollow solid propellant (4) so ​​as to apply a force for inserting the hollow solid propellant into the combustion chamber.

10. 10. A rocket motor according to claim 9, characterized in that the threads (9) that form the surface of the hollow solid propellant form the inner surface of the hollow solid propellant (4).

11. 11. A rocket motor according to claim 9 or 10, characterized in that the end cap is provided with the screw.

12. The rotation of the screw (8) further drives a pump suitable for increasing the pressure of the fluid propellant when it is introduced into the combustion chamber (1).

12. A rocket motor according to any one of claims 9 to 11.

13. 13. A rocket motor according to any one of claims 9 to 12, characterized in that the screw (8) is rotated by an electric motor powered by an energy source such as a battery, a fuel cell or a gas generator.

14. A rocket motor according to any one of claims 9 to 12, characterized in that the screw (8) is rotated by a turbine driven by gases produced by combustion.

15. 15. A rocket motor according to any one of claims 1 to 14, characterized in that the hollow solid propellant (4) is provided with a heat-ablative outer layer suitable for releasing cold gases during combustion in order to insulate the walls of the combustion chamber (1) and the nozzle (6).

16. A rocket motor according to any one of claims 1 to 15, characterized in that the solid propellant (4) is made of composite material.

17. A rocket motor according to any one of claims 1 to 16, characterized in that the solid propellant (4) contains one or more additives.

18. A rocket motor according to any one of claims 1 to 17, characterized in that the solid propellant (4) is manufactured by additive manufacturing.

19. 1. A hybrid rocket motor comprising: a pressurized combustion chamber (1) closed by an end cap (2) and a valve (3) containing a hollow solid propellant (4), the inner surface of which combusts with a fluid propellant (5) injected through the end cap (2) to generate hot gases (6) that are expelled through a nozzle (6) to generate thrust for a rocket; and a portion of the hollow solid propellant (4) defined by the end cap (2) serving as a container for the fluid propellant (5) until both the hollow solid propellant and the fluid propellant are inserted into the combustion chamber (1).

20. 20. The rocket motor of claim 19, wherein a portion of the hollow solid propellant travels around the end cap beyond the end cap outside the combustion chamber.

21. 21. A rocket motor according to claim 19 or 20, characterized in that the hollow solid propellant comprises a cavity, the cavity containing the fluid propellant and closed by the end cap and the valve.

22. 22. A rocket motor according to any one of claims 19 to 21, characterized in that the combustion chamber is further closed by the hollow solid propellant inserted into the combustion chamber.

23. The hollow solid propellant is a first portion inserted into the combustion chamber to be combusted in the combustion chamber together with a fluid propellant (5) injected into the combustion chamber through the valve; a second portion extending outside the combustion chamber (1) and containing the fluid propellant (5); 23. A rocket motor according to any one of claims 19 to 22, characterized in that it comprises:

24. 24. A rocket motor according to any one of claims 19 to 23, further comprising connection means connecting at least one wall of the combustion chamber (1) with the end cap (2).

25. 25. The rocket motor of claim 24, wherein the connecting means comprises at least one knife that mechanically connects the at least one wall of the combustion chamber to the end cap, the hollow solid propellant contained in the combustion chamber being pierced by the at least one knife during insertion of the hollow solid propellant into the combustion chamber.

26. 26. A rocket motor according to claim 24 or 25, wherein the connecting means comprises a plurality of knives that mechanically connect the at least one wall of the combustion chamber to the end cap at different heights within the combustion chamber.

27. 27. A rocket motor according to any one of claims 19 to 26, further comprising an insertion system for the propellant in the combustion chamber.

28. 28. The rocket motor of claim 27, wherein the end cap comprises the insertion system for the propellant.

29. 29. A rocket motor according to claim 27 or 28, characterized in that the insertion system for the propellant comprises means for generating a translational movement of the hollow solid propellant to insert the hollow solid propellant into the combustion chamber.

30. 30. A rocket motor according to claim 29, characterized in that the means for generating a translational movement of the hollow solid propellant comprises a screw (8) suitable for being rotated on a thread (9) forming a face of the hollow solid propellant (4) so ​​as to apply a force for inserting the hollow solid propellant into the combustion chamber.

31. A rocket motor according to claim 30, characterized in that the threads (9) that form the surface of the hollow solid propellant form the inner surface of the hollow solid propellant (4).

32. 32. A rocket motor according to claim 30 or 31, characterized in that the end cap comprises the screw.

33. 20. The rocket motor according to claim 19, characterized in that a certain number of knives (7) connect the combustion chamber (1) to the end cap (2), the exterior of which is a screw (8) that rotates within a thread (9) that forms the interior surface of the hollow solid propellant (4) so ​​as to apply a force to insert the hollow solid propellant (4) into the chamber.

34. 34. A rocket motor according to any one of claims 30 to 33, characterized in that the rotation of the screw (8) also drives a pump allowing further pressurization of the fluid propellant between the interior of the solid propellant (4) and the combustion chamber (1).

35. 35. A rocket motor according to any one of claims 30 to 34, characterized in that the screw (8) is rotated by an electric motor powered by an energy source such as a battery, a fuel cell or a gas generator.

36. A rocket motor according to any one of claims 30 to 34, characterized in that the screw (8) is rotated by a turbine driven by gases produced by combustion.

37. 37. A rocket motor according to any one of claims 19 to 36, characterized in that a thermally ablative layer is arranged on the outside of the solid propellant (4) and emits cold gas to insulate the walls of the combustion chamber (1) and the nozzle (6).

38. A rocket motor according to any one of claims 19 to 37, characterized in that the solid propellant (4) is a composite material.

39. A rocket motor according to any one of claims 19 to 38, characterized in that the solid propellant (4) comprises one or more additives.

40. A rocket motor according to any one of claims 19 to 39, characterized in that the solid propellant (4) is manufactured by additive manufacturing.

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