A composite flame tube sealed by principle of Tesla valve and an aero-engine

Abstract

The application discloses a composite flame tube sealed by Tesla valve principle and an aero-engine, which comprises a tube body made of a first material, a head part arranged at the periphery of the end of the tube body, the head part being made of a second material, the expansion coefficients of the first material and the second material being different, the head part being sealed with the tube body in a cold state, a gap being formed between the head part and the tube body in a hot state, and a Tesla valve sealing structure arranged between the head part and the tube body, the Tesla valve sealing structure comprising a Tesla valve arranged on the head part and the tube body, and the Tesla valve being used for guiding airflow to form a counterflow at the gap so as to prevent leakage. The application seals the gap between the tube body and the head part by adopting the Tesla valve principle, and realizes the sealing effect by using the resistance generated by the forward and reverse flow of the airflow in the flow channel, so that the elastic sealing structure is not needed, the structure is simple, the number of parts is small, and the problem of the decline of the sealing performance of the elastic structure under high temperature is fundamentally solved.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, specifically to a composite material flame tube and aero-engine with Tesla valve principle sealing. Background Technology

[0002] The combustion chamber is one of the three core components of an aero-engine. The flame tube is the part of the combustion chamber that organizes combustion, and it is prone to creep deformation when operating under high temperature and high pressure. Advanced aero-engine combustion chambers are developing towards higher temperature rise, requiring the use of more heat-resistant materials to ensure high-performance and stable operation of the combustion chamber and extend its service life.

[0003] Non-metallic composite materials, such as ceramic matrix composites, have higher temperature resistance and lower density than traditional metallic materials, making them one of the most promising high-temperature resistant materials for aero-engines and a high-quality choice for advanced aero-engine combustion chambers. However, when using non-metallic composite materials to manufacture flame tubes, the connection and sealing between non-metallic composite components and metallic components inevitably involves the issue of connection.

[0004] Existing non-metallic composite flame tubes and metal structures often use elastic structures for connection and sealing to mitigate the difference in expansion between the two materials under hot conditions and prevent air leakage under hot conditions.

[0005] The existing technical solution has the following two shortcomings: 1) The seal between the metal and non-metal is achieved using an elastic structure, which is complex, has many parts, and is difficult to assemble. 2) An elastic structure is used to seal between metal and non-metal, but the elastic structure is easily damaged at high temperatures. Summary of the Invention

[0006] In view of this, the present invention provides a composite material flame tube and an aero engine with a Tesla valve principle seal, so as to solve the problems of complex structure, large number of parts, and easy wear and tear of elastic structure at high temperature that exist in the existing non-metallic composite material flame tube and metal structure using elastic sealing structure.

[0007] In a first aspect, the present invention provides a composite material flame tube sealed based on the Tesla valve principle, comprising: A cylindrical body, said cylindrical body being made of a first material; The head is disposed on the outer periphery of the end of the cylinder, and the head is made of a second material, the first material and the second material having different coefficients of expansion; in the cold state, the head is fitted and sealed to the cylinder; in the hot state, a gap is formed between the head and the cylinder. A Tesla valve sealing structure is disposed between the head and the cylinder. The Tesla valve sealing structure includes a Tesla valve disposed on the head and the cylinder. The Tesla valve is used to guide airflow to form a countercurrent flow at the gap to prevent leakage.

[0008] The beneficial effects of the above technical solution are as follows: The composite material flame tube seals the gap between the first and second materials using the Tesla valve principle. It achieves the sealing effect by utilizing the resistance generated by the forward and reverse flow of air in the flow channel. This eliminates the need for an elastic sealing structure, resulting in a simple structure with fewer parts. It fundamentally solves the problem of decreased sealing performance of elastic structures at high temperatures due to stress relaxation, creep, and fatigue, thus improving the reliability and service life of the sealing structure. Furthermore, in the cold state, the head directly seals against the tube body, while in the hot state, the Tesla valve sealing structure is automatically activated, achieving dual sealing in both cold and hot states, adapting to the full operating conditions of the flame tube.

[0009] In one alternative embodiment, the cylinder has a first end and a second end disposed opposite to each other, and the head is sleeved on the first end of the cylinder.

[0010] The beneficial effects of the above technical solution are: the head is sleeved on the end of the cylinder, and an annular gap is formed between the two when hot. At the same time, the sleeved structure facilitates assembly and has low manufacturing cost.

[0011] In one alternative embodiment, the Tesla valve includes a first-layer Tesla valve, which includes at least one exhaust flow channel disposed on the head, the outlet of the airflow channel facing the gap, the airflow channel being inclined from the outside to the inside toward the second end of the cylinder, the airflow channel being used to eject a stream of airflow and counteract two streams of airflow entering the gap from the outside.

[0012] The beneficial effects of the above technical solution are as follows: by using the first-layer Tesla valve, the airflow ejected from the airflow channel and the airflow entering the gap from the outside are counteracted, forming the first fluid sealing barrier at the gap between the metal and non-metal walls, effectively preventing the two airflow channels from leaking into the flame tube through the gap.

[0013] In one optional embodiment, the airflow channel is provided in two rows, the two rows of airflow channels are arranged alternately in the circumferential direction, and the outlet directions of the two rows of airflow channels are staggered, so that the ejected airflow is distributed in a 360° circumferential direction.

[0014] The beneficial effects of the above technical solution are as follows: the two exhaust channels are arranged in a staggered manner along the circumference and the outlet directions are staggered, so that the ejected airflow can be evenly distributed in the 360° circumferential direction, forming a full circumferential airflow counter-sealing, avoiding local sealing blind spots, and significantly improving the sealing effect.

[0015] In one optional embodiment, the Tesla valve further includes a second Tesla valve, which includes a chamber, an inlet channel, and an outlet channel respectively disposed on the cylinder. The inlet channel connects the gap and the chamber, and the outlet channel connects the chamber and the gap. The inlet channel is inclined from the outside to the inside toward the first end of the cylinder, and the outlet channel is inclined from the inside to the outside toward the second end of the cylinder, so that the two airflows entering the gap from the outside are divided into a first airflow and a second airflow. The first airflow flows through the inlet channel, the chamber, and the outlet channel and is discharged into the gap, and forms a countercurrent with the second airflow flowing toward the gap.

[0016] The beneficial effects of the above technical solution are as follows: The second-layer Tesla valve diverts the two streams of airflow entering the gap, which then re-enter the gap through the inlet channel, chamber, and outlet channel, counteracting the continuing forward flow of air and forming a second fluid sealing barrier. The combined action of the first and second-layer Tesla valves creates multiple sealing barriers, further improving the sealing effect.

[0017] In one optional embodiment, the angle between the inlet channel and the central axis of the cylinder is smaller than the angle between the outlet channel and the central axis of the cylinder.

[0018] The beneficial effects of the above technical solution are as follows: by reasonably setting the angle between the inlet channel and the outlet channel, the flow path and direction of the airflow in the chamber are optimized, the airflow counter-current effect is enhanced, and the sealing efficiency is significantly improved.

[0019] In one alternative embodiment, the first material is a non-metallic composite material, and the second material is a metallic material.

[0020] The beneficial effects of the above technical solution are: non-metallic composite materials have higher temperature resistance and lower density, while metallic materials have good processing performance and structural strength. The combination of the two can give full play to their respective advantages and meet the requirements of high temperature and lightweight design for aero-engine combustion chambers.

[0021] In one alternative embodiment, the non-metallic composite material is a ceramic matrix composite material.

[0022] The beneficial effects of the above technical solution are: ceramic matrix composite materials have excellent high temperature resistance, oxidation resistance and low density, making them ideal materials for the combustion chamber flame tube of aero-engines.

[0023] In one optional embodiment, the cylinder includes an outer ring and an inner ring; the head includes a horizontal section, a vertical section, and a horizontal section of the inner ring, and the Tesla valve sealing structure is respectively disposed between the outer ring and the horizontal section of the outer ring and between the inner ring and the horizontal section of the inner ring.

[0024] The beneficial effects of the above technical solution are as follows: by setting Tesla valve sealing structures between the outer ring of the flame tube and the horizontal section of the outer ring of the head, and between the inner ring of the flame tube and the horizontal section of the inner ring of the head, a complete seal between the inner and outer rings of the flame tube and the head is achieved, ensuring the overall sealing performance of the combustion chamber.

[0025] Secondly, the present invention provides an aero-engine, including the composite material flame tube sealed according to the Tesla valve principle described above.

[0026] The aero-engine of the second aspect of the present invention includes the above-described composite material flame tube and has the same effects as the above-described composite material flame tube, which will not be described again here. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the assembly relationship of a composite material flame tube with Tesla valve principle sealing provided by the present invention.

[0029] Figure 2 This is a schematic diagram of the head of a composite material flame tube with a Tesla valve principle seal, provided by the present invention.

[0030] Figure 3 This is a partial structural diagram of the head of a composite material flame tube with a Tesla valve principle seal, provided by the present invention.

[0031] Figure 4 This invention provides a schematic diagram of the outer ring structure of a composite material flame tube sealed based on the Tesla valve principle.

[0032] Figure 5 This invention provides a schematic diagram of the sealing principle of a composite material flame tube based on the Tesla valve principle.

[0033] Figure 6 This invention provides a schematic diagram of the structure of the second-layer Tesla valve in a composite material flame tube sealed based on the Tesla valve principle.

[0034] Explanation of reference numerals in the attached figures: 1. Flame tube outer ring; 11. Profile; 12. Chamber; 13. Inlet channel; 14. Outlet channel; 2. Head; 21. Outer ring horizontal section; 211. First airflow channel; 212. Second airflow channel; 22. Vertical section; 23. Inner ring horizontal section; 3. Inner ring of the flame tube; 100. Cylinder body; 101. First end; 102. Second end; 200. Gap; a. Angle between the inlet channel and the central axis of the cylinder; b. Angle between the outlet channel and the central axis of the cylinder. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Traditional high-temperature alloy combustion chambers are prone to creep deformation under high-temperature and high-pressure environments. Therefore, materials with higher temperature resistance are needed to ensure the high-performance and stable operation of the combustion chamber and extend its lifespan. Non-metallic composite materials, such as ceramic matrix composites, have higher temperature resistance and lower density than metallic materials, making them a superior choice for advanced aero-engine combustion chambers.

[0037] Currently, elastic structures are often used to connect and seal non-metallic composite flame tubes with metal structures to mitigate the difference in thermal expansion between the two materials. However, elastic structures are prone to stress relaxation, creep, and fatigue loss at high temperatures, leading to a decline in sealing performance over time and affecting the reliability and service life of aero engines.

[0038] To address the aforementioned issues, this invention proposes a composite material flame tube and aero-engine sealed using the Tesla valve principle. By employing the Tesla valve principle to seal the gap between metallic and non-metallic materials under hot conditions, the sealing effect is achieved by utilizing the resistance generated by the forward and reverse flow of air in the flow channel. This eliminates the need for an elastic sealing structure, resulting in a simple structure with fewer parts. It fundamentally solves the problem of decreased sealing performance of elastic structures at high temperatures due to stress relaxation, creep, and fatigue.

[0039] Reference Figures 1 to 6The specific embodiments of the present invention will now be described in detail with reference to the first aspect of the present invention, in conjunction with the composite material flame tube.

[0040] It should be noted that the composite material flame tube of the first aspect of the present invention is only a preferred embodiment of the present invention. The composite material flame tube of the present invention can adopt the composite material flame tube of the first aspect of the present invention or other structures. For ease of explanation, the following description will be based on the composite material flame tube of the first aspect of the present invention.

[0041] According to an embodiment of the present invention, in a first aspect, a composite material flame tube with a Tesla valve principle seal is provided, with reference to... Figure 1 This composite material flame tube is mainly used in the combustion chamber of aero-engines. It has excellent sealing performance and can effectively solve the sealing failure problem caused by the difference in thermal expansion between non-metallic composite materials and metallic materials.

[0042] The composite material flame tube includes a tube body 100, a head 2, and a Tesla valve sealing structure. The tube body 100 is made of a first material, and the head 2 is made of a second material, the first and second materials having different coefficients of thermal expansion. In a cold state, the head 2 is tightly sealed to the tube body 100; in a hot state, a gap 200 is formed between the head 2 and the tube body 100. The Tesla valve sealing structure is disposed between the head 2 and the tube body 100, and includes a Tesla valve disposed on both the head 2 and the tube body 100, used to guide airflow to form a countercurrent flow at the gap 200 to prevent leakage.

[0043] The first material is a non-metallic composite material, and the second material is a metallic material. The non-metallic composite material has higher temperature resistance and lower density, while the metallic material has good processing performance and structural strength. Combining the two allows them to fully leverage their respective advantages. Furthermore, the non-metallic composite material is a ceramic matrix composite material. Ceramic matrix composite materials have excellent high-temperature resistance, oxidation resistance, and low density, making them ideal materials for the combustion chamber flame tube of aero-engines.

[0044] The aforementioned composite material flame tube seals the gap between the metal and non-metal materials under hot conditions by employing the Tesla valve principle. It achieves the sealing effect by utilizing the resistance generated by the forward and reverse flow of air in the flow channel. It eliminates the need for an elastic sealing structure, resulting in a simple structure with fewer parts. This fundamentally solves the problem of decreased sealing performance caused by stress relaxation, creep, and fatigue of elastic structures at high temperatures, thereby improving the reliability and service life of the sealing structure.

[0045] Reference Figure 1 and Figure 4In some embodiments, the cylinder 100 has a first end 101 and a second end 102 disposed opposite to each other, and the head 2 is sleeved on the first end 101 of the cylinder 100. Specifically, the head 2 is sleeved on the front end of the cylinder 100, and an annular gap 200 is formed between the two in the hot state. At the same time, the sleeved structure facilitates assembly and has low manufacturing cost.

[0046] Reference Figure 1 and Figure 5 In some embodiments, the Tesla valve includes a first-layer Tesla valve. The first-layer Tesla valve includes at least one exhaust channel disposed at the head 2, with the outlet of the exhaust channel facing the gap 200. The exhaust channel is inclined from the outside inwards towards the second end of the cylinder 100. Therefore, when an exhaust stream enters the gap from the outside, it forms an airflow in the opposite direction to the two exhaust streams entering the gap. The exhaust channel is used to eject an exhaust stream and counteract the two exhaust streams entering the gap 200 from the outside, directly blocking the two exhaust streams entering the gap 200, completing a primary seal, and reducing the amount of leaked gas flowing into the inside of the flame tube.

[0047] Specifically, refer to Figure 2 The head 2 includes an outer horizontal section 21, a vertical section 22, and an inner horizontal section 23. Two exhaust channels are respectively provided on the outer horizontal section 21 and the inner horizontal section 23. Each exhaust channel includes multiple first airflow channels 211 and multiple second airflow channels 212. The two exhaust channels are arranged in a staggered circumferential direction, and their outlet directions are also staggered, so that the ejected airflow is distributed in a 360° circumferential direction. This staggered arrangement of the two exhaust channels and their staggered outlet directions ensures that the ejected airflow is evenly distributed in a 360° circumferential direction, forming a full-circumferential airflow counter-sealing, avoiding local sealing blind spots, and significantly improving the sealing effect.

[0048] Multiple first airflow channels 211 are spaced apart circumferentially along the head 2, and multiple second airflow channels 212 are also spaced apart circumferentially along the head 2. The first airflow channels 211 and second airflow channels 212 are staggered. The first airflow channels 211 and second airflow channels 212 can be elongated oblique holes, and the second airflow channels 212 can also be elongated oblique holes. This ensures that the gap between two adjacent first airflow channels corresponds exactly to the air outlet position of the second airflow channel, guaranteeing that there are no airflow sealing gaps in the entire circumferential direction, thus forming a complete and continuous full-circumferential counteracting air seal barrier. Compared with traditional round hole openings, the elongated oblique hole structure can provide a wider and more continuous air outlet coverage area with the same opening area, allowing the ejected airflow to spread evenly. At the same time, the staggered and dispersed opening method will not weaken the overall mechanical performance of the head structure.

[0049] It should be noted that the first airflow refers to the airflow ejected from the airflow channel on the head 2, while the second airflow refers to the airflow entering the gap 200 from the outside. The two airflows are in opposite directions and collide at the gap 200, thus preventing the second airflow from leaking into the flame tube through the gap 200.

[0050] The working process of the first-layer Tesla valve is as follows: When the two airflow channels flow into the flame tube through the gap 200, the jets ejected through the first airflow channel 211 and the second airflow channel 212 form airflows in opposite directions with the two airflow channels. The two airflows collide with each other, hindering the two airflow channels from flowing into the gap 200, thus forming a seal of the first-layer Tesla valve.

[0051] Reference Figure 4 and Figure 5 In some embodiments, the Tesla valve further includes a second Tesla valve. The second Tesla valve includes a chamber 12, an inlet channel 13, and an outlet channel 14 respectively disposed on the cylinder 100. The inlet channel 13 connects the gap 200 and the chamber 12, and the outlet channel 14 connects the chamber 12 and the gap 200. The inlet channel 13 is inclined from the outside to the inside toward the first end of the cylinder 100, and the outlet channel 14 is inclined from the inside to the outside toward the second end of the cylinder 100, so that the two airflows entering the gap 200 from the outside are divided into a first airflow and a second airflow. The second airflow continues to move along the gap 200, while the first airflow flows through the inlet channel 13, the chamber 12, and the outlet channel 14 and is discharged into the gap 200, forming a countercurrent with the second airflow flowing toward the gap 200.

[0052] In this embodiment, the outlet channel 14 is closer to the first end of the cylinder 100 than the inlet channel 13, and the outlet channel 14 is inclined from the inside to the outside toward the second end of the cylinder 100, so that after the first split gas flows out of the outlet channel, it can collide with the second split gas flowing toward the second end. The two airflows collide to form a pneumatic sealing layer, which effectively blocks the high-temperature gas from leaking into the cylinder along the gap 200 without adding additional sealing components.

[0053] The working process of the second-layer Tesla valve is as follows: the airflow that continues to flow forward enters the chamber 12 through the inlet channel 13 and then flows out through the outlet channel 14. The direction of this airflow is opposite to that of the mainstream airflow, which hinders the mainstream airflow from flowing in further and forms a second-layer Tesla valve seal.

[0054] It should be noted that the first airflow refers to the portion of the two airflows that enters chamber 12 through inlet channel 13 and exits through outlet channel 14, while the second airflow refers to the portion of the two airflows that continues to flow forward along gap 200. After the first airflow turns through chamber 12, it exits through outlet channel 14 in the opposite direction to the second airflow, creating a countercurrent.

[0055] Reference Figure 6 In some embodiments, the angle α between the inlet channel and the central axis of the cylinder is smaller than the angle b between the outlet channel and the central axis of the cylinder. By rationally setting the angle relationship between the inlet channel and the outlet channel, the flow path and direction of the airflow in the chamber 12 are optimized, enhancing the airflow counter-current effect and significantly improving the sealing efficiency.

[0056] The smaller angle between the inlet channel 13 and the central axis of the cylinder 100 means that the airflow channel is closer to the axial direction. The smaller angle can guide more of the split airflow flowing forward along the gap to smoothly enter the inlet channel, effectively increasing the airflow rate entering the chamber. Furthermore, when the airflow enters the chamber 12, the axial velocity component is large and the radial velocity component is small, which can flow into the chamber more smoothly and reduce flow resistance. The larger angle between the outlet channel 14 and the central axis of the cylinder 100 means that the airflow can be smoothly discharged from the outlet channel 14, avoiding the pressure accumulation in the chamber due to flow obstruction, which would affect the continuous entry of subsequent airflow.

[0057] Through the combined action of two Tesla valves, an effective fluid seal is formed between the metal and non-metal walls, preventing high-temperature gas leakage. The specific sealing process is as follows: In the cold state, the metal wall of the head 2 and the non-metal wall of the cylinder 100 are in contact for sealing. In the hot state, as the temperature rises, a gap 200 appears between the metal wall of the head 2 and the non-metal wall of the cylinder 100 due to the difference in thermal expansion coefficients between the metal and non-metal materials. At this time, the first Tesla valve takes effect first, with the jets ejected through the first airflow channel 211 and the second airflow channel 212 opposing the two airflows, preventing the two airflows from flowing into the gap, forming the first sealing barrier; part of the airflow continues forward, with the first branch airflow passing through the inlet channel 13, chamber 12, and outlet channel 14 of the second Tesla valve, opposing the second branch airflow, forming the second sealing barrier, thus achieving effective self-sealing in the hot state.

[0058] Reference Figure 1 In some embodiments, the cylinder 100 includes an outer ring 1 and an inner ring 3 of the flame tube. The head 2 includes a horizontal section 21 of the outer ring, a vertical section 22, and a horizontal section 23 of the inner ring. Tesla valve sealing structures are respectively disposed between the outer ring 1 and the horizontal section 21 of the outer ring, and between the inner ring 3 and the horizontal section 23 of the inner ring. By disposing Tesla valve sealing structures between the outer ring 1 and the horizontal section 21 of the head, and between the inner ring 3 and the horizontal section 23 of the head, a complete seal between the inner and outer rings of the flame tube and the head is achieved, ensuring the overall sealing performance of the combustion chamber. Since the sealing principle between the head 2 and the outer ring 1 and the inner ring 3 of the flame tube is similar, this article only describes the seal between the outer ring 1 and the head.

[0059] In the above embodiment, the outer ring 1 of the flame tube includes a profile 11 and a chamber 12. An inlet channel 13 and an outlet channel 14 are designed on the outer wall of the chamber 12. A first airflow channel 211 and a second airflow channel 212 are designed on the horizontal section 21 of the outer ring of the head 2. The sealing structure between the inner ring 3 of the flame tube and the horizontal section 23 of the inner ring of the head is similar to that described above and will not be repeated here. Specifically, the chamber 12 is formed on the protrusion, which is connected to the profile 11 and protrudes towards the inside of the tube relative to the profile 11. The outer wall of the profile 11 is smoothly connected to the outer wall of the chamber 12.

[0060] In summary, the aforementioned composite material flame tube, by applying the Tesla valve principle to the sealing between the metallic and non-metallic materials of the flame tube, eliminates the traditional elastic sealing structure, significantly simplifying the structure, reducing the number of parts, and lowering assembly difficulty. Furthermore, due to the use of a non-contact fluid sealing method, it avoids the stress relaxation, creep, and fatigue wear problems of elastic elements at high temperatures, resulting in stable and reliable sealing performance and a long service life.

[0061] The specific embodiments of the present invention will now be described in detail with reference to the aero-engine of the second aspect of the present invention.

[0062] It should be noted that the aero-engine of the second aspect of the present invention is only a preferred embodiment of the present invention. The aero-engine of the present invention can be the aero-engine of the second aspect of the present invention or other structures. For ease of explanation, the following description will be based on the aero-engine of the second aspect of the present invention.

[0063] According to an embodiment of the present invention, in a second aspect, an aero-engine is provided, comprising a composite material flame tube sealed according to the Tesla valve principle as described in any of the preceding claims.

[0064] When the aforementioned aero-engine is operating, the flame tube inside the combustion chamber operates at high temperatures, creating a gap 200 between the metal wall of the head 2 and the non-metallic wall of the cylinder 100 due to the difference in their coefficients of thermal expansion. At this time, the Tesla valve sealing structure automatically activates: the first-layer Tesla valve ejects a stream of air through the first airflow channel 211 and the second airflow channel 212 on the head 2, counteracting the two streams of airflow entering the gap 200 from the outside, thus preventing leakage; the second-layer Tesla valve diverts and redirects part of the airflow through the chamber 12, inlet channel 13, and outlet channel 14, again counteracting the continuing forward-flowing airflow, further preventing leakage. Through the synergistic action of the two Tesla valves, effective sealing under hot conditions is achieved, ensuring stable and reliable operation of the aero-engine under high-temperature conditions.

[0065] The aforementioned aero-engines, by employing a composite material flame tube sealed using the Tesla valve principle, eliminate the need for an elastic sealing structure, simplifying the combustion chamber structure, reducing manufacturing and maintenance costs, and improving engine reliability and service life. Furthermore, the application of ceramic matrix composite flame tubes allows the engine to operate at higher temperatures, which is beneficial for improving combustion efficiency.

[0066] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A composite material flame tube with Tesla valve principle sealing, characterized in that, include: A cylindrical body (100) made of a first material; The head (2) is disposed on the periphery of the end of the cylinder (100). The head (2) is made of a second material, and the expansion coefficients of the first material and the second material are different. In the cold state, the head (2) is fitted and sealed to the cylinder (100). In the hot state, a gap (200) is formed between the head (2) and the cylinder (100). A Tesla valve sealing structure is disposed between the head (2) and the cylinder (100). The Tesla valve sealing structure includes a Tesla valve disposed on the head (2) and the cylinder (100). The Tesla valve is used to guide the airflow to form a counterflow at the gap (200) to prevent leakage.

2. The composite material flame tube according to claim 1, characterized in that, The cylinder (100) has a first end (101) and a second end (102) disposed opposite to each other, and the head (2) is sleeved on the first end (101) of the cylinder (100).

3. The composite material flame tube according to claim 2, characterized in that, The Tesla valve includes a first-layer Tesla valve, which includes at least one exhaust flow channel disposed on the head (2), the outlet of the airflow channel facing the gap (200), the airflow channel being inclined from the outside to the inside toward the second end (102) of the cylinder (100), the airflow channel being used to eject a stream of airflow and to counteract the two streams of airflow entering the gap (200) from the outside.

4. The composite material flame tube according to claim 3, characterized in that, The airflow channel is provided in two rows, which are staggered in the circumferential direction, and the outlet directions of the two rows of airflow channels are staggered so that the ejected airflow is distributed in a 360° circumferential direction.

5. The composite material flame tube according to claim 1, characterized in that, The Tesla valve also includes a second Tesla valve, which includes a chamber (12), an inlet channel (13), and an outlet channel (14) respectively disposed on the cylinder (100). The inlet channel (13) connects the gap (200) and the chamber (12), and the outlet channel (14) connects the chamber (12) and the gap (200). The inlet channel (13) is inclined from the outside to the inside toward the first end (101) of the cylinder (100), and the outlet channel (14) is inclined from the inside to the outside toward the second end (102) of the cylinder (100), so that the two streams of airflow entering the gap (200) from the outside are divided into a first stream flow and a second stream flow. The first stream flow flows through the inlet channel (13), the chamber (12) and the outlet channel (14) and is discharged into the gap (200), and forms a countercurrent with the second stream flow flowing toward the gap (200).

6. The composite material flame tube according to claim 5, characterized in that, The angle between the inlet channel (13) and the central axis of the cylinder (100) is smaller than the angle between the outlet channel (14) and the central axis of the cylinder (100).

7. The composite material flame tube according to claim 1, characterized in that, The first material is a non-metallic composite material, and the second material is a metallic material.

8. The composite material flame tube according to claim 7, characterized in that, The non-metallic composite material is a ceramic matrix composite material.

9. The composite material flame tube according to claim 1, characterized in that, The cylinder (100) includes an outer ring (1) of the flame tube and an inner ring (3) of the flame tube; The head (2) includes an outer ring horizontal section (21), a vertical section (22) and an inner ring horizontal section (23). The Tesla valve sealing structure is respectively disposed between the outer ring (1) of the flame tube and the outer ring horizontal section (21) and between the inner ring (3) of the flame tube and the inner ring horizontal section (23).

10. An aircraft engine, characterized in that, The composite flame tube includes the Tesla valve principle seal as described in any one of claims 1-9.

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