An air-inflating atomizing air-breathing rocket injector

Abstract

The present invention relates to the field of rocket injector technology, and solves the technical problem that it is difficult to take into account both high-quality atomization of fuel and efficient mixing of gas over a wide range of operating conditions by adjusting the nozzle opening. In particular, it relates to an air-inflated atomizing air-inhaling rocket injector, wherein the central pintle is provided with a plurality of atomizing nozzles uniformly distributed along the circumference of its wall, and an injection gas injection confluence chamber connected to an injection gas inlet flow channel and into which the injection gas is introduced. After the fuel and the injection gas are mixed in the gas mixing chamber, they are ejected from the atomizing nozzle into the oxidant annular flow channel to form a transverse jet, and are mixed with the incoming oxidant gas flow. The present invention does not require changing the nozzle cross-sectional area, adopts an air-inflated atomization method, and obtains a gas-liquid mass ratio that maintains high-quality atomization of fuel and efficient mixing of gas under different operating conditions by adjusting the injection gas flow rate, thereby taking into account high-quality atomization of fuel and efficient mixing of gas over a wide range of operating conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of rocket injectors, and in particular to an air-inflating, atomizing, and air-breathing rocket injector. Background Art

[0002] Air-breathing rocket engines capture oxidizer from the denser atmosphere of near-Earth space, combining the high thrust-to-weight ratio of liquid rocket engines with the high specific impulse of air-breathing engines, enabling high-speed cruising and maneuvering flight in near-Earth space. The injectors in air-breathing rocket engines are responsible for achieving high-quality fuel atomization and efficient mixing of fuel and oxidizer gas across a wide operating range, meeting the requirements for variable thrust regulation under different flight conditions.

[0003] Currently, engines adjust thrust by varying fuel flow. To maintain fuel atomization, the nozzle opening must be adjusted according to flow variations. However, because nozzle openings typically vary discontinuously with operating conditions, maintaining high-quality atomization over a wide operating range is difficult. This is especially true at extremely low operating conditions, where low fuel flow and injection pressure lead to poor atomization and poor engine combustion. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides an air-inflating atomizing and aspirating rocket injector, which solves the technical problem that it is difficult to achieve both high-quality atomization of fuel in a wide operating range and efficient mixing of gas by adjusting the nozzle opening.

[0005] To solve the above technical problems, the present invention provides the following technical solutions: a bleed air atomizing air-breathing rocket injector, comprising a central pintle disposed within an injector housing, the injector housing supporting the central pintle via an integrally formed fuel inlet flow channel and a bleed air inlet flow channel, the injector housing having an oxidizer gas inlet flange and an injector outlet section, the internal passage of the injector housing and the central pintle forming an oxidizer annular flow channel for oxidizer gas to flow from the oxidizer gas inlet flange to the injector outlet section;

[0006] The central pintle is provided with a plurality of aerosol spray holes uniformly distributed along the circumference of its wall surface, and an induced gas injection confluence cavity connected to the induced gas inlet flow channel and into which the induced gas is introduced. The circumferential surface of the induced gas injection confluence cavity is provided with a plurality of gas mixing cavities connected to it and into which the fuel is introduced. After the fuel and the induced gas are mixed in the gas mixing cavity, they are ejected from the aerosol spray holes into the oxidant annular flow channel to form a lateral jet, and are mixed with the oxidant gas flow.

[0007] Furthermore, the central pintle is provided with a pintle cooling channel evenly distributed along the circumference of the pintle wall, and a fuel annular cavity communicating with the pintle cooling channel is provided at the end of the fuel inlet flow channel;

[0008] The central pintle has a downstream head end face that is indented into the injector outlet section to form a flame stabilizing step structure, and the fuel flows from the fuel inlet flow channel to the fuel ring cavity and then enters the pintle cooling channel to cool the side wall surface and downstream head end face of the central pintle.

[0009] Furthermore, the central pintle is provided with a cooling channel manifold connected to the pintle cooling channel, and a fuel injection annular cavity coaxial with the gas mixing chamber, and a fuel injection distribution pipeline is connected between the fuel injection annular cavity and the cooling channel manifold;

[0010] After passing through the pintle cooling channel, the fuel converges in the cooling channel manifold and is evenly distributed by the fuel injection distribution pipeline to the fuel injection annular cavity coaxially arranged with the gas mixing chamber. A plurality of circumferentially evenly distributed oil holes are provided on the wall surface between the gas mixing chamber and the fuel injection annular cavity, and the fuel enters the gas mixing chamber through the oil holes.

[0011] Furthermore, the center pintle has an upstream end surface at one end close to the oxidant gas inlet flange, and the upstream end surface is configured to be a blunt head shape for circumferentially and evenly distributing the oxidant gas flow.

[0012] Furthermore, the fuel inlet flow channel and the induced gas inlet flow channel have a fuel inlet and an induced gas inlet respectively at one end located outside the injector housing, and the end of the induced gas inlet flow channel is provided with an induced gas ring cavity connected to the induced gas injection confluence cavity through an induced gas delivery pipeline.

[0013] Furthermore, the cross-sections of the fuel inlet flow channel and the ejector gas inlet flow channel may be configured to be any one of rectangular, raindrop-shaped, spindle-shaped, circular or elliptical;

[0014] The cross section of the aerosol spray hole is at least one of circular, elliptical, rectangular, diamond-shaped or raindrop-shaped.

[0015] Furthermore, the aerosol spray holes are multiple transverse spray holes perpendicular to the central pintle wall and evenly distributed circumferentially, and each aerosol spray hole corresponds to a fuel injection distribution pipeline, a fuel injection annular cavity and a gas mixing cavity.

[0016] Furthermore, the minimum cross-sectional area of the oxidant annular flow channel is greater than 2 times the critical cross-sectional area of the oxidant gas, and the critical cross-sectional area A of the oxidant gas is greater than 2 times the critical cross-sectional area of the oxidant gas. * for:

[0017]

[0018] in, is the oxidant gas flow rate; T0 and P0 are the total temperature and total pressure of the oxidant gas, respectively; R is the oxidant gas constant; γ is the specific heat ratio of the oxidant gas.

[0019] Furthermore, the diameter of the central pintle is one fifth to one third of the diameter of the injector outlet cross section;

[0020] The distance that the central pintle is retracted into the injector outlet cross section is no greater than the diameter of the central pintle.

[0021] Furthermore, the momentum of the fuel entering the gas mixing chamber through the oil hole The momentum of the jet gas in the gas mixing chamber Ratio Less than 0.1.

[0022] By means of the above technical solution, the present invention provides an air-inflating atomizing air-breathing rocket injector, which has at least the following beneficial effects:

[0023] 1. The air-inflated atomizing air-breathing rocket injector proposed in the present invention does not require changing the cross-sectional area of the nozzle hole. It adopts the method of induced air-inflated atomization and adjusts the induced air flow rate to obtain a gas-liquid mass ratio that maintains high-quality fuel atomization and efficient mixing of gas under different working conditions, thereby taking into account high-quality fuel atomization and efficient mixing of gas under a wide range of working conditions.

[0024] 2. The present invention provides pintle cooling channels evenly distributed along the circumference of the pintle wall, which can effectively cool the side wall and head end face of the center pintle 3 during the process of fuel entering the cooling channel manifold from the pintle cooling channels.

[0025] 3. This invention uses oxygen-enriched fuel gas as the induced fuel atomizer. High-temperature oxygen-enriched fuel gas not only improves fuel atomization performance through aeration and atomization, but also enhances fuel mixing performance by increasing fuel lateral penetration depth. It also increases reactivity and enhances ignition performance. The induced fuel flow rate can be adjusted by varying the total pressure of the gas generator or the throat cross-sectional area of the sonic flowmeter. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0027] Figure 1 Schematic diagram of the structure of the air-inflating atomizing air-breathing rocket injector of the present invention;

[0028] Figure 2 It is a partial schematic diagram of the aerosol spray hole in the present invention;

[0029] Figure 3 This is a schematic diagram of the oxygen-enriched gas generator in the present invention providing injection gas to the rocket injector.

[0030] In the figure: 1. Oxidant gas inlet flange; 2. Injector housing; 3. Center pintle; 4. Gas mixing chamber; 5. Atomizing nozzle; 6. Fuel inlet; 7. Fuel inlet flow channel; 8. Fuel annular cavity; 9. Pintle cooling channel; 10. Cooling channel manifold; 11. Fuel injection distribution pipeline; 12. Fuel injection annular cavity; 13. Entrained gas inlet; 14. Entrained gas inlet flow channel; 15. Entrained gas annular cavity; 16. Entrained gas delivery pipeline; 17. Entrained gas injection confluence cavity; 18. Oil hole; 19. Upstream end face; 20. Downstream head end face; 21. Injector outlet cross section; 22. Oxygen-enriched gas generator; 23. Sonic flowmeter. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] In order to solve the problem that existing technologies are difficult to achieve both high-quality atomization of fuel over a wide operating range and efficient mixing of gas, please refer to Figure 1-Figure 3 This embodiment proposes a bleed air atomizing rocket injector. This injector utilizes a bleed air atomization method. By adjusting the bleed air flow rate, a gas-liquid mass ratio is achieved that maintains high-quality fuel atomization and efficient gas mixing under various operating conditions. Specifically, the injector housing 2 supports the center pintle 3 via the fuel inlet flow channel 7 and the bleed air inlet flow channel 14. The cross-sections of the fuel inlet flow channel 7 and the bleed air inlet flow channel 14 can be designed to be rectangular, raindrop-shaped, spindle-shaped, circular, elliptical, or other shapes. The upstream end face 19 of the center pintle 3 is blunt-ended, evenly distributing the oxidizer gas flow around the circumference while minimizing flow losses. The downstream head end face 20 of the center pintle 3 is flat and recessed into the injector outlet cross-section 21, forming a flame-stabilizing step structure. Furthermore, the distance the center pintle 3 is recessed into the injector outlet cross-section 21 is no greater than the diameter of the center pintle 3, which should be between one-fifth and one-third of the diameter of the injector outlet cross-section 21.

[0033] like Figure 1 As shown, the oxidant gas flows into the injector through the oxidant gas inlet flange 1 and flows through the oxidant annular flow channel formed by the injector housing 2 and the central pintle 3. The minimum cross-sectional area of the oxidant annular flow channel is greater than 2 times the critical cross-sectional area of the oxidant gas. The critical cross-sectional area A * for:

[0034]

[0035] in, is the oxidant gas flow rate; T0 and P0 are the total temperature and total pressure of the oxidant gas, respectively; R is the oxidant gas constant; γ is the specific heat ratio of the oxidant gas.

[0036] Fuel enters the injector through fuel inlet 6, flows through fuel inlet flow channel 7, and reaches fuel annulus 8. The bottom of fuel annulus 8 connects to pintle cooling channels 9, which are evenly distributed along the circumference of the pintle wall. Fuel enters pintle cooling channels 9 from fuel annulus 8, cools the sidewalls and head end of the central pintle 3, and then converges at cooling channel manifold 10. Fuel is then evenly distributed by fuel injection distribution line 11 to fuel injection annulus 12, which is coaxial with gas mixing chamber 4.

[0037] The atomizing nozzles 5 consist of multiple transverse nozzle holes perpendicular to the wall of the central pintle 3 and evenly distributed around the circumference. The cross-section of the atomizing nozzles 5 can be at least one of the following: circular, elliptical, rectangular, diamond-shaped, or raindrop-shaped. Each atomizing nozzle 5 corresponds to a fuel injection distribution pipeline 11, a fuel injection annular cavity 12, and a gas mixing chamber 4. The wall between the gas mixing chamber 4 and the fuel injection annular cavity 12 is provided with multiple oil holes 18 evenly distributed around the circumference. Fuel enters the gas mixing chamber 4 through the oil holes 18.

[0038] like Figure 3 As shown, the induced gas is provided by the high-temperature oxygen-rich gas generated by the oxygen-rich gas generator 22, and the induced gas flow rate is determined by the sonic flowmeter 23. The oxygen-rich gas generator 22 can be a gas generator for the catalytic decomposition of hydrogen peroxide or nitrous oxide, or it can be a gas generator for the oxygen-rich combustion of an oxidant (such as liquid oxygen, hydrogen peroxide, etc.) and a fuel. The high-temperature oxygen-rich gas not only improves the fuel atomization performance through aeration atomization, but also enhances the gas mixing performance by increasing the penetration depth of the fuel cross jet in the oxidant flow channel. The oxygen-rich gas can also improve the reaction activity and enhance the ignition performance. When the fuel flow rate changes, the induced gas flow rate is adjusted by changing the total pressure of the gas generator or the throat cross-sectional area of the sonic flowmeter to obtain the gas-liquid mass ratio required to maintain high-quality atomization and mixing of the fuel. The gas-liquid mass ratio is defined as the ratio of the induced gas flow rate to the fuel flow rate, which is usually not less than 5%.

[0039] The jet gas enters the injector through the jet gas inlet 13, flows through the jet gas inlet channel 14, the jet gas annular cavity 15, the jet gas delivery pipeline 16, the jet gas injection confluence cavity 17, and evenly enters the gas mixing cavity 4 corresponding to each gas atomization nozzle hole 5. Figure 2 As shown, after the fuel and the pilot gas are mixed in the gas mixing chamber 4, they are ejected from the atomizing nozzle 5 to form a transverse jet in the oxidant flow channel and mix with the oxidant gas flow. At the same time, the momentum of the fuel entering the gas mixing chamber 4 through the oil hole 18 is The momentum of the induced gas in the gas mixing chamber 4 Ratio Less than 0.1.

[0040] The air-injection atomizing air-breathing rocket injector proposed in the present invention does not require changing the cross-sectional area of the nozzle hole. It adopts the method of induced air-injection atomization and adjusts the induced air flow rate to obtain a gas-liquid mass ratio that maintains high-quality fuel atomization and efficient mixing of fuel gas under different working conditions.

[0041] The present invention uses oxygen-enriched fuel gas from an oxygen-enriched fuel generator as the induced gas for fuel aeration and atomization. High-temperature oxygen-enriched fuel gas not only improves fuel atomization performance through aeration and atomization, but also enhances fuel mixing performance by increasing fuel lateral penetration depth. It also increases reactivity and enhances ignition performance. The induced gas flow rate can be adjusted by varying the total pressure of the gas generator or the throat cross-sectional area of the sonic flowmeter.

[0042] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements that are inherent to such process, method, article or apparatus.

[0043] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A bleed air atomizing air-breathing rocket injector, comprising a central pintle (3) disposed in an injector housing (2), the injector housing (2) supporting the central pintle (3) through an integrally formed fuel inlet flow channel (7) and an bleed air inlet flow channel (14), and the injector housing (2) having an oxidant gas inlet flange (1) and an injector outlet section (21), characterized in that: The internal channel of the injector housing (2) and the central pintle (3) form an oxidant annular flow channel for the oxidant gas to flow from the oxidant gas inlet flange (1) to the injector outlet section (21); The central pintle (3) is provided with a plurality of atomizing spray holes (5) uniformly distributed along the circumference of its wall surface, and an ejection gas injection confluence cavity (17) connected to the ejection gas inlet flow channel (14) and into which the ejection gas is introduced. The ejection gas injection confluence cavity (17) is circumferentially distributed on the wall surface thereof, and is connected to the ejection gas influx cavity (17) and into which the fuel is introduced. After the fuel and the ejection gas are mixed in the gas mixing cavity (4), they are ejected from the atomizing spray holes (5) into the oxidant annular flow channel to form a transverse jet, and are mixed with the incoming oxidant gas flow. The central pintle (3) is provided with a pintle cooling channel (9) uniformly distributed along the circumference of the pintle wall, a fuel annular cavity (8) communicating with the pintle cooling channel (9) is provided at the end of the fuel inlet flow channel (7), a cooling channel manifold (10) communicating with the pintle cooling channel (9), and a fuel injection annular cavity (12) coaxial with the gas mixing cavity (4) are provided on the central pintle (3), and a fuel injection distribution pipeline (11) is communicated between the fuel injection annular cavity (12) and the cooling channel manifold (10); After passing through the pintle cooling channel (9), the fuel is combined in the cooling channel manifold (10) and evenly distributed by the fuel injection distribution pipeline (11) to the fuel injection annular cavity (12) coaxially arranged with the gas mixing cavity (4). A plurality of oil holes (18) evenly distributed in the circumferential direction are provided on the wall surface between the gas mixing cavity (4) and the fuel injection annular cavity (12), and the fuel enters the gas mixing cavity (4) through the oil holes (18).

2. The rocket injector according to claim 1, characterized in that The central pintle (3) has a downstream head end face (20) that is indented into the injector outlet cross section (21) to form a flame stabilizing step structure, and fuel flows from the fuel inlet flow channel (7) to the fuel annular cavity (8) and then enters the pintle cooling channel (9) to cool the side wall surface and the downstream head end face (20) of the central pintle (3).

3. The rocket injector according to claim 1 or 2, characterized in that: The center pintle (3) has an upstream end surface (19) at one end close to the oxidant gas inlet flange (1), and the upstream end surface (19) is configured to be blunt-headed for circumferentially and evenly distributing the oxidant gas flow.

4. The rocket injector according to claim 1 or 2, characterized in that: The fuel inlet flow channel (7) and the ejector gas inlet flow channel (14) are located at one end outside the injector housing (2), and each has a fuel inlet (6) and an ejector gas inlet (13), and the end of the ejector gas inlet flow channel (14) is provided with an ejector gas ring cavity (15) that is connected to the ejector gas injection confluence cavity (17) through an ejector gas delivery pipeline (16).

5. The rocket injector according to claim 1, characterized in that The cross-sections of the fuel inlet flow channel (7) and the ejector gas inlet flow channel (14) are configured to be any one of rectangular, raindrop-shaped, spindle-shaped, circular or elliptical; The cross section of the aerosol spray hole (5) is at least one of a circular, elliptical, rectangular, diamond-shaped or raindrop-shaped shape.

6. The rocket injector according to claim 1, characterized in that The aerosol spray holes (5) are a plurality of transverse spray holes perpendicular to the wall of the central pintle (3) and uniformly distributed circumferentially. Each aerosol spray hole (5) corresponds to a fuel injection distribution pipeline (11), a fuel injection annular cavity (12) and a gas mixing cavity (4).

7. The rocket injector according to claim 1, characterized in that The minimum cross-sectional area of the oxidant annular flow channel is greater than 2 times the critical cross-sectional area of the oxidant gas. for: ； in, is the oxidant gas flow rate; and Total temperature and total pressure of oxidant gas respectively; is the oxidant gas constant; is the specific heat ratio of the oxidant gas.

8. The rocket injector according to claim 1, characterized in that The diameter of the central pintle (3) is one fifth to one third of the diameter of the injector outlet cross section (21); The distance that the central pintle (3) is retracted into the injector outlet cross section (21) is no greater than the diameter of the central pintle (3).

9. The rocket injector according to claim 1, characterized in that The momentum of the fuel entering the gas mixing chamber (4) through the oil hole (18) The momentum of the induced gas in the gas mixing chamber (4) Ratio Less than 0.1.

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