Afterburner adopting gas-liquid bimodal-cross hole spray rod for oil supply

Abstract

The invention discloses an afterburner adopting a gas-liquid bimodal-cross hole spray rod for oil supply, and relates to the technical field of aero-engines. Comprising a turbine located at the axis position of an inner duct in the air incoming flow direction; the mixer is arranged between the turbine and the inner duct wall body; the rectification support plates are provided with air inlet channels, and the multiple rectification support plates penetrate through the outer duct and are vertically and uniformly arranged in the circumferential direction of the inner duct; the oil injection rod is provided with an air flow channel and a fuel oil channel, and the air inlet channel is communicated with the air flow channel; and the oil injection rod is radially arranged in the rectification support plate. On the basis that the structural complexity of an afterburner of a turbine engine and a combustion chamber of a subsonic combustion ramjet engine is not increased, the atomization performance and the oil-gas mixing uniformity of fuel oil in the afterburner / ramjet combustion chamber are remarkably improved, the combustion efficiency of the engine is improved, and the combustion instability is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of aero-engines, and particularly to an afterburner adopting a gas-liquid dual-mode - cross-hole spray bar for fuel supply. Background Art

[0002] In the technical field of modern aero-engines, there is a fundamental technical contradiction in the design process, that is, it is difficult to achieve optimal performance simultaneously within the entire operating range of the engine. The thrust requirements of the aircraft vary significantly at different flight stages. For example, maximum thrust is required during takeoff and accelerating climb stages, while fuel economy is prioritized during the cruise stage. This contradiction constitutes the core challenge in engine design: if the maximum takeoff thrust is taken as the design point, the size of the engine core will increase, resulting in increased mass, degraded characteristics during the cruise stage, and increased fuel consumption rate; conversely, if the cruise state is taken as the design optimization point, the engine will not be able to provide sufficient takeoff thrust and cannot meet the basic performance requirements of the aircraft.

[0003] To solve the above contradiction, the afterburner technology has emerged. By adding a secondary combustion device in the exhaust system behind the turbine, this technology can provide significant additional thrust during specific demand stages and has become an important means to improve engine performance. To improve the performance and flight envelope of the aircraft, it is necessary to further optimize the fuel atomization effect in the afterburner to achieve full mixing of fuel and air and uniform spatial distribution, because the fuel atomization effect directly affects the quality of the combustion chamber operating characteristics. Therefore, the research on fuel atomization is an important part of the aero-engine research field.

[0004] However, the fuel injection rods in the afterburners of common turbofan engines currently generally adopt direct-injection fuel nozzles, which have many problems. Their fuel spray expansion angle is small, the atomization effect is poor, and the equivalent diameter of the nozzle is small, which is extremely likely to cause nozzle blockage, significantly affecting the stability and reliability of the engine combustion chamber operation.

[0005] In addition, for the next-generation engines aiming for higher thrust-to-weight ratio and working efficiency, it is necessary to integrate components such as the rear frame of the turbine, the fairing struts, the fuel nozzle, and the flame stabilizer to a certain extent to reduce the length and mass of the afterburner. However, if the traditional direct-injection fuel spray bar form continues to be used in the afterburner and the scramjet combustion chamber, although its structure is simple, the spatial distribution of the injected fuel is extremely uneven, which will seriously affect the combustion efficiency; at the same time, it results in an overly long flow distance for atomization and mixing in the high-speed cross-flow, making it difficult to meet the requirement of further shortening the length of the afterburner for the next-generation engines; moreover, the inlet temperature of the next-generation afterburner is higher and the auto-ignition delay time is shorter, and it is necessary to complete full atomization, evaporation, and mixing of the fuel within 50 mm to prevent fuel auto-ignition, while the conventional direct-injection fuel spray bar is difficult to achieve the above design goals. Summary of the Invention

[0006] The object of the present invention is to provide an afterburner that uses a gas-liquid dual-mode - cross-hole spray bar for fuel supply, which significantly expands the fuel spray expansion angle, reduces the number of nozzles and decreases the atomization particle size. At the same time, it optimizes the radial and circumferential concentration distribution of the fuel, effectively improving the reliability and stability of the afterburner.

[0007] To achieve the above object, the technical solution of the present application is: an afterburner that uses a gas-liquid dual-mode - cross-hole spray bar for fuel supply, including:

[0008] A turbine located at the axial position of the inner duct along the air inflow direction;

[0009] A mixer arranged between the turbine and the inner duct wall;

[0010] A rectifying strut with an air inlet channel, and a plurality of rectifying struts pass through the outer duct and are vertically and evenly arranged along the circumferential direction of the inner duct;

[0011] An injection rod with an air flow channel and a fuel channel, and the air inlet channel is communicated with the air flow channel; the injection rod is radially arranged in the rectifying strut.

[0012] As a preferred solution of the present invention, the side wall of the injection rod is provided with cross-hole nozzles communicated with the fuel channel, and the openings of the cross-hole nozzles extend out of the side wall of the rectifying strut.

[0013] As a preferred solution of the present invention, the cross-sectional shape of the opening of the cross-hole nozzle is "peanut"-shaped, and the fuel forms a fan-shaped oil mist cone film after being ejected from the cross-hole nozzle.

[0014] As a preferred solution of the present invention, the tails of the fan-shaped oil mist cone films between adjacent cross-hole nozzles overlap each other.

[0015] As a preferred solution of the present invention, the fan-shaped oil mist cone films are evenly distributed in the radial space of the afterburner.

[0016] As a preferred solution of the present invention, the cross-hole nozzles are arranged on the side wall of the injection rod along the radius direction of the afterburner, and the number is 1 to 20.

[0017] As a preferred solution of the present invention, the side wall of the injection rod is provided with an inclined cut groove communicated with the air flow channel, and the inclined cut groove is located above the corresponding cross-hole nozzle.

[0018] As a preferred solution of the present invention, the air flow applies an impact force to the fan-shaped oil mist cone film through the inclined cut groove, generating Kelvin-Helmholtz instability waves and accelerating the fragmentation of the cone film into droplets.

[0019] As a preferred embodiment of the present invention, the included angle α between the two sub-nozzles inside the cross-hole nozzle is 30 to 60°.

[0020] As a preferred embodiment of the present invention, a flame stabilizer is provided on one side of the rectifying splitter plate.

[0021] Due to the adoption of the above technical solutions, the present invention can achieve the following technical effects: The fuel injection rod adopts a cross-hole nozzle design, and the number of nozzles is significantly reduced by increasing the fuel spray expansion angle. An inclined cut is provided above the outlet of the cross-hole, and its inclination direction matches the fan-shaped oil mist cone film. The air flow impacts the cone film to generate Kelvin-Helmholtz instability waves, accelerating the fragmentation of the cone film into fine droplets and effectively reducing the atomization particle size. By adjusting the overlapping angle of adjacent oil mist cone films, the radial distribution uniformity of the fuel is optimized, and the combustion characteristics are improved. The fuel injection rod is integrated inside the rectifying splitter plate, effectively reducing the flow resistance loss and total pressure loss. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] Figure 1 Simplified schematic diagram of an afterburner using a gas-liquid dual-mode - cross-hole spray rod for fuel supply;

[0024] Figure 2 Schematic diagram of the appearance of the fuel injection rod;

[0025] Figure 3 Two-dimensional sectional view of the fuel injection rod;

[0026] Figure 4 Schematic diagram of the oil mist field formed by all cross-hole nozzles.

[0027] Explanation of the numbers in the figure: 1. Afterburner; 2. Mixer; 3. Air intake passage; 4. Flame stabilizer; 5. Turbine; 6. Turbine blade; 7. Rectifying splitter plate; 8. Cross-hole nozzle; 9. Outer bypass duct; 10. Inner bypass duct; 11. Fuel injection rod; 12. Fuel passage; 13. Air flow passage; 14. Inclined cut; 15. Fan-shaped oil mist cone film. Detailed Embodiments

[0028] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the following further details the present application in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0029] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0030] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0031] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0032] As Figures 1-3 shown, the present embodiment provides an afterburner with gas-liquid dual-mode cross-hole spray bar fuel supply, including:

[0033] A turbine, on which a plurality of turbine blades are distributed, and the turbine is disposed at the axial position of the inner duct along the air flow direction;

[0034] A mixer, arranged between the turbine and the inner duct wall;

[0035] A rectifying strut, provided with an air inlet passage, and a plurality of rectifying struts are evenly and vertically distributed along the circumferential direction of the inner duct and penetrate the outer duct;

[0036] An injection rod, internally provided with an air flow passage and a fuel passage, the air inlet passage is communicated with the air flow passage, and the injection rod is radially installed in the rectifying strut;

[0037] Cross-hole nozzle, which is arranged on the side wall of the fuel injection rod and communicates with the fuel channel. The nozzle orifice of the cross-hole nozzle extends to the outside of the side wall of the rectifying strut. Preferably, the crossing angle between two sub-nozzle orifices inside the cross-hole nozzle is 30-60°; the cross-section of the nozzle orifice of the cross-hole nozzle is peanut-shaped, and after the fuel is ejected, a fan-shaped oil mist cone film is formed. The tails of the fan-shaped oil mist cone films ejected from adjacent cross-hole nozzles overlap with each other; the fan-shaped oil mist cone films are evenly distributed along the radial direction of the afterburner; the cross-hole structure enhances the interaction between the fuel and the wall surface. A large radial velocity component in the outlet plane is a significant feature that differentiates it from the single-hole of the traditional direct-injection fuel injection rod. The radial internal force of the liquid is the main factor for forming a large spray cone angle, and the difference in the magnitude of the liquid internal force in the radial and axial directions leads to different growth rates of the spray in these two directions, ultimately forming a fan-shaped oil mist cone film;

[0038] Oblique cut groove, which is arranged on the side wall of the fuel injection rod and communicates with the air flow channel. The oblique cut groove is located above the corresponding cross-hole nozzle; it should be noted that the distances between the position of the oblique cut groove, the position of the cross-hole nozzle and the trailing edge of the rectifying strut can be optimized and adjusted according to the working condition parameters to ensure the formation of a stable combustion zone behind the strut;

[0039] Flame stabilizer, which is arranged on one side of the rectifying strut.

[0040] Preferably, the cross-hole nozzles are arranged along the side wall of the fuel injection rod in the radial direction of the afterburner, and the number is 1-20; the specific number is determined according to the fan-shaped oil mist cone angle, the radius of the afterburner and the size of the fuel injection rod to ensure that the fan-shaped oil mists ejected from the nozzles in the radial direction overlap with each other, improving the spatial uniformity of fuel atomization and combustion efficiency.

[0041] As Figure 4 shown, during operation, the fuel enters the fuel channel from the fuel manifold. When the fuel flows through the cross-hole nozzle, the nozzle structure causes a converging and squeezing effect on the liquid-phase fuel, converting part of the jet kinetic energy into turbulent kinetic energy. While effectively reducing the spray penetration distance, it significantly increases the spray cone angle after the fuel is ejected. The gas is ejected from the oblique cut groove through the air flow channel, and the oblique cut direction is directly opposite to the fan-shaped oil mist cone film area at the nozzle outlet. The high-speed air flow impacts the fan-shaped oil mist cone film through the oblique cut groove, inducing Kelvin-Helmholtz instability waves, accelerating the fragmentation of the liquid film into fine droplets, thereby further reducing the atomization particle size. The fan-shaped oil mist cone films ejected from each cross-hole nozzle collide with each other in the intersection area, making the circumferential fuel distribution in the afterburner more uniform, enhancing the circumferential flame linking performance at the same time, and improving the combustion stability.

[0042] The effect of this embodiment is that, on the basis of not increasing the structural complexity of the afterburner of the turbine engine and the combustion chamber of the subsonic combustion ramjet engine, this structure significantly improves the atomization performance of the fuel and the uniformity of the fuel-air mixture in the afterburner / ramjet combustion chamber, improves the combustion efficiency of the engine and reduces combustion instability.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An afterburner using a gas-liquid dual-mode cross-hole spray bar fuel supply, characterized in that: include: The turbine is located at the axial position of the inner channel along the direction of air flow; A mixer is arranged between the turbine and the inner channel wall; A rectifying support plate has an air intake passage, and a plurality of rectifying support plates pass through the outer duct and are vertically and evenly arranged along the circumferential direction of the inner duct; The fuel injection rod is provided with an air flow channel and a fuel channel, wherein the air inlet channel is connected with the air flow channel; the fuel injection rod is radially arranged in the rectifying support plate.

2. According to claim 1, the afterburner adopting gas-liquid dual-mode cross-hole spray rod fuel supply is characterized in that: The side wall of the fuel injection rod is provided with a cross hole nozzle which is communicated with the fuel channel, and the opening of the cross hole nozzle extends out of the side wall of the rectifying support plate.

3. The afterburner using a gas-liquid dual-mode cross-hole spray bar fuel supply according to claim 2, characterized in that: The opening cross section of the cross hole nozzle is in a "peanut" shape, and the fuel forms a fan-shaped oil mist cone film after being sprayed out from the cross hole nozzle.

4. The afterburner using a gas-liquid dual-mode cross-hole spray bar fuel supply according to claim 3, characterized in that: The tails of the fan-shaped oil mist cone films between adjacent cross-hole nozzles overlap each other.

5. The afterburner using gas-liquid dual-mode cross-hole spray bar fuel supply according to claim 3, characterized in that: The fan-shaped oil mist cone film is evenly distributed along the radial space of the afterburner.

6. The afterburner using gas-liquid dual-mode cross-hole spray bar fuel supply according to claim 2, characterized in that: The cross hole nozzles are arranged on the side wall of the injection rod along the radial direction of the afterburner chamber, and the number thereof is 1 to 20.

7. The afterburner using gas-liquid dual-mode cross-hole spray bar fuel supply according to claim 3, characterized in that: The side wall of the oil spray rod is provided with an oblique groove communicating with the air flow channel, and the oblique groove is located above the corresponding cross hole nozzle.

8. The afterburner using gas-liquid dual-mode cross-hole spray bar fuel supply according to claim 7, characterized in that: The airflow exerts impact force on the fan-shaped oil mist cone film through the oblique grooves, generating Kelvin-Helmholtz unstable waves and accelerating the cone film to break into droplets.

9. The afterburner using gas-liquid dual-mode cross-hole spray bar fuel supply according to claim 1, characterized in that: The intersection angle α of the two sub-spray holes inside the cross-hole nozzle is 30-60°.

10. The afterburner using gas-liquid dual-mode cross-hole spray bar fuel supply according to claim 1, characterized in that: A flame stabilizer is provided on one side of the rectifying support plate.

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