CN115468188B

CN115468188B - Afterburner with staged combustion

Info

Publication number: CN115468188B
Application number: CN202211120893.4A
Authority: CN
Inventors: 刘玉英; 刘广海; 张权; 何志杰
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2022-09-15
Filing date: 2022-09-15
Publication date: 2023-05-12
Anticipated expiration: 2042-09-15
Also published as: CN115468188A

Abstract

The present invention provides a staged combustion afterburner comprising: the device comprises a casing, a central cone, a split ring, a rear culvert ejector, a rectifying support plate, an inner culvert stabilizer and an outer culvert stabilizer. The invention forms a first airflow channel in the area where the diverter ring and/or the rear duct ejector are/is located, and the first airflow channel is used for communicating the outer culvert area with the inner culvert area. And the invention can selectively open the first air flow channel to make the afterburner enter a three-culvert working mode or close the first air flow channel to make the afterburner enter a double-culvert working mode through the adjusting element. The invention can be suitable for the application scene with larger scope of change of the bypass ratio of the afterburner of the three-bypass self-adaptive cycle engine, overcomes the defects of the existing scheme of the afterburner with small bypass ratio or medium bypass ratio, and effectively improves the combustion efficiency of the afterburner and simultaneously gives consideration to flow loss.

Description

Afterburner with staged combustion

Technical Field

The invention belongs to the field of aerospace, relates to a staged combustion afterburner, and particularly relates to a staged combustion afterburner applied to a three-way self-adaptive cycle engine.

Background

The self-adaptive cycle engine (Adaptive Cycle Engine, ACE) is a main research direction of the sixth-generation military aeroengine at present, and can automatically change a plurality of operating parameters such as internal and external culvert pressure ratio, temperature rise, flow, culvert ratio (ratio of external culvert flow to internal culvert airflow) and the like by moving a plurality of component positions, so that the engine obtains better performance at different heights and speed points in a flight envelope.

The US patent 20120131902A1 proposes a double culvert adaptive cycle engine: in the single culvert working mode, the first culvert channel is closed, and the high-temperature content airflow and the low-temperature content airflow are mixed after the split-flow ring, so that conditions are created for the tissue combustion of the flame stabilizer; under the double culvert working mode, the high-temperature airflow of the culvert and the low-temperature airflow of the first culvert are mixed before the turbine, and then are mixed with the low-temperature airflow of the second culvert after the flow dividing ring. By adopting the scheme of graded mixing of the high-temperature inclusion airflow and the low-temperature inclusion airflow, the engine can select afterburner schemes with small bypass ratio (0.2-0.4) or medium bypass ratio (0.6-1.0) according to the flow rate of the second outer inclusion airflow, such as U.S. Pat. No. 005385015A, european patent EP2821627B1 and Chinese patent CN102538010A.

Based on the double-external-inclusion self-adaptive cycle engine, a research article entitled Matching mechanism analysis on an adaptive cycle engine is published in Chen Minyu 2018 for further improving the variable cycle capacity of the self-adaptive cycle engine. The research article proposes a three culvert self-adapting cycle engine having a dual culvert mode of operation and a three culvert mode of operation. As shown in fig. 1, in the dual culvert operation mode, the second culvert channel is closed, the high-temperature air flow of the connotation and the low-temperature air flow of the first culvert are mixed after the split ring, and the third culvert air flow is directly discharged into the atmosphere; and as shown in fig. 2, in the three-culvert operation mode, the first culvert low-temperature air flow and the second culvert low-temperature air flow are mixed after the front culvert ejector, then are mixed with the high-temperature air flow of the culvert after the split ring, and the third culvert air flow is directly discharged into the atmosphere.

Compared with the double-culvert self-adaptive cycle engine, the three-culvert self-adaptive cycle engine has the advantages of more distance and larger thrust, and thus has more development prospect. However, in different working modes, the external low-temperature air flow and the internal high-temperature air flow of the three-external self-adaptive cycle engine are mixed after the split ring, so that the range of the change of the bypass ratio of the afterburner is extremely large (0.2-1.0), the conventional low bypass ratio or medium bypass ratio afterburner scheme cannot be adopted, and therefore, the scheme of the bypass ratio-variable afterburner suitable for the three-external self-adaptive cycle engine needs to be provided.

Disclosure of Invention

In view of the above, the invention provides a staged combustion afterburner which can adapt to the application scene of large scope of change of bypass ratio of the afterburner of a three-bypass self-adaptive cycle engine, overcomes the defects of the prior technical scheme of the afterburner with small bypass ratio or medium bypass ratio, effectively improves the combustion efficiency of the afterburner and simultaneously gives consideration to flow loss.

In one aspect of the invention, there is provided a staged combustion afterburner comprising:

a casing;

the central cone is arranged along the central shaft of the casing;

the split ring is circumferentially arranged on the outer side of the center cone and divides a gas flow area in the afterburner into an outer culvert area between the split ring and the casing and an inner culvert area between the split ring and the center cone;

the rear duct ejector is in an annular structure, is circumferentially arranged on the outer side of the flow dividing ring, and is provided with an airflow mixing structure at the tail edge;

the rectifying support plate is arranged between the center cone and the flow dividing ring and is provided with a plurality of first injection holes capable of selectively injecting the oil-gas mixture outwards;

the connotation stabilizer is arranged on the inner side of the shunt ring and is arranged in a staggered manner with the rectifying support plate along the circumferential direction; and

The external culvert stabilizer is arranged on the inner side of the casing and positioned on the rear side of the rear culvert ejector, and a plurality of second injection holes capable of selectively injecting the oil-gas mixture outwards are formed in the external culvert stabilizer;

the first airflow channel is formed in the area where the split ring and/or the rear duct ejector are/is located and is used for communicating the outer culvert area with the inner culvert area; and

the adjusting element can selectively open the first air flow channel to enable the afterburner to enter a three-culvert working mode, or close the first air flow channel to enable the afterburner to enter a double-culvert working mode;

wherein, in the three-culvert operation mode, the afterburner is organized with at least one of the following three-stage combustions, which includes:

-a first combustion, wherein part of the air flow of the culvert area enters the culvert area through the first air flow channel, is mixed with the air flow of the culvert area, and is organized and combusted in the area where the culvert stabilizer is located after receiving the air-fuel mixture sprayed out from the first spray hole;

-a second combustion, in which the air flow after the first combustion is mixed with a part of the air flow in the outer culvert area, which does not enter the first air flow channel, at the air flow mixing structure, and after receiving the air-fuel mixture ejected from the second ejection hole, is organized to burn in the area where the outer culvert stabilizer is located; and

-a third combustion, part of the air flow in the connotation area receiving the air-fuel mixture ejected from the first ejection holes and organizing combustion in the area where the rectifying support is located;

wherein, in the dual culvert mode of operation, the afterburner is organized with at least one of the following two-stage combustions, including:

-fourth combustion, the air flow in the connotation area receiving the air-fuel mixture ejected from the first ejection holes and organizing combustion in the area where the rectifying support and connotation stabilizer are located; and

-fifth combustion, in which the air flow of the culvert section is mixed with a part of the air flow of the culvert section at the air flow mixing structure, and after receiving the air-fuel mixture ejected from the second ejection hole, is organized to burn in the area where the culvert stabilizer is located.

Preferably, a first airflow hole is formed in the split ring, a second airflow hole opposite to the first airflow hole is formed in the rear duct ejector, and the first airflow hole and the second airflow hole are communicated with each other to form the first airflow channel;

the adjusting element comprises an actuating device, and the actuating device can drive the split ring and the rear duct ejector to relatively move, so that the first air flow channel is opened or closed by controlling the first air flow hole and the second air flow hole to be mutually overlapped or staggered.

Preferably, the staged combustion afterburner further comprises:

the first end of the guide ring is arranged on the outer side of the rear duct ejector and is positioned at the rear part of the second airflow hole, and the second end of the guide ring extends forwards and outwards relative to the first end of the guide ring so as to guide part of airflow in the outer duct area to enter the second airflow hole.

Preferably, the inside of the rectifying support plate is of a hollow structure, an inclusion oil injection rod is arranged in the rectifying support plate, an oil injection port of the inclusion oil injection rod is opposite to the first injection hole, a third air flow hole is formed in the position, opposite to the rectifying support plate, of the split ring, and a fourth air flow hole is formed in the position, corresponding to the third air flow hole, of the rear duct ejector;

wherein the third and fourth airflow apertures are configured to: and the flow dividing ring and the rear duct ejector are communicated in the process of being driven by the actuating device to relatively move, so that a second air flow channel which enters the rectification support plate from the outer culvert area through the fourth air flow hole and the third air flow hole is formed.

Preferably, the fuel injection hole of the content fuel injection rod is arranged with the first injection hole in a clearance manner, so that the air flow entering the content area inside the rectifying support plate through the second air flow channel can flow outwards from the clearance between the fuel injection hole of the content fuel injection rod and the first injection hole, and is mixed with the fuel injected from the content fuel injection rod to form an oil-gas mixture.

Preferably, the connotation stabilizer comprises:

an inner stabilizer ring comprising a first annulus extending axially and a second annulus extending outwardly from a leading edge of the first annulus to an inner side of the splitter ring; and

an outer stabilizer ring comprising a third annulus extending axially and spaced inwardly of said first annulus, and a fourth annulus extending outwardly from a leading edge of said third annulus to an inner side of said splitter ring;

the first annular surface, the second annular surface and the third annular surface are attached to the rectifying support plate at two ends in the circumferential direction, and the fourth annular surface is axially positioned at the front side of the second annular surface and is arranged at intervals with the rectifying support plate in the circumferential direction;

and wherein a projection of at least one of the plurality of first injection holes, which is adjacent to the flow divider ring, in a circumferential direction falls inside an area surrounded by the second annulus, the fourth annulus, and the flow divider ring.

Preferably, the fourth annulus extends forward and outwardly to the inside of the diverter ring relative to the leading edge of the third annulus, the intersection of the fourth annulus and the diverter ring is located aft of the first airflow aperture, and the fourth annulus has a circumferential dimension that is not less than the circumferential dimension of the first airflow aperture.

Preferably, the culvert stabilizer is of a hollow structure, an culvert oil injection rod is arranged in the culvert stabilizer, and an oil injection port of the culvert oil injection rod is opposite to the second injection hole;

wherein the staged combustion afterburner further comprises:

the vibration-proof heat shield is arranged between the external culvert stabilizer and the casing, and is arranged at intervals with the casing, and a fifth airflow hole is formed in the position, which is opposite to the external culvert stabilizer, of the vibration-proof heat shield, so that airflow in the external culvert area passes through the fifth airflow hole from the gap between the vibration-proof heat shield and the casing to enter the external culvert stabilizer.

Preferably, the fuel injection hole of the outer culvert fuel injection rod is arranged with the second injection hole in a clearance mode, so that the air flow entering the outer culvert area inside the outer culvert stabilizer through the fifth air flow hole can flow outwards from the clearance between the fuel injection hole of the outer culvert fuel injection rod and the second injection hole and is mixed with the fuel injected from the outer culvert fuel injection rod to form an oil-gas mixture.

Preferably, the air flow mixing structure at the tail edge of the rear duct ejector is a lobe structure, and the lobe structure is composed of first lobes and second lobes which are staggered along the circumferential direction;

Wherein, on a cross section perpendicular to the axial direction, the cross section patterns of the first and second petals are arc-shaped structures protruding inwards and outwards in the radial direction respectively.

Preferably, the rear duct ejector and the airflow mixing structure are of an integrated structure.

Preferably, the casing outside the shunt ring protrudes outwards in the radial direction to form a casing outer convex section, and the casing outer convex section and the casing outside the outer culvert stabilizer are connected with each other through a casing contraction section;

wherein the casing outer lobe is configured to:

when the first air flow channel is opened, the area of a first throat between the front edge of the guide ring and the outer convex section of the casing meets the pneumatic thermal design requirement of an external culvert area of the afterburner in a three-culvert working mode; and

when the first air flow channel is closed, the area of the second throat between the rear edge of the casing contraction section and the rear duct ejector meets the pneumatic thermodynamic design requirement of an afterburner outdoor culvert area in a double-culvert working mode.

Preferably, the rectifying support plate is a first hollow structure extending from the central cone to the flow distribution ring along the radial direction, the front edge of the first hollow structure is of a first flow line structure, the rear edge of the first hollow structure is of a first blunt body structure, a plurality of first injection holes are distributed on two circumferential sides of the rectifying support plate along the radial direction, and the first injection holes are arranged in an area close to the front edge of the rectifying support plate.

Preferably, at least two of the rectifying support plate, the connotation stabilizer and the connotation oil injection rod are in an integrated structure.

Preferably, the outer culvert stabilizer is of a second hollow structure extending inwards from the casing along the radial direction, the front edge of the second hollow structure is of a second fluid structure, the rear edge of the second hollow structure is of a second blunt body structure, a plurality of second injection holes are distributed on two circumferential sides of the outer culvert stabilizer along the radial direction, and the second injection holes are arranged in an area close to the front edge of the outer culvert stabilizer.

Preferably, the external culvert stabilizer and the external culvert oil injection rod are of an integrated structure.

Preferably, the plurality of culvert stabilizers are uniformly distributed along the circumferential direction, and the number of the culvert stabilizers is 1-2 times that of the rectifying support plates.

Thus, the beneficial technical effects of the present invention include at least:

in the three-culvert working mode, the afterburner for staged combustion of the invention introduces part of culvert air flow into the connotation and organizes and combusts in the area where the culvert stabilizer is located, and the burnt culvert air flow and the unburned culvert low-temperature air flow are mixed at the air flow mixing structure at the tail part of the rear culvert ejector and are organized and combusts in the area where the culvert stabilizer is located. Compared with the traditional afterburner with medium bypass ratio, the invention carries out low-temperature airflow staged combustion on the bypass, thereby reducing the size of an airflow mixing structure and reducing the flow loss on the premise of not influencing the combustion efficiency;

In the double culvert working mode, the afterburner for staged combustion mixes part of the low-temperature air flow of the culvert with the high-temperature air flow of the culvert at the air flow mixing structure at the tail part of the rear culvert ejector and organizes combustion in the area where the culvert stabilizer is located. The added flow mixing structure of the present invention, while resulting in a slight increase in flow losses, greatly improves combustion efficiency over conventional low bypass afterburners.

Drawings

The accompanying drawings are included to provide a further understanding of the technical aspects of the present application and are incorporated in and constitute a part of this specification, illustrate the technical aspects of the present application and together with the examples of the present application, but do not constitute a limitation of the technical aspects of the present application.

FIG. 1 is a schematic cross-sectional view of a three-culvert adaptive cycle engine in a direction parallel to the axial direction corresponding to a staged combustion afterburner of the present invention;

FIG. 2 is a schematic cross-sectional view of a three-culvert adaptive cycle engine in a dual culvert mode of operation in a parallel axial direction corresponding to a staged combustion afterburner of the present invention;

FIG. 3 is a schematic cross-sectional view of a three-culvert adaptive cycle engine in a three-culvert mode of operation in a parallel axial direction corresponding to a staged combustion afterburner of the present invention;

FIG. 4 is a schematic cross-sectional view of the staged combustion afterburner of the present invention in a direction perpendicular to the axial direction;

FIG. 5 is a schematic cross-sectional view of the staged combustion afterburner of the present invention taken at an angle A in FIG. 4 and parallel to the axial direction;

FIG. 6 is a schematic cross-sectional view of the staged combustion afterburner of the present invention taken at an angle B in FIG. 4 and parallel to the axial direction;

FIG. 7 is a schematic cross-sectional view of the staged combustion afterburner of the present invention taken along the direction A of FIG. 4 and parallel to the axial direction and illustrating the flow direction of the gas stream when in the three-connotation mode of operation;

FIG. 8 is a schematic cross-sectional view of the staged combustion afterburner of the present invention in a three-connotation mode of operation, taken along the direction B of FIG. 4, and parallel to the axial direction, and illustrating the flow direction of the gas stream;

FIG. 9 is a schematic cross-sectional view of the staged combustion afterburner of the present invention in a dual bypass mode of operation, taken along the direction A of FIG. 4, and parallel to the axial direction, and illustrating the flow direction of the gas stream;

FIG. 10 is a schematic cross-sectional view of the staged combustion afterburner of the present invention in a dual bypass mode of operation, taken along the direction B of FIG. 4, and taken parallel to the axial direction, and illustrating the flow direction of the gas stream;

FIG. 11 is a schematic view of the structure of the splitter ring, inclusion stabilizer and rectifying support plate of the staged combustion afterburner of the present invention;

FIG. 12 is a schematic view of the structure of the post-duct injector of the staged combustion afterburner of the present invention;

FIG. 13 is a schematic view of the inclusion stabilizer of the staged combustion afterburner of the present invention;

FIG. 14 is a schematic view of the construction of the culvert stabilizer of the staged combustion afterburner of the present invention;

FIG. 15 is a schematic structural view of a rectifying support plate of a staged combustion afterburner of the present invention;

reference numerals illustrate:

1-a case; 11-a casing outer convex section; 12-a casing contraction section;

2-a center cone;

3-a shunt ring; 31-a first airflow aperture; 32-a third airflow aperture;

4-a rear duct ejector; 41-an air flow mixing structure; 411-lobe structure; 411 a-first lobe; 411 b-second lobe; 42-a second airflow aperture; 43-fourth airflow aperture;

5-rectifying support plates; 51-first injection holes; 52-connotation oil injection rod; 53-a first streamlined body; 54-a first blunt body structure;

6-connotation stabilizer; 61-an inner stabilizing ring; 61 a-a first annulus; 61 b-a second annulus; 62-an outer stabilizing ring; 62 a-a third annulus; 62 b-a fourth torus;

7-an external culvert stabilizer; 71-a second injection hole; 72-an external culvert oil spraying rod; 73-a second streamlined body structure; 74-a second blunt body structure;

81-a first air flow channel; 82-a second airflow channel;

9-a guide ring;

10-shockproof heat shields; 101-a fifth airflow aperture;

a-an connotation region; b-an ectory region;

c1-a first throat; c2—a second throat;

d1-a first culvert; d2-second connotation; d3-third culvert; d4-connotation;

e 1-a fan; e 2-a low pressure compressor; e 3-front duct injector; e 4-a high-pressure compressor; e 5-combustion chamber.

Detailed Description

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 invention, its application or use. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It should be noted that: the relative arrangement of the components and steps set forth in these embodiments should be construed as exemplary only and not as limiting unless specifically stated otherwise.

The present invention will be described in detail with reference to fig. 1 to 14.

The afterburner is mainly applied to a military aircraft engine, is also called a afterburner, is positioned between a turbine and a tail nozzle, and can utilize residual oxygen in gas after the turbine to re-spray fuel oil for combustion so as to achieve the technical effects of increasing the temperature of the gas and the jet speed, thereby increasing the thrust of the aircraft engine.

In order to facilitate the description of the structure of each component in the afterburner, the invention establishes a cylindrical coordinate system by taking the central axis of the aero-engine as the axis:

the direction coinciding with the centre axis of the afterburner is axial, i.e. left-right in fig. 1-3 and 5-10, and in fig. 4 perpendicular to the plane of the paper, either inwards or outwards. Wherein, the direction pointing towards the air inlet end of the afterburner along the axial direction is the forward direction, and the direction pointing towards the air outlet end of the afterburner along the axial direction is the backward direction.

The radial direction with the central axis as the apex in fig. 4 is the radial direction with the distance from the central axis in the plane perpendicular to the axial direction, that is, the up-down direction in fig. 1 to 3 and fig. 5 to 10. Wherein, the direction pointing along the radial direction far away from the central axis is outward, and the direction pointing along the radial direction close to the central axis is inward;

the circumferential direction around the central axis is the circumferential direction, that is, the direction around the central axis in the direction of rotation in the paper surface or out of the paper surface in fig. 1 to 3 and 5 to 10, and the circumferential direction around the central axis is the apex in fig. 4. The direction of clockwise rotation around the central axis is clockwise and the direction of anticlockwise rotation around the central axis is anticlockwise under the view angle from the air inlet end to the air outlet end of the afterburner.

For a person skilled in the art, since the afterburner is typically of a central symmetrical construction, the centre axes of the afterburner are represented by dashed lines in fig. 1-3 and fig. 5-10 for saving the drawing figures, and only the areas above the centre axes are shown, the areas below the centre axes not being in an axisymmetric or axidependent pattern with respect to the centre axes of the afterburner and the areas shown in the figures. Similarly, only a schematic cross-sectional view of the afterburner in a partial circumferential angular range is shown in fig. 4, and other patterns not shown should be angularly symmetrical or angularly related to the areas shown in the figures with the centre axis of the afterburner as the centre of symmetry.

As shown in fig. 1, a schematic cross-sectional structure of a typical three-culvert adaptive circulation engine along an axial direction is shown. The black filled blades fixedly connected to the central shaft in the figure are rotor blades in the usual sense, while the white filled blades are stator blades in the usual sense. The rotor blades and stator blades are respectively positioned in the fan e1 area, the low-pressure compressor e2 area, the high-pressure compressor e4 area and the turbine area from front to back along the axial direction.

The air flow channel flowing through the high-pressure compressor e4 area, the combustion chamber e5 area and the turbine area is called an internal duct, and is called an connotation d4 for short; radially outward from connotation d4, the air flow passage through the area of fan e1 and the area of low pressure compressor e2 without entering high pressure compressor e4 is referred to as a first connotation d1, the air flow passage through the area of fan e1 without entering low pressure compressor e2 is referred to as a second connotation d2, and the air flow passage through only the area of the first stage fan without passing through the area of the second stage fan is referred to as a third connotation d3.

And regulating valve structures are respectively arranged at the outlets of the first culvert d1, the second culvert d2 and the third culvert d3 and used for controlling the corresponding on-off of the culvert airflow and the corresponding airflow. The regulating valves and other adjustable geometric structures in the three-culvert self-adaptive circulation engine can be matched with each other, such as a rear culvert ejector, so as to change the thermodynamic cycle of the aeroengine, and enable the engine to obtain better performance at different heights and speed points in a flight envelope.

On the basis, the applicant researches and discovers that in the prior art, under different working modes, the three-culvert self-adaptive cycle engine mixes the low-temperature air flow of the culvert and the high-temperature air flow of the culvert after the split ring 3, so that the range of the change of the bypass ratio of the afterburner is extremely large and is between 0.2 and 1.0, and therefore the scheme of the afterburner with the existing small bypass ratio or the intermediate bypass ratio cannot be adopted.

Specifically, as shown in fig. 2, a schematic cross-sectional structure of the three-culvert adaptive circulation engine in a double-culvert operation mode along an axial direction is shown, and arrows in the figure show the flow directions of air flows in different culverts. The air flow of the third outer culvert d3 is directly discharged after being pressurized by the fan e1, does not participate in the combustion process of the combustion chamber e5 and the combustion process of the afterburner, the channel of the second outer culvert d2 is closed, the air flow of the first outer culvert d1 flows into the afterburner area after being pressurized by the fan e1 and the low-pressure air compressor e2, and the air flow of the inner culvert d4 enters the combustion chamber e5 to participate in combustion after being pressurized by the fan e1, the low-pressure air compressor e2 and the high-pressure air compressor e4, and enters the afterburner area after passing through the turbine area. In the afterburner, the air flow of the first culvert d1 and the air flow of the connotation d4 are mixed with each other after the splitter 3 and are organized to burn after receiving the fuel.

As shown in fig. 3, a schematic cross-sectional structure of the three-culvert adaptive circulation engine in a three-culvert operation mode along a direction parallel to an axial direction is shown, and arrows in the figure show flow directions of air flows in different culverts. The air flow of the third culvert d3 is directly discharged after being pressurized by the fan e1, and does not participate in the combustion process of the combustion chamber e5 and the combustion process of the afterburner; the air flow of the second culvert d2 is pressurized by the fan e1 and flows to the area of the front culvert ejector e 3; the air flow of the first culvert d1 is pressurized by a fan e1 and a low-pressure air compressor e2 and then flows to the area of the front culvert ejector e 3; the air flow of the connotation d4 enters the combustion chamber e5 to participate in combustion after being pressurized by the fan e1, the low-pressure compressor e2 and the high-pressure compressor e4, and enters the afterburner region after passing through the turbine region. At the rear end of the rear duct ejector 4, the air flow of the first culvert d1 and the air flow of the second culvert d2 are mixed with each other and flow to the afterburner zone. In the afterburner, the mixed air flow of the first and second outer culverts d1 and d2 and the air flow of the inner culvert d4 are mixed with each other after the split ring 3, and after receiving the injection, the afterburner is organized.

For a wide range of bypass ratio variations for a three-bypass adaptive cycle engine, as shown in FIGS. 4-6, in one aspect of the invention, a staged combustion afterburner is provided comprising:

The casing 1 has a substantially cylindrical structure, the outside of which flows through the third external duct d3 which does not take part in the combustion of the combustion chamber e5 and in the afterburner, and the inside of which is the internal and external duct areas a and b of the afterburner. The casing 1 mainly serves to define the range of airflow and support frame, and is also provided with a partial accessory structure on the outside of the casing 1, typically including a fuel accessory system (not shown) for providing fuel to the outer and inner

fuel injection rods

72, 52.

A central cone 2, disposed along the central axis of the casing 1, presenting a conical structure with a tapering cross-section area axially rearward. The central cone 2 functions similarly to the casing 1, mainly to define the flow range of the air flow and the supporting frame, and also has a partial attachment structure on the inner side of the central cone 2.

The flow divider 3 is arranged circumferentially outside the central cone 2 and is essentially a ring-shaped structure arranged downstream along the inner casing of the turbine section. The inner side of the flow dividing ring 3 is high Wen Nahan airflow flowing through the turbine, and the outer side of the flow dividing ring 3 is the culvert low-temperature airflow after the first culvert d1 and the second culvert d2 are mixed in the three-culvert working mode or the culvert low-temperature airflow of the first culvert d1 in the double-culvert working mode. The splitter 3 thus divides the gas flow area in the afterburner into an outer culvert area b between the splitter 3 and the casing 1 and an inner culvert area a between the splitter 3 and the center cone 2.

The rear duct injector 4, which is of annular configuration corresponding to the splitter ring 3, is arranged circumferentially outside the splitter ring 3. Because the radial gap between the rear duct ejector 4 and the split ring 3 is smaller or the axial front ends of the rear duct ejector 4 and the split ring 3 are provided with sealing structures, less or no airflow can flow between the radial gap between the rear duct ejector 4 and the split ring 3, and therefore the split ring 3 and the rear duct ejector 4 can be regarded as a radial integrated structure for discussion in the pneumatic analysis process. The invention is provided with the air flow mixing structure 41 at the tail edge position of the rear duct ejector 4, so that the low-temperature external air flow outside the split ring 3 (or the rear duct ejector 4) and the high-temperature internal air flow inside the split ring 3 (or the rear duct ejector 4) can be better mixed.

A flow straightening support 5, which is arranged between the central cone 2 and the flow dividing ring 3, is shown in fig. 4, and is essentially in the form of a cavity structure with a certain circumferential width arranged radially in a section perpendicular to the axial direction. The rectification support plates 5 are periodically distributed at equal angles by taking the central shaft as a rotation center, so that high-temperature inclusion airflow flowing through the inner sides of the central cone 2 and the splitter ring 3 (or the rear duct injector 4) is divided into different airflow channels along the circumferential direction.

On the basis of the above, the rectifying support plate 5 of the present invention is provided with a plurality of first spray holes 51 for selectively spraying the oil-gas mixture outwards, so that oil spray can be provided in each air flow passage to high Wen Nahan air flow which is divided into different air flow passages in the circumferential direction.

The content stabilizers 6 are arranged on the inner side of the flow divider ring 3 and are arranged circumferentially staggered with respect to the flow divider plate 5, i.e. the content stabilizers 6 are located radially outside the different flow channels of the high Wen Nahan flow separated by the flow divider plate 5. The connotation stabilizer 6 is used as a flame stabilizer in the connotation area a, and the function of the connotation stabilizer comprises that partial burnt high-temperature combustion products in the connotation area a generate back flow movement, so that fresh and unburned combustible mixture is continuously ignited as a continuous ignition source with automatic compensation capability, and the aim of stabilizing flame is achieved.

An external stabilizer 7, which is arranged inside the casing 1 and on the rear side of the rear duct injector 4, has a structure similar to the rectifying support 5 and is a cavity structure with a certain circumferential width, which is basically arranged radially on a section perpendicular to the axial direction. The plurality of culvert stabilizers 7 are periodically distributed at equal angles with the central axis as the rotation center, thereby dividing the high Wen Nahan air flow and the low-temperature culvert air flow mixed by the air flow mixing structure 41 into different inner unsealed air flow channels along the circumferential direction.

On the basis of this, the culvert stabilizer 7 of the present invention is provided with a plurality of second injection holes 71 for selectively injecting the oil and gas mixture outwardly, so that injection of oil can be provided to each gas flow passage. The external stabilizer 7 also has the function of a flame stabilizer, and can enable the burnt high-temperature combustion products to generate backflow movement, so that fresh and unburned combustible mixture is continuously ignited as a continuous ignition source with automatic compensation capability, and the aim of stabilizing flame is fulfilled.

On the basis of the structure of the afterburner comprising the casing 1, the central cone 2, the split ring 3, the rear duct ejector 4, the content stabilizer 6 and the content stabilizer 7, aiming at the pneumatic design condition of the afterburner with larger duct ratio variation range, the invention adds the first air flow channel 81 in the area where the split ring 3 and/or the rear duct ejector 4 are positioned, and then selectively opens the first air flow channel 81 to communicate the content area b with the content area a by arranging the adjusting element capable of controlling the opening or closing of the first air flow channel 81 so as to enable the afterburner to enter a three-content working mode, or closes the first air flow channel 81 to disconnect the communication between the content area b and the content area a so as to enable the afterburner to enter a double-content working mode.

As shown in fig. 7 and 8, in the three-connotation mode of operation, the afterburner is organized with at least one of the following three-stage combustions, including:

the first combustion, the partial air flow of the outer culvert area b enters the inner culvert area a through the first air flow channel 81, is mixed with the air flow of the inner culvert area a, and is organized and combusted in the area where the inner culvert stabilizer 6 is located after receiving the air-fuel mixture ejected from the first ejection hole 51;

second combustion, in which the air flow after the first combustion is mixed with the partial air flow which does not enter the first air flow passage 81 in the outer culvert section b at the air flow mixing structure 41, and after receiving the air-fuel mixture ejected from the second ejection hole 71, is organized to burn in the section where the outer culvert stabilizer 7 is located; and

the third combustion, in which part of the air flow in the connotation zone a receives the air-fuel mixture ejected from the first ejection holes 51 and organizes combustion in the zone where the rectifying support 5 is located.

Based on this, the principle of staged combustion in an afterburner in a three-connotation mode of operation is described below.

When the duct ratio rises, the three-culvert self-adaptive cycle engine is switched from the double-culvert working mode to the three-culvert working mode, and the adjusting element is in an opening state by controlling the first air flow channel 81, so that part of the low-temperature air flow of the culvert enters the culvert area a through the first air flow channel 81 formed on the split ring 3 and/or the rear duct ejector 4, and the other part of the low-temperature air flow of the culvert flows to the air flow mixing structure 41 at the tail edge of the rear duct ejector 4 to wait for mixing. At this time, a part of the connotation high-temperature air flow is organized and burned at the trailing edge of the rectifying support plate 5, and the other part enters the connotation stabilizer 6 to evaporate the fuel injected by the connotation fuel injection rod 52 and is discharged from the trailing edge of the connotation stabilizer 6, thereby igniting the connotation low-temperature air flow entering the connotation, i.e., the organization first combustion. The first burnt outer culvert air flow and the unburned outer culvert low-temperature air flow are mixed at the air flow mixing structure 41 at the tail part of the rear culvert ejector 4, and the second combustion is organized at the tail edge after the oil injection of the outer culvert stabilizer 7 is received.

Thus, in a three culvert mode of operation with a medium bypass ratio, the present invention organizes the first combustion by introducing a portion of the culvert low temperature air flow into the culvert and into the area of the culvert stabilizer 6. The first burnt outer culvert air flow and the unburned outer culvert low-temperature air flow are mixed at the lobe structure 411 at the tail part of the rear culvert ejector 4, and the second combustion is organized at the tail edge of the outer culvert stabilizer 7. Compared with the traditional afterburner with medium bypass ratio, the external bypass low-temperature airflow staged combustion can reduce the size of the gas mixing structure 41 and reduce the flow loss on the premise of not influencing the combustion efficiency.

As shown in fig. 9 and 10, in the dual bypass mode of operation, the afterburner is organized with at least one of the following two-stage combustions, including:

a fourth combustion, in which part of the air flow in the connotation region a receives the air-fuel mixture ejected from the first ejection holes 51 and is organized and burned in the region where the rectifying support 5 and the connotation stabilizer 6 are located; and

the fifth combustion, the air flow of the culvert section b is mixed with the partial air flow of the culvert section a at the air flow mixing structure 41, and after receiving the air-fuel mixture ejected from the second ejection holes 71, is organized to burn in the area where the culvert stabilizer 7 is located.

Based on this, the principle of staged combustion in afterburners in dual bypass mode operation is further described below.

When the bypass ratio is reduced, the three-bypass self-adaptive cycle engine is switched from the three-bypass operation mode to the double-bypass operation mode, and the adjusting element controls the first air flow channel 81 to be in a closed state, so that the bypass low-temperature air flows to the air flow mixing structure 41 at the tail edge of the rear bypass ejector 4. At this time, the high temperature air flow of the connotation organizes the fourth combustion at the trailing edge of the rectifying support plate 5 and the connotation stabilizer 6, the high temperature air flow of the connotation and the low temperature air flow of the connotation through the fourth combustion are mixed at the air flow mixing structure 41 at the tail part of the rear culvert ejector 4, and the fifth combustion is organized at the trailing edge of the connotation stabilizer 7.

Thus, in the dual-duct mode of operation with a small duct ratio, the present invention mixes the outer-duct low-temperature air flow with the inner-duct high-temperature air flow at the air flow mixing structure 41 at the rear of the rear duct ejector 4. The addition of the air flow mixing structure 41, while resulting in a slight increase in flow losses, greatly improves combustion efficiency compared to conventional low bypass ratio afterburners.

In general, in the three-culvert mode of operation, the afterburner of the present invention is organized with three stages of combustion, namely, a first combustion, a second combustion and a third combustion, simultaneously, and in the dual-culvert mode of operation, the afterburner of the present invention is organized with a fourth combustion and a fifth combustion simultaneously. Therefore, the invention can maximally utilize each flame stabilizing structure in the afterburner for organizing combustion, and enable the working condition of the afterburner to be close to a design value, thereby meeting the overall aerodynamic heating requirement of the three-way self-adaptive variable cycle engine.

However, it should be noted that the present invention may selectively organize at least one stage or at least two stages of the first combustion, the second combustion, and the third combustion in the three-bypass mode of operation, or may selectively organize at least one stage of the fourth combustion and the fifth combustion in the dual-bypass mode of operation, thereby making the adjustable operating range of the afterburner of the present invention broader and further suitable for more multiple operating demands of the aircraft engine. For example, the present invention can adjust the condition of the combustion structure by controlling the injection states of the plurality of first injection holes 51 and the plurality of second injection holes 71.

As shown in fig. 11 and 12, in a preferred embodiment, the splitter ring 3 is provided with a first airflow hole 31, and the rear bypass injector 4 is provided with a second airflow hole 42 opposite to the first airflow hole 31, and the first airflow hole 31 and the second airflow hole 42 are mutually communicated to form a first airflow channel 81;

wherein the adjusting element comprises an actuating device which can drive the split ring 3 and the rear duct injector 4 to move relatively, so that the first air flow channel 81 is opened or closed by controlling the first air flow hole 31 and the second air flow hole 42 to be mutually overlapped or staggered.

In a preferred embodiment, the actuating device is capable of controlling the rear duct injector 4 to move forward or backward in the axial direction, so as to indirectly drive the second airflow hole 42 to move relative to the first airflow hole 31, so that the first airflow hole 31 and the second airflow hole 42 are mutually overlapped or mutually staggered, and the first airflow channel 81 is respectively in an open state or a closed state.

In another preferred embodiment, the actuating device is capable of controlling the rear bypass injector 4 to perform a circumferential rotational movement relative to the splitter ring 3, thereby indirectly moving the second airflow aperture 42 relative to the first airflow aperture 31, wherein the first airflow aperture 31 and the second airflow aperture 42 are configured to be in an open state or a closed state when the rear bypass injector 4 rotates to a first circumferential included angle and a second circumferential Xiang Gajiao relative to the splitter ring 3, respectively.

It will be appreciated that the actuator may alternatively drive the cylinder to provide the axial drive force as the actuator drives the rear duct injector 4 in an axial direction. And when the actuation device drives the rear duct injector 4 to move in the circumferential direction, the actuation device can select a rotary motor to provide a rotary driving force.

In a preferred embodiment, the actuator is arranged on the side of the rear duct injector 4 remote from the splitter ring 3 or between the rear duct injector 4 and the splitter ring 3 to avoid direct contact of the actuator with the high temperature air flow inside the splitter ring 3, thereby improving the reliability and lifetime of the actuator.

Since the second airflow hole 42 formed in the rear duct ejector 4 is in a flat hole configuration, that is, the plane where the orifice of the second airflow hole 42 is located is substantially parallel to the airflow direction of the outer culvert area b, the airflow in the outer culvert area b will flow to the second airflow hole 42 only under the action of the pressure difference. It can be seen that the second airflow hole 42 lacks the capability of guiding the airflow flowing into the culvert area b, so in order to meet the airflow requirement from the culvert area b to the culvert area a in the three-culvert operation mode, it is necessary to add an airflow guiding device to force more airflow in the culvert area b into the second airflow hole 42, and further flows into the culvert area a when the first airflow channel 81 is in the open state.

7-10, in a preferred embodiment, the staged combustion afterburner further comprises a baffle ring 9, the first end of the baffle ring 9 being disposed outboard of the rear duct injector 4 and rearward of the second airflow aperture 42 to avoid a shielding effect on the second airflow aperture 42, thereby more fully utilizing the full intake area of the second airflow aperture 42, the second end of the baffle ring 9 extending forwardly and outwardly relative to the first end of the baffle ring 9 to direct a portion of the airflow of the outer duct region b into the second airflow aperture 42.

In a preferred embodiment, the tangential direction of the deflector ring 9 is substantially parallel to the flow direction of the air flow in the outer culvert area b at its second end in a section through the centre axis of the afterburner, and the tangential direction of the deflector ring 9 is uniformly changed from its second end to its first end, whereby the flow direction change of the air flow guided by the deflector ring 9 into the second air flow holes 42 at the deflector ring 9 can be made more gentle, thereby avoiding a strong flow separation phenomenon due to too fast flow direction change.

As shown in fig. 11 and 12, in a preferred embodiment, the inside of the rectifying support plate 5 is of a hollow structure, an inner culvert injection rod 52 is arranged in the rectifying support plate 5, an injection port of the inner culvert injection rod 52 is opposite to the first injection hole 51, a third airflow hole 32 is arranged on the position of the split ring 3 opposite to the rectifying support plate 5, and a fourth airflow hole 43 is arranged on the position of the rear culvert injector 4 corresponding to the third airflow hole 32; wherein the third and fourth airflow holes 32 and 43 are configured to: and the split ring 3 and the rear duct injector 4 are communicated in the process of being driven by an actuating device to relatively move so as to form a second air flow channel 82 which enters the interior of the rectifying support plate 5 from the outer culvert area b through the fourth air flow holes 43 and the third air flow holes 32.

Compared with the first airflow channel 81, the second airflow channel 82 formed by the third airflow hole 32 and the fourth airflow hole 43 can be communicated in the process that the rear duct ejector 4 moves relative to the split ring 3, so that the low-temperature airflow source in the outer duct area b continuously enters the inside of the rectifying support plate 5. And, the inside is hollow structure's rectification extension board 5 not only can hold connecing oil spout pole 52, can also be with connecing oil spout pole 52 and the high temperature gas mutually isolated outside the rectification extension board 5 effectively, prevent connecing oil spout pole 52 because of the high-temperature of working appear the fuel coking stop up the hydraulic fluid port or the failure trouble such as overall structure deformation.

The low-temperature air flow of the outer culvert area b flows into the rectifying support plate 5, so that on one hand, the rectifying support plate 5 can be effectively and pneumatically cooled from the inside, the surface temperature of the rectifying support plate 5 is maintained in a reasonable range, structural damage such as ablation or deformation of the rectifying support plate 5 caused by overhigh surface temperature is prevented, on the other hand, the low-temperature air flow of the outer culvert area b can be effectively mixed with fuel sprayed out by the inner culvert oil spraying rod 52, the fuel and the low-temperature air flow of the unburned outer culvert area b are fully mixed, and further, the third combustion in the three outer culvert working mode and the fourth combustion in the double outer culvert working mode organized at the rectifying support plate 5 are fully combusted.

In a preferred embodiment, the injection port of the content injection rod 52 is spaced apart from the first injection hole 51 so that the air flow entering the content region b inside the rectifying support 5 through the second air flow passage 82 can flow outwardly from the space between the injection port of the content injection rod 52 and the first injection hole 51 and be mixed with the fuel injected from the content injection rod 52 to form an air-fuel mixture.

The air flowing out from the gap between the injection port of the content injection rod 52 and the first injection hole 51 can accelerate its own flow rate by the narrow throat formed by the gap, resulting in the effect of high-speed injection. In addition, since the air ejected from the gap at a high speed is annularly located outside the fuel or the air-fuel mixture ejected from the first ejection hole 51, the ejection speed of the fuel is increased and the mixing uniformity of the fuel and the air is improved.

As shown in fig. 11 and 13, in a preferred embodiment, the content stabilizer 6 includes an inner stabilizer ring 61 and an outer stabilizer ring 62. The inner stabilizer ring 61 includes a first annular surface 61a extending in the axial direction, and a second annular surface 61b extending outwardly from the leading edge of the first annular surface 61a to the inside of the splitter ring 3; the outer stabilizer ring 62 includes a third annular surface 62a extending in the axial direction and disposed inside the first annular surface 61a at a spacing, and a fourth annular surface 62b extending outwardly from the leading edge of the third annular surface 62a to the inside of the splitter ring 3.

Wherein, the two ends of the first annular surface 61a, the second annular surface 61b and the third annular surface 62a along the circumferential direction are attached to the rectifying support plate 5, and the fourth annular surface 62b is located at the front side of the second annular surface 61b along the axial direction and is spaced from the rectifying support plate 5 along the circumferential direction. Thus, the high-temperature air flow in the inner region a enters between the inner stabilizing ring 61 and the outer stabilizing ring 62 from the empty region between the fourth annular surface 62b and the rectifying support 5, and forms a low-speed backflow region filled with the high-temperature air flow between the fourth annular surface 62b and the second annular surface 61 b.

And wherein a projection of at least one first injection hole 51 of the plurality of first injection holes 51, which is close to the flow distribution ring 3, in the circumferential direction falls inside an area surrounded by the second annular surface 61b, the fourth annular surface 62b, and the flow distribution ring 3. Thus, the fuel is injected from the first injection hole 51 between the second annular surface 61b and the fourth annular surface 62b, and mixed with the high-temperature air flow in the low-speed recirculation region, thereby forming a vaporization chamber for the fuel, and the fuel is fully vaporized after being mixed with the high-temperature air flow. In the evaporation chamber, the fuel does not burn because the fuel-air ratio is higher than the combustion limit. After the mixture of air and fuel in the evaporating chamber exits the content stabilizer 6 from the gap between the first annular surface 61a and the third annular surface 62a, the mixture of air and fuel will receive more air from the content area a, and will self-ignite to form a duty flame after the air and fuel ratio reaches the combustion limit.

In a preferred embodiment, the first annulus 61a and the third annulus 62a have a gap width therebetween of 1-5 mm.

The flame on duty formed at the tail edge of the connotation stabilizer 6 can be used as an ignition source to promote third combustion of the area where the rectifying support plate 5 is located in the three-connotation working mode and fourth combustion of the area where the connotation stabilizer 6 is located in the double-connotation working mode, and promote first combustion of the area where the connotation stabilizer 6 is located in the three-connotation working mode and fourth combustion of the area where the connotation stabilizer is located in the double-connotation working mode.

Although the first combustion and the on-duty flame are both formed at the trailing edge of the content stabilizer 6, the flame forming process of the two is quite different. Wherein the fuel of the first combustion is an oil-gas mixture ejected from the first injection hole 51 not entering the inside of the connotation stabilizer 6, and the combustion improver in the first combustion is a mixed gas flow of a high-temperature gas flow of the connotation region a and a low-temperature gas flow entering the connotation region a from the first gas flow passage 81. The fuel of the duty flame is the oil-gas mixture sprayed from the first spray hole 51 and enters the interior of the content stabilizer 6, and the combustion improver is only the high-temperature air flow entering the interior of the content stabilizer 6 from the content area a.

It can be seen that in order to form a stable on-duty flame at the trailing edge of the content stabilizer 6, it is necessary to prevent the low-temperature air flow of the outer culvert area b from entering the inside of the evaporation chamber of the content stabilizer 6, so as to prevent the low-temperature air flow from adversely affecting the evaporation process of the oil-gas mixture.

In this regard, in a preferred embodiment, the fourth annulus 62b extends forwardly and outwardly to the inside of the splitter ring 3 relative to the leading edge of the third annulus 62a, the intersection of the fourth annulus 62b with the splitter ring 3 is located aft of the first airflow aperture 31, and the fourth annulus 62b has a circumferential dimension that is not less than the circumferential dimension of the first airflow aperture 31. The fourth annulus 62b thus forms a toroidal structure with its trailing edge radially inclined inwardly relative to the leading edge, so that the flow of cryogenic air entering the content zone a from the first air flow channel 81 is directed from the leading edge of the content stabiliser 6 past the leading edge of the fourth annulus 62b, creating a barrier to cryogenic air flow from flowing into the interior of the content stabiliser 6.

As shown in fig. 14, in a preferred embodiment, the culvert stabilizer 7 has a hollow structure, and an culvert injection rod 72 is provided inside the culvert stabilizer 7, and an injection port of the culvert injection rod 72 is disposed opposite to the second injection hole 71. The afterburner for staged combustion further comprises a shockproof heat shield 10, wherein the shockproof heat shield 10 is arranged between the outer culvert stabilizer 7 and the casing 1 and is arranged at intervals with the casing 1, and a fifth airflow hole 101 is arranged at the position of the outer culvert stabilizer 7, so that airflow in the outer culvert area b enters the outer culvert stabilizer 7 from a gap between the shockproof heat shield 10 and the casing 1 through the fifth airflow hole 101.

The gap between the shock-proof heat shield 10 and the casing 1 can enter the low-temperature air flow of the culvert area b, and the low-temperature air flow passes through the fifth air flow hole 101 to enter the hollow structure of the culvert stabilizer 7. Therefore, the outer culvert stabilizer 7 with the hollow structure not only can accommodate the outer culvert oil spraying rod 72, but also can effectively isolate the outer culvert oil spraying rod 72 from high-temperature fuel gas outside the outer culvert stabilizer 7, and prevent the outer culvert oil spraying rod 72 from failure faults such as fuel coking blocking oil spraying ports or integral structure deformation and the like due to overhigh working temperature.

In addition, the low-temperature air flow of the culvert area b flows into the culvert stabilizer 7, so that on one hand, the culvert stabilizer 7 can be effectively and pneumatically cooled from the inside, the surface temperature of the culvert stabilizer 7 is maintained in a reasonable range, the structural damage such as ablation or deformation of the culvert stabilizer 7 caused by overhigh surface temperature is prevented, on the other hand, the low-temperature air flow of the culvert area b can be effectively mixed with fuel sprayed out by the culvert oil spraying rod 72, the fuel and the low-temperature air flow of the unburned culvert area b are fully mixed, and further, the combustion effect of the second combustion in the three-culvert working mode and the fifth combustion in the double-culvert working mode of the tissue at the culvert stabilizer 7 is fully achieved.

In a preferred embodiment, the oil injection port of the outer culvert injection rod 72 is spaced from the second injection hole 71 so that the air flow entering the outer culvert area b inside the outer culvert stabilizer 7 through the fifth air flow hole 101 can flow outwardly from the space between the oil injection port of the outer culvert injection rod 72 and the second injection hole 71 and mix with the fuel injected from the outer culvert injection rod 72 to form an air-fuel mixture.

Air flowing outwards from the gap between the oil injection port of the outer culvert oil injection rod 72 and the second injection hole 71 can utilize the narrow throat formed by the gap to accelerate the flow speed of the air, so that the high-speed injection effect is achieved. Further, since the air ejected from the gap at a high speed is annularly located outside the fuel or the oil-gas mixture ejected from the second ejection hole 71, the ejection speed of the fuel is increased and the mixing uniformity of the fuel and the air is improved.

As shown in fig. 12, in a preferred embodiment, the air flow mixing structure 41 at the trailing edge of the aft ducted ejector 4 is a lobe structure 411, the lobe structure 411 being comprised of first lobes 411a and second lobes 411b that are staggered circumferentially. Wherein, on a cross section perpendicular to the axial direction, the cross section patterns of the first and

second lobes

411a and 411b are arc-shaped structures protruding radially inward and outward, respectively. The first lobes 411a and the second lobes 411b with different orientations, which are staggered in the lobe structure 411, can disturb the air flow at two sides, so that the low-temperature air flow in the outer culvert area b and the high-temperature air flow in the inner culvert area a generate stronger mixing motion at the lobe structure 411.

In a preferred embodiment, the lobe height of the lobe structure 411, i.e. the outermost end of the first lobe 411a or the second lobe 411b is 10-20 mm compared to the radial dimension of the circular dividing line between the first lobe 411a and the second lobe 411 b.

In a preferred embodiment, as shown in fig. 12, the rear duct injector 4 is integrally formed with the air flow mixing structure 41, resulting in a higher degree of accuracy in the assembly between the rear duct injector 4 and the air flow mixing structure 41, thereby increasing the integrity of the afterburner. In a preferred embodiment, the rear duct injector 4 and the air flow mixing structure 41 may be connected to each other by a detachable fixing connection, for example, a screw-nut or a mortise-tenon structure, so that the maintenance process is more convenient. In another preferred embodiment, the rear duct injector 4 and the air flow mixing structure 41 may be integrally formed using additive manufacturing techniques, thereby reducing the difficulty in machining and assembling parts of the afterburner and further improving the positional and structural accuracy of the rear duct injector 4 and the air flow mixing structure 41 in the afterburner.

As shown in fig. 7 and 9, in a preferred embodiment, the casing 1 located outside the shunt ring 3 protrudes radially outwards to form a casing outer section 11, and the casing outer section 11 is interconnected with the casing 1 located outside the outer culvert stabilizer 7 by a casing contraction section 12. Wherein the casing outer portion 11 is configured as: when the first air flow channel 81 is opened, the area of a first throat channel c1 between the front edge of the guide ring 9 and the outer convex section 11 of the casing meets the aerodynamic thermal design requirement of an afterburner outdoor culvert area b in a three-culvert working mode; and when the first air flow channel 81 is closed, the area of the second throat channel c2 between the rear edge of the casing contraction section 12 and the rear duct ejector 4 meets the aerodynamic thermal design requirement of the afterburner outdoor culvert area b in the double-culvert operation mode.

The outer casing convex section 11 and the inner casing contraction section 12 of the casing 1 are integrally in a folded wall structure, and are combined with the rear duct ejector 4, so that the rear duct ejector 4 at different axial positions can be matched under the three-outer-culvert working mode and the double-outer-culvert working mode, and the flow area of an outer duct can meet the design requirement.

In a preferred embodiment, the rectifying support plate 5 is a first hollow structure extending from the central cone 2 to the flow dividing ring 3 along the radial direction, the front edge of the first hollow structure is a first flow line structure 53, the rear edge of the first hollow structure is a first blunt body structure 54, the plurality of first injection holes 51 are arranged along the radial direction and are respectively distributed on two circumferential sides of the rectifying support plate 5, and the first injection holes 51 are arranged in a region close to the front edge of the rectifying support plate 5.

Similar to the structure of the rectifying support 5, in a preferred embodiment, the culvert stabilizer 7 is a second hollow structure extending radially inward from the casing 1, a front edge of the second hollow structure is a second fluid line structure 73, a rear edge of the second hollow structure is a second blunt body structure 74, a plurality of second injection holes 71 are arranged radially and distributed on both circumferential sides of the culvert stabilizer 7, respectively, and the second injection holes 71 are disposed in regions near the front edge of the culvert stabilizer 7.

The front edges of the rectifying support plate 5 and the culvert stabilizer 7 are of streamline structures, so that resistance of airflow flowing through the rectifying support plate can be reduced, and the overall efficiency of the afterburner is improved. In addition, the rectifying support plate 5 is different from the front edge structure of the culvert stabilizer 7 under the influence of the difference of the air flow speed at the position so as to adapt to the air flow state at different positions.

The rear edges of the rectifying support plate 5 and the culvert stabilizer 7 are of blunt structures, so that the flow loss can be reduced, and a certain flow-around phenomenon is generated in a downstream area so as to better organize combustion. As shown in fig. 14, the trailing edge of the culvert stabilizer 7 has a substantially rectangular cross-sectional shape, whereby a turbulent flow region can be generated in a downstream region of the rear wall surface to reduce the air flow velocity, thereby improving flame stability of the tissue combustion at the trailing edge of the bluff body.

As shown in fig. 11, in a preferred embodiment, at least two of the rectifying support plate 5, the content stabilizer 6, and the content injection rod 52 are in an integrated structure. Compared with the prior art that the rectifying support plate 5 only has the bearing function, the rectifying support plate 5 has the front edge of the streamline structure and the rear edge of the blunt body structure, so that the bearing function and the flame stabilizing function can be well borne, and the third combustion and the fourth combustion of the staged combustion afterburner in the three-connotation working mode and the double-connotation working mode are possible under the cooperation of the on-duty flame of the connotation stabilizer 6.

On the basis, the invention integrally embeds the connotation oil spraying rod 52 in the rectifying support plate 5, and compared with the technical scheme that the connotation oil spraying rod 52 is axially arranged in front of the rectifying support plate 5 in the prior art, the invention can avoid the direct impact of air flow caused by the exposure of the connotation oil spraying rod 52, so that the installation position of the connotation oil spraying rod 52 is more fixed, the oil spraying position is more accurate, thereby reducing the pneumatic loss and improving the combustion efficiency. In addition, by using the hollow structure of the rectifying support plate 5 and the low-temperature external air flow introduced from the second air flow passage, the internal oil spray rod 52 can be effectively cooled, and the occurrence of faults such as high-temperature thermal deformation or high-temperature coking can be prevented.

In a preferred embodiment, the rectifying support plate 5, the connotation stabilizer 6 and the connotation oil spraying rod 52 are connected with each other in a detachable and fixed connection mode to form an integrated structure, for example, the integrated structure is formed by means of plug-in connection, rotary connection, mortise-tenon connection, bolt connection and the like, so that convenience of the afterburner in the process of disassembling and replacing parts is improved. In another preferred embodiment, the rectifying support plate 5, the connotation stabilizer 6 and the connotation oil injection rod 52 are integrally formed by adopting additive manufacturing technology or are connected by adopting welding technology, so that the part processing difficulty and the assembly difficulty of the afterburner are reduced, and the position and the structural precision of the rectifying support plate 5, the connotation stabilizer 6 and the connotation oil injection rod 52 in the afterburner are further improved.

As shown in FIG. 14, in a preferred embodiment, the inclusion stabilizer 7 is of unitary construction with the inclusion injection rod 72 to enhance the integrity of the components in the afterburner. Similar to the technical scheme that the inner culvert oil spraying rod 52 is arranged in the rectifying support plate 5, the outer culvert oil spraying rod 72 is integrally arranged in the outer culvert stabilizer 7, so that the outer culvert oil spraying rod 72 is prevented from being exposed to the outside and is directly impacted by air flow, the installation position of the outer culvert oil spraying rod 72 is fixed, the oil spraying position is accurate, the pneumatic loss is reduced, and the combustion efficiency is improved. In addition, by using the hollow structure of the culvert stabilizer 7 and the low-temperature culvert air flow introduced from the shock-proof heat shield 10, the culvert oil spray rod 72 can be effectively cooled, and the occurrence of faults such as high-temperature thermal deformation and high-temperature coking can be prevented.

In a preferred embodiment, the outer culvert stabilizer 7 and the outer culvert oil injection rod 72 are integrally formed in a detachable and fixed connection manner, such as a plug-in connection, a rotary connection, a mortise-tenon connection and the like, so as to improve the convenience of the afterburner in the process of disassembling and replacing parts. In another preferred embodiment, the outer culvert stabilizer 7 and the outer culvert oil injection rod 72 are integrally formed by adopting additive manufacturing technology, so that the part processing difficulty and the assembly difficulty of the afterburner are reduced, and the position and the structural precision of the outer culvert stabilizer 7 and the outer culvert oil injection rod 72 in the afterburner are further improved.

In a preferred embodiment, the plurality of culvert ejectors are circumferentially uniform, and the number of culvert stabilizers 7 is 1-2 times the number of rectifying support plates 5. Typically, the number of rectifying support plates 5 is 10 to 20, preferably 12, and the number of culvert stabilizers 7 is 10 to 20, preferably 12. When the number of the rectifying support plates 5 and the culvert stabilizers 7 is 12, the included angles between the adjacent rectifying support plates 5 and the adjacent culvert stabilizers 7 are 30 degrees.

In a preferred embodiment, the width of the slots of the rectifying support plate 5 is 20 to 40mm and the width of the slots of the fourth face of the outer stabilizer ring 62 in the content stabilizer 6 is 20 to 40mm. The above-described groove width is defined as the circumferential dimension of the rectifying support 5 or the fourth surface when viewed from the rear to the front in the axial direction.

In a preferred embodiment, the inner culvert injection rods 52 in the rectifying support plate 5 and the outer culvert injection rods 72 in the outer culvert stabilizer are both used for injecting fuel outwards in a direct injection nozzle structure, and the direct injection nozzle has the advantages of simple structure, strong injection direction controllability, difficult coking and the like, and is more suitable for the afterburner of the invention.

in the three-culvert working mode, the afterburner for staged combustion of the invention introduces part of the culvert low-temperature air flow into the connotation and organizes and combusts in the area where the culvert stabilizer is positioned, and the burnt culvert air flow and the unburned culvert low-temperature air flow are mixed at the air flow mixing structure 411 at the tail part of the rear culvert ejector 4 and are organized and combusts at the tail edge of the culvert stabilizer 7. Compared with the traditional afterburner with medium bypass ratio, the invention carries out low-temperature airflow staged combustion on the bypass, thereby reducing the lobe size and the flow loss on the premise of not influencing the combustion efficiency;

In the double culvert operation mode, the afterburner for staged combustion mixes the low-temperature air flow of the culvert with the high-temperature air flow of the culvert at the air flow mixing structure 411 at the tail part of the rear culvert ejector 4 and combusts the air flow at the tail edge of the culvert stabilizer 7. The addition of the air flow mixing structure 411 of the present invention, while resulting in a slight increase in flow losses, greatly increases combustion efficiency compared to conventional low bypass afterburners.

So far, some specific embodiments of the invention have been described in detail by way of example, it will be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the invention. It will be understood by those skilled in the art that the foregoing embodiments may be modified and equivalents substituted for elements thereof without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A staged combustion afterburner comprising:

a casing (1);

the center cone (2) is arranged along the central shaft of the casing (1);

a splitter ring (3) which is arranged circumferentially outside the central cone (2) and divides the gas flow area in the afterburner into an outer culvert area (b) between the splitter ring (3) and the casing (1) and an inner culvert area (a) between the splitter ring (3) and the central cone (2);

The rear duct ejector (4) is in an annular structure, is circumferentially arranged on the outer side of the split ring (3), and is provided with an airflow mixing structure (41) at the tail edge;

the rectifying support plate (5) is arranged between the central cone (2) and the flow dividing ring (3) and is provided with a plurality of first injection holes (51) capable of selectively injecting the oil-gas mixture outwards;

the connotation stabilizer (6) is arranged on the inner side of the flow distribution ring (3) and is arranged in a staggered manner with the rectification support plate (5) along the circumferential direction; and

the external culvert stabilizer (7) is arranged on the inner side of the casing (1) and is positioned on the rear side of the rear culvert ejector (4), and a plurality of second injection holes (71) capable of selectively injecting the oil-gas mixture outwards are formed in the external culvert stabilizer;

the first airflow channel (81) is formed in the area where the split ring (3) and/or the rear duct ejector (4) are/is located and is used for communicating the outer culvert area (b) with the inner culvert area (a); and

an adjustment element capable of selectively opening said first air flow passage (81) to bring the afterburner into a three-culvert operation mode, or closing said first air flow passage (81) to bring the afterburner into a double-culvert operation mode;

-a first combustion, a portion of the air flow of the culvert area (b) entering the culvert area (a) through the first air flow passage (81), being mixed with the air flow of the culvert area (a) and being organized to burn in the area where the culvert stabilizer (6) is located after receiving the air-fuel mixture ejected from the first ejection hole (51);

-a second combustion, in which the air flow after the first combustion is mixed at the air flow mixing structure (41) with the partial air flow in the culvert area (b) which does not enter the first air flow channel (81), and after receiving the air-fuel mixture ejected from the second ejection hole (71), is organized and burned in the area where the culvert stabilizer (7) is located; and

-a third combustion, a portion of the air flow in the connotation zone (a) receiving the air-fuel mixture ejected by the first ejection holes (51) and organizing combustion in the zone where the rectifying support (5) is located;

-fourth combustion, the air flow in the connotation zone (a) receiving the air-fuel mixture ejected by the first ejection holes (51) and organizing combustion in the zone where the rectifying support (5) and connotation stabilizer (6) are located; and

-fifth combustion, the air flow of the culvert area (b) being mixed with part of the air flow of the culvert area (a) at the air flow mixing structure (41) and being organized to burn in the area where the culvert stabilizer (7) is located after receiving the air-fuel mixture ejected by the second ejection holes (71).

2. The afterburner for staged combustion according to claim 1, wherein the splitter ring (3) is provided with a first air flow hole (31) and the rear duct injector (4) is provided with a second air flow hole (42) opposite to the first air flow hole (31), and the first air flow hole (31) and the second air flow hole (42) are communicated with each other to form the first air flow channel (81);

wherein the adjusting element comprises an actuating device which can drive the split ring (3) and the rear duct injector (4) to move relatively, so that the first airflow channel (81) is opened or closed by controlling the first airflow hole (31) and the second airflow hole (42) to be mutually overlapped or staggered.

3. The staged combustion afterburner of claim 2, further comprising:

and a guide ring (9) with a first end arranged outside the rear duct ejector (4) and positioned at the rear part of the second airflow hole (42), and a second end extending forwards and outwards relative to the first end of the guide ring (9) so as to guide part of airflow in the outer culvert area (b) to enter the second airflow hole (42).

4. The afterburner for staged combustion according to claim 2, wherein the inside of the rectifying support plate (5) is of a hollow structure, an inclusion injection rod (52) is arranged inside the rectifying support plate (5), an injection port of the inclusion injection rod (52) is opposite to the first injection hole (51), a third air flow hole (32) is arranged on the position opposite to the rectifying support plate (5) of the splitter ring (3), and a fourth air flow hole (43) is arranged on the position corresponding to the third air flow hole (32) of the rear duct injector (4);

wherein the third airflow aperture (32) and the fourth airflow aperture (43) are configured to: and the flow dividing ring (3) and the rear duct ejector (4) are communicated in the process of being driven by the actuating device to relatively move, so that a second air flow channel (82) which enters the interior of the rectifying support plate (5) from the outer culvert area (b) through the fourth air flow holes (43) and the third air flow holes (32) is formed.

5. The afterburner for staged combustion according to claim 4 wherein the fuel injection openings of the content fuel injection bars (52) are arranged in spaced relation to the first injection holes (51) such that the air flow entering the outer culvert area (b) inside the rectifying support plate (5) through the second air flow channel (82) can flow outwardly from the space between the fuel injection openings of the content fuel injection bars (52) and the first injection holes (51) and intermix with the fuel injected from the content fuel injection bars (52) to form an oil-gas mixture.

6. The staged combustion afterburner according to claim 2, wherein the connotation stabilizer (6) comprises:

an inner stabilizer ring (61) comprising a first annulus (61 a) extending axially and a second annulus (61 b) extending outwardly from a leading edge of the first annulus (61 a) to an inner side of the diverter ring (3); and

an outer stabilizer ring (62) including a third ring surface (62 a) extending axially and disposed at intervals inside the first ring surface (61 a), and a fourth ring surface (62 b) extending outwardly from a leading edge of the third ring surface (62 a) to an inside of the splitter ring (3);

the first annular surface (61 a), the second annular surface (61 b) and the third annular surface (62 a) are attached to the rectifying support plate (5) along two ends in the circumferential direction, and the fourth annular surface (62 b) is axially positioned at the front side of the second annular surface (61 b) and is arranged at intervals with the rectifying support plate (5) along the circumferential direction;

and wherein a projection of at least one of the plurality of first injection holes (51) near the flow distribution ring (3) in the circumferential direction falls inside an area surrounded by the second annular surface (61 b), the fourth annular surface (62 b) and the flow distribution ring (3).

7. The staged combustion afterburner according to claim 6 wherein the fourth annulus (62 b) extends forward and outwardly to the inside of the splitter ring (3) relative to the leading edge of the third annulus (62 a), the intersection of the fourth annulus (62 b) with the splitter ring (3) is located aft of the first airflow aperture (31), and the fourth annulus (62 b) has a circumferential dimension no less than the circumferential dimension of the first airflow aperture (31).

8. The afterburner for staged combustion according to claim 1, characterized in that the culvert stabilizer (7) is of a hollow structure, an culvert oil injection rod (72) is arranged inside the culvert stabilizer (7), and an oil injection port of the culvert oil injection rod (72) is arranged opposite to the second injection hole (71);

wherein the staged combustion afterburner further comprises:

the vibration-proof heat shield (10) is arranged between the external culvert stabilizer (7) and the casing (1) and is arranged at intervals with the casing (1), and a fifth airflow hole (101) is arranged at the position, opposite to the external culvert stabilizer (7), on the vibration-proof heat shield, so that airflow in the external culvert area (b) passes through the fifth airflow hole (101) from a gap between the vibration-proof heat shield (10) and the casing (1) to enter the internal part of the external culvert stabilizer (7).

9. The afterburner for staged combustion according to claim 8, wherein the injection openings of the outer culvert injection bars (72) are arranged in a spaced relationship with the second injection holes (71) such that the air flow entering the outer culvert area (b) inside the outer culvert stabiliser (7) through the fifth air flow holes (101) can flow outwardly from the gap between the injection openings of the outer culvert injection bars (72) and the second injection holes (71) and intermix with the fuel injected from the outer culvert injection bars (72) to form an air-fuel mixture.

10. The staged combustion afterburner according to claim 1, characterized in that the air flow mixing structure (41) at the trailing edge of the rear duct ejector (4) is a lobe structure (411), the lobe structure (411) being constituted by first and second lobes (411 a, 411 b) arranged alternately in the circumferential direction;

wherein, on a cross section perpendicular to the axial direction, the cross section patterns of the first lobe (411 a) and the second lobe (411 b) are arc-shaped structures protruding inward and outward in the radial direction, respectively.

11. Staged combustion afterburner according to claim 10, wherein the rear duct ejector (4) is of integral construction with the air flow mixing structure (41).

12. A staged combustion afterburner according to claim 3, characterized in that the casing (1) outside the splitter ring (3) protrudes radially outwards to form a casing outer section (11), the casing outer section (11) being interconnected with the casing (1) outside the outer culvert stabiliser (7) in a casing constriction (12);

wherein the outer casing portion (11) is configured as:

when the first airflow channel (81) is opened, the area of a first throat (c 1) between the front edge of the guide ring (9) and the outer convex section (11) of the casing meets the aerodynamic thermal design requirement of an afterburner outer culvert area (b) in a three-culvert working mode; and

When the first airflow channel (81) is closed, the area of a second throat (c 2) between the rear edge of the casing contraction section (12) and the rear duct ejector (4) meets the aerodynamic thermal design requirement of an afterburner outdoor culvert area (b) in a double-culvert working mode.

13. The afterburner for staged combustion according to claim 4, wherein the rectifying support plate (5) has a first hollow structure extending radially from the central cone (2) to the splitter ring (3), a front edge of the first hollow structure has a first streamlined body structure (53), a rear edge of the first hollow structure has a first blunt body structure (54), a plurality of the first injection holes (51) are radially arranged and respectively distributed on both circumferential sides of the rectifying support plate (5), and the first injection holes (51) are provided in a region near the front edge of the rectifying support plate (5).

14. Afterburner for staged combustion according to claim 13, wherein at least two of the rectifying support plate (5), the content stabilizer (6) and the content injection rod (52) are of integrated construction.

15. The afterburner for staged combustion according to claim 8, wherein the outer culvert stabilizer (7) is in a second hollow structure extending radially inwards from the casing (1), a leading edge of the second hollow structure is in a second streamlined body structure (73), a trailing edge of the second hollow structure is in a second blunt body structure (74), a plurality of the second injection holes (71) are arranged radially and distributed on both circumferential sides of the outer culvert stabilizer (7), respectively, and the second injection holes (71) are provided in a region near the leading edge of the outer culvert stabilizer (7).

16. The afterburner for staged combustion according to claim 15, wherein the culvert stabilizer (7) is of unitary construction with the culvert injection rod (72).

17. Afterburner for staged combustion according to claim 1, characterized in that a plurality of the culvert stabilizers (7) are evenly distributed in the circumferential direction and the number of the culvert stabilizers (7) is 1-2 times the number of the rectifying support plates (5).