A supersonic combustion chamber structure and a method for improving its anti-backpressure ability

Abstract

The present invention discloses a supersonic combustion chamber structure and a method for enhancing its anti-backpressure ability, belonging to the technical field of scramjet engines. It includes a combustion chamber main body and a center strut flameholder. The structure of the combustion chamber main body is divided into four parts: an isolator, a diffuser, a constant-area section, and a nozzle. The center strut flameholder is assembled at the center position of the lower wall surface of the supersonic combustion chamber, and the assembly position of the center strut flameholder can be adjusted back and forth in the combustion chamber. During high Mach number flight, the center strut flameholder is located at the end of the isolator. During low Mach number flight, the center strut flameholder moves backward into the diffuser. The backward movement of the center strut flameholder cooperates with the diffuser to improve the anti-backpressure ability. The present invention can effectively enhance the working stability of the scramjet engine and lay a foundation for the wide-speed-range flight of hypersonic aircraft.

Description

Technical Field

[0001] The present invention relates to the technical field of scramjet engines, and particularly to a supersonic combustion chamber structure and a method for improving its anti-backpressure ability. Background Technique

[0002] Hypersonic aircraft have the capabilities of instant penetration strikes and detecting and destroying targets immediately, and are the high points of research in the field of aerospace in the world today. Scramjet engines have no rotating components and do not need to carry oxidants, with the advantages of high specific impulse and high speed, and have become the best power devices capable of achieving hypersonic flight. In order to meet the future development direction of scramjet engines with a wide speed range and a large airspace, the working range and performance of supersonic combustion chambers have become the key research points. In a supersonic combustion chamber, the mainstream velocity can reach the order of kilometers per second, which brings difficulties to the mixing and stable combustion of fuel. Especially, the coupling process of flow and combustion brings difficulties to the high-performance and reliable operation of the engine.

[0003] Under different flight conditions, the combustion process disturbs the oncoming flow and blocks the oncoming flow, resulting in the engine being prone to non-starting phenomena, bringing potential safety hazards to scramjet engines. Therefore, it is necessary to improve the anti-backpressure ability of the combustion chamber. Under high Mach number conditions, the supersonic airflow has a relatively high anti-backpressure ability after compression, and is also affected by the injection and combustion processes, which can ensure the normal operation of the engine; under low Mach number conditions, the supersonic airflow is easily blocked by the injection and combustion processes, resulting in engine non-starting. A single fixed combustion chamber structure cannot meet the requirements of wide speed range flight. Adjusting the combustion chamber structure and formulating a combustion organization plan to improve the anti-backpressure ability of the combustion chamber have become the key research points. Summary of the Invention

[0004] The purpose of the present invention is to provide a supersonic combustion chamber structure and a method for improving its anti-backpressure ability to solve the problems existing in the above-mentioned prior art, effectively improve the working stability of scramjet engines, and lay a foundation for the wide speed range flight of hypersonic aircraft.

[0005] To achieve the above purpose, the present invention provides the following solution: The present invention provides a supersonic combustion chamber structure, including

[0006] a combustion chamber main body, a front fuselage, an intake duct and the combustion chamber main body are connected in sequence. The combustion chamber main body includes a isolation section, a expansion section, a constant cross-section section and a nozzle arranged in sequence. The isolation section is connected to the intake duct; and

[0007] a center strut flame stabilizer, the center strut flame stabilizer is movably arranged on the inner wall of the combustion chamber main body, the position of the center strut flame stabilizer in the combustion chamber main body can be adjusted back and forth, and an igniter is arranged on the bottom wall of the combustion chamber main body and behind the center strut flame stabilizer.

[0008] Preferably, during high Mach number flight, the central strut flame stabilizer is located at the end of the isolator section.

[0009] Preferably, during low Mach number flight, the central strut flame stabilizer is located in the divergent section.

[0010] Preferably, the inner diameter of the constant diameter section is greater than the inner diameter of the isolator section.

[0011] Preferably, the inner diameter of the end of the nozzle is greater than the inner diameter of the constant diameter section.

[0012] Preferably, the central strut flame stabilizer is located at the central position of the lower wall surface of the combustion chamber main body.

[0013] Preferably, the central strut flame stabilizer includes a flame stabilizer main body and a flame stabilizer front body which are integrally arranged. The flame stabilizer main body is a rectangular body, and the flame stabilizer front body is a wedge-shaped structure. Fuel injection holes are arranged on both side surfaces of the front hypotenuse of the wedge-shaped structure of the flame stabilizer front body; the fuel injection holes are evenly distributed on the side surface of the wedge-shaped structure, and the opening inclination angle of the fuel injection holes is the same as the inclination angle of the front hypotenuse of the wedge-shaped structure.

[0014] Preferably, a through groove is formed along the height direction in the middle of the rear side edge of the rectangular body, and two rows of oxygen supply holes are symmetrically distributed on both sides of the rectangular body where the groove is located.

[0015] The present invention also provides a method for improving the anti-backpressure ability of a supersonic combustion chamber structure, which is applied to the above-mentioned supersonic combustion chamber structure and includes the following steps:

[0016] During high Mach number flight, the central strut flame stabilizer is located at the end of the isolator section, and the flame is established at the end of the isolator section. Only relying on the divergent section can prevent the excessive pressure rise caused by concentrated heat release, and has the anti-backpressure ability;

[0017] During low Mach number flight, the anti-backpressure ability of the combustion chamber decreases. Move the central strut flame stabilizer backward into the divergent section. The backward movement of the central strut flame stabilizer cooperates with the structure of the divergent section. On the one hand, it realizes the backward movement of the heat release area, and on the other hand, it reduces the heat release concentration by releasing heat in the divergent section to improve the anti-backpressure ability of the combustion chamber.

[0018] The present invention has obtained the following beneficial technical effects compared with the prior art:

[0019] The supersonic combustion chamber structure and the method for enhancing its anti-backpressure ability in the present invention include a combustion chamber main body and a central strut flame stabilizer. The structure of the combustion chamber main body is divided into four parts: an isolator, a diffuser, a constant cross-section section, and a nozzle. The central strut flame stabilizer is assembled at the center position of the lower wall surface of the supersonic combustion chamber, and the assembly position of the central strut flame stabilizer can be adjusted forward and backward in the combustion chamber; during high Mach number flight, the central strut flame stabilizer is located at the end of the isolator, and during low Mach number flight, the central strut flame stabilizer moves backward into the diffuser. The backward movement of the central strut flame stabilizer cooperates with the diffuser to improve the anti-backpressure ability. The present invention can effectively improve the working stability of the scramjet engine and lay a foundation for the wide-speed-range flight of hypersonic aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a schematic diagram of the overall structure of the supersonic combustion chamber structure in the embodiment of the present invention;

[0022] Figure 2 It is an internal top view of the supersonic combustion chamber structure;

[0023] Among them, 1. Combustion chamber main body; 2. Isolator; 3. Diffuser; 4. Constant cross-section section; 5. Nozzle; 6. Central strut flame stabilizer; C. Front fuselage; D. Inlet; E. Heat release area. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0025] The purpose of the present invention is to provide a supersonic combustion chamber structure and a method for enhancing its anti-backpressure ability to solve the problems existing in the above-mentioned prior art, effectively improve the working stability of the scramjet engine, and lay a foundation for the wide-speed-range flight of hypersonic aircraft.

[0026] To make the above-mentioned objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0027] As Figure 1 - Figure 2As shown in the figure, the present invention provides a supersonic combustion chamber structure, including

[0028] a combustion chamber main body 1, a front fuselage C, an intake duct D and the combustion chamber main body 1 are connected in sequence. The combustion chamber main body 1 includes a isolation section 2, a divergent section 3, a constant diameter section 4 and a nozzle 5 arranged in sequence. The isolation section 2 is connected to the intake duct D; and

[0029] a center strut flame stabilizer 6 is movably arranged on the inner wall of the combustion chamber main body 1. The position of the center strut flame stabilizer 6 in the combustion chamber main body 1 can be adjusted back and forth. The igniter is located on the bottom wall of the combustion chamber main body 1 and behind the center strut flame stabilizer 6.

[0030] In one embodiment, during high Mach number flight, the center strut flame stabilizer 6 is located at the end of the isolation section 2; during low Mach number flight, the center strut flame stabilizer 6 is located in the divergent section 3.

[0031] In one embodiment, the inner diameter of the constant diameter section 4 is larger than that of the isolation section 2, and the inner diameter of the end of the nozzle 5 is larger than that of the constant diameter section 4; the inner diameters of each section in the combustion chamber main body 1 can also be adjusted according to specific implementation requirements.

[0032] In one embodiment, the center strut flame stabilizer 6 is located at the center of the lower wall surface of the combustion chamber main body 1.

[0033] In one embodiment, the center strut flame stabilizer 6 includes a flame stabilizer main body and a flame stabilizer front body integrally arranged. The flame stabilizer main body is a rectangular body, and the flame stabilizer front body is a wedge-shaped structure. 11 fuel injection holes are arranged on both side surfaces of the front hypotenuse of the wedge-shaped structure of the flame stabilizer front body; the fuel injection holes are evenly distributed on the side surface of the wedge-shaped structure, and the opening inclination angle of the fuel injection holes is the same as the inclination angle of the front hypotenuse of the wedge-shaped structure; a through groove is opened along the height direction in the middle of the rear side edge of the rectangular body, and two rows of oxygen supply holes are symmetrically distributed on both sides of the groove on the rectangular body, and the number of oxygen supply holes in each row is 10.

[0034] A method for improving the anti-back pressure ability of the supersonic combustion chamber structure has the following working principle:

[0035] During high Mach number flight, the center strut flame stabilizer 6 is located at the end of the isolation section 2, that is Figure 2 position A in, the flame is established at the end of the isolation section 2, and only relying on the divergent section 3 can prevent the excessive pressure rise caused by concentrated heat release, and has the anti-back pressure ability;

[0036] During low Mach number flight, the anti-back pressure ability of the combustion chamber decreases, and the center strut flame stabilizer 6 moves backward into the divergent section 3, that is Figure 2At position B in [the above], the structure of the expansion section 3 is combined with the rearward movement of the center strut flame stabilizer 6; on the one hand, it realizes the backward movement of the heat release area E, and on the other hand, it reduces the heat release concentration by releasing heat in the expansion section 3 to improve the anti-backpressure ability of the combustion chamber.

[0037] Based on the combustion chamber of a scramjet engine, the present invention proposes a supersonic combustion chamber structure and a method for improving its anti-backpressure ability. To cope with the wide-speed-range flight conditions and ensure the stable operation of the engine under different flight conditions, the combustion chamber structure and the position of the center strut flame stabilizer 6 are designed, and a scheme for improving the anti-backpressure of the combustion chamber is formulated. In short, the present invention can effectively improve the stability of the scramjet engine operation, laying a foundation for the wide-speed-range flight of hypersonic vehicles.

[0038] It should be noted that for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention, and any reference signs in the claims should not be regarded as limiting the claimed rights.

[0039] Specific examples are used in the present invention to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, there will be changes in the specific implementation manner and application scope according to the idea of the present invention. In summary, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for improving the anti-backpressure ability of a supersonic combustor structure, characterized in that Comprising the following steps: During high Mach number flight, the central strut flame stabilizer is located at the end of the isolator section, and the flame is established at the end of the isolator section. Only relying on the divergent section can prevent the excessive pressure rise caused by concentrated heat release, and it has the ability to resist backpressure. During low Mach number flight, the backpressure resistance ability of the combustor decreases. Move the central strut flame stabilizer backward into the divergent section. The backward movement of the central strut flame stabilizer, combined with the structure of the divergent section, on the one hand, realizes the backward movement of the heat release area, and on the other hand, reduces the heat release concentration by releasing heat in the divergent section to improve the backpressure resistance ability of the combustor. A supersonic combustor structure for a method of enhancing the backpressure resistance ability of a supersonic combustor structure, comprising A combustor main body, a front fuselage, an inlet duct are sequentially connected and arranged in communication with the combustor main body. The combustor main body includes an isolator section, a divergent section, a constant diameter section, and a nozzle arranged in sequence. The isolator section is connected to the inlet duct; and A central strut flame stabilizer, the central strut flame stabilizer is movably arranged on the inner wall of the combustor main body, and the position of the central strut flame stabilizer in the combustor main body can be adjusted forward and backward. An igniter is arranged on the bottom wall of the combustor main body and is located behind the central strut flame stabilizer.

2. The method for improving the anti-backpressure ability of the supersonic combustion chamber structure according to claim 1, characterized in that: During high Mach number flight, the central strut flame stabilizer is located at the end of the isolator section.

3. The method for enhancing the anti-backpressure ability of the supersonic combustion chamber structure according to claim 1, characterized in that: During low Mach number flight, the central strut flame stabilizer is located in the divergent section.

4. The method for enhancing the anti-backpressure ability of the supersonic combustor structure according to claim 1, wherein: The inner diameter of the constant diameter section is larger than the inner diameter of the isolator section.

5. The method for improving the anti-backpressure ability of the supersonic combustion chamber structure according to claim 1, wherein: The inner diameter of the end of the nozzle is larger than the inner diameter of the constant diameter section.

6. The method for enhancing the anti-backpressure ability of the supersonic combustion chamber structure according to claim 1, characterized in that: The central strut flame stabilizer is located at the central position of the lower wall surface of the combustor main body.

7. The method for enhancing the anti-backpressure ability of the supersonic combustor structure according to claim 1, characterized in that: The central strut flame stabilizer includes a flame stabilizer main body and a flame stabilizer front body integrally arranged. The flame stabilizer main body is a rectangular body, the flame stabilizer front body is a wedge-shaped structure, and fuel injection holes are arranged on both side surfaces of the front hypotenuse of the wedge-shaped structure of the flame stabilizer front body; the fuel injection holes are evenly distributed on the side surface of the wedge-shaped structure, and the opening inclination angle of the fuel injection holes is the same as the inclination angle of the front hypotenuse of the wedge-shaped structure.

8. The method for enhancing the anti-backpressure ability of the supersonic combustion chamber structure according to claim 7, characterized in that: A through groove is opened along the height direction in the middle of the rear side edge of the rectangular body, and two rows of oxygen supply holes are symmetrically distributed on both sides of the rectangular body where the groove is located.

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