A rotating detonation ramjet combustor for an aeroengine
By introducing an airflow ejector channel into the rotating detonation combustion chamber, the turbine exhaust gas is mixed with the outside air, solving the problem of unstable detonation combustion in an oxygen-deficient environment, improving combustion efficiency and engine thrust, and reducing engine weight.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- QINGHANG AEROSPACE (BEIJING) TECH CO LTD
- Filing Date
- 2023-04-07
- Publication Date
- 2026-05-29
AI Technical Summary
Existing rotary detonation combustors have difficulty generating and maintaining stable detonation waves in oxygen-deficient exhaust gas environments, resulting in low cycle thermal efficiency of afterburners, incomplete combustion, and heavy engine weight.
By setting an airflow ejector channel between the air inlet and the exhaust port of the rotating detonation combustion chamber, the high-speed flow of turbine exhaust gas draws outside air into the combustion chamber, mixes it with the exhaust gas, and increases the oxygen concentration. The opening and closing of the airflow ejector channel is controlled by an ejector control switch to ensure the stability and efficiency of detonation combustion.
It increases the oxygen concentration in the rotating detonation combustion chamber, ensuring the stability and efficiency of detonation combustion, increasing engine thrust, and reducing combustion chamber length and engine weight.
Smart Images
Figure CN116557915B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of gas turbine engines, and more particularly to a rotating detonation afterburner for an aircraft engine. Background Technology
[0002] Current research on the application of rotating detonation combustors in traditional turbine power systems mainly focuses on their use as the main combustion chamber of engines, while research on their use as afterburners is relatively limited. Afterburners are an indispensable basic component of aero engines and a primary means of generating greater thrust in a short time. The afterburner works by injecting a portion of fuel into the exhaust gas stream after the turbine while maintaining the engine's operating conditions. The unburned oxygen in the exhaust gas is then used for re-combustion, further increasing the gas temperature and jet velocity, thereby increasing thrust.
[0003] However, because the fuel in a traditional afterburner is in a low-pressure combustion chamber, the afterburner has a lower cycle thermal efficiency, resulting in low combustion efficiency and a sharp increase in fuel consumption. Generally speaking, without increasing the engine's frontal area, the afterburner will maintain a relatively long size to ensure complete combustion of air. Replacing the traditional afterburner with a detonation combustor offers several advantages. First, it effectively addresses the low cycle thermal efficiency of the afterburner. Second, due to its simpler structure, the rotary detonation combustor allows for higher intake velocity of the mixed air, eliminating the need for mixers and diffusers. Third, its simpler ignition system allows the detonation wave to propagate continuously within the combustion chamber after a single ignition, with the flame propagating as a shock wave, eliminating the need for flame stabilizers found in traditional combustors. Fourth, combustion products can expand and accelerate to Mach 1 within the annular afterburner. Excessive combustion chamber length increases losses, so the length of the detonation afterburner is significantly shorter than that of a traditional afterburner, reducing engine weight. Finally, using a rotary detonation combustor as the afterburner allows for efficient use of the annular cavity structure at the turbine outlet, resulting in a more compact engine.
[0004] However, the exhaust gas after the turbine is the exhaust gas after combustion, and its oxygen content is more than 20% lower than that in the air. This oxygen-deficient environment is unfavorable for detonation combustion, and it may be difficult to generate detonation waves or obtain stable detonation waves. Summary of the Invention
[0005] In view of this, this application provides a rotating detonation afterburner for an aero-engine, which solves the problem that detonation combustion in the exhaust gas of the existing detonation combustor is difficult to generate, stabilizes the detonation wave, and improves the working stability of the rotating detonation afterburner.
[0006] The rotating detonation afterburner for an aero-engine provided in this application adopts the following technical solution:
[0007] A rotating detonation afterburner for an aero-engine includes a rotating detonation combustor connected to the exhaust end of the engine casing. The air inlet of the rotating detonation combustor is connected to the exhaust port of the engine casing. An airflow ejection channel is provided on the exhaust end of the engine casing and / or the air inlet of the rotating detonation combustor. The airflow ejection channel connects the internal space and the external space of the air inlet of the rotating detonation combustor. When the exhaust gas from the engine exhaust end passes through the air inlet of the detonation combustor, it introduces air from the external space at the connection between the rotating detonation combustor and the engine casing into the rotating detonation combustor through the airflow ejection channel.
[0008] Optionally, the rotating detonation combustion chamber includes an outer ring and an inner ring. The outer ring surrounds the outer periphery of the inner ring, and the cavity between the outer ring and the inner ring forms a combustion chamber cavity. In the axial direction of the outer ring, one end of the combustion chamber cavity serves as the air inlet of the rotating detonation combustion chamber, and the other end of the combustion chamber cavity serves as the exhaust port of the rotating detonation combustion chamber. The inner diameter of the outer ring is larger than the outer diameter of the casing exhaust port, and the air inlet end of the outer ring surrounds the outer periphery of the casing exhaust end. The gap between the air inlet end of the outer ring and the sidewall of the casing exhaust end forms an airflow ejection channel.
[0009] Optionally, the rotary detonation afterburner further includes an ejector control switch, which is installed on the exhaust end of the casing and / or the air intake end of the rotary detonation combustion chamber, and controls the closure and opening of the airflow ejection channel.
[0010] Optionally, the ejector control switch includes multiple adjusting plates and multiple driving mechanisms. The multiple adjusting plates are surrounded on the outer wall of the exhaust end of the casing. One end of the adjusting plate is rotatably connected to the outer wall of the exhaust end of the casing, and the other end of the adjusting plate is a free end. The edge of the free end matches the inner wall of the outer ring. The driving mechanism is mounted on the casing. The output end of the driving mechanism is connected to the adjusting plate and drives the adjusting plate to rotate, so that the free end moves away from the casing and abuts against or approaches the inner wall of the outer ring.
[0011] When the free end abuts against the inner wall of the outer ring, the edge of the free end fits against the inner wall of the outer ring, and the adjacent edges of the adjacent adjustment pieces overlap or align with each other, so that the multiple adjustment pieces form a continuous structure that closes the airflow ejection channel.
[0012] Optionally, when the free end abuts against the inner wall of the outer ring, the end of the adjusting plate connected to the casing is closer to the air intake of the engine than the free end.
[0013] Optionally, the drive mechanism includes an actuator cylinder that is closer to the engine's air intake than the adjusting plate. The housing of the actuator cylinder is rotatably mounted on the casing, and the telescopic shaft of the actuator cylinder is rotatably connected to the side of the adjusting plate.
[0014] Optionally, the outer ring and the inner ring are coaxially arranged, and the outer diameter of the end of the inner ring near the air outlet gradually decreases along the airflow direction.
[0015] In summary, this application includes the following beneficial technical effects:
[0016] The rotating detonation combustion chamber of this application is connected to the exhaust end of the engine turbine. The exhaust gas from the turbine is the main combustion chamber's burnt-out exhaust gas. When the high-speed exhaust gas passes through the connection between the rotating detonation combustion chamber and the casing, it draws in outside air through the airflow ejector channel. This mixing of exhaust gas and outside air increases the oxygen concentration in the rotating detonation combustion chamber, after which fuel injection and ignition begin, initiating afterburner operation. Engine thrust is directly proportional to the exhaust gas flow rate from the exhaust nozzle. As the oxygen content increases, appropriately increasing the amount of fuel will increase the amount of combusted gas, thus increasing the exhaust gas flow rate from the rotating detonation combustion chamber. The airflow ejector channel increases the exhaust flow rate at the exhaust end of the detonation combustion chamber, thereby increasing the exhaust gas flow rate from the engine exhaust nozzle, which in turn increases the engine thrust during afterburner operation. The increased oxygen content in the exhaust gas through the airflow ejector allows for successful and more stable detonation combustion. This also shortens the length of the engine's afterburner, reducing engine weight. Attached Figure Description
[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 A schematic diagram of the overall structure of the rotating detonation afterburner of an aero-engine;
[0019] Figure 2 A schematic diagram of the structure with the ejector control switch in the off state;
[0020] Figure 3 A schematic diagram of the structure with the ejector control switch in the open state.
[0021] Explanation of reference numerals in the attached drawings: 1. Casing; 11. Compressor; 12. Main combustion chamber; 13. Turbine; 2. Rotary detonation combustion chamber; 21. Outer ring; 22. Inner ring; 23. Fuel inlet passage; 24. Fuel nozzle; 25. Combustion chamber cavity; 26. Airflow ejector passage; 3. Ejector control switch; 31. Adjusting vane; 32. Free end. Detailed Implementation
[0022] The embodiments of this application will now be described in detail with reference to the accompanying drawings.
[0023] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0024] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.
[0025] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.
[0026] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.
[0027] This application provides a rotating detonation afterburner for an aero-engine.
[0028] like Figure 1 As shown, a rotating detonation afterburner for an aero-engine includes a rotating detonation combustor 2 connected to the exhaust end of the engine casing 1. The air inlet of the rotating detonation combustor 2 is connected to the exhaust port of the casing 1, and an airflow ejection channel 26 is provided on the exhaust end of the casing 1 and / or the air inlet of the rotating detonation combustor 2. The airflow ejection channel 26 connects the internal space and the external space of the air inlet of the rotating detonation combustor 2. When the high-speed exhaust gas from the exhaust end of the engine casing 1 passes through the air inlet of the detonation combustor, it introduces the air from the external space at the connection between the rotating detonation combustor 2 and the casing 1 into the rotating detonation combustor 2 through the airflow ejection channel 26.
[0029] In this embodiment, the engine further includes a compressor 11, a main combustion chamber 12, and a turbine 13 disposed within the casing 1 and arranged sequentially along the airflow direction. The rotary detonation combustion chamber 2 of this application is connected to the exhaust end of the turbine 13. The combustion gas flow through the turbine 13 is the exhaust gas that has been burned in the main combustion chamber 12. The exhaust gas at the turbine 13 outlet has a high flow velocity. When the high-speed exhaust gas passes through the connection between the rotary detonation combustion chamber 2 and the casing 1, due to the viscosity of the air, the high-speed exhaust gas will carry away the gas around the exhaust flow, thereby creating a low-pressure area around the exhaust flow. That is, a low-pressure area is generated inside the airflow ejector channel 26, and the air pressure in the area outside the airflow ejector channel 26 is relatively high. The high-pressure gas will flow to the low-pressure area. Therefore, the high-speed exhaust gas at the exhaust port of the casing 1 and the air inlet of the rotary detonation combustion chamber 2 can draw outside air into the rotary detonation combustion chamber 2 through the airflow ejector channel 26. The exhaust gas mixes with the incoming outside air, increasing the oxygen concentration of the airflow in the rotary detonation combustion chamber. Then the rotary detonation combustion chamber 2 starts fuel injection and ignition, and the afterburner is activated. Engine thrust is directly proportional to the exhaust gas flow rate from the tailpipe. As the oxygen content of combustion increases, appropriately increasing the amount of fuel will increase the amount of gas produced after combustion, thereby increasing the exhaust gas flow rate from the rotating detonation combustion chamber 2. The airflow ejector channel 26 can increase the exhaust gas flow rate at the exhaust end of the detonation combustion chamber, thus increasing the exhaust gas flow rate from the engine tailpipe, and therefore increasing the thrust during afterburning. The airflow ejection entering the rotating detonation combustion chamber 2 increases the oxygen content in the exhaust gas, enabling successful and more stable detonation combustion. This also shortens the length of the engine afterburner, reducing engine weight.
[0030] In this embodiment, the rotating detonation combustion chamber 2 includes an outer ring 21 and an inner ring 22. The outer ring 21 surrounds the outer circumference of the inner ring 22, and the outer ring 21 and inner ring 22 are coaxially arranged. The cavity between the outer ring 21 and inner ring 22 forms a combustion chamber cavity 25. In the axial direction of the outer ring 21, one end of the combustion chamber cavity 25 serves as the air inlet of the rotating detonation combustion chamber 2, and the other end of the combustion chamber cavity 25 serves as the exhaust port of the rotating detonation combustion chamber 2. Specifically, the outer ring 21 and inner ring 22 are fixedly connected together at one end of the airflow inlet by a plurality of spaced connecting rods. The plurality of spaced connecting rods are evenly distributed along the circumference of the inner ring 22, and the gaps between the connecting rods form an air intake channel. The rotary detonation combustion chamber 2 also includes an oil inlet channel 23 and a plurality of fuel nozzles 24 connected to the oil inlet channel 23. The oil inlet channel 23 includes an oil supply pipe and an annular pipe. The annular pipe surrounds the inner ring 22 and the outer ring 21 and is located at one end of the air inlet of the rotary detonation combustion chamber 2. The plurality of fuel nozzles 24 are distributed circumferentially on the annular pipe. The fuel nozzles 24 are connected to the annular pipe and are directed toward the exhaust end of the rotary detonation combustion chamber 2. The oil supply pipe passes through the side wall of the outer ring 21. The end of the oil supply pipe inside the outer ring 21 is connected to the annular pipe, and the end of the oil supply pipe outside the outer ring 21 is connected to the fuel supply system.
[0031] The inner diameter of the outer ring 21 is larger than the outer diameter of the exhaust port of the casing 1, and the air intake end of the outer ring 21 surrounds the outer periphery of the exhaust port of the casing 1. The air intake portion of the inner ring 22 is located inside the casing 1. To ensure that the air intake portions of the outer ring 21 and the inner ring 22 coincide with the casing 1, the connecting rod is spaced apart from the edges of the air intake ends of the outer ring 21 and the inner ring 22 to ensure that the casing 1 can enter the combustion chamber 25. The outer diameter of the inner ring 22 is smaller than the inner diameter of the exhaust port of the casing 1. The gap between the air intake end of the outer ring 21 and the side wall of the exhaust port of the casing 1 forms an airflow ejection channel 26. The airflow ejection channel 26 of this application faces the incoming direction of the external airflow, which can increase the amount of external air entering the rotating detonation combustion chamber 2.
[0032] In other embodiments, the diameter of the air inlet of the outer ring 21 can be the same as the diameter of the exhaust port of the casing 1, and the two ports can be connected. Multiple small holes distributed circumferentially are opened on the side wall of the air inlet end of the outer ring 21, or multiple small holes distributed circumferentially are opened on the side wall of the casing 1 at the exhaust end of the casing 1, or multiple small holes distributed circumferentially are opened at the junction of the outer ring 21 and the casing 1 to form an airflow ejection channel 26. Such an airflow ejection channel is not directly facing the airflow direction, but the high-speed exhaust gas discharged from the turbine 13 can draw outside air into the detonation combustion chamber through the small holes, so that the exhaust gas discharged from the turbine 13 and the outside air are mixed at the inlet position of the rotating detonation combustion chamber 2.
[0033] In this embodiment, the rotary detonation afterburner further includes an ejector control switch 3, which is installed on the exhaust end of the casing 1 and / or the intake end of the rotary detonation combustion chamber 2. The ejector control switch 3 controls the opening and closing of the airflow ejection channel 26. When the rotary detonation afterburner needs to be activated, the ejector control switch 3 opens, and the high-speed exhaust gas from the turbine 13 outlet draws outside air into the rotary detonation combustion chamber 2, mixes with the exhaust gas, and increases the oxygen concentration in the airflow. Then, the rotary detonation combustion chamber 2 begins fuel injection and ignition, activating the afterburner state. When the afterburner state is deactivated, the ejector control switch 3 closes the airflow ejection channel 26, and the engine no longer draws outside air into the rotary detonation combustion chamber 2.
[0034] like Figure 2 and Figure 3 As shown in the embodiment of this application, the ejector control switch 3 includes multiple adjusting plates 31 and multiple driving mechanisms. The multiple adjusting plates 31 surround the outer wall of the exhaust end of the casing 1. One end of the adjusting plate 31 is rotatably connected to the outer wall of the exhaust end of the casing 1, and the other end of the adjusting plate 31 is a free end 32. The edge of the free end 32 matches the inner wall of the outer ring 21. The driving mechanism is mounted on the casing 1. The output end of the driving mechanism is connected to the adjusting plate 31 and drives the adjusting plate 31 to rotate, so that the free end 32 moves away from the casing 1 and abuts against the inner wall of the outer ring 21 or approaches the casing 1. When the free end 32 abuts against the inner wall of the outer ring 21, the edge of the free end 32 fits against the inner wall of the outer ring 21, and the adjacent edges of adjacent adjusting plates 31 overlap or align with each other, so that the multiple adjusting plates 31 form a continuous structure that closes the airflow ejection channel 26.
[0035] In one embodiment, when the free end 32 abuts against the inner wall of the outer ring 21, the end of the adjusting plate 31 connected to the housing 1 is closer to the engine's air intake than the free end 32. This causes the ejector control switch 3 to be tilted relative to the engine axis when it is in the closed state, reducing the resistance of the ejector control switch 3.
[0036] In other embodiments, when the free end 32 abuts against the inner wall of the outer ring 21, the adjusting piece 31 may also be perpendicular to the engine axis direction, that is, forming an annular ring.
[0037] The drive mechanism includes an actuator (not shown in the figure), which is closer to the engine's air intake than the adjusting plate 31. The housing of the actuator is rotatably mounted on the casing 1, and the telescopic shaft of the actuator is rotatably connected to the side of the adjusting plate 31. When the telescopic shaft of the actuator extends, it pushes the adjusting plate 31 to rotate, causing the free end 32 of the adjusting plate 31 to press against the side wall of the casing 1. The angle between the adjusting plate 31 and the engine axis gradually decreases, and the airflow ejection channel 26 opens. When the telescopic shaft of the actuator retracts, it moves the free end 32 of the adjusting plate 31 away from the side wall of the casing 1, and the free end 32 of the adjusting plate 31 moves closer to the outer ring 21 until it abuts against the outer ring 21, closing the airflow ejection channel 26.
[0038] The outer diameter of the inner ring 22 near the exhaust port gradually decreases along the airflow direction. The inner ring 22 has a constant diameter section and a tapered section distributed along the airflow direction. The constant diameter section is connected to the end of the exhaust port of the casing 1, and the outer diameter of the tapered section gradually decreases along the airflow direction.
[0039] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A rotating detonation afterburner for an aero-engine, characterized in that, The system includes a rotating detonation combustion chamber connected to the exhaust end of the engine casing. The air inlet of the rotating detonation combustion chamber is connected to the exhaust port of the engine casing. An airflow ejection channel is provided on the exhaust end of the engine casing and / or the air inlet of the rotating detonation combustion chamber. The airflow ejection channel connects the internal space and the external space of the air inlet of the rotating detonation combustion chamber. When the exhaust gas from the engine exhaust end passes through the air inlet of the detonation combustion chamber, it introduces the air from the external space of the connection between the rotating detonation combustion chamber and the engine casing into the rotating detonation combustion chamber through the airflow ejection channel. The rotating detonation combustion chamber includes an outer ring and an inner ring. The outer ring surrounds the outer circumference of the inner ring, and the cavity between the outer ring and the inner ring forms a combustion chamber cavity. In the axial direction of the outer ring, one end of the combustion chamber cavity serves as the air inlet of the rotating detonation combustion chamber, and the other end of the combustion chamber cavity serves as the exhaust port of the rotating detonation combustion chamber. The inner diameter of the outer ring is larger than the outer diameter of the exhaust port of the casing, and the air inlet end of the outer ring surrounds the outer circumference of the exhaust end of the casing. The gap between the sidewall of the air inlet end of the outer ring and the exhaust end of the casing forms an airflow ejection channel.
2. The rotating detonation afterburner of an aero-engine according to claim 1, characterized in that, The rotary detonation afterburner also includes an ejector control switch, which is installed on the exhaust end of the casing and / or the air intake end of the rotary detonation combustion chamber. The ejector control switch controls the closure and opening of the airflow ejection channel.
3. The rotating detonation afterburner of an aero-engine according to claim 2, characterized in that, The ejector control switch includes multiple adjusting plates and multiple driving mechanisms. The multiple adjusting plates are surrounded on the outer wall of the exhaust end of the casing. One end of the adjusting plate is rotatably connected to the outer wall of the exhaust end of the casing, and the other end of the adjusting plate is a free end. The edge of the free end matches the inner wall of the outer ring. The driving mechanism is mounted on the casing. The output end of the driving mechanism is connected to the adjusting plate and drives the adjusting plate to rotate, so that the free end moves away from the casing and abuts against or approaches the inner wall of the outer ring. When the free end abuts against the inner wall of the outer ring, the edge of the free end fits against the inner wall of the outer ring, and the adjacent edges of the adjacent adjustment pieces overlap or align with each other, so that the multiple adjustment pieces form a continuous structure that closes the airflow ejection channel.
4. The rotating detonation afterburner of an aero-engine according to claim 3, characterized in that, When the free end abuts against the inner wall of the outer ring, the end of the adjusting plate connected to the casing is closer to the air intake of the engine than the free end.
5. The rotating detonation afterburner of an aero-engine according to claim 3, characterized in that, The drive mechanism includes an actuator cylinder, which is closer to the engine's air intake than the adjusting plate. The housing of the actuator cylinder is rotatably mounted on the casing, and the telescopic shaft of the actuator cylinder is rotatably connected to the side of the adjusting plate.
6. The rotating detonation afterburner of an aero-engine according to claim 1, characterized in that, The outer ring and the inner ring are coaxially arranged, and the outer diameter of the end of the inner ring near the air outlet gradually decreases along the airflow direction.