External excitation device for transition of combustion state of space engine

Abstract

The invention provides an external excitation device for transition of a combustion state of a space engine, which belongs to the technical field of aerospace propulsion systems and comprises a shell, a front component, a rear component and a powder component. The shell is of a hollow cylinder-like structure, and the shapes of the front end and the rear end of the shell are matched with those of the front assembly and the rear assembly respectively; the front assembly is arranged at the front end of the shell in a matched mode, the rear assembly is arranged at the rear end of the shell, and the medicine body assembly is arranged in an inner cavity of the shell. Through precise control over the explosive loading amount, precise machining and control over the diaphragm and acceleration and decompression supersonic speed flow of the expansion section in the device, deceleration and pressurization supersonic speed flow is formed in the contraction section after the supersonic speed flow reaches and explodes the diaphragm, the effect that the explosive amount is small and the outlet pressure is high can be achieved through cooperation of the internal structure, and the explosion pressure design of the diaphragm is combined; the excitation intensity range is 0.1-40 MPa, the excitation precision is 0.1 MPa, and the problems that the external excitation adjustable range of a space engine is not wide enough, and the precision is not high enough are solved.

Description

Technical Field

[0001] This invention belongs to the field of aerospace propulsion system technology, specifically, it relates to an external excitation device for the transition of combustion state in a space engine. Background Technology

[0002] As the core power unit for spacecraft orbital maneuvers and attitude adjustments, the combustion stability of space engines directly determines the success or failure of missions. Space engines need to convert the chemical energy of propellants into kinetic energy in an extremely short time. The mechanical and thermal environment within their combustion chambers is extremely complex, and the high-pressure, high-flow-rate propellant flow and combustion process can easily induce various forms of disturbances. Under specific conditions, when these disturbances couple with the propellant injection, atomization, evaporation, mixing, and combustion processes within the combustion chamber, they may couple with the formation of disturbance sources, leading to a transition in the combustion state within the combustion chamber. This results in large-amplitude, periodic pressure oscillations, causing strong vibrations and a sharp increase in heat transfer in the engine structure, leading to engine structural damage or combustion chamber ablation, ultimately resulting in engine failure and mission failure. Therefore, it is necessary to understand the mechanism and influence of combustion state transition during steady-state operation of space engines and clarify the mechanism by which external excitation induces combustion state transition in space engines.

[0003] Currently, external excitation is often used to simulate strong disturbances during steady-state engine operation, thereby triggering combustion state transition. However, the adjustable range and accuracy of existing external excitation sources cannot meet the usage requirements of space engines.

[0004] Currently, the relevant existing technologies include: A high-frequency pulse trigger for evaluating the combustion stability of solid rocket engines (patent document CN117267017A) discloses a high-frequency pulse trigger for evaluating the combustion stability of solid rocket engines. It uses a throttling ring to throttle the engine and excites pressure oscillations at a natural frequency by adjusting the throttling orifice diameter, diaphragm thickness, channel length, and chamber size of the pulse trigger. However, the pressure oscillations excited by the high-frequency pressure pulser in the acoustic cavity exhibit nonlinear characteristics in the early stage, triggering nonlinear oscillations within the solid rocket engine combustion chamber. Therefore, the excitation to the engine is dynamically changing, and the evaluation of the excitation is based on the oscillation frequency rather than the peak pressure of the oscillation. Furthermore, the products generated by the continuous ignition of the propellant entering the combustion chamber can affect the engine's operation. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the purpose of this invention is to provide an external excitation device for the transition of combustion state in a space engine.

[0006] An external excitation device for combustion state transition in a space engine, according to the present invention, comprises: a housing, a front assembly, a rear assembly, and a propellant assembly; The shell is a hollow, columnar structure, with the front and rear ends of the shell having shapes that are adapted to the front and rear components, respectively. The front component is fitted at the front end of the shell, the rear component is located at the rear end of the shell, and the drug assembly is located in the internal cavity of the shell.

[0007] Preferably, the front assembly includes: an adapter, a front nut, a front ring, a front sealing ring, and a diaphragm; The adapter is connected to the housing via the front nut, front ring, and front sealing ring. A diaphragm is provided between the adapter and the housing; The front sealing ring and the front ring are abutted and sleeved on the outer periphery of the rear section of the adapter, with a coaxial gap between the adapter and the housing; the diaphragm, the front sealing ring and the front ring are pressed together by the threads of the front nut and the outer periphery of the housing.

[0008] Preferably, the rear assembly includes: a rear nut, a rear sealing ring, and a rear ring; The rear sealing ring is located at the rear end of the housing. The rear ring abuts against the rear sealing ring. After the rear nut is fitted onto the rear side of the rear ring, the rear sealing ring is pressed against the rear ring by the threads between the rear nut and the outer circumference of the housing.

[0009] Preferably, the drug assembly includes: a drug cartridge and a wire; the drug cartridge is installed in the rear cavity of the housing and is ignited by an electric current through the wire connected to the drug cartridge; the wire passes through the rear nut, and the gap between the wire and the rear nut is filled and cured with epoxy resin.

[0010] Preferably, the epoxy resin is selected with a temperature resistance >300℃ and a compressive strength >50MPa.

[0011] Preferably, the drug column uses Rexoxane as the excitation source, and the drug content is 0.05 to 2g, with a drug dispensing interval of 0.005 to 0.01g as required.

[0012] Preferably, the diaphragm is 0.2 mm thick and 20 to 30 mm in diameter. A cross groove is milled into the diaphragm by machining. The groove depth is 0.08 to 0.12 mm, and the intersection of the grooves is located at the center of the diaphragm.

[0013] Preferably, the housing has an expansion section with an expansion angle of 5 to 30°; the adapter has a contraction section with a contraction angle of 30 to 60°, and is coaxially connected with the housing.

[0014] Preferably, a supersonic flow that accelerates and depressurizes along the shape of the expansion section is generated upstream of the expansion section. After reaching and bursting the diaphragm, a supersonic flow that decelerates and increases pressure is formed in the contraction section. The outlet pressure of the device is adjusted by the combination of the expansion section and the contraction section and the burst pressure design of the diaphragm (10).

[0015] A space engine employs an external excitation device for combustion state transition in a space engine, as provided in this invention, to achieve external excitation for combustion state transition.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention achieves an excitation intensity range of 0.1 to 40 MPa and an excitation accuracy of 0.1 MPa through precise control of propellant quantity, precise processing and control of diaphragms, and precise adjustment of the internal structure of the device. This solves the technical problems of insufficient adjustable range and insufficient accuracy of external excitation in space engines. 2. This invention accelerates and depressurizes the supersonic flow in the expansion section, and after the diaphragm bursts, it forms a decelerated and pressurized supersonic flow in the contraction section. By coordinating the expansion and contraction sections, the effect of small amount of explosive and high outlet pressure can be achieved. Combined with the diaphragm burst pressure design, the outlet pressure of the device can be precisely adjusted. Attached Figure Description

[0017] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 A schematic diagram of an external excitation device provided for an example of the present invention.

[0018] The diagram shows: Detailed Implementation

[0019] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0020] like Figure 1 As shown, this embodiment of the invention provides an external excitation device for the transition of combustion state in a space engine, comprising: a housing 5, a front assembly, a rear assembly, and a propellant assembly; The shell 5 is a hollow, columnar structure. The front and rear ends of the shell 5 are respectively adapted to the front and rear components. The front component is fitted at the front end of the shell 5, the rear components are respectively disposed at the rear end of the shell 5, and the drug body component is disposed in the internal cavity of the shell 5. Further, the front assembly includes: an adapter 1, a front nut 2, a front ring 3, a front sealing ring 4, and a diaphragm 10; the adapter 1 and the housing 5 are connected together by the front nut 2, the front ring 3, and the front sealing ring 4; a diaphragm 10 is provided between the tail of the adapter 1 and the housing 5; the front sealing ring 4 and the front ring 3 are abutted and sleeved on the outer periphery of the rear section of the adapter 1, forming a coaxial gap between the adapter 1 and the housing 5; the diaphragm 10, the front sealing ring 4, and the front ring 3 are pressed together by the threads of the front nut 2 and the outer periphery of the housing 5. Furthermore, the rear assembly includes: a rear nut 6, a rear sealing ring 8, and a rear ring 9; the rear sealing ring 8 is disposed at the rear end of the housing 5, the rear ring 9 abuts against the rear side of the rear sealing ring 8, and the rear nut 6 is sleeved on the rear side of the rear ring 9, and the rear sealing ring 8 and the rear ring 9 are pressed together by the threads of the rear nut 6 and the outer periphery of the housing 5. Furthermore, the propellant assembly includes: a propellant grain 11 and a wire 7; the propellant grain 11 is installed in the rear cavity of the shell 5, and is ignited by electricity through the wire 7 connected to the propellant grain 11; the wire 7 passes through the rear nut 6, and the gap between the wire 7 and the rear nut 6 (point A in the figure) is filled and cured with epoxy resin, the epoxy resin being selected with a temperature resistance >300℃ and a compressive strength >50MPa; furthermore, the propellant grain 11 uses RDX as the excitation source, with a charge amount of 0.05 to 2g, and the charge can be dispensed at intervals of 0.005 to 0.01g as needed; furthermore, because the charge amount is small, on the gram scale, and the ignition is instantaneous, the timing and magnitude of the excitation process for liquid rocket engines can be precisely controlled, the combustion products are minimal, and the impact of entering the combustion chamber on engine operation is negligible; compared to solid rocket engines, which can assess combustion stability at a continuous frequency, it is more suitable for instantaneous excitation assessment methods; Furthermore, the diaphragm 10 has a thickness of 0.2 mm and a diameter of 20 to 30 mm. A cross groove is milled into the diaphragm 10 by machining, with a groove depth of 0.08 to 0.12 mm. The intersection of the grooves is located at the center of the diaphragm. Furthermore, the shell 5 has an expansion section, in Figure 1 The center is marked with 51, and the angle is 5 to 30°; the adapter 1 has a shrink section, in Figure 1Marked with 12, with an angle of 30 to 60°, it is coaxially connected with the shell 5, so that the shock wave generated after the ignition of RDX can enhance the control of the excitation intensity by passing through the expansion section and the contraction section. More specifically, the upstream expansion section 51 generates a supersonic flow that accelerates and depressurizes along the shape of the expansion section 51. After reaching and detonating the diaphragm 10, it forms a supersonic flow that decelerates and increases pressure in the contraction section 12. Through the cooperation of the expansion section 51 and the contraction section 12, the effect of small amount of explosive and high outlet pressure can be achieved. Combined with the burst pressure design of the diaphragm 10, the outlet pressure of the device can be precisely adjusted.

[0021] Furthermore, the external excitation device can achieve an excitation intensity range of 0.1 to 40 MPa and an excitation accuracy of 0.1 MPa by controlling the charge amount, diaphragm thickness, diaphragm groove depth, and internal structure. In summary, this invention provides an external excitation device for combustion state transition in a space engine, comprising: a housing 5, a front assembly, a rear assembly, and a propellant assembly; the housing 5 is a hollow, cylindrical structure, with the front and rear ends of the housing 5 adapted to the front and rear assemblies, respectively; the front assembly is fitted at the front end of the housing 5, the rear assemblies are respectively disposed at the rear end of the housing 5, and the propellant assembly is disposed within the internal cavity of the housing 5; through precise control of the propellant charge, precise processing and control of the diaphragm, and precise adjustment of the internal structure of the device, an excitation intensity range of 0.1 to 40 MPa and an excitation accuracy of 0.1 MPa can be achieved, solving the problems of insufficient adjustable range and insufficient accuracy of external excitation for space engines.

[0022] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0023] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. An external excitation device for combustion state transition in a space engine, characterized in that, include: The shell (5), the front assembly, the rear assembly, and the drug body assembly; The shell (5) is a hollow columnar structure. The front and rear ends of the shell (5) are respectively adapted to the front and rear components. The front component is disposed at the front end of the shell (5), the rear component is disposed at the rear end of the shell (5), and the drug body component is disposed in the internal cavity of the shell (5).

2. The external excitation device for combustion state transition in a space engine according to claim 1, characterized in that, The front assembly includes: adapter (1), front nut (2), front ring (3), front sealing ring (4), and diaphragm (10). The adapter (1) is connected to the housing (5) via a front nut (2), a front ring (3), and a front sealing ring (4). A diaphragm (10) is provided between the adapter (1) and the housing (5). The front sealing ring (4) and the front ring (3) are abutted and sleeved on the outer periphery of the rear section of the adapter (1) and the housing (5) with a coaxial gap; the diaphragm (10), the front sealing ring (4) and the front ring (3) are pressed together by the threads of the front nut (2) and the outer periphery of the housing (5).

3. The external excitation device for combustion state transition in a space engine according to claim 1, characterized in that, The rear assembly includes: a rear nut (6), a rear sealing ring (8), and a rear ring (9); The rear sealing ring (8) is located at the rear end of the housing (5). The rear ring (9) abuts against the rear sealing ring (8) on the rear side. After the rear nut (6) is fitted onto the rear ring (9), the rear sealing ring (8) and the rear ring (9) are pressed together by the threads of the rear nut (6) and the outer circumference of the housing (5).

4. The external excitation device for combustion state transition in a space engine according to claim 3, characterized in that, The drug assembly includes: a drug column (11) and a wire (7); the drug column (11) is installed in the rear cavity of the housing (5) and is ignited by the wire (7) connected to the drug column (11); the wire (7) passes through the rear nut (6), and the gap between the wire (7) and the rear nut (6) is filled and cured with epoxy resin.

5. The external excitation device for combustion state transition in a space engine according to claim 4, characterized in that, The epoxy resin is selected with a temperature resistance >300℃ and a compressive strength >50MPa.

6. The external excitation device for combustion state transition in a space engine according to claim 4, characterized in that, The drug column (11) uses Rexoxane as the excitation source, with a drug content of 0.05 to 2g, and the drug dispensing interval is 0.005 to 0.01g as required.

7. The external excitation device for combustion state transition in a space engine according to claim 2, characterized in that, The diaphragm (10) has a thickness of 0.2 mm and a diameter of 20 to 30 mm. A cross groove is milled on the diaphragm (10) by machining. The groove depth is 0.08 to 0.12 mm, and the intersection of the grooves is located at the center of the diaphragm.

8. The external excitation device for combustion state transition in a space engine according to claim 1, characterized in that, The housing (5) has an expansion section (51) with an expansion angle of 5 to 30°; the adapter (1) has a contraction section (12) with a contraction angle of 30 to 60°, and is coaxially connected with the housing (5).

9. The external excitation device for combustion state transition in a space engine according to claim 8, characterized in that, The supersonic flow that accelerates and depressurizes along the shape of the expansion section (51) is generated upstream of the expansion section (51). After reaching and bursting the diaphragm (10), the supersonic flow that decelerates and increases pressure is formed in the contraction section (12). The outlet pressure of the device is adjusted by the combination of the expansion section (51) and the contraction section (12) and the burst pressure design of the diaphragm (10).

10. A space engine, characterized in that, The external excitation device for combustion state transition of a space engine as described in any one of claims 1 to 9 is used to achieve the external excitation for combustion state transition.

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