Flow active control heat screen and afterburner applying same

Abstract

The invention relates to the technical field of aero-engine air flow control, and discloses an active flow control heat shield and an afterburner applying the same, and the heat shield is of an annular structure and is coaxially arranged at the downstream of a shunt ring of the afterburner; the flow blocking assembly further comprises a fixed throttling ring, a movable throttling ring and a driving source used for driving the movable throttling ring to rotate, and the flow area of the ventilation hole is adjusted through the flow blocking assembly. Active control over the throttling area (the circulation area of the vent hole) of the cooling channel of the heat shield of the integrated afterburner can be achieved, active control over the cooling air flow and the mixed air flow in the outer culvert airflow is achieved, and it is guaranteed that the cooling air flow entering the heat shield is within a stable and controllable range when the bypass ratio is small; the reliability of cooling design is guaranteed, meanwhile, the mixed air flow is increased when the bypass ratio is large, and the combustion efficiency of the afterburner is improved; the problem that the cooling air flow and the mixing air flow cannot be actively controlled in the prior art is solved.

Description

Technical Field

[0001] This invention relates to the field of airflow control technology for aero-engines, and discloses an active flow control heat shield and its application in an afterburner. Background Technology

[0002] Current turbofan engines have a large range of bypass ratio variations within their flight envelope, resulting in significant fluctuations in the cooling airflow entering the afterburner heat shield under different bypass ratio conditions. To ensure the cooling performance of the afterburner heat shield, the minimum cooling airflow is usually limited. This results in the cooling airflow being much greater than the actual required cooling airflow under high bypass ratio conditions, causing excess cooling air to not enter the internal combustion chamber and participate in combustion, thus affecting the combustion efficiency of the afterburner. Summary of the Invention

[0003] The purpose of this invention is to provide an active flow control heat shield and its application in an afterburner, which can ensure that the cooling air flow rate entering the heat shield is within a stable and controllable range when the bypass ratio is small, thus ensuring the reliability of the cooling design. At the same time, it increases the mixed air flow rate when the bypass ratio is large, thereby improving the combustion efficiency of the afterburner and solving the problem that the cooling air flow rate and mixed air flow rate cannot be actively controlled in the prior art.

[0004] To achieve the above-mentioned technical effects, the technical solution adopted by the present invention is as follows: A flow-actively controlled heat insulation screen, comprising: The heat shield is a ring-shaped structure, coaxially positioned downstream of the afterburner's flow divider ring; A fixed throttling ring is coaxially fixed in the outer bypass between the flow divider ring and the heat insulation screen, and a plurality of vent holes are uniformly arranged circumferentially on the fixed throttling ring; A movable throttle ring is coaxially and movably installed in the outer duct of the afterburner, and the movable throttle ring is provided with multiple flow-blocking components that cooperate with the vent holes; A drive source is used to rotate the movable throttling ring so as to adjust the flow area of ​​the vent through the baffle assembly.

[0005] Furthermore, the vent includes a first airflow hole near the inner ring of the fixed throttling ring and a second airflow hole near the outer ring of the fixed throttling ring, wherein the area of ​​each first airflow hole is smaller than the area of ​​the second airflow hole.

[0006] Furthermore, the first airflow hole or the second airflow hole is a porous structure composed of a single hole or multiple hole structures.

[0007] Furthermore, the driving source includes a drive motor, a gear is provided on the drive motor transmission shaft, and a driven rack that meshes with the gear is provided on the movable throttle ring.

[0008] Furthermore, the inner wall of the outer casing of the outer bypass duct is provided with a positioning groove, and the movable throttling ring is provided with a limiting component that cooperates with the positioning groove.

[0009] To achieve the above-mentioned technical effects, the present invention also provides an afterburner with the aforementioned flow active control heat insulation screen.

[0010] Furthermore, a central cone is also provided inside the flow divider ring, and an inner channel is formed between the outer wall of the central cone and the inner wall of the flow divider ring, and a flame stabilizer is provided inside the inner channel.

[0011] Furthermore, the diversion ring is also provided with an air intake channel, which is used to introduce the airflow of the outer bypass duct into the inner bypass duct.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention can realize the active control of the throttling area (flow area of ​​the vent) of the cooling channel of the integrated afterburner heat shield, and realize the active control of the cooling air flow and mixed air flow in the bypass airflow, ensuring that the cooling air flow entering the heat shield is within a stable and controllable range when the bypass ratio is small, thus ensuring the reliability of the cooling design. At the same time, it increases the mixed air flow when the bypass ratio is large, thereby improving the combustion efficiency of the afterburner. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the afterburner structure containing an active flow control heat insulation screen in the embodiment; Figure 2 This is a schematic diagram illustrating the interaction between the fixed and movable throttling rings in the embodiment. Figure 3 This is a schematic diagram of the structure of the first airflow hole and the second airflow hole in the embodiment; Among them, 1. heat shield; 2. flow divider ring; 3. fixed throttling ring; 4. outer bypass duct; 5. vent; 501. first airflow hole; 502. second airflow hole; 6. movable throttling ring; 7. outer casing; 8. air intake channel; 9. drive motor; 10. gear; 11. driven rack; 12. rotating groove; 13. limiting assembly; 14. center cone; 15. flame stabilizer. Detailed Implementation

[0014] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0015] Example 1 See Figures 1 to 3 A flow-actively controlled heat insulation screen, comprising: The heat insulation screen 1 is a ring structure and is coaxially arranged downstream of the afterburner flow divider ring 2; A fixed throttling ring 3 is coaxially fixed in the outer bypass 4 between the flow divider ring 2 and the heat insulation screen 1. A plurality of vent holes 5 are uniformly arranged circumferentially on the fixed throttling ring 3. The movable throttling ring 6 is coaxially and movably disposed in the outer duct 4 of the afterburner. The movable throttling ring 6 is provided with a plurality of flow-blocking components that cooperate with the vent 5. A drive source is used to rotate the active throttling ring 6 so as to adjust the flow area of ​​the vent 5 through the baffle assembly.

[0016] In this embodiment, when the engine bypass ratio changes, at a larger bypass ratio, the regulating device is closed to reduce the flow rate of external bypass cold air entering the cooling channel through the regulating device, thus reducing the relative cooling air volume entering the cooling channel. More cold air mixes with the high-temperature internal air in the mixing section, participating in combustion and improving combustion efficiency. At a smaller bypass ratio, the regulating device is opened to increase the flow rate of external bypass cold air entering the cooling channel through the regulating device, thus increasing the relative cooling air volume entering the cooling channel and ensuring the cooling of the heat shield 1, preventing ablation. This embodiment can achieve active control of the throttling area (flow area of ​​the vent 5) of the integrated afterburner heat shield 1 cooling channel, realizing active control of the cooling air flow rate and mixed air flow rate in the external bypass airflow. It ensures that the cooling air flow rate entering the heat shield 1 is within a stable and controllable range at a small bypass ratio, ensuring the reliability of the cooling design. At the same time, at a large bypass ratio, the mixed air flow rate is increased, improving the combustion efficiency of the afterburner, solving the problem that the cooling air flow rate and mixed air flow rate cannot be actively controlled in the prior art.

[0017] In this embodiment, the vent 5 includes a first airflow vent 501 near the inner ring of the fixed throttling ring 3 and a second airflow vent 502 near the outer ring of the fixed throttling ring 3. The area of ​​each first airflow vent 501 is smaller than the area of ​​the second airflow vent 502. The first airflow vent 501 near the inner ring has a small vent area and a high flow velocity, which is beneficial for carrying away heat, especially heat in the downstream area of ​​the diversion ring 2, thus improving the cooling effect. The second airflow vent 502 on the outer ring has a large vent area and a low flow velocity, which can save on the consumption of external cooling airflow.

[0018] In some other embodiments, the first airflow hole 501 or the second airflow hole 502 is a porous structure composed of a single hole or multiple hole structures.

[0019] In this embodiment, the driving source includes a drive motor 9, a gear 10 is provided on the transmission shaft of the drive motor 9, and a driven rack 11 that meshes with the gear 10 is provided on the movable throttling ring 6.

[0020] Example 2 See Figures 1 to 3 An afterburner is provided, wherein an outer bypass duct 4 and an inner bypass duct are arranged adjacently, the inner bypass duct carrying high-temperature gas and the outer bypass duct 4 carrying low-temperature gas; furthermore, it includes a method for controlling the mixing of air into the outer bypass gas. Figure 1 (middle dashed arrow) flow rate and cooling air ( Figure 1 (Solid arrow in the middle) Active flow control structure, where: The active control structure functions by controlling the flow rate of cooling air based on the input amount of cryogenic gas from the bypass gas, thereby cooling the heat shield 1. It can also deliver air to the afterburner chamber via the bleed air channel 8 on the flow divider ring 2, and control the flow rate of mixed air in the bypass gas. The active control structure includes a rotatable movable throttling ring 6, a fixed throttling ring 3 that fits against the movable throttling ring 6, a drive source, and a transmission shaft. The fixed throttling ring 3 is connected to and fixed to the outer casing 7. The drive source is fixedly mounted on the outer casing 7 and drives the transmission gear 10 to rotate via the transmission shaft. This rotation, through the driven rack 11 structure on the movable throttling ring 6, causes the movable throttling ring 6 to reciprocate, changing the overlap between the movable throttling ring 6 and the fixed throttling ring 3, controlling the flow area of ​​the movable throttling ring 6, and thus controlling the flow rate of mixed air in the bypass gas and the cooling air flow rate. Specifically: At a larger bypass ratio, the drive source rotates the active throttling ring 6, reducing the overlap of the active throttling ring 6, decreasing the flow area of ​​the active throttling ring 6, reducing the cooling air flow of the cooling channel, and allowing more cold air to mix with the high-temperature air in the mixing section and participate in combustion, thereby improving the combustion efficiency of the afterburner.

[0021] When the bypass ratio is small (or the high-temperature gas flow rate in the inner duct is too large), the drive source drives the movable throttling ring 6 to rotate, improve the overlap of the movable throttling ring 6, increase the flow area of ​​the movable throttling ring 6, increase the cooling air flow rate of the cooling channel, and allow more cold air to enter the cooling channel of the heat insulation screen 1, ensuring the cooling of the heat insulation screen 1 and avoiding ablation.

[0022] In this embodiment, the outer casing 7 of the afterburner has a pre-set rotating groove 12, and the driven rack 11 structure on the movable throttling ring 6 reciprocates within the rotating groove 12 of the outer casing 7.

[0023] In this embodiment, the movable throttling ring 6 is attached to the inner surface of the outer casing 7. A positioning ball (equivalent to the limiting component 13) is preset on the contact surface of the movable throttling ring 6, and a positioning groove is preset on the inner surface of the outer casing 7. The positioning ball is placed in the positioning groove to limit the movable throttling ring 6 to only reciprocate.

[0024] In this embodiment, a central cone 14 is also provided inside the flow divider ring 2. An inner channel is formed between the outer wall of the central cone 14 and the inner wall of the flow divider ring 2. A flame stabilizer 15 is provided inside the inner channel.

[0025] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A flow-actively controlled heat insulation screen, characterized in that, include: The heat shield (1) is a ring structure and is coaxially arranged downstream of the afterburner flow divider ring (2); A fixed throttling ring (3) is coaxially fixed in the outer bypass (4) between the flow divider ring (2) and the heat insulation screen (1). A plurality of vent holes (5) are uniformly arranged circumferentially on the fixed throttling ring (3). The movable throttle ring (6) is coaxially and movably disposed in the outer duct (4) of the afterburner. The movable throttle ring (6) is provided with a plurality of flow-blocking components that cooperate with the vent (5). A drive source is used to rotate the active throttling ring (6) to adjust the flow area of ​​the vent (5) through the baffle assembly.

2. The flow-active control heat insulation screen according to claim 1, characterized in that, The vent (5) includes a first airflow hole (501) near the inner ring of the fixed throttling ring (3) and a second airflow hole (502) near the outer ring of the fixed throttling ring (3), wherein the area of ​​each first airflow hole (501) is smaller than the area of ​​the second airflow hole (502).

3. The flow-active control heat insulation screen according to claim 2, characterized in that, The first airflow hole (501) or the second airflow hole (502) is a porous structure composed of a single hole or multiple hole structures.

4. The flow-active control heat insulation screen according to claim 1, characterized in that, The driving source includes a drive motor (9), a gear (10) is provided on the transmission shaft of the drive motor (9), and a driven rack (11) that meshes with the gear (10) is provided on the movable throttle ring (6).

5. The flow-active control heat insulation screen according to claim 1, characterized in that, The outer casing (7) of the outer duct (4) is provided with a positioning groove on its inner wall, and the movable throttle ring (6) is provided with a limiting component (13) that cooperates with the positioning groove.

6. An afterburner, characterized in that, A flow-active control heat insulation screen (1) as described in any one of claims 1-5.

7. The afterburner according to claim 6, characterized in that, The flow divider ring (2) is also provided with a central cone (14), and an inner channel is formed between the outer wall of the central cone (14) and the inner wall of the flow divider ring (2), and a flame stabilizer (15) is provided in the inner channel.

8. The afterburner according to claim 7, characterized in that, The diversion ring (2) is also provided with an air intake channel (8), which is used to introduce the airflow of the outer bypass (4) into the inner bypass.

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