An inner and outer flame combination device and an afterburner having the same

Abstract

The present invention provides an inner and outer sump flame combination device, including a first diverter ring, a second diverter ring, a guide ring, a sealing ring, a mixing chamber, an oil injection ring and a trailing edge. The present invention utilizes the first airflow channel between the first diverter ring and the second diverter ring to allow the outer sump air to enter the mixing chamber and mix with the inner combustion gas, and utilizes the oil injection ring disposed in the mixing chamber to spray oil to form an oil-gas mixture that is easy to burn. The oil-gas mixture is then ignited by the flame stabilizer at the rear of the mixing chamber, thereby achieving inner and outer sump staged combustion of the outer sump air, greatly reducing the difficulty of outer sump organization combustion of an adaptive cycle engine in a large bypass ratio mode. In addition, the present invention also utilizes an axially movable sealing ring to achieve continuous control of the flow area of ​​the first airflow channel, thereby meeting the variable cycle engine's demand for adjusting the outer sump area in different working modes. The present invention also provides an afterburner having the inner and outer sump flame combination device.

Description

Technical Field

[0001] The present application relates to the technical field of afterburner combustion chambers for adaptive variable cycle engines, and in particular to an inner and outer flame-linking device and an afterburner combustion chamber having the inner and outer flame-linking device. Background Art

[0002] The adaptive cycle engine is a very promising future aircraft power plant that can change the bypass ratio and fan pressure ratio according to different working conditions and requirements, thereby achieving high performance in a wide flight envelope. The operating characteristics of the adaptive cycle engine require that its afterburner chamber can achieve low flow resistance, efficient ignition, and efficient joint flame of the inner and outer bypass within a large range of bypass ratio changes.

[0003] The adaptive cycle engine is a variable cycle engine. General Electric conducted research on variable cycle aircraft engines in the last century and proposed many configurations. Their summary report "Variable Cycle Engine Developments at General Electric-1955-1995" was published in AIAA (American Institute of Aeronautics and Astronautics). In the early 21st century, the US Air Force launched the VAATE (Versatile, Affordable Advanced Turbine Engine) program to verify the adaptive cycle engine. In 2007, the US Air Force and General Electric launched the ADVENT (Adaptive Versatile Engine Technology Research) program. As a continuation, the AETD (Adaptive Engine Technology Development) program was launched in 2013, with the goal of developing adaptive cycle engines to power the next generation of fighters.

[0004] In order to adapt to a wide range of working conditions, the adaptive cycle engine has multiple working modes, and the bypass ratio will change over a wide range. For example, the adaptive cycle engine proposed in US Patent (US20120131902A1) has a bypass ratio variation range of 0.2-1. Therefore, the afterburner of the adaptive cycle engine faces the technical problems of difficulty in organizing combustion of the outer bypass at a large bypass ratio and difficulty in adjusting the outer bypass flow area when the bypass ratio changes over a wide range. Summary of the invention

[0005] In view of this, the present invention provides an inner and outer sump combined flame device and an afterburner having the inner and outer sump combined flame device, by segmenting the diverter ring of the traditional afterburner, a first airflow channel from the outer sump to the inner sump is constructed, and the area of ​​the first airflow channel is adjusted by controlling the axial translation of the sealing ring to match different working modes of the adaptive cycle engine. Therefore, the present invention introduces part of the outer sump gas through the first airflow channel to mix and burn with the inner sump, reduces the difficulty of the afterburner outer sump to organize combustion under the large bypass ratio mode, and improves the overall working efficiency of the afterburner.

[0006] In one aspect of the present invention, there is provided an inner and outer flame device, comprising:

[0007] A first shunt ring is separated between the outer region and the inner region;

[0008] a second flow-dividing ring, arranged at intervals on the axial rear side of the first flow-dividing ring and separated between the outer region and the inner region; and

[0009] A mixing chamber, located in the inner region and arranged at intervals on the radial inner side of the second flow dividing ring;

[0010] Wherein, a first airflow channel from the outer region to the inner region is formed between the first flow dividing ring and the second flow dividing ring, and the mixing chamber is connected to the outlet end of the first airflow channel, so that the outer air of the outer region enters the interior of the mixing chamber through the first airflow channel;

[0011] And wherein, a second air flow channel is formed between the mixing chamber and the first flow dividing ring, so that the contained gas in the contained area enters the interior of the mixing chamber through the second air flow channel.

[0012] Preferably, the inner and outer flame combining device further comprises:

[0013] The airflow control device is arranged on at least one of the first splitter ring, the second splitter ring and the mixing chamber, and is configured to adjust the flow area of ​​the first airflow channel to control the flow rate of the external air entering the internal area from the first airflow channel.

[0014] Preferably, the airflow control device comprises:

[0015] a sealing ring, movably disposed on the radially outer side of the first flow dividing ring and capable of axially moving toward the second flow dividing ring to adjust the flow area of ​​the first air flow channel; and

[0016] The actuating device is configured to drive the sealing ring to move.

[0017] Preferably, the second diverter ring comprises:

[0018] The inner wall of the flow dividing ring is arranged perpendicular to the radial direction and radially outside the mixing chamber;

[0019] A front wall of the splitter ring extends obliquely outward and forward from the front end of the inner wall of the splitter ring to the outer cladding area, and forms the first airflow channel with the rear end of the first splitter ring; and

[0020] The outer wall of the diverter ring extends obliquely inwardly and rearwardly from the outer end of the front wall of the diverter ring to the rear end of the inner wall of the diverter ring.

[0021] Preferably, the inner and outer flame combining device further comprises:

[0022] The guide ring is fixedly arranged on the second diverter ring and extends forward from the outer end of the front wall of the diverter ring.

[0023] Preferably, the inclination angle of the front wall of the diverter ring relative to the inner wall of the diverter ring is in the range of 5° to 60°, so that the difference between the static pressure of the external air entering the internal area from the first airflow channel and the static pressure of the internal gas in the internal area does not exceed the set pressure difference.

[0024] Preferably, the projection of the outer wall of the diverter ring on the cross section perpendicular to the circumferential direction is a straight line structure, and the inclination angle of the outer wall of the diverter ring relative to the inner wall of the diverter ring is in the range of 3° to 30°, so that the external air flowing through the outer wall of the diverter ring does not produce airflow separation; or

[0025] The projection of the outer wall of the diverter ring on the section perpendicular to the circumferential direction is a curved structure with a gradually increasing expansion angle, that is, the outer wall of the diverter ring adopts an isobaric gradient design so that the static pressure change rate of the external air flowing through the outer wall of the diverter ring is a constant with the flow direction.

[0026] Preferably, the ratio of the flow area of ​​the first airflow channel to the outer flow area at the inlet of the guide ring is constructed so that the percentage of outer air entering the inner area from the first airflow channel is in the range of 5% to 65%, wherein the length of the guide ring is in the range of 1 to 16 cm.

[0027] Preferably, the ratio of the flow area of ​​the second airflow channel to the flow area of ​​the first airflow channel is configured as follows: when the first airflow channel is at the maximum design air intake volume, the temperature of the mixed gas after the internal combustion gas entering the mixing chamber from the second airflow channel and the external combustion air entering the mixing chamber from the first airflow channel is mixed is not lower than the ignition point temperature of the fuel.

[0028] Preferably, the mixing chamber comprises:

[0029] An inner wall of the mixing chamber is arranged perpendicular to the radial direction and radially inward of the second flow dividing ring;

[0030] a mixing chamber front wall extending obliquely outward and forward from the front end of the mixing chamber inner wall and forming the second air flow channel with the rear end of the first flow dividing ring; and

[0031] The mixing chamber rear wall extends obliquely outward and rearward from the rear end of the mixing chamber inner wall.

[0032] Preferably, the mixing chamber further comprises:

[0033] The trailing edge is fixedly arranged on the rear wall of the mixing chamber and extends backward from the outer end of the rear wall of the mixing chamber.

[0034] Preferably, the inclination angle of the front wall of the mixing chamber relative to the inner wall of the mixing chamber is in the range of 5° to 60°, so that the contained combustion gas flowing through the front wall of the mixing chamber does not produce airflow separation.

[0035] Preferably, the inner and outer flame combining device further comprises:

[0036] The oil injection ring is arranged in a circumferential manner inside the mixing chamber and close to the inner wall of the mixing chamber. The distance between the oil injection ring and the inner wall of the mixing chamber is 1 to 10 cm.

[0037] In another aspect of the present invention, an afterburner is provided, comprising the inner and outer flame cascade device according to any one of the foregoing embodiments.

[0038] Preferably, the afterburner chamber further comprises:

[0039] outer cylinder;

[0040] A central cone, arranged on the central axis of the outer cylinder;

[0041] an integrated support plate, which passes through the mixing chamber and the second flow dividing ring and is connected between the outer cylinder and the central cone, and is provided with a plurality of first oil injection holes; and

[0042] The radial stabilizer is arranged on the inner side of the outer cylinder and is located axially rearward of the second flow divider ring, and is provided with a plurality of second oil injection holes.

[0043] Preferably, the afterburner chamber further comprises:

[0044] The variable outer duct area ejector is arranged at the axial rear end of the second diverter ring and can move axially to change the flow area of ​​the outer duct area.

[0045] In summary, the present invention realizes staged mixing and staged combustion in the afterburner by constructing an adjustable-area outer duct intake slit on the diverter ring; by providing a movable sealing ring and an actuator, the sealing ring can axially translate according to aerodynamic requirements to change the flow area of ​​the first airflow channel; by uniformly mixing the inner combustion gas, outer duct air and fuel in the mixing chamber, an easily ignitable oil-gas mixture is formed; and by forming a low-speed recirculation zone through the sudden expansion at the rear of the mixing chamber, the oil-gas mixture ejected from the slit at the rear of the mixing chamber is better ignited.

[0046] Based on this, the present invention has at least one of the following advantages:

[0047] 1. Staged mixing and staged combustion are conducive to reducing the length of the afterburner, and greatly reduce the difficulty of external mixing and organizing combustion at a large bypass ratio;

[0048] 2. The flow area of ​​the first airflow channel is controlled by the axial translation of the sealing ring, which relatively simply realizes the outer duct area adjustment requirement of the adaptive cycle engine, and can be used in combination with other outer duct area adjustment devices;

[0049] 3. Introducing high-temperature inner air in the front of the mixing chamber to heat the outer air, effectively reducing the difficulty of ignition of the outer air;

[0050] 4. The sudden expansion at the rear of the mixing chamber enhances the mixing effect of the mixing chamber with a simple structure, and can also serve as an ignition source for the oil-gas mixture ejected from the rear. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The accompanying drawings are used to provide a further understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application, but do not constitute a limitation on the technical solution of the present application.

[0052] Figure 1 A schematic cross-sectional structure diagram of an inner and outer flame-linking device provided by the present invention on a cross section perpendicular to the circumferential direction;

[0053] Figure 2 A schematic diagram of the three-dimensional structure of an inner and outer flame-linking device provided by the present invention;

[0054] Figure 3 A schematic diagram of the cross-sectional structure of the inner and outer flame combined device provided by the present invention in a state of maximum air intake area on a cross section perpendicular to the circumferential direction;

[0055] Figure 4 A schematic diagram of the cross-sectional structure of the inner and outer flame-linking device provided by the present invention in a state of minimum air intake area on a cross section perpendicular to the circumferential direction;

[0056] Figure 5A schematic diagram of the working mode of the afterburner chamber with inner and outer bypass flame devices provided by the present invention when the adaptive cycle engine is at the maximum bypass ratio;

[0057] Figure 6 A schematic diagram of the working mode of the afterburner combustion chamber with inner and outer bypass flame devices provided by the present invention when the adaptive cycle engine is at the minimum bypass ratio.

[0058] Reference numerals:

[0059] 1- the first diversion ring;

[0060] 2-second diverter ring; 21-inner wall of diverter ring; 22-front wall of diverter ring; 23-outer wall of diverter ring;

[0061] 3-mixing chamber; 31-inner wall of the mixing chamber; 32-front wall of the mixing chamber; 33-rear wall of the mixing chamber;

[0062] 4- Sealing ring;

[0063] 5- guide ring;

[0064] 6- tail edge;

[0065] 7-Injection ring;

[0066] 81-outer cylinder; 82-center cone; 83-integrated support plate; 831-first injection hole; 84-radial stabilizer; 841-second injection hole; 85-variable outer area ejector;

[0067] a-external area; a1-external air; b-internal area; b1-internal gas;

[0068] c1-first air flow channel; c2-second air flow channel. DETAILED DESCRIPTION

[0069] Various exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is not intended to be any limitation on the present invention and its application or use. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present invention clear and complete and to fully express the scope of the present invention to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps described in these embodiments should be interpreted as being merely exemplary and not as a limitation.

[0070] like Figures 1 to 4As shown, in one aspect of the present invention, there is provided an inner and outer flame device, which includes a first diverter ring 1 separated between an outer region a and an inner region b, a second diverter ring 2 arranged at intervals on the axial rear side of the first diverter ring 1 and separated between the outer region a and the inner region b, and a mixing chamber 3 located in the inner region b and arranged at intervals on the radial inner side of the second diverter ring 2.

[0071] The first flow dividing ring 1 and the second flow dividing ring 2 form a first air flow channel c1 from the outer region a to the inner region b, and the mixing chamber 3 is connected to the outlet end of the first air flow channel c1, so that the outer air a1 enters the interior of the mixing chamber 3 through the first air flow channel c1;

[0072] A second air flow channel c2 is formed between the mixing chamber 3 and the first flow dividing ring 1 , so that the gas in the inner region b enters the interior of the mixing chamber 3 through the second air flow channel c2 .

[0073] like Figure 1 , Figure 2 As shown, under the connection of the first air flow channel c1, part of the external air a1 will enter the internal area b from the annular gap between the first flow splitter ring 1 and the second flow splitter ring 2, and will be received by the mixing chamber 3 located at the outlet end of the first air flow channel c1. At the same time, part of the internal combustion gas b1 will enter between the mixing chamber 3 and the second flow splitter ring 2 from the second air flow channel c2, and will be mixed with the external air a1 in the mixing chamber 3.

[0074] Thus, through the first airflow channel c1, the second airflow channel c2 and the mixing chamber 3, the present invention introduces part of the outer air a1 into the mixing chamber 3 of the inner region b, and mixes with the inner gas b1 for fuel injection combustion, thereby utilizing the high temperature characteristics of the inner gas b1 and the high oxygen content characteristics of the outer air a1 to make the temperature and oxygen ratio of the mixed gas in the mixing chamber 3 more suitable for organizing combustion. And because part of the outer air a1 is led away from the outer region a, the remaining outer air a1 will have a lower speed and a smaller flow rate, which is more conducive to fuel injection combustion in the outer region a.

[0075] It should be noted that the idea of ​​the present invention is to introduce part of the external air a1 into the mixing chamber 3 of the internal area b to fully mix it with the internal combustion gas b1, so that both the internal area b and the external area a can be more easily organized for afterburning. Figure 1 The first airflow channel c1 shown is composed of an annular gap between a first diverter ring 1 and a second diverter ring 2 which are spaced apart. However, for those skilled in the art, the first airflow channel c1 may also adopt other structural forms and opening positions, such as opening a hole or installing an air duct on the diverter ring, or segmenting the diverter ring with other cross-sectional shapes or numbers of segments. The concept of the present invention can be realized by only realizing staged combustion of the external air.

[0076] In a preferred embodiment, the inner and outer flame combining device also includes an airflow control device, which is arranged on at least one of the first diverter ring 1, the second diverter ring 2 and the mixing chamber 3, and is configured to adjust the flow area of ​​the first airflow channel c1 to control the flow rate of the outer air a1 entering the inner region b from the first airflow channel c1.

[0077] The structural form of the airflow control device corresponds to the structural form of the first airflow channel c1. If the first airflow channel c1 adopts the structural form of an opening on the diverter ring, the airflow control device can adopt the structural form of a sleeve, and utilize the axial or circumferential movement of the sleeve relative to the diverter ring to cover the opening; if the first airflow channel c1 adopts the structural form of an air duct, the airflow control device can adopt the structural form of a flow valve, which is arranged inside the air duct or at the inlet and outlet ends to control the size of the airflow.

[0078] In the present invention, since the first airflow channel c1 is formed between the first diverter ring 1 and the second diverter ring 2, and the mixing chamber 3 is connected to the outlet end of the first airflow channel c1, the airflow control device can be selectively arranged on the physical structure around the first airflow channel c1, that is, the airflow control device can be arranged on at least one of the first diverter ring 1, the second diverter ring 2 and the mixing chamber 3.

[0079] The setting of the airflow control device makes the intake area from the outer area a to the inner area b adjustable, so as to better adapt to the outer area adjustment requirements of the adaptive cycle engine under different working modes, and cooperate with other forms of outer area adjustment devices, such as the variable outer area ejector 85 set at the axial rear end of the second diverter ring 2, to increase the adjustable range of the outer area.

[0080] For Figure 1 , Figure 2 In the first air inlet channel of the annular slit structure shown in the figure, in a preferred embodiment, the airflow control device comprises a sealing ring 4 and an actuating device. The sealing ring 4 is movably arranged on the radially outer side of the first flow dividing ring 1 and can be moved axially toward the second flow dividing ring 2 to adjust the flow area of ​​the first airflow channel c1. The actuating device is configured to drive the sealing ring 4 to move.

[0081] In the above embodiment, the structure of the annular sealing ring 4 is simpler, the processing difficulty is lower, and the structural reliability is higher. The sealing ring 4 is arranged on the radial outer side of the first diverter ring 1. On the one hand, the first diverter ring 1 can be used to bear the pressure from the outer region a to the inner region b on the sealing ring 4. On the other hand, the lower temperature outer region air a1 can be used to reduce the working temperature of the sealing ring 4 and increase the service life of the sealing ring 4. The actuator is used to drive the axial movement of the sealing ring 4. It can use a hydraulically driven or pneumatically driven actuator cylinder, and the actuator preferably has multiple actuators that are evenly distributed at equal angles on the outer side of the sealing ring 4, so that the driving force of the actuator on the sealing ring 4 is more evenly distributed, reducing the force deformation of the sealing ring 4.

[0082] Figure 3 and Figure 4 The schematic diagrams of the cross-sectional structure of the inner and outer flame devices provided by the present invention in the state of maximum air intake area and the state of minimum air intake area are respectively shown on the cross section perpendicular to the circumferential direction. Figure 3 , 4 As shown, based on the airflow control device composed of the sealing ring 4 and the actuator, when the bypass ratio of the adaptive cycle engine increases, the sealing ring 4 can move in the direction of increasing the area of ​​the outer duct intake slit to ensure the static pressure balance of the inner and outer ducts; when the bypass ratio of the adaptive cycle engine decreases, the sealing ring 4 can move in the direction of reducing the area of ​​the outer duct intake slit to ensure the static pressure balance of the inner and outer ducts.

[0083] When the adaptive cycle engine only uses the inner and outer spool flame combination device provided by the present invention to adjust the outer spool area, Figure 3 The outer duct intake area when the sealing ring 4 is fully opened corresponds to the maximum outer duct intake area of ​​the adaptive cycle engine, as shown in FIG. Figure 4 The outer duct air intake area when the sealing ring 4 is fully closed corresponds to the minimum outer duct air intake area of ​​the adaptive cycle engine. Therefore, the maximum area of ​​the first air flow channel c1 corresponds to the maximum adjustable range of the outer duct air intake area of ​​the adaptive cycle engine.

[0084] When the inner and outer flame combining device and other outer area adjusting device provided by the present invention are combined, for example, Figure 5 and Figure 6When the variable outer shroud area ejector 85 shown in the figure is used in combination to control the outer shroud air intake area of ​​the adaptive cycle engine, the adjustable range of the outer shroud air intake area of ​​the adaptive cycle engine is the sum of the adjustable area ranges of the inner and outer shroud flame combination device and other outer shroud area adjustment devices. In addition, considering the difference in axial positions of the inner and outer shroud flame combination device and other outer shroud area adjustment devices, the same outer shroud air intake area may have different intake flow rates due to different inner and outer shroud static pressure differences. Therefore, the mutual matching of the control rules of the inner and outer shroud flame combination device and other outer shroud area adjustment devices also needs to consider the static pressure differences at different axial positions to better meet the working mode requirements of the adaptive cycle engine.

[0085] like Figure 1 As shown, in a preferred embodiment, the second diverter ring 2 is composed of a diverter ring inner wall 21, a diverter ring front wall 22 and a diverter ring outer wall 23. The diverter ring inner wall 21 is arranged perpendicular to the radial direction on the radially outer side of the mixing chamber 3; the diverter ring front wall 22 extends obliquely outward and forward from the front end of the diverter ring inner wall 21 to the outer culvert area a, and forms a first air flow channel c1 with the rear end of the first diverter ring 1; and the diverter ring outer wall 23 extends obliquely inward and backward from the outer end of the diverter ring front wall 22 to the rear end of the diverter ring inner wall 21. Therefore, on a cross section perpendicular to the circumferential direction, the diverter ring inner wall 21, the diverter ring front wall 22 and the diverter ring outer wall 23 enclose an obtuse triangle, the obtuse vertex of which is located at the intersection of the diverter ring inner wall 21 and the diverter ring front wall 22.

[0086] In a preferred embodiment, the inner and outer sump combined flame device further comprises a guide ring 5, which is fixedly arranged on the second diverter ring 2 and extends forward from the outer end of the diverter ring front wall 22. The arrangement of the guide ring 5 can improve the air intake capacity of the outer sump air a1 into the first air flow channel c1.

[0087] The following combination Figure 1 , on a cross section perpendicular to the circumferential direction, each wall structure of the second diverter ring 2 and its corresponding aerodynamic effect are specifically described.

[0088] The inner wall 21 of the flow dividing ring and the guide ring 5

[0089] The inner wall 21 of the second flow dividing ring 2 is arranged axially with the first flow dividing ring 1 and spaced apart from each other, so that the gap between the two forms the first airflow channel c1 and together plays the role of dividing the inner region b and the outer region a.

[0090] The amount of external air intake from the first airflow channel c1 into the inner region b is affected by the flow area of ​​the first airflow channel c1, the extension length of the guide ring 5, and the ratio of the area of ​​the first airflow channel c1 to the area of ​​the second airflow channel c2. Based on this, in a preferred embodiment, the ratio of the flow area of ​​the first airflow channel c1 to the external airflow area at the guide ring 5 is constructed so that the maximum amount of external air a1 entering the inner region b from the first airflow channel c1 accounts for 5% to 65% of the total air volume of the external air region a. Among them, the guide ring 5 plays a role in rectification, and its length can be selected in the range of 1 to 16 cm. This enables the internal and external flame combination device of the present invention to distribute airflow more appropriately and flexibly, so that the technical difficulty of organizing afterburner combustion is reduced in the process of staged mixing and staged combustion in the afterburner.

[0091] In conjunction with this, considering the mixing process of the internal gas b1 and the external air a1 in the mixing chamber 3, in a preferred embodiment, the proportion of the internal gas b1 in the mixed gas should be ensured. The ratio of the flow area of ​​the second air flow channel c2 to the flow area of ​​the first air flow channel c1 will simultaneously affect the intake flow rate of the first air flow channel c1 and the intake flow rate of the second air flow channel c2, thereby affecting the state parameters of the mixed gas. This ratio depends on the gas state parameters of the external air a1, the gas state parameters of the internal gas b1 and the maximum design intake volume parameters of the first air flow channel c1. The present invention can flexibly adjust the combination of these parameters under different working conditions, so that the temperature of the mixed gas is not lower than the ignition point temperature of the fuel when the first air flow channel c1 is at the maximum design intake volume.

[0092] Diverter ring front wall 22

[0093] The splitter ring front wall 22 of the second splitter ring 2 extends obliquely forward and outward relative to the splitter ring inner wall 21 to the outer shroud area a, thereby guiding a portion of the outer shroud air a1 to flow into the first air flow channel c1 along the splitter ring front wall 22 .

[0094] Among them, the angle between the front wall 22 of the diverter ring and the inner wall 21 of the diverter ring should be controlled in the range of 5° to 60°. When the angle between the front wall 22 of the diverter ring and the inner wall 21 of the diverter ring is greater than 60°, the airflow entering the first airflow channel c1 will have serious aerodynamic losses due to the excessive angle deflection, and will also increase the axial force from the airflow received by the second diverter ring 2; and when the angle between the front wall 22 of the diverter ring and the inner wall 21 of the diverter ring is less than 5°, the external air a1 entering the first airflow channel c1 will easily be difficult to be received by the mixing chamber 3 due to insufficient turning angle, and will directly flow out from between the mixing chamber 3 and the inner wall 21 of the diverter ring of the second diverter ring 2, resulting in poor mixing effect.

[0095] Furthermore, in a preferred embodiment, the inclination angle of the front wall 22 of the splitter ring relative to the inner wall 21 of the splitter ring is configured such that the difference between the static pressure of the air entering the inner region b from the first airflow channel c1 and the static pressure of the gas in the inner region b does not exceed the set pressure difference. It should be understood that since the front wall 22 of the splitter ring is located in front of the flow direction of the outer air a1, its obstruction to the outer air a1 will cause the velocity loss of the outer air a1, thereby causing the dynamic pressure of the outer air a1 entering the first airflow channel c1 to decrease and the static pressure to increase. If the static pressure difference between the inner region b and the outer region a inside and outside the first airflow channel c1 is too large, it will cause a large mixing loss.

[0096] Back wall of shunt ring

[0097] The mixing chamber rear wall 33 of the second diverter ring 2 extends obliquely outward and backward from the rear end of the mixing chamber inner wall 31. Part of the external air a1 that has not entered the internal area b will re-occupy the entire space of the external area a under the guidance of the diverter ring rear wall. Therefore, the angle between the mixing chamber rear wall 33 and the mixing chamber inner wall 31 should not be too large, exceeding 30°, so as to prevent the external air a1 from undergoing airflow separation at the mixing chamber rear wall 33, which in turn leads to adverse effects such as reduced aerodynamic stability, increased flow losses, and even structural damage.

[0098] Therefore, the rear wall of the diverter ring can preferably be designed with a small inclination angle or an isobaric gradient design.

[0099] Among them, for the design with a small inclination angle, the projection of the outer wall 23 of the diverter ring on the cross section perpendicular to the circumferential direction is a straight line structure, and the inclination angle of the outer wall 23 of the diverter ring relative to the inner wall 21 of the diverter ring is selected within the range of 3° to 30°: this can ensure that the external air a1 flowing through the outer wall 23 of the diverter ring does not produce airflow separation. At this time, the inclination angle of the outer wall 23 of the diverter ring relative to the inner wall 21 of the diverter ring is preferably not more than 12°.

[0100] For the isobaric gradient design, the projection of the outer wall 23 of the flow divider ring on the cross section perpendicular to the circumferential direction is a curved structure with a gradually increasing expansion angle, so that the static pressure change rate of the outer air a1 flowing through the outer wall 23 of the flow divider ring is a constant along the axial direction, that is, In the isobaric gradient design, the static pressure gradients are equal at all locations, giving full play to the deceleration and pressurization effects of the front and rear sections, which is beneficial to preventing excessive pressure gradients in local areas and preventing local airflow separation.

[0101] like Figure 1As shown, in a preferred embodiment, the mixing chamber 3 includes a mixing chamber inner wall 31, a mixing chamber front wall 32 and a mixing chamber rear wall 33. The mixing chamber inner wall 31 is arranged perpendicular to the radial direction on the radial inner side of the second flow dividing ring 2; the mixing chamber front wall 32 extends obliquely outward and forward from the front end of the mixing chamber inner wall 31, and forms a second air flow channel c2 with the rear end of the first flow dividing ring 1; and the mixing chamber rear wall 33 extends obliquely outward and backward from the rear end of the mixing chamber inner wall 31.

[0102] Thus, the mixing chamber inner wall 31, the mixing chamber front wall 32 and the mixing chamber rear wall 33 together constitute a cavity structure that is opened radially outward, which together with the diverter ring inner wall 21 of the second diverter ring 2 forms a cavity structure that is open only at the front and rear ends axially, for achieving mixing of the external air a1 entering from the first air flow channel c1 and the internal air entering from the second air flow channel c2.

[0103] like Figure 1 As shown, in the cross section perpendicular to the circumferential direction, the mixing chamber 3 is given a certain radial depth by the mixing chamber front wall 32 and the mixing chamber rear wall 33, so that the cross-sectional shape of the mixing chamber 3 is similar to a concave bowl-shaped structure. This bowl-shaped structure with a certain depth can not only better receive the external air a1 that flows backward and downward by the diverter ring front wall 22, but also can use its own depth to provide more sufficient mixing space for the external air a1 and the internal combustion gas b1, thereby improving the mixing effect in the mixing chamber 3.

[0104] In a preferred embodiment, the mixing chamber 3 further comprises a trailing edge 6 , which is fixedly disposed on the mixing chamber rear wall 33 and extends backward from the outer end of the mixing chamber rear wall 33 .

[0105] The following combination Figure 1 , on a cross section perpendicular to the circumferential direction, each wall structure of the mixing chamber 3 and its corresponding aerodynamic effect are specifically described.

[0106] Mixing chamber inner wall 31

[0107] The mixing chamber inner wall 31 extends axially, and its axial length determines the axial size of the mixing chamber 3. The axial length mainly depends on the amount of external air entering from the first air flow channel c1. If the axial length of the mixing chamber inner wall 31 is too small, it is easy to cause insufficient mixing of the external air a1 and the internal combustion gas b1 in the mixing chamber 3; and if the axial length of the mixing chamber inner wall 31 is too large, it will cause unnecessary weight burden.

[0108] Mixing chamber front wall 32

[0109] The mixing chamber front wall 32 extends outward and forward from the axial front end of the mixing chamber inner wall 31, and the front end of the mixing chamber front wall 32 and the rear end of the first flow dividing ring 1 form a second airflow channel c2, so its extension length not only affects the flow rate of the internal combustion gas b1 entering the mixing chamber 3, but also affects the radial depth of the mixing chamber 3. In addition, the internal combustion gas b1 entering the mixing chamber 3 will have a tendency to flow along the inner side of the mixing chamber front wall 32, so in a preferred embodiment, the inclination angle of the mixing chamber front wall 32 relative to the mixing chamber inner wall 31 is 3° to 36°: so that the internal combustion gas b1 flowing through the mixing chamber front wall 32 does not produce airflow separation.

[0110] The mixing chamber rear wall 33 and the trailing edge 6

[0111] like Figure 1 As shown, the mixing chamber rear wall 33 can produce a certain blocking effect on the mixed gas in the mixing chamber 3, thereby accelerating the mixing process in the mixing chamber 3. At the same time, under the semi-enclosure of the mixing chamber rear wall 33 and the trailing edge 6, a sudden expansion structure will appear in the axial rear of the mixing chamber 3, thereby generating a stable reflux area. The internal combustion gas b1 entering the reflux area has a slow flow speed, so it can be used as a stable high-temperature ignition source to ignite the oil-gas mixture ejected from the rear of the mixing chamber 3.

[0112] The inclination angle and size of the mixing chamber rear wall 33 and the trailing edge 6 need to be optimized in consideration of the flame stabilization capability and the degree of flow blockage in the mixing chamber 3 .

[0113] like Figure 1 As shown, in a preferred embodiment, the inner and outer sump combined flame device further includes an oil injection ring 7, which is disposed circumferentially inside the mixing chamber 3 and close to the inner wall 31 of the mixing chamber, and the distance between the oil injection ring 7 and the inner wall 31 of the mixing chamber is preferably 1 to 10 cm. The oil injection ring 7 sprays oil in the mixing chamber 3, so that the oil is mixed with the inner combustion gas b1 and the outer combustion air a1 during the mixing process, thereby forming an oil-gas mixture that is easy to burn and is sprayed backward from the rear end of the mixing chamber 3.

[0114] The specific fuel injection device and injection method are selected in combination with the actual application.

[0115] It should be understood that the above angle or length parameter ranges are reference values ​​for the afterburner chamber of the adaptive cycle engine under typical operating conditions. When the typical operating conditions of the afterburner chamber are adjusted, these angle or length parameter ranges should also be adjusted accordingly.

[0116] For the convenience of expression, the above angle value refers to the size of the acute angle between the straight lines where the projections of the two planes are located on a specific cross section. Taking the technical feature of "the angle between the front wall 22 of the diverter ring and the inner wall 21 of the diverter ring should be controlled within the range of 5° to 60°" as an example, this technical feature is Figure 1 The meaning is: on the cross section perpendicular to the circumferential direction, the acute angle between the straight line where the projection of the front wall 22 of the diverter ring is located and the straight line where the projection of the inner wall 21 of the diverter ring is located is 5° to 60°.

[0117] like Figures 5-6 As shown, in another aspect of the present invention, an afterburner is provided, comprising an inner and outer flame cascade device according to any one of the foregoing embodiments.

[0118] like Figures 5-6 As shown, the inner and outer flame device provided by the present invention is installed at the tail of the splitter ring of the afterburner of the adaptive cycle engine. The afterburner provided by the present invention specifically includes: an outer cylinder 81, a center cone 82 arranged at the central axis of the outer cylinder 81, an integrated support plate 83 passing through the mixing chamber 3 and the second splitter ring 2 and connected between the outer cylinder 81 and the central axis, and a radial stabilizer 84 arranged on the inner side of the outer cylinder 81 and located axially rearward of the second splitter ring 2.

[0119] In addition, the integrated support plate 83 is provided with a plurality of first oil injection holes 831, and the radial stabilizer 84 is provided with a plurality of second oil injection holes 841. In the afterburner scheme shown in the figure, the integrated support plate 83 and the radial stabilizer 84 are evenly arranged along the circumferential direction, with a number of 10-20. As the main flame stabilizer of the afterburner, the integrated support plate 83 also plays the role of oil injection, rectification and support.

[0120] On the basis of the above structure, the internal combustion gas b1 is flame stabilized and burned through the low-speed zone behind the integrated support plate 83, and for the external combustion gas a1, a part of it enters the mixing chamber 3 through the first air flow channel c1, and is mixed with the internal combustion gas b1 introduced by the second air flow channel c2, and is side-sprayed through the first oil injection hole 831 on the integrated support plate 83 to form an easily combustible oil-gas mixture in the mixing chamber 3, and finally sprayed out from the slit at the rear of the mixing chamber 3. The low-speed recirculation zone at the rear of the mixing chamber 3 can ignite the mixture, thereby forming the first-stage combustion of the external combustion gas a1 in the internal combustion area b; the rest of the external combustion gas enters the mixing chamber of the afterburner from above the second diverter ring 2, and the second-stage combustion is organized by the radial stabilizer 84 and the second oil injection hole 841 thereon.

[0121] In a preferred embodiment, the afterburner also includes a variable outer duct area ejector 85, which is disposed at the axial rear end of the second diverter ring 2 and can move axially to change the flow area of ​​the outer duct area a. The variable outer duct area ejector 85 can control the outer duct area and enhance the mixing of the inner and outer ducts together with the inner and outer duct flame combination device.

[0122] The following introduces two extreme operating conditions in the control law of the adaptive cycle engine.

[0123] like Figure 5 As shown, in the maximum bypass ratio mode, the sealing ring 4 is fully opened, and the variable area culvert ejector is at the maximum radius of the outer cylinder 81 of the afterburner. At this time, the afterburner has the largest culvert intake area, and a large amount of low-temperature culvert air enters the mixing chamber 3 through the culvert intake slit, and is heated by the high-temperature inner combustion gas b1 and then burns. Since a large amount of low-temperature culvert air a1 has been consumed before reaching the radial stabilizer 84, it can effectively reduce the difficulty of culvert combustion organization in the large bypass ratio mode.

[0124] like Figure 6 As shown, in the minimum bypass ratio mode, the sealing ring 4 is completely closed, and the variable area duct ejector is at the minimum radius of the afterburner outer cylinder 81. At this time, the afterburner has the smallest duct intake area, and all duct gas is burned through the radial stabilizer 84 and the injection holes thereon. At this time, it has the technical effect of adjusting the duct intake area and matching different working conditions of the afterburner.

[0125] The above two modes are only an introduction to the extreme area adjustment capability of this scheme. In the specific afterburner design, a suitable area adjustment range can be selected between these two modes to achieve optimal performance.

[0126] In summary, the present invention realizes the staged mixing and staged combustion of the afterburner by constructing an outer duct intake slit with an adjustable area on the diverter ring; by providing a movable sealing ring 4 and an actuating device, the sealing ring 4 can axially translate according to aerodynamic requirements to change the flow area of ​​the first air flow channel c1; by uniformly mixing the internal combustion gas b1, the outer duct air a1 and the fuel in the mixing chamber 3, an oil-gas mixture that is easy to ignite is formed; and by forming a low-speed reflux zone at the tail of the mixing chamber 3 through the sudden expansion, the oil-gas mixture sprayed out from the slit at the tail of the mixing chamber 3 is better ignited.

[0127] Based on this, the present invention has at least one of the following advantages:

[0128] 1. Staged mixing and staged combustion are conducive to reducing the length of the afterburner, and greatly reduce the difficulty of external mixing and organizing combustion at a large bypass ratio;

[0129] 2. The flow area of ​​the first airflow channel c1 is controlled by the axial translation of the sealing ring 4, which relatively simply realizes the requirements of adjusting the outer circumference area of ​​the afterburner of the adaptive cycle engine and matching different working conditions, and can be used in combination with other outer circumference area adjustment devices;

[0130] 3. Introducing high-temperature inner air into the front of the mixing chamber 3 to heat the outer air, effectively reducing the difficulty of ignition of the outer air a1;

[0131] 4. The sudden expansion at the rear of the mixing chamber 3 enhances the mixing effect of the mixing chamber 3 with a simple structure, and can also serve as an ignition source for the oil-gas mixture ejected at the rear.

[0132] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An inner and outer flame device, characterized in that: include: A first flow dividing ring (1) is separated between the outer region (a) and the inner region (b); A second flow dividing ring (2) is arranged at intervals on the axial rear side of the first flow dividing ring (1) and is separated between the outer region (a) and the inner region (b); and A mixing chamber (3), located in the inner end region (b), and arranged at intervals on the radial inner side of the second flow dividing ring (2); Wherein, a first air flow channel (c1) is formed between the first flow dividing ring (1) and the second flow dividing ring (2) from the outer cladding area (a) to the inner cladding area (b), and the mixing chamber (3) is connected to the outlet end of the first air flow channel (c1), so that the outer cladding air (a1) of the outer cladding area (a) enters the interior of the mixing chamber (3) through the first air flow channel (c1); Furthermore, a second air flow channel (c2) is formed between the mixing chamber (3) and the first flow dividing ring (1), so that the contained gas (b1) in the contained area (b) enters the interior of the mixing chamber (3) through the second air flow channel (c2); The second diverter ring (2) comprises: An inner wall (21) of the flow dividing ring is arranged perpendicular to the radial direction and on the radial outer side of the mixing chamber (3); A splitter ring front wall (22) extends obliquely outward and forward from the front end of the splitter ring inner wall (21) to the outer cladding area (a), and forms the first airflow channel (c1) with the rear end of the first splitter ring (1); and The splitter ring outer wall (23) extends obliquely inwardly and backwards from the outer end of the splitter ring front wall (22) to the rear end of the splitter ring inner wall (21).

2. The inner and outer flame device according to claim 1, characterized in that: Also includes: An airflow control device is arranged on at least one of the first diverter ring (1), the second diverter ring (2) and the mixing chamber (3), and is configured to adjust the flow area of ​​the first airflow channel (c1) to control the flow rate of the external air (a1) entering the internal area (b) from the first airflow channel (c1).

3. The inner and outer flame device according to claim 2, characterized in that: The airflow control device comprises: a sealing ring (4) movably arranged on the radially outer side of the first flow dividing ring (1) and capable of moving axially toward the second flow dividing ring (2) to adjust the flow area of ​​the first air flow channel (c1); and The actuating device is configured to drive the sealing ring (4) to move.

4. The inner and outer flame device according to claim 1, characterized in that: Also includes: The guide ring (5) is fixedly arranged on the second diverter ring (2) and extends forward from the outer end of the diverter ring front wall (22).

5. The inner and outer flame device according to claim 4, characterized in that: The inclination angle of the front wall (22) of the diverter ring relative to the inner wall (21) of the diverter ring is within the range of 5° to 60°, so that the difference between the static pressure of the external air (a1) entering the internal area (b) from the first air flow channel (c1) and the static pressure of the internal combustion gas (b1) in the internal area (b) does not exceed a set pressure difference.

6. The inner and outer flame device according to claim 4, characterized in that: The projection of the splitter ring outer wall (23) on a cross section perpendicular to the circumferential direction is a straight line structure, and the inclination angle of the splitter ring outer wall (23) relative to the splitter ring inner wall (21) is in the range of 3° to 30°, so that the external air (a1) flowing through the splitter ring outer wall (23) does not produce airflow separation; or The projection of the outer wall (23) of the diverter ring on a cross section perpendicular to the circumferential direction is a curved structure with a gradually increasing expansion angle, that is, the outer wall (23) of the diverter ring adopts an isobaric gradient design so that the static pressure change rate of the outer air (a1) flowing through the outer wall (23) of the diverter ring is a constant along the flow direction.

7. The inner and outer flame device according to claim 4, characterized in that: The ratio of the flow area of ​​the first airflow channel (c1) to the outer flow area at the inlet of the guide ring (5) is constructed so that the percentage of the outer flow air (a1) entering the inner region (b) from the first airflow channel (c1) is within a range of 5% to 65%; Wherein, the length of the guide ring (5) is in the range of 1 to 16 cm.

8. The inner and outer flame device according to claim 5, characterized in that: The ratio of the flow area of ​​the second air flow channel (c2) to the flow area of ​​the first air flow channel (c1) is configured such that when the first air flow channel (c1) is at the maximum designed air intake volume, the temperature of the mixed gas after the internal combustion gas (b1) entering the mixing chamber (3) from the second air flow channel (c2) and the external combustion air (a1) entering the mixing chamber (3) from the first air flow channel (c1) are mixed is not lower than the ignition point temperature of the fuel.

9. The inner and outer flame device according to claim 1, characterized in that: The mixing chamber (3) comprises: An inner wall (31) of the mixing chamber is arranged perpendicular to the radial direction and on the radial inner side of the second flow dividing ring (2); A mixing chamber front wall (32) extends obliquely outward and forward from the front end of the mixing chamber inner wall (31) and forms the second air flow channel (c2) with the rear end of the first flow dividing ring (1); and The mixing chamber rear wall (33) extends obliquely outward and backward from the rear end of the mixing chamber inner wall (31).

10. The inner and outer flame device according to claim 9, characterized in that: The mixing chamber (3) further comprises: The trailing edge (6) is fixedly arranged on the mixing chamber rear wall (33) and extends backward from the outer end of the mixing chamber rear wall (33).

11. The inner and outer flame device according to claim 9, characterized in that: The inclination angle of the mixing chamber front wall (32) relative to the mixing chamber inner wall (31) is within a range of 5° to 60°, so that the internal combustion gas (b1) flowing through the mixing chamber front wall (32) does not produce airflow separation.

12. The inner and outer flame device according to claim 9, characterized in that: Also includes: The oil injection ring (7) is arranged in a circumferential manner inside the mixing chamber (3) and close to the inner wall (31) of the mixing chamber. The distance between the oil injection ring (7) and the inner wall (31) of the mixing chamber is 1 to 10 cm.

13. An afterburner, characterized in that: It comprises an inner and outer flame device according to any one of claims 1-12.

14. The afterburner according to claim 13, characterized in that Also includes: Outer cylinder (81); A central cone (82) is arranged on the central axis of the outer cylinder (81); an integrated support plate (83), which passes through the mixing chamber (3) and the second flow dividing ring (2) and is connected between the outer cylinder (81) and the central cone (82), and is provided with a plurality of first oil injection holes (831); and The radial stabilizer (84) is arranged on the inner side of the outer cylinder (81) and is located axially rearward of the second flow divider ring (2), and is provided with a plurality of second oil injection holes (841).

15. The afterburner chamber according to claim 14, characterized in that Also includes: The variable outer duct area ejector (85) is arranged at the axial rear end of the second diverter ring (2) and is capable of moving axially to change the flow area of ​​the outer duct area (a).

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