High-efficiency film cooling structure, combustion chamber and aero-engine

Abstract

This invention discloses a high-efficiency film cooling structure, a combustion chamber, and an aero-engine. It includes a cooling ring for enclosing and forming a flow channel in the combustion chamber, and cantilevered tongues arranged on the cooling ring. The cantilevered tongues are disposed on the cooling ring, and a film cooling channel is formed between the cantilevered tongues and the cooling ring. An air intake channel is provided on the cooling ring for introducing cooling airflow into the film cooling channel. Biomimetic shark shield scale structures are respectively arranged on the hot side of the cooling ring, the hot side of the cantilevered tongues, and the cold side of the cantilevered tongues. The biomimetic shark shield scale structures include grooves for reducing the flow resistance of the cooling airflow. The grooves have a polygonal or arc-shaped cross-section and are arranged along the flow direction of the cooling airflow. The thickness of the cantilevered tongues is 0.3–0.5 mm, and the depth h of the grooves is 0.01–0.1 mm. This structure can maintain a long-distance wall-adhering cooling film, delay the formation of turbulence, extend the combustion chamber life, reduce the number of cooling film cooling sections, and lower the cost of the combustion chamber.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, and in particular, to a high-efficiency film cooling structure. Furthermore, this invention also relates to a combustion chamber including the aforementioned high-efficiency film cooling structure. This invention further relates to an aero-engine including the aforementioned combustion chamber. Background Technology

[0002] Film cooling (FS) is a common cooling method for the combustor of aero-engines. Cooling gas is ejected through a number of small holes or annular slits, forming a protective film between the combustor wall and the combustion gases. FFS is suitable for various pressure drop environments and different parts of the combustor. Its inlet methods include total pressure inlet, static pressure inlet, a mixture of total and static pressure inlet, and inlet methods between total pressure and static pressure inlet. FFS can be used alone for combustor cooling or combined with convection cooling, impingement cooling, etc. Pure FFS is most widely used in the combustors of currently in service and under development engines, and it also shows promise for application in advanced engine combustors.

[0003] Existing film cooling structures for aero-engine combustion chamber flame tubes include wall panels, film cooling holes, and cantilevered tongues, such as... Figure 1 As shown. Its function is to form a protective gas film between the inner wall of the flame tube and the combustion gas, and to remove heat from the wall surface through the gas film pores. This gas film cooling structure has the following disadvantages: 1. The length of the gas film covering the wall is short. Due to the continuous friction between the high-speed cooling airflow and the flame tube wall, the boundary layer will be destroyed after a certain distance, forming turbulence; 2. The velocity gradient between the high-speed cooling airflow and the mainstream combustion gas is large, and the gas film covering the wall is easily carried into the mainstream by the high-temperature combustion gas; 3. The step height at the end face of the cantilever tongue is relatively large. A low-speed zone is usually formed downstream of this end face, and the risk of ablation of the cantilever tongue is high; 4. The shorter gas film covering the wall means that the flame tube needs more gas film cooling structures, resulting in high cost and weight of the flame tube. Summary of the Invention

[0004] This invention provides a high-efficiency film cooling structure, combustion chamber, and aero-engine to solve the technical problems of existing film cooling structures, such as short coverage length of the wall-attached film, easy induction of the wall-attached film into the mainstream by high-temperature combustion gases, high risk of ablation of the cantilever tongue, and high cost and weight of the flame tube.

[0005] According to one aspect of the present invention, a high-efficiency film cooling structure is provided, comprising a cooling ring for enclosing and forming a flame tube flow channel and a cantilevered tongue disposed on the cooling ring. The cantilevered tongue is disposed on the cooling ring, and a film channel is formed between the cantilevered tongue and the cooling ring. An air inlet channel for introducing cooling airflow into the film channel is provided on the cooling ring. Biomimetic shark shield scale structures are respectively disposed on the hot side of the cooling ring, the hot side of the cantilevered tongue, and the cold side of the cantilevered tongue. The biomimetic shark shield scale structure includes grooves for reducing the flow resistance of the cooling airflow. The grooves have a polygonal or arc-shaped cross-section and are arranged along the flow direction of the cooling airflow. The thickness of the cantilevered tongue is 0.3-0.5 mm, and the depth h of the groove is 0.01-0.1 mm.

[0006] Furthermore, the groove includes continuously arranged V-shaped grooves, the cross-section of the V-shaped grooves is triangular, and the included angle α of the opening of the V-shaped grooves is 45° to 135°.

[0007] Furthermore, the trench includes rectangular grooves arranged at intervals, the cross-section of the rectangular grooves is rectangular, and the width of the rectangular grooves is s, then 0.5≤s / h≤2.

[0008] Furthermore, the trench includes trapezoidal grooves arranged at intervals, the cross-section of the trapezoidal grooves is trapezoidal, the opening width of the trapezoidal grooves is s1, and the bottom width of the trapezoidal grooves is s2, then 0.5≤s1 / s2≤2.

[0009] Furthermore, the groove includes continuously arranged bow-shaped grooves, the cross-section of which is bow-shaped, and the radius of which is R, then 0.01mm≤R≤0.1mm.

[0010] Furthermore, the extension length of the groove is 10~60mm.

[0011] Furthermore, the angle between the air intake channel and the cold side of the cantilever tongue is 0~30°.

[0012] Furthermore, the cold side of the cantilever tongue is arranged parallel to the hot side of the cantilever tongue, and the angle between the hot side of the cooling ring and the hot side of the cantilever tongue is 0~20°.

[0013] According to another aspect of the present invention, a combustion chamber is provided, comprising a diffuser, an outer casing, an inner casing, a nozzle, a vortex generator, a flame tube head, an outer ring of the flame tube, and an inner ring of the flame tube, wherein the outer ring of the flame tube comprises the aforementioned high-efficiency film cooling structure, and the inner ring of the flame tube comprises the aforementioned high-efficiency film cooling structure.

[0014] The present invention also provides an aircraft engine, including the combustion chamber described above.

[0015] The present invention has the following beneficial effects: The high-efficiency film cooling structure of this invention uses a cooling ring to enclose and form the flame tube flow channel as the flame tube wall. The inner cylindrical surface of the cooling ring is the hot side, and the outer cylindrical surface is the cold side. The inner and outer cylindrical surfaces of the cantilever tongue are the hot side, and the outer cylindrical surface is the cold side. An annular film cooling channel is formed between the cold side of the cantilever tongue and the hot side of the cooling ring. In use, cooling gas enters the film cooling channel through the inlet channel and forms a high-speed cooling airflow in the film cooling channel. The cooling airflow flows at high speed along the hot side of the cooling ring. Biomimetic shark shield scale structures are arranged on the hot side of the cooling ring, the hot side of the cantilever tongue, and the cold side of the cantilever tongue. The grooves of the biomimetic shark shield scale structures are microgrooves (0.01mm≤h≤0.1mm) arranged in an orderly manner along the fluid flow direction. When the groove depth h≤0.01mm, the processing is difficult and it is hard to guarantee processing accuracy. When the groove depth h≥0.01mm, the effect of the film cooling structure in inhibiting the transition from laminar to turbulent flow is significantly reduced. The fish-scale structure reduces the frictional resistance between the cooling airflow and the hot side of the cooling ring, maintains the stability of the boundary layer on the hot side of the cooling ring and the high-speed cooling airflow, suppresses the formation of turbulence, improves the wall adhesion of the cooling airflow, prevents the cooling airflow from prematurely merging with the mainstream, and avoids the degradation of the cooling airflow quality. This maintains a long-distance wall-adhering cooling film on the hot side of the cooling ring, thereby reducing the number of cooling ring segments that make up the flame tube, reducing the cost and weight of the flame tube. Since grooves need to be opened on both the cold and hot sides of the cantilever tongue, when the thickness of the cantilever tongue is ≤0.3mm, it is difficult to ensure the strength of the cantilever tongue while reserving space for the opening of the grooves. When the thickness of the cantilever tongue is ≥0.5mm, there is a risk of forming a low-speed zone on the end face of the cantilever tongue, which will cause the cantilever tongue to ablate. Using an ultra-thin design of the cantilever tongue (thickness of 0.3~0.5mm) can prevent the formation of a low-speed zone downstream of the end face of the cantilever tongue and reduce the risk of high-temperature gas accumulating at the end of the cantilever tongue.

[0016] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of an existing film cooling structure; Figure 2 This is a schematic diagram of the high-efficiency air film cooling structure according to a preferred embodiment of the present invention; Figure 3This is one of the structural schematic diagrams of the biomimetic shark dermal scale structure of a preferred embodiment of the present invention; Figure 4 This is the second schematic diagram of the biomimetic shark dermal scale structure of a preferred embodiment of the present invention; Figure 5 This is the third schematic diagram of the biomimetic shark dermal scale structure of a preferred embodiment of the present invention; Figure 6 This is the fourth schematic diagram of the biomimetic shark dermal scale structure of a preferred embodiment of the present invention; Figure 7 This is a schematic diagram of the combustion chamber of a preferred embodiment of the present invention.

[0018] Legend: 1. Cooling ring; 11. Intake passage; 2. Cantilever tongue; 3. Film air passage; 4. Groove; 41. V-groove; 42. Rectangular groove; 43. Trapezoidal groove; 44. Bow-shaped groove; 100. Diffuser; 200. Outer casing; 300. Inner casing; 400. Nozzle; 500. Swirl generator; 600. Flame tube head; 700. Flame tube outer ring; 800. Flame tube inner ring; 7. Outer ring flow channel; 8. Inner ring flow channel; 9. Flame tube flow channel. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, and back), the orientation or positional relationship of the directional indications is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the embodiments according to this application and simplifying the description, and is not intended to indicate or imply that the device or unit referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the embodiments according to this application.

[0021] Furthermore, if the embodiments of this invention involve descriptions using terms such as "first," "second," and "third," these terms are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," or "third" may explicitly or implicitly include at least one of those features. The term "multiple" refers to two or more unless otherwise explicitly defined. Terms such as "installed," "connected," "attached," and "fixed" should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "attached" can be a direct connection or an indirect connection through an intermediate medium.

[0022] If the words "and / or" or "and / or" appear in the text, they mean three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that satisfies both A and B. In addition, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] To better understand the above technical solution, the following detailed explanation is provided in conjunction with the accompanying drawings.

[0024] Please refer to the following: Figures 2 to 7 The high-efficiency film cooling structure of this embodiment includes a cooling ring 1 for enclosing and forming a flame tube flow channel and a cantilevered tongue 2 arranged on the cooling ring 1. The cantilevered tongue 2 is disposed on the cooling ring 1, and a film channel 3 is formed between the cantilevered tongue 2 and the cooling ring 1. An air inlet channel 11 is provided on the cooling ring 1 for introducing cooling airflow into the film channel 3. Bionic shark shield scale structures are respectively arranged on the hot side of the cooling ring 1, the hot side of the cantilevered tongue 2, and the cold side of the cantilevered tongue 2. The bionic shark shield scale structure includes grooves 4 for reducing the flow resistance of the cooling airflow. The cross-section of the grooves 4 is polygonal or arc-shaped, and the grooves 4 are arranged along the flow direction of the cooling airflow. The thickness of the cantilevered tongue 2 is 0.3-0.5 mm, and the depth h of the grooves 4 is 0.01-0.1 mm.

[0025] The high-efficiency film cooling structure of this embodiment uses a cooling ring 1 to enclose and form the flame tube flow channel as the flame tube wall. The inner cylindrical surface of the cooling ring 1 is the hot side, and the outer cylindrical surface of the cooling ring 1 is the cold side. The inner and outer cylindrical surfaces of the cantilever tongue 2 are the hot side, and the outer cylindrical surface of the cantilever tongue 2 is the cold side. An annular film cooling channel 3 is formed between the cold side of the cantilever tongue 2 and the hot side of the cooling ring 1. In use, cooling gas enters the film cooling channel 3 through the air inlet channel 11 and forms a high-speed cooling airflow in the film cooling channel 3. The cooling airflow flows along... High-speed flow occurs on the hot side of cooling ring 1; biomimetic shark shield scale structures are arranged on the hot side of cooling ring 1, the hot side of cantilever tongue 2, and the cold side of cantilever tongue 2. The grooves 4 of the biomimetic shark shield scale structures are microgrooves (0.01mm≤h≤0.1mm) arranged in an orderly manner along the fluid flow direction. When the depth h of the grooves 4 is ≤0.01mm, the processing is difficult and it is hard to guarantee the processing accuracy. When the depth h of the grooves 4 is ≥0.01mm, the effect of the gas film in inhibiting the transition from laminar to turbulent flow is significantly reduced; biomimetic shark shield scale structures The structure can reduce the frictional resistance between the cooling airflow and the hot side of the cooling ring 1, maintain the stability of the boundary layer between the high-speed cooling airflow and the hot side of the cooling ring 1, suppress the formation of turbulence, improve the wall adhesion of the cooling airflow, prevent the cooling airflow from prematurely merging with the mainstream, and avoid the degradation of the cooling airflow quality. This maintains a long-distance wall-adhering cooling film on the hot side of the cooling ring 1, thereby reducing the number of segments of the cooling ring 1 that make up the flame tube, reducing the cost and weight of the flame tube. Since grooves are opened on both the cold and hot sides of the cantilever tongue 2... 4. When the thickness of the cantilever tongue 2 is ≤0.3mm, it is difficult to ensure the strength of the cantilever tongue 2 while reserving space for the groove 4. When the thickness of the cantilever tongue 2 is ≥0.5mm, there is a risk of a low-speed zone forming on the end face of the cantilever tongue 2, which will cause the cantilever tongue 2 to burn. The cantilever tongue 2 with an ultra-thin design (thickness of 0.3~0.5mm) can make it difficult for a low-speed zone to form downstream of the end face of the cantilever tongue 2, reduce the risk of high-temperature gas accumulating at the end of the cantilever tongue 2, and extend the service life of the cantilever tongue 2.

[0026] like Figure 3As shown, in this embodiment, the groove 4 includes continuously arranged V-shaped grooves 41. The cross-section of the V-shaped grooves 41 is triangular, and the included angle α of the opening of the V-shaped grooves 41 is 45° to 135°. The V-shaped grooves 41 have a simple structure, are easy to process, and can reduce processing costs. Optionally, in a certain aero-engine combustion chamber flame tube project, the design α is 90°, h is 0.05mm, and the thickness of the cantilever tongue 2 is 0.4mm. When the combustion chamber inlet temperature is 600K, the gas temperature is 1600K, and the cooling gas volume is consistent, the average wall temperature of the existing gas film cooling structure is 880K. When using the V-shaped groove 41 scheme, the average wall temperature is 781K, which is nearly 100K lower, and the service life of the flame tube is significantly improved. Optionally, the cross-section of the V-shaped grooves 41 is an isosceles triangle, which ensures that the cooling airflow is evenly distributed along the groove 4 and can improve the stability of the gas film.

[0027] like Figure 5 As shown, in this embodiment, the groove 4 includes trapezoidal grooves 43 arranged at intervals. The cross-section of the trapezoidal groove 43 is trapezoidal. The opening width of the trapezoidal groove 43 is s1, and the bottom width of the trapezoidal groove 43 is s2. Then, 0.5≤s1 / s2≤2, the risk of stress concentration under the trapezoidal groove is minimized, and the structural stability is strong. Optionally, in a certain aero-engine combustion chamber flame tube project, the design s1 is 0.07mm, s2 is 0.10mm, h is 0.06mm, and the thickness of the cantilever tongue 2 is 0.4mm. When the combustion chamber inlet temperature is 720K, the gas temperature is 1820K, and the cooling gas volume is consistent; the average wall temperature of the existing gas film cooling structure is 920K. When using the trapezoidal groove 43 scheme, the average wall temperature is 835K, which is 85K lower, and the service life of the flame tube is significantly improved. Optionally, the cross-section of the trapezoidal groove 43 is an isosceles trapezoid to ensure that the cooling airflow is evenly distributed along the groove 4, which can improve the stability of the air film. Optionally, the distance between two adjacent trapezoidal grooves 43 is 0.01 to 0.1 mm. When the distance between two adjacent grooves 4 is greater than 0.1 mm, a large circumferential temperature gradient on the wall surface will occur, resulting in a short life of the flame tube; when the distance between two adjacent grooves 4 is greater than 0.1 mm, it is difficult to guarantee the machining accuracy.

[0028] like Figure 4As shown, in this embodiment, the groove 4 includes rectangular grooves 42 arranged at intervals. The cross-section of the rectangular groove 42 is rectangular, and the width of the rectangular groove 42 is s, where 0.5 ≤ s / h ≤ 2. The cooling effect of the rectangular groove 42 is comparable to that of the trapezoidal groove 43. However, the processing difficulty is slightly greater than that of the trapezoidal groove 43, and the processing cost is higher. But compared with the existing air film cooling structure, it can still significantly improve the service life of the flame tube. Optionally, the distance between two adjacent rectangular grooves 42 is 0.01 to 0.1 mm. When the distance between two adjacent grooves 4 is greater than 0.1 mm, a large circumferential temperature gradient on the wall surface will occur, resulting in a low lifespan of the flame tube; when the distance between two adjacent grooves 4 is greater than 0.1 mm, it is difficult to guarantee the processing accuracy.

[0029] like Figure 6 As shown, in this embodiment, the groove 4 includes continuously arranged arc-shaped grooves 44. The cross-section of the arc-shaped grooves 44 is circular arc-shaped, and the radius of the arc-shaped grooves 44 is R. Then, 0.01mm≤R≤0.1mm. The arc-shaped grooves 44 have the most uniform wall temperature distribution, the smallest wall temperature gradient on the entire flame tube wall, and the smallest temperature stress. However, the arc-shaped grooves 44 are more difficult to process and are suitable for 3D printing, so the cost is relatively high. The radius R of the arc-shaped grooves 44 depends on the processing accuracy. When R<0.01mm, it is difficult to guarantee the processing accuracy. When 0.1mm<R, the effect of the gas film in inhibiting the transition from laminar to turbulent flow will be significantly reduced.

[0030] In this embodiment, the extension length of the groove 4 is 10~60mm; if the extension length of the groove 4 is less than 10mm, an effective wall-adhering cooling air film cannot be formed; when the extension length of the groove 4 reaches 60mm, it can ensure that the cooling air film can cover the entire cooling structure well, and there is no need to make it longer.

[0031] In this embodiment, the angle between the air intake channel 11 and the cold side of the cantilever tongue 2 is 0~30°. If the angle between the air intake channel 11 and the cold side of the cantilever tongue 2 is greater than 30°, the normal velocity (i.e., perpendicular to the cantilever tongue 2) of the cooling airflow flowing out of the air intake channel 11 will be too high, which will reduce the coverage distance of the cooling air film.

[0032] In this embodiment, the air intake channel 11 is an air intake hole and / or an air intake groove. The air intake channels 11 are evenly spaced on the cooling ring 1 to ensure that the cooling air can cool the cooling ring 1 evenly.

[0033] In this embodiment, the cold side of the cantilever tongue 2 is arranged parallel to the hot side of the cantilever tongue 2, and the angle between the hot side of the cooling ring 1 and the hot side of the cantilever tongue 2 (the cold side of the cantilever tongue 2 is biased towards the hot side of the cooling ring 1) is 0~20°. If the angle between the hot side of the cooling ring 1 and the hot side of the cantilever tongue 2 is greater than 20°, the high-temperature combustion gas will destroy the wall-mounted cooling gas film, or even directly impact the hot side of the cooling ring 1, causing the wall temperature of the cooling ring 1 to be too high. Optionally, the hot side of the cooling ring 1 is arranged parallel to the cantilever tongue 2, that is, the angle between the hot side of the cooling ring 1 and the hot side of the cantilever tongue 2 is 0°, which allows the high-speed cooling airflow to flow along the hot side of the cooling ring 1, forming a stable protective gas film on the hot side of the cooling ring 1. Optionally, the angle between the hot side of the cooling ring 1 and the hot side of the cantilever tongue 2 is 2° to 5°. On the one hand, the high-speed cooling airflow can impact the end of the cantilever tongue 2, reducing the risk of ablation. On the other hand, the narrowing of the outlet of the air film channel 3 can increase the speed of the cooling airflow, thereby extending the effective coverage length of the air film, and thus reducing the number of segments of the cooling ring 1 that make up the flame tube, which can reduce the cost and weight of the flame tube.

[0034] like Figure 7 As shown, the combustion chamber of this embodiment includes a diffuser 100, an outer casing 200, an inner casing 300, a nozzle 400, a vortex generator 500, a flame tube head 600, a flame tube outer ring 700, and a flame tube inner ring 800. The flame tube outer ring 700 includes the aforementioned high-efficiency film cooling structure, and the flame tube inner ring 800 also includes the aforementioned high-efficiency film cooling structure. The high-efficiency film cooling structure can improve the wall adhesion of the cooling airflow, prevent the cooling airflow from prematurely merging with the mainstream, and avoid the degradation of the cooling airflow quality. This maintains a long-distance wall-adhering cooling film on the hot side of the cooling ring 1, thereby reducing the number of cooling film sections on the flame tube outer ring 700 and the flame tube inner ring 800, reducing the cost of the flame tube, and reducing its weight. It can also reduce the risk of high-temperature combustion gas accumulating at the end of the cantilever tongue 2 and extend the service life of the cantilever tongue 2.

[0035] An aero-engine includes the aforementioned combustion chamber. High-pressure air, compressed by a compressor, enters the combustion chamber through a diffuser 100. Cooling air is split into two streams, entering the outer annular flow channel 7 and the inner annular flow channel 8. Subsequently, it enters the flame tube flow channel 9 through openings on the inner ring 800, outer ring 700, and flame tube head 600 of the flame tube. Fuel enters the flame tube flow channel 9 through a fuel nozzle 400, mixes and combusts with the high-pressure air within the flame tube flow channel, and flows along with it to form high-temperature, high-pressure combustion gas. The high-temperature, high-pressure combustion gas flows backward out of the combustion chamber, driving the turbine to perform work. The efficient film cooling structure on the inner ring 800 and outer ring 700 of the flame tube protects the flame tube from ablation.

[0036] The high-efficiency cooling structure, combustion chamber, and aero-engine provided by this invention maintain the boundary layer between the high-speed cooling airflow and the flame tube wall through the grooved surface of the biomimetic shark shield scale structure, suppressing the formation of turbulence and reducing flow resistance. On the one hand, it can maintain a long-distance wall-attached cooling film, reduce the number of cooling film sections, reduce the cost and weight of the flame tube; on the other hand, the cooling effect is better, reducing the axial wall temperature gradient of the flame tube, reducing temperature stress, and extending the life of the flame tube. Based on the stability of the laminar air film, the long distance of the cooling film coverage, and the biomimetic shark shield scale structure also arranged on the cold and hot sides of the cantilever tongue 2, laminar flow between fresh cold air and upstream end cold air is ensured, delaying the formation of turbulence. The design of thinning the cantilever tongue 2 avoids the formation of a low-speed zone downstream of the end face of the cantilever tongue 2, reducing the risk of ablation.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-efficiency film cooling structure, characterized in that, The device includes a cooling ring (1) for enclosing and forming a flow channel for a flame tube, and a cantilevered tongue (2) arranged on the cooling ring (1). The cantilevered tongue (2) is disposed on the inner wall of the cooling ring (1). An air film channel (3) is formed between the cantilevered tongue (2) and the cooling ring (1). An air inlet channel (11) for introducing cooling airflow into the air film channel (3) is provided on the cooling ring (1). A biomimetic shark shield scale structure is respectively arranged on the hot side of the cooling ring (1), the hot side of the cantilevered tongue (2), and the cold side of the cantilevered tongue (2). The biomimetic shark shield scale structure includes a groove (4) for reducing the flow resistance of the cooling airflow. The cross section of the groove (4) is polygonal or arc-shaped, and the groove (4) is arranged along the flow direction of the cooling airflow. The thickness of the cantilevered tongue (2) is 0.3 to 0.5 mm, and the depth h of the groove (4) is 0.01 to 0.1 mm.

2. The high-efficiency film cooling structure as described in claim 1, characterized in that, The groove (4) includes continuously arranged V-shaped grooves (41), the cross-section of the V-shaped grooves (41) is triangular, and the included angle α of the opening of the V-shaped grooves (41) is 45 to 135°.

3. The high-efficiency film cooling structure as described in claim 1, characterized in that, The trench (4) includes rectangular grooves (42) arranged at intervals. The cross-section of the rectangular grooves (42) is rectangular. The width of the rectangular grooves (42) is s, and 0.5≤s / h≤2.

4. The high-efficiency film cooling structure as described in claim 1, characterized in that, The groove (4) includes trapezoidal grooves (43) arranged at intervals. The cross-section of the trapezoidal groove (43) is trapezoidal. The opening width of the trapezoidal groove (43) is s1, and the bottom width of the trapezoidal groove (43) is s2, and 0.5≤s1 / s2≤2.

5. The high-efficiency film cooling structure as described in claim 1, characterized in that, The groove (4) includes continuously arranged arc-shaped grooves (44), the cross-section of which is circular arc, and the radius of which is R, and 0.01mm≤R≤0.1mm.

6. The high-efficiency film cooling structure as described in claim 1, characterized in that, The extension length of the groove (4) is 10~60mm.

7. The high-efficiency film cooling structure as described in claim 1, characterized in that, The angle between the air intake channel (11) and the cold side of the cantilever tongue (2) is 0~30°.

8. The high-efficiency film cooling structure as described in claim 1, characterized in that, The cold side of the cantilever tongue (2) is arranged parallel to the hot side of the cantilever tongue (2), and the angle between the hot side of the cooling ring (1) and the hot side of the cantilever tongue (2) is 0~20°.

9. A combustion chamber, comprising a diffuser (100), an outer casing (200), an inner casing (300), a nozzle (400), a vortex generator (500), a flame tube head (600), a flame tube outer ring (700), and a flame tube inner ring (800), characterized in that, The outer ring (700) of the flame tube includes the high-efficiency gas film cooling structure according to any one of claims 1 to 8, and the inner ring (800) of the flame tube includes the high-efficiency gas film cooling structure according to any one of claims 1 to 8.

10. An aircraft engine, characterized in that, Includes the combustion chamber as described in claim 9.

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