A radial flame stabilizer with airflow-assisted jet

Abstract

This invention discloses a radial flame stabilizer with airflow-assisted jet, comprising an outer wall and an inner wall. Both the outer and inner wall surfaces have V-shaped cross-sections, including a pointed tip and two tail ends. The two corresponding tail ends of the outer and inner wall surfaces are connected by a flow-rectifying wall. An air-guiding groove is provided at the pointed tip of the outer wall, and several injection holes are provided near the tail ends. The air-guiding groove, the interlayer between the outer and inner wall surfaces, and the injection holes form an airflow channel. A fuel injection extension pipe is provided near the tail ends of the inner wall, extending from the inner wall towards the injection holes. The fuel injection extension pipe guides the fuel injection from the injection holes. By introducing a portion of the incoming flow through the air-guiding groove at the stabilizer head, and utilizing the method of coaxial injection of the introduced incoming gas and fuel, the problem of shallow fuel jet depth and difficult evaporation under high-speed, large-flow conditions is improved, resulting in better fuel evaporation and mixing performance compared to conventional radial flame stabilizers.

Description

Technical Field

[0001] This invention relates to afterburners for turbofan engines, combustion chambers for subsonic ramjet engines, multi-mode combustion chambers for turbofan / ramjet combined cycle engines, and combustion chambers for hypersonic engines. Specifically, it relates to a radial flame stabilizer for an airflow-assisted jet. Background Technology

[0002] Turbine-based combined cycle (TBCC) engines, as a type of air-breathing engine, have advantages such as wide flight range, conventional takeoff and landing, and reusability, and are considered to be the most promising power plant for hypersonic aircraft at present.

[0003] With the increasing airflow velocity in modern high-performance afterburners, radial flame stabilizers are typically used to enhance flame propagation. Fuel is injected into the core flow from the side of the stabilizer's trailing edge. The fuel nozzle and flame stabilizer employ a "close-fitting" technology, utilizing the recirculation zone formed by the stabilizer's rearward expansion to stabilize the flame. The quality of fuel evaporation significantly impacts combustion efficiency. Injection points too close to the combustion zone mean fuel evaporation relies heavily on jet depth. However, the high-speed, high-flow conditions in multi-mode combustion chambers place even greater demands on fuel evaporation. Higher flow velocities lead to increased kinetic energy. Since the fuel jet direction is perpendicular to the flow direction, this increased kinetic energy reduces the fuel jet depth, making the fuel jet more susceptible to being blown into the recirculation zone. This reduced jet depth further decreases fuel evaporation capacity. Under high-speed flow conditions, the reduced jet depth of conventional radial flame stabilizers results in insufficient fuel evaporation, decreased evaporation efficiency, and ultimately, reduced combustion efficiency in the combustion chamber. Summary of the Invention

[0004] Purpose of the invention: To address the above-mentioned shortcomings, the present invention provides a radial flame stabilizer with an airflow-assisted jet that can achieve better evaporation in high-speed incoming flow.

[0005] Technical Solution: To solve the above problems, the present invention employs a radial flame stabilizer with airflow-assisted jet, comprising an outer wall surface and an inner wall surface. The outer wall surface has a V-shaped cross-section, and the inner wall surface is located inside the outer wall surface, also having a V-shaped cross-section. Both the outer and inner wall surfaces include a tip and two tail ends, which are connected by a flow-rectifying wall surface. An air-guiding groove is provided at the tip of the outer wall surface, and the air-guiding groove communicates with the interlayer between the outer and inner wall surfaces. Several ejector holes are provided near the tail ends of the outer wall surface, and the ejector holes communicate with the interlayer between the outer and inner wall surfaces. The air-guiding groove, the interlayer between the outer and inner wall surfaces, and the ejector holes form an airflow channel. A fuel injection extension pipe is provided near the tail ends of the inner wall surface, extending from the inner wall surface to the ejector holes. The fuel injection extension pipe is used to guide fuel injection from the ejector holes.

[0006] Furthermore, the fuel injection extension pipe extends obliquely from its inner wall surface along the airflow direction in the airflow channel. The side wall surface of the ejector hole extends parallel to the extension direction of the fuel injection extension pipe. The rectifier wall surface extends parallel to the extension direction of the fuel injection extension pipe.

[0007] Furthermore, the radial flame stabilizer also includes a rear wall surface connected between the two tail ends of the outer wall surface, with an angle between the rectifying wall surface and the rear wall surface, and an oil supply chamber formed between the inner wall surface, the two rectifying wall surfaces, and the rear wall surface.

[0008] Furthermore, the tip of the outer wall surface is a circular arc transition surface. The outer wall surface includes a first outer wall surface, a second outer wall surface, and a circular arc transition surface connecting the first outer wall surface and the second outer wall surface. The first outer wall surface and the second outer wall surface are symmetrically distributed, and the air duct is located on the circular arc transition surface.

[0009] Furthermore, both the first outer wall surface and the second outer wall surface include an inclined section and a vertical section. The vertical section of the first outer wall surface is perpendicular to the rear wall surface. One end of the inclined section of the first outer wall surface is connected to the arc transition surface, and the other end is connected to the vertical section of the first outer wall surface. One end of the vertical section of the first outer wall surface is connected to the inclined section of the first outer wall surface, and the other end is connected to the rear wall surface.

[0010] Furthermore, the inner wall surface includes a symmetrically distributed first inner wall surface and a second inner wall surface. Both the first inner wall surface and the second inner wall surface include an inclined section and a vertical section. The vertical section of the inner wall surface is perpendicular to the rear wall surface. One end of the inclined section of the first inner wall surface is connected to the inclined section of the second inner wall surface, and the other end is connected to the vertical section of the first inner wall surface. One end of the vertical section of the first inner wall surface is connected to the inclined section of the first inner wall surface, and the other end is connected to the rectifying wall surface.

[0011] Furthermore, the ejector hole is located in a vertical section on the first outer wall surface or the second outer wall surface. The fuel injection extension pipe, starting from the inner wall surface, is located in a vertical section on the first inner wall surface or the second inner wall surface.

[0012] Beneficial Effects: Compared with existing technologies, the significant advantage of this invention is that by introducing a portion of the incoming flow through the bleed air groove at the stabilizer head, the bleed air channel is gradually narrowed, increasing the bleed airflow velocity, dynamic pressure, and static pressure. This coaxially guides the injected fuel. Through the guiding effect of the airflow, on the one hand, coaxial guidance increases the fuel jet velocity and kinetic energy, achieving rapid fuel outflow and increasing fuel jet depth; on the other hand, the bleed airflow protects the fuel, reducing the impact of the mainstream airflow on the injection process and improving fuel evaporation. Furthermore, the bleed airflow process enhances the mixing of fuel and bleed air, improving fuel-air mixing efficiency. These two factors combined increase fuel evaporation capacity and improve combustion efficiency. This invention addresses the problem of shallow fuel jet depth and difficult evaporation under high-speed, large-flow conditions, giving it better fuel evaporation and mixing performance compared to conventional radial flame stabilizers. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of the radial flame stabilizer of the present invention.

[0014] Figure 2 This is a schematic diagram of the working cross-section of the radial flame stabilizer of the present invention.

[0015] Figure 3 This is a schematic diagram of the airflow direction at the front of the stabilizer in this invention.

[0016] Figure 4 This is a schematic diagram of the airflow-assisted fuel jet flow near the stabilizer ejector hole in this invention. Detailed Implementation

[0017] like Figure 1 and 2 As shown, a radial flame stabilizer with airflow-assisted jet in this embodiment includes an outer wall surface 1 and an inner wall surface 2. Based on the original radial flame stabilizer outer wall surface 1, an air intake groove 3 is opened at the position of its head facing the incoming flow direction, and an interlayer is formed between the radial flame stabilizer inner wall surface 2 and the outer wall surface 1 to serve as an air flow channel.

[0018] The outer wall surface 1 has a V-shaped cross-section, and the inner wall surface 2 is located inside the outer wall surface 1. The cross-section of the inner wall surface 2 is also V-shaped. Both the outer wall surface 1 and the inner wall surface 2 include a tip and two tail ends. The two corresponding tail ends of the outer wall surface and the inner wall surface are connected by a flow-rectifying wall surface. An air intake groove 3 is provided at the tip of the outer wall surface. The air intake groove is connected to the interlayer between the outer wall surface and the inner wall surface. Several injection holes 7 are provided near the tail end of the outer wall surface. The injection holes 7 are connected to the interlayer between the outer wall surface and the inner wall surface. The air intake groove, the interlayer between the outer wall surface and the inner wall surface, and the injection holes form an air flow channel. Fuel injection extension pipes 4 and 6 are provided near the tail end of the inner wall surface. The fuel injection extension pipes extend from the inner wall surface to the injection holes. The fuel injection extension pipes are used to guide the fuel injection from the injection holes. The radial flame stabilizer also includes a rear wall surface 9 connected between the two tail ends of the outer wall surface. There is an angle between the rectifying wall surface 5 and the rear wall surface 9. The inner wall surface 2, the two rectifying wall surfaces 5, and the rear wall surface 9 form a fuel supply chamber 8. Fuel enters the flame stabilizer from the fuel supply chamber 8 and is ejected from the fuel injection extension pipe 4 / 6 at the injection port 7, where it is ignited by the ignition gas.

[0019] The tip of the outer wall surface 1 is a circular arc transition surface 13. The outer wall surface includes a first outer wall surface 11, a second outer wall surface 12, and a circular arc transition surface 13 connecting the first and second outer wall surfaces. The first outer wall surface 11 and the second outer wall surface 12 are symmetrically distributed, and the air intake groove 3 is located on the circular arc transition surface 13. Both the first outer wall surface 11 and the second outer wall surface 13 include inclined sections 111 and 121 and vertical sections 112 and 122. The vertical section of the first outer wall surface is perpendicular to the rear wall surface. One end of the inclined section of the first outer wall surface is connected to the circular arc transition surface, and the other end is connected to the vertical section of the first outer wall surface. One end of the vertical section of the first outer wall surface is connected to the inclined section of the first outer wall surface, and the other end is connected to the rear wall surface. The second outer wall surface 13 is symmetrically arranged with the same connection relationship as the first outer wall surface 11, which will not be described again here.

[0020] The inner wall surface 2 includes a symmetrically distributed first inner wall surface 21 and a second inner wall surface 22. Both the first and second inner wall surfaces 21 and 22 include inclined sections 211 and 221 and vertical sections 212 and 222. The vertical sections of the inner wall surfaces are perpendicular to the rear wall surface. One end of the inclined section of the first inner wall surface connects to the inclined section of the second inner wall surface, and the other end connects to the vertical section of the first inner wall surface. One end of the vertical section of the first inner wall surface connects to the inclined section of the first inner wall surface, and the other end connects to the rectifying wall surface. The second inner wall surface 22 and the first inner wall surface 21 are symmetrically arranged and have the same connection relationship, which will not be described further here. The ejector hole 7 is located on the vertical section of either the first or second outer wall surface. The fuel injection extension pipe starts from the inner wall surface and is located on the vertical section of either the first or second inner wall surface.

[0021] like Figure 3 , 4As shown, the combustion gas entering the combustion chamber, when flowing through the head of the flame stabilizer, is partially introduced from the air intake groove 3, which faces the direction of gas flow, into the interlayer between the outer wall surface 1 and the inner wall surface 2 of the radial flame stabilizer. It then flows along the interlayer direction to the rear of the flame stabilizer, and after being rectified by the flow-rectifying wall 5, it flows out through the injection hole 7. The flow-rectifying wall 5 is parallel to the walls of the fuel injection extension pipe 4 and the injection hole 7, and the fuel injection extension pipe 4 and the injection hole 7 are coaxial, ensuring that the gas flow direction is coaxial with the fuel injection direction, thus guaranteeing injection. When the gas flows through the injection hole 7, the flow area decreases, the gas flow velocity increases, and the dynamic pressure increases. The overall flow process can be considered as having a basically constant total pressure, therefore the static pressure of the gas decreases. When the fuel flows near the injection hole 7, due to the decrease in the static pressure of the gas, coaxial injection occurs.

[0022] In this embodiment, the fuel injection extension pipe extends obliquely from the inner wall surface along the airflow direction in the airflow channel. This invention protects a method for improving combustion efficiency by using coaxial ejectors to promote fuel evaporation and blending performance, but is not limited to the obliquely backward ejection direction and the ejection location at the stabilizer tail end proposed in this invention.

Claims

1. A radial flame stabilizer for a gas flow assisted jet, characterized in that, It includes an outer wall surface (1) and an inner wall surface (2). The outer wall surface (1) has a V-shaped cross-section. The inner wall surface (2) is located inside the outer wall surface (1). The cross-section of the inner wall surface (2) is also V-shaped. Both the outer wall surface (1) and the inner wall surface (2) include a tip and two tail ends. The two corresponding tail ends of the outer wall surface (1) and the inner wall surface (2) are connected by a flow-rectifying wall surface (5). An air-drawing groove (3) is provided at the tip of the outer wall surface. The air-drawing groove is connected to the interlayer between the outer wall surface and the inner wall surface. The outer wall surface (1) Several injection holes (7) are provided near the tail end. The injection holes (7) are connected to the interlayer between the outer wall surface and the inner wall surface. The air intake groove (3), the interlayer between the outer wall surface and the inner wall surface, and the injection holes (7) form an air flow channel. The inner wall surface (2) is provided with an oil injection extension pipe (4) near the tail end. The oil injection extension pipe (4) extends from the inner wall surface to the injection hole (7). The side wall surface of the injection hole (7) extends in a direction parallel to the extension direction of the oil injection extension pipe (4). The oil injection extension pipe is used to guide the oil to be sprayed out from the injection hole.

2. The radial flame stabilizer of claim 1, wherein, The fuel injection extension pipe (4) extends obliquely from the inner wall surface along the airflow direction in the air channel.

3. The radial flame stabilizer of claim 2, wherein, The extension direction of the rectifying wall (5) is parallel to the extension direction of the fuel injection extension pipe (4).

4. The radial flame stabilizer of claim 3, wherein, It also includes a rear wall surface connected between the two tail ends of the outer wall surface (1), and there is an angle between the rectifier wall surface (5) and the rear wall surface. An oil supply cavity (8) is formed between the inner wall surface (2), the two rectifier wall surfaces (5), and the rear wall surface.

5. The radial flame stabilizer of claim 4, wherein, The tip of the outer wall surface (1) is a circular arc transition surface. The outer wall surface (1) includes a first outer wall surface, a second outer wall surface, and a circular arc transition surface connecting the first outer wall surface and the second outer wall surface. The first outer wall surface and the second outer wall surface are symmetrically distributed. The air duct (3) is located on the circular arc transition surface.

6. The radial flame stabilizer of claim 5, wherein, Both the first outer wall surface and the second outer wall surface include an inclined section and a vertical section. The vertical section of the first outer wall surface is perpendicular to the rear wall surface. One end of the inclined section of the first outer wall surface is connected to the arc transition surface, and the other end is connected to the vertical section of the first outer wall surface. One end of the vertical section of the first outer wall surface is connected to the inclined section of the first outer wall surface, and the other end is connected to the rear wall surface.

7. The radial flame stabilizer of claim 6, wherein, The inner wall surface includes a first inner wall surface and a second inner wall surface that are symmetrically distributed. Both the first inner wall surface and the second inner wall surface include an inclined section and a vertical section. The vertical section of the inner wall surface is perpendicular to the rear wall surface. One end of the inclined section of the first inner wall surface is connected to the inclined section of the second inner wall surface, and the other end is connected to the vertical section of the first inner wall surface. One end of the vertical section of the first inner wall surface is connected to the inclined section of the first inner wall surface, and the other end is connected to the rectifying wall surface (5).

8. The radial flame stabilizer of claim 7, wherein, The ejector hole (7) is located in the vertical section of the first outer wall or the second outer wall.

9. The radial flame stabilizer of claim 8, wherein, The oil injection extension pipe (4) is a vertical section located on the first inner wall or the second inner wall from the starting end of the inner wall.

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