A distributed fuel injection device and method for a rotary detonation combustion chamber

Abstract

The application provides a distributed fuel injection device and method for a rotating detonation combustion chamber, and relates to the field of aircraft engines.The fuel injection device comprises a combustor, a first fuel injection unit and a second fuel injection unit.The combustor is provided with a combustion chamber, an air inlet and an air outlet.The air inlet is used for being communicated with an air inlet device of an engine, and the air outlet is used for discharging combusted gas.The first fuel injection unit comprises a swirl nozzle, which is installed on the combustor and used for injecting fuel into the combustion chamber so that the fuel forms a first atomized flow field in a wall surface area of the combustion chamber under the action of airflow.The second fuel injection unit comprises a straight injection nozzle, which is installed on the combustor and located downstream of the swirl nozzle in the airflow flow direction.The straight injection nozzle is used for injecting fuel into the combustion chamber so that the fuel forms a second atomized flow field in an area of the combustion chamber far from the wall surface under the action of airflow.The engine can be stably and reliably operated under a wide Mach number condition.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of jet propulsion devices, in particular to a distributed fuel injection device and method for a rotary detonation combustion chamber. BACKGROUND

[0002] The rotary detonation engine belongs to an engine using combustion to generate airflow, and the thrust of the engine is obtained according to the reaction force principle by the airflow. The rotary detonation engine works by detonation combustion, and has great potential in improving the performance of traditional engines. The rotary detonation engine usually adopts an annular combustion chamber, the reactants enter the annular combustion chamber along the axial direction, the detonation wave rotates continuously along the circumferential direction, and the combustion products are discharged from the engine along the axial direction through a nozzle, thereby avoiding the problems of limited combustion chamber length and working frequency caused by the axial and intermittent movement of the pulse detonation engine. The rotary detonation engine has high thermodynamic efficiency, small volume and light weight, thereby improving the thrust-to-weight ratio of the aircraft.

[0003] At present, the combustion chamber is composed of a diffuser, a flame tube, a fuel injection device and an ignition device. The function of the fuel injection device is to atomize the fuel, accelerate the formation of the mixture, promote stable combustion of the fuel and improve the fuel combustion efficiency, so as to provide stable reaction thrust. Whether the jet propulsion engine works reliably depends largely on the reliability of the fuel injection device, and the fuel supply in the fuel injection device is the core point.

[0004] The inventor has found that the rotary detonation engine in the prior art at least has the following disadvantages:

[0005] The atomization quality of the fuel in the fuel injection device under wide flight Mach number conditions is poor, and the fuel combustion is not sufficient, so that the performance of the jet propulsion engine is low and the working stability is poor. SUMMARY

[0006] The purpose of the present application is to provide a distributed fuel injection device and method for a rotary detonation combustion chamber, which can improve the performance and working stability of the jet propulsion engine under wide flight Mach number conditions.

[0007] The embodiment of the present application is implemented as follows:

[0008] In a first aspect, the present application provides a distributed fuel injection device for a rotary detonation combustion chamber, comprising:

[0009] a combustor, the combustor being provided with a combustion chamber, an air inlet and an air outlet which are all in communication with the combustion chamber, the air inlet being used for communication with an air inlet device of an engine, and the air outlet being used for discharging the combusted gas;

[0010] a first fuel injection unit comprising a swirl nozzle mounted on the combustor for injecting fuel into the combustion chamber to form a first atomized flow field of fuel in a region of the combustion chamber away from the wall surface under the action of the gas flow;

[0011] and a second fuel injection unit comprising a direct injection nozzle mounted on the combustor, the direct injection nozzle being located downstream of the swirl nozzle in the direction of gas flow, the direct injection nozzle being used for injecting fuel into the combustion chamber to form a second atomized flow field of fuel in a region of the combustion chamber away from the wall surface under the action of the gas flow.

[0012] In an optional embodiment, the combustor comprises a first cylinder and a second cylinder, the first cylinder being sleeved outside the second cylinder, the first cylinder and the second cylinder together defining the annular combustion chamber; one end of the first cylinder and the second cylinder defines the annular gas inlet, the other end of the first cylinder and the second cylinder defines the annular gas outlet; the swirl nozzle and the direct injection nozzle are both mounted on the cylinder wall of the first cylinder.

[0013] In an optional embodiment, the first cylinder comprises a first guide cylinder section, a first diffuser cylinder section and a first combustion cylinder section connected in sequence, the first guide cylinder section and the first combustion cylinder section are both constant diameter sections, the diameter of the first guide cylinder section is smaller than the diameter of the first combustion cylinder section; the diameter of the first diffuser cylinder section gradually increases in the direction from the first guide cylinder section to the first combustion cylinder section; the first guide cylinder section is provided with a first inlet on the cylinder wall, and the swirl nozzle is mounted on the first guide cylinder section and communicates with the first inlet.

[0014] In an optional embodiment, the first cylinder further comprises a first outer flange structure and a second outer flange structure, the first outer flange structure is connected to one end of the first guide cylinder section away from the first diffuser cylinder section, and the second outer flange structure is connected to one end of the first combustion cylinder section away from the first diffuser cylinder section.

[0015] In an optional embodiment, the second cylinder comprises a second guide cylinder section, a second diffuser cylinder section and a second combustion cylinder section connected in sequence, the second guide cylinder section and the second combustion cylinder section are both constant diameter sections, the diameter of the second guide cylinder section is greater than the diameter of the second combustion cylinder section; the diameter of the second diffuser cylinder section gradually decreases in the direction from the second guide cylinder section to the second combustion cylinder section; the second guide cylinder section is provided with a second inlet on the cylinder wall, and the direct injection nozzle is mounted on the second diffuser cylinder section and communicates with the second inlet; the end of the first guide cylinder section and the second guide cylinder section defines the annular gas inlet; the end of the first combustion cylinder section and the second combustion cylinder section defines the annular gas outlet;

[0016] The combustion chamber comprises a flow guide section, a diffuser section and a combustion chamber connected in sequence, the flow passage section of the flow guide section is smaller than the flow passage section of the combustion chamber, and the flow passage section of the diffuser section gradually increases in the direction from the flow guide section to the combustion chamber.

[0017] In an optional embodiment, the second cylinder further comprises a first inner flange structure and a second inner flange structure, the first inner flange structure is connected to one end of the second guide cylinder section away from the second diffuser cylinder section, and the second inner flange structure is connected to one end of the second combustion cylinder section away from the second diffuser cylinder section.

[0018] In an optional embodiment, the swirl nozzle comprises an outer shell and a swirl shell, the outer shell has opposite first open end and first closed end, the first open end is used for inputting fuel; the swirl shell has opposite second open end and second closed end, a plurality of swirl holes are arranged on the peripheral wall of the swirl shell, the plurality of swirl holes are arranged at intervals in the circumferential direction of the swirl shell, the axis of each swirl hole is tangent to the peripheral wall of the swirl shell, each swirl hole is communicated with the second open end, and the second open end is communicated with the combustion chamber; the swirl shell is installed in the outer shell, the second open end penetrates the first closed end, and the swirl shell cooperates with the outer shell to define an annular oil channel communicated with the swirl holes, and the annular oil channel is communicated with the first open end.

[0019] In an optional embodiment, the swirl shell has a diameter-expanding hole section, the diameter of the diameter-expanding hole section gradually decreases in the direction from the second open end to the second closed end, one end of the diameter-expanding hole section away from the second closed end is arranged as the second open end, and the plurality of swirl holes are located between the second closed end and the diameter-expanding hole section.

[0020] In an optional embodiment, the direct injection nozzle is provided with a variable-diameter oil injection hole, the end with a larger opening of the variable-diameter oil injection hole is used for inputting fuel, and the end with a smaller opening of the variable-diameter oil injection hole is communicated with the combustion chamber.

[0021] In a second aspect, the present application provides a distributed oil injection method for a rotary detonation combustion chamber, which is suitable for the distributed oil injection device of any one of the foregoing embodiments, and the method comprises:

[0022] When the engine operates at a high altitude in a low Mach number state, the first oil injection unit is started, fuel enters the combustion chamber, is atomized under the action of airflow, and forms a first atomized flow field uniformly distributed in the combustion chamber;

[0023] When the engine is working at high altitude in a high Mach number state, the first fuel injection unit and the second fuel injection unit are started, fuel enters the combustion chamber, and under the action of the airflow, the fuel entering from the first fuel injection unit is atomized and forms a first atomized flow field distributed in the combustion chamber; the fuel entering from the second fuel injection unit is atomized and forms a second atomized flow field distributed in the combustion chamber; the first atomized flow field and the second atomized flow field cooperate to uniformly distribute in the combustion chamber.

[0024] The beneficial effects of the embodiment of the present application are:

[0025] In summary, the distributed fuel injection device of the rotating detonation combustion chamber provided in the embodiment is configured with zoned and distributed swirl nozzles and direct injection nozzles on the combustion chamber, and the swirl nozzles and the direct injection nozzles cooperate to ensure stable operation of the engine under wide flight Mach number conditions and improve the reliability and stability of the engine under wide flight Mach number conditions. That is, in order to ensure the stability of the rotating detonation engine when working in a wide speed range, it is required that the fuel atomization quality be high at high altitude and low Mach number, and the fuel penetration ability be strong at high altitude and high Mach number. Therefore, the embodiment adopts a combined distributed fuel injection scheme of swirl nozzles and direct injection nozzles, which is as follows:

[0026] When the engine is working at high altitude in a low Mach number state, the engine flow is small, the airflow dynamic pressure is small, and the fuel is easy to penetrate in the airflow. The swirl nozzles are opened, and after the fuel is injected into the combustion chamber through the swirl nozzles, the fuel has flow velocities in the radial and circumferential directions of the combustion chamber. After the fuel contacts the airflow, it is torn into fuel droplets under the joint action of centrifugal force and airflow, achieving atomization, and finally forming an atomized flow field in the entire combustion chamber. At this time, the stable operation of the engine under low Mach number conditions can be met.

[0027] When the engine is working at high Mach number, the fuel flow and penetration depth required are large. At this time, the swirl nozzles and the direct injection nozzles work simultaneously. The swirl nozzles can form a first atomized flow field in the wall area of the combustion chamber, and the direct injection nozzles can form a second atomized flow field in the central area of the combustion chamber. In this way, the first atomized flow field and the second atomized flow field cooperate to form a high-quality full-atomized flow field, which ensures both atomization quality and penetration depth, so that the atomized flow field can be uniformly distributed in the combustion chamber, ensuring stable operation of the engine under high Mach number conditions.

[0028] At the same time, the swirl nozzles are installed in the flow guide section, and the flow guide section has a small combustion chamber height, which is suitable for the characteristics of high atomization quality and small penetration depth of the swirl nozzles. The direct injection nozzles are installed in the diffuser section, and the diffuser section has a large combustion chamber height, which is suitable for the characteristics of large penetration depth of the direct injection nozzles. The first diffuser section and the second diffuser section are both installed with direct injection nozzles, which meets the full flow field penetration of fuel in the diffuser section under high Mach number conditions of the engine, and the fuel is uniformly distributed, the atomization quality is high, and the combustion efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0030] Figure 1 A perspective view of the structure of the distributed fuel injection device of the rotating detonation combustion chamber according to the embodiment of the present application;

[0031] Figure 2 Another perspective view of the structure of the distributed fuel injection device of the rotating detonation combustion chamber according to the embodiment of the present application;

[0032] Figure 3 A sectional view of the structure of the distributed fuel injection device of the rotating detonation combustion chamber according to the embodiment of the present application;

[0033] Figure 4 A perspective view of the structure of the first cylinder according to the embodiment of the present application;

[0034] Figure 5 A sectional view of the structure of the second cylinder according to the embodiment of the present application;

[0035] Figure 6 A sectional view of the structure of the rotating flow nozzle according to the embodiment of the present application;

[0036] Figure 7 A sectional view of the structure of the direct injection nozzle according to the embodiment of the present application.

[0037] FIG.:

[0038] 100 - combustor; 101 - air inlet; 102 - air outlet; 103 - combustion chamber; 1031 - flow guide section; 1032 - diffuser section; 1033 - combustion cavity; 110 - first cylinder; 111 - first guide cylinder section; 112 - first diffuser cylinder section; 113 - first combustion cylinder section; 114 - first flange structure; 115 - second flange structure; 116 - first inlet; 117 - second inlet; 120 - second cylinder; 121 - second guide cylinder section; 122 - second diffuser cylinder section; 123 - second combustion cylinder section; 124 - first flange structure; 125 - second flange structure; 200 - first oil injection unit; 210 - swirl nozzle; 211 - housing; 2111 - first open end; 2112 - first closed end; 212 - swirl housing; 2121 - second open end; 2122 - second closed end; 2123 - swirl cavity; 2124 - swirl hole; 2125 - diameter expanding hole section; 213 - annular oil channel; 220 - first oil delivery pipe; 300 - second oil injection unit; 310 - straight jet nozzle; 311 - diameter changing oil injection hole; 320 - second oil delivery pipe; 400 - high frequency pressure sensor. DETAILED DESCRIPTION

[0039] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative work fall within the scope of protection of the present application.

[0041] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0042] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like indicate positions or locations based on the positions shown in the accompanying drawings, or the positions or locations in which the inventive product is typically placed when in use. These terms are intended solely to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0043] Furthermore, terms such as "horizontal" and "vertical" do not necessarily mean that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0044] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0045] In the prior art, a rotating detonation engine is a type of jet propulsion device. The combustion device of a rotating detonation engine includes a diffuser, a flame tube, a fuel injection device, and an initiator. The function of the fuel injection device is to atomize the fuel, accelerate the formation of the mixture, promote stable combustion, and improve combustion efficiency. The reliability of the operation of a jet propulsion engine depends to a large extent on the reliability of the fuel injection device. The inventors found in their research that when the rotating detonation engine operates at a low Mach number, the airflow pressure is small and the fuel atomization is relatively simple; when the rotating detonation engine operates at a high Mach number, the airflow pressure is large, forming a large obstacle to the fuel entering the combustion chamber, the penetration depth of the fuel in the airflow is small, and atomization is relatively difficult. As a result, the existing rotating detonation engine has poor fuel atomization quality under wide Mach number conditions, and the fuel combustion is not sufficient, resulting in low performance and poor working stability of the jet propulsion engine.

[0046] In view of this, the designer provides a rotating detonation combustion chamber distributed fuel injection device, which can ensure the stable operation of the engine under high altitude and low Mach number conditions, and can also ensure stable operation under high altitude and high Mach number conditions. In this way, the engine can operate stably and reliably under wide Mach number conditions.

[0047] Please refer to Figures 1-7 In the embodiment, the distributed fuel injection device of the rotary detonation combustion chamber comprises a combustor 100, a first fuel injection unit 200 and a second fuel injection unit 300. The combustor 100 is provided with a combustion chamber 103, an air inlet 101 and an air outlet 102 which are all communicated with the combustion chamber 103. The air inlet 101 is used to communicate with the air inlet device of the engine, and the air outlet 102 is used to discharge the burned gas. The first fuel injection unit 200 comprises a swirl nozzle 210 which is installed on the combustor 100 and used to inject fuel into the combustion chamber 103 so that the fuel forms a first atomized flow field in the wall area of the combustion chamber 103 under the action of the airflow. The second fuel injection unit 300 comprises a direct injection nozzle 310 which is installed on the combustor 100 and located downstream of the swirl nozzle 210 in the airflow direction. The direct injection nozzle 310 is used to inject fuel into the combustion chamber 103 so that the fuel forms a second atomized flow field in the area away from the wall of the combustion chamber 103 under the action of the airflow.

[0048] As described above, the working mode of the distributed fuel injection device of the rotary detonation combustion chamber provided in the embodiment is as follows:

[0049] When the engine works in the high-altitude low-Mach number state, the engine flow is small, the airflow dynamic pressure is small, the influence of the airflow dynamic pressure on the combustion exhaust into the combustion channel is small, the resistance is small, and the fuel is easy to penetrate in the airflow. The swirl nozzle 210 is opened, and after the fuel is injected into the combustion chamber 103 through the swirl nozzle 210, the fuel has flow velocity in the radial and circumferential directions of the combustion chamber 103 at the same time. After the fuel contacts with the airflow, it is torn into fuel liquid beads in the form of droplets under the joint action of centrifugal force and airflow shear, realizing atomization, and finally forming a first atomized flow field in the entire combustion chamber 103. The first atomized flow field is distributed in the entire cross-sectional area of the combustion chamber 103. At this time, the stable operation of the engine in the low-Mach number state can be met.

[0050] When the engine works in high Mach number state, the fuel flow and the penetration depth are large, at this time, the swirl nozzle 210 and the straight jet nozzle 310 work simultaneously, the swirl nozzle 210 can form a first atomized flow field in the wall area of the combustion chamber 103, and the straight jet nozzle 310 can form a second atomized flow field in the central area of the combustion chamber 103, in this way, the first atomized flow field and the second atomized flow field cooperate to form a high-quality full-atomized flow field, which not only ensures the atomization quality, but also ensures the penetration depth, so that the atomized flow field can be uniformly distributed in the combustion chamber 103, ensuring the stable operation of the engine in high Mach number state. Wherein, uniform distribution can be understood as the fuel can move from the outside to the inside of the annular cross-sectional area of the combustion chamber 103, in this way, the fuel can be well distributed in the entire cross-sectional area of the combustion chamber 103, and the fuel can be atomized in the cross-sectional area of the combustion chamber 103, thereby realizing full-atomized flow field, in this way, the atomized flow field has high quality, and the engine works stably and reliably. The cross section of the combustion chamber 103 is a plane perpendicular to the axis of the combustion chamber 103.

[0051] The following embodiments illustrate the details of the distributed fuel injection device of the rotating detonation combustion chamber of the present application.

[0052] Please refer to Figure 3 and Figure 4 , in this embodiment, optionally, the combustor 100 includes a first cylinder 110 and a second cylinder 120, the first cylinder 110 is sleeved outside the second cylinder 120, and the first cylinder 110 and the second cylinder 120 jointly define an annular combustion chamber 103, that is, the cross-sectional shape of the combustion chamber 103 is a circular ring. One end of the first cylinder 110 and the second cylinder 120 defines an annular air inlet 101, and the other end of the first cylinder 110 and the second cylinder 120 defines an annular air outlet 102. The swirl nozzle 210 and the straight jet nozzle 310 are both installed on the cylinder wall of the first cylinder 110, and at the same time, a plurality of straight jet nozzles 310 are also installed on the cylinder wall of the second cylinder 120. In this way, the combustor 100 has simple structure, is convenient for processing and manufacturing, has high assembly quality, and is also convenient for cooperating with other parts of the engine, such as the air inlet device.

[0053] Specifically, the first cylinder 110 includes a first guide cylinder segment 111, a first diffuser cylinder segment 112, a first combustion cylinder segment 113, a first outer flange structure 114, and a second outer flange structure 115. The first outer flange structure 114, the first guide cylinder segment 111, the first diffuser cylinder segment 112, the first combustion cylinder segment 113, and the second outer flange structure 115 are connected in sequence. It should be understood that the first cylinder 110 can be provided as an integral structure, which is convenient for processing and manufacturing, has good overall structural integrity, high structural strength, strong anti-deformation ability, and long service life. At the same time, the first guide cylinder segment 111 and the first combustion cylinder segment 113 are equal-diameter segments, the cross-sectional shape of the first guide cylinder segment 111 and the first combustion cylinder segment 113 is a circular ring, and the diameter of the first guide cylinder segment 111 is smaller than the diameter of the first combustion cylinder segment 113. A plurality of first inlets 116 are arranged on the cylinder wall of the first guide cylinder segment 111, and the plurality of first inlets 116 are uniformly and spacedly arranged in the circumferential direction of the first guide cylinder segment 111. For example, in the embodiment, the number of first inlets 116 is five, and the axis of each first inlet 116 extends in the radial direction of the first guide cylinder segment 111. The cross-sectional profile of the first diffuser cylinder segment 112 is a circular ring, the diameter of the first diffuser cylinder segment 112 gradually increases in the direction from the first guide cylinder segment 111 to the first combustion cylinder segment 113, that is, the diameter of one end of the first diffuser cylinder segment 112 connected to the first guide cylinder segment 111 is smaller than the diameter of one end of the first diffuser cylinder segment 112 connected to the first combustion cylinder segment 113, and the diameter of the end of the first diffuser cylinder segment 112 communicated with the first guide cylinder segment 111 is equal to the diameter of the first guide cylinder segment 111. At the same time, the diameter of the end of the first diffuser cylinder segment 112 communicated with the first combustion cylinder segment 113 is equal to the diameter of the first combustion cylinder segment 113. A plurality of second inlets 117 are arranged on the first diffuser cylinder segment 112, and the plurality of second inlets 117 are uniformly and spacedly arranged in the circumferential direction of the first diffuser cylinder segment 112. For example, in the embodiment, the number of second inlets 117 can be eight, and the axis of each second inlet 117 is perpendicular to the peripheral wall of the first diffuser cylinder segment 112.

[0054] Please combine Figure 3 and Figure 5The second cylinder 120 includes a second guide cylinder segment 121, a second diffuser cylinder segment 122, a second combustion cylinder segment 123, a first inner flange structure 124, and a second inner flange structure 125. The first inner flange structure 124, the second guide cylinder segment 121, the second diffuser cylinder segment 122, the second combustion cylinder segment 123, and the second inner flange structure 125 are sequentially connected. It should be understood that the second cylinder 120 can be provided as an integral structure, facilitating machining and manufacturing, and having good overall structural integrity, high structural strength, strong anti-deformation capability, and long service life. At the same time, the second guide cylinder segment 121 and the second combustion cylinder segment 123 are constant-diameter segments, the cross-sectional shape of the second guide cylinder segment 121 and the second combustion cylinder segment 123 is a circular ring, and the diameter of the second guide cylinder segment 121 is smaller than the diameter of the second combustion cylinder segment 123. The cross-sectional profile of the second diffuser cylinder segment 122 is a circular ring, and the diameter of the second diffuser cylinder segment 122 gradually decreases in the direction from the second guide cylinder segment 121 to the second combustion cylinder segment 123, that is, the diameter of one end of the second diffuser cylinder segment 122 connected to the second guide cylinder segment 121 is greater than the diameter of one end of the second diffuser cylinder segment 122 connected to the second combustion cylinder segment 123, and the diameter of the one end of the second diffuser cylinder segment 122 communicated with the second guide cylinder segment 121 is equal to the diameter of the second guide cylinder segment 121. At the same time, the diameter of the one end of the second diffuser cylinder segment 122 communicated with the second combustion cylinder segment 123 is equal to the diameter of the second combustion cylinder segment 123.

[0055] It should be noted that the first cylinder 110 is sleeved outside the second cylinder 120, and the two define an annular combustion chamber 103. The combustion chamber 103 includes a flow guiding segment 1031, a diffuser segment 1032, and a combustion cavity 1033 which are sequentially communicated. Specifically, the first guide cylinder segment 111 and the second guide cylinder segment 121 cooperatively define the flow guiding segment 1031, the first diffuser cylinder segment 112 and the second diffuser cylinder segment 122 cooperatively define the diffuser segment 1032, and the first combustion cylinder segment 113 and the second combustion cylinder segment 123 cooperatively define the combustion cavity 1033. The flow passage cross section of the flow guiding segment 1031 is smaller than the flow passage cross section of the combustion cavity 1033, and the flow passage cross section of the diffuser segment 1032 gradually increases in the direction from the flow guiding segment 1031 to the combustion cavity 1033. In this way, the fuel needs to penetrate to a small depth to enter the flow guiding segment 1031, and needs to penetrate to a large depth to enter the diffuser segment 1032 and the combustion cavity 1033. The flow passage cross section is a plane perpendicular to the axis of the combustion chamber 103. In this way, the plurality of first inlets 116 are communicated with the flow guiding segment 1031, and the plurality of second inlets 117 are communicated with the diffuser segment 1032.

[0056] Please refer to Figure 3 and Figure 6In the embodiment, the first fuel injection unit 200 can include a first fuel supply pipe 220 and a plurality of swirl nozzles 210. The first fuel supply pipe 220 can be an annular pipe and can be configured to communicate with a fuel supply device of the engine. One end of each of the plurality of swirl nozzles 210 can be configured to communicate with a wall of the first fuel supply pipe 220, and the other end of each of the plurality of swirl nozzles 210 can be configured to communicate with a corresponding first inlet 116. For example, in the embodiment, the number of swirl nozzles 210 can be equal to the number of first inlets 116, and both can be five. It should be understood that the structures of the five swirl nozzles 210 can be the same. In the embodiment, to avoid repetitive and tedious description, only the structure of one swirl nozzle 210 is exemplarily described.

[0057] Specifically, the swirl nozzle 210 can include a housing 211 and a swirl shell 212. The housing 211 can be a circular shell having a first open end 2111 opposite to a first closed end 2112. The first open end 2111 can be configured to connect with the fuel supply device of the engine, so that fuel can be input. The swirl shell 212 can be a circular shell having a second open end 2121 opposite to a second closed end 2122. The swirl shell 212 can have a swirl cavity 2123. A plurality of swirl holes 2124 can be arranged on a circumferential wall of the swirl shell 212 and can communicate with the swirl cavity 2123. The number of swirl holes 2124 can be selected as required, and the number of swirl holes 2124 is not specifically limited in the embodiment. The plurality of swirl holes 2124 can be arranged at intervals in the circumferential direction of the swirl shell 212. An axis of each of the plurality of swirl holes 2124 can be tangent to the circumferential wall of the swirl shell 212. Each of the plurality of swirl holes 2124 can communicate with the second open end 2121. The end of the swirl cavity 2123 away from the second closed end 2122 can be the second open end 2121. The second open end 2121 can communicate with the combustion chamber 103 through the first inlet 116. Meanwhile, the swirl shell 212 can be installed in the housing 211. The second open end 2121 can penetrate the first closed end 2112. The second closed end 2122 can be opposite to the first open end 2111. The swirl shell 212 and the housing 211 can cooperate to define an annular oil channel 213 that communicates with the plurality of swirl holes 2124. The annular oil channel 213 can communicate with the first open end 2111. The housing 211 can be connected with the first fuel supply pipe 220. The first open end 2111 can communicate with the first fuel supply pipe 220. In this way, after the fuel enters from the first fuel supply pipe 220, the fuel can flow to the annular oil channel 213 first, and then enter the swirl cavity 2123 from the plurality of swirl holes 2124 distributed on the circumferential wall of the swirl shell 212. After the fuel forms a swirl in the swirl cavity 2123, the fuel can be discharged from the second open end 2121 and enter the combustion chamber 103. When the fuel in the swirl state enters the combustion chamber 103, the fuel can have circumferential and radial velocities, so that the fuel can be better distributed in the combustion chamber 103, contact with the airflow, and be atomized to form an atomized flow field.

[0058] Further, the swirl chamber 2123 of the swirl shell 212 has a diameter-expanding hole section 2125, the diameter of the diameter-expanding hole section 2125 gradually decreases in the direction from the second open end 2121 to the second closed end 2122, one end of the diameter-expanding hole section 2125 away from the second closed end 2122 is arranged as the second open end 2121, and the plurality of swirl holes 2124 are all located between the second closed end 2122 and the diameter-expanding hole section 2125. In this way, the fuel in the swirl chamber 2123 can be injected into the combustion chamber 103 in the form of a conical surface, the distribution area is wider, the contact effect with the airflow is good, and the atomization effect is good.

[0059] Please refer to Figure 3 and Figure 7 In the embodiment, optionally, the second fuel injection unit 300 includes a second fuel supply pipe 320 and a plurality of direct injection nozzles 310. The second fuel supply pipe 320 can be an annular pipe, and the second fuel supply pipe 320 is used to communicate with the fuel supply device of the engine to input fuel. One end of each of the plurality of direct injection nozzles 310 is connected to the pipe wall of the second fuel supply pipe 320, the plurality of direct injection nozzles 310 are uniformly spaced in the extension direction of the second fuel supply pipe 320, and the other end of each of the plurality of direct injection nozzles 310 respectively communicates with a plurality of second inlets 117. For example, in the embodiment, the number of direct injection nozzles 310 is equal to the number of second inlets 117, and both are five. The structure of each direct injection nozzle 310 can be the same, and in the embodiment, to avoid repetitive and tedious description, only the structure of one direct injection nozzle 310 is exemplified.

[0060] Optionally, the direct injection nozzle 310 is provided with a variable-diameter fuel injection hole 311, one end of the variable-diameter fuel injection hole 311 with a larger opening communicates with the second fuel supply pipe 320 for inputting fuel, and the other end of the variable-diameter fuel injection hole 311 with a smaller opening communicates with the corresponding second inlet 117. The fuel injected from the direct injection nozzle 310 into the combustion chamber 103 has an acceleration effect under the action of the variable-diameter fuel injection hole 311, and has a greater penetration depth.

[0061] It should be understood that in other embodiments, the number of second fuel injection units 300 can be two. One of the second fuel injection units 300 is installed on the first diffuser section 112, and the other second fuel injection unit 300 is installed on the second diffuser section 122, both of the second fuel injection units 300 inject fuel into the combustion chamber 103, and the penetration depth of the fuel injected into the combustion chamber 103 by each second fuel injection unit 300 is reduced, which can reduce the fuel injection pressure of the second fuel injection unit 300 and reduce the cost.

[0062] In other embodiments, optionally, a high-frequency pressure sensor 400 for detecting detonation waves is arranged on the wall surface of the first cylinder 110. By analyzing the high-frequency pressure signal, it is determined whether the detonation is successful, and then it is determined whether the fuel injection nozzle and the direct injection nozzle 310 are working.

[0063] The rotating detonation combustion chamber distributed fuel injection device provided by the embodiment is provided with five rotating flow nozzles 210 in the flow guide section 1031 and sixteen direct injection nozzles 310 in the diffuser section 1032, and the rotating flow nozzles 210 and the direct injection nozzles 310 can be controlled to operate in cooperation, so that the engine can be stably operated in the working conditions of low Mach number and high Mach number.

[0064] The embodiment also provides a rotating detonation combustion chamber distributed fuel injection method, which is based on the rotating detonation combustion chamber distributed fuel injection device mentioned in the above embodiment, and the engine can adapt to different Mach number working conditions, so that the engine can be stably and reliably operated in a wide Mach number condition.

[0065] It should be noted that the Mach number between 2 and 4 represents a wide speed range and a wide Mach number range, and the Mach number less than 3.0 is a low Mach number state, and the Mach number greater than 3.0 is a high Mach number state.

[0066] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A distributed fuel injection device for a rotating detonation combustion chamber, characterized in that: include: a burner, the burner being provided with a combustion chamber and an air inlet and an air outlet both connected to the combustion chamber, the air inlet being used to communicate with an air intake device of an engine, and the air outlet being used to discharge combusted gas; a first fuel injection unit, the first fuel injection unit comprising a swirl nozzle, the swirl nozzle being mounted on the burner and configured to inject fuel into the combustion chamber so that the fuel forms a first atomized flow field at least in a wall region of the combustion chamber under the action of an airflow; and a second fuel injection unit, the second fuel injection unit comprising a straight nozzle, the straight nozzle being mounted on the burner and located downstream of the swirl nozzle in the direction of airflow, the straight nozzle being used to inject fuel into the combustion chamber so that the fuel forms a second atomization flow field in an area of ​​the combustion chamber away from the wall under the action of the airflow; The burner includes a first tube and a second tube, the first tube is sleeved outside the second tube, and the first tube and the second tube together define the annular combustion chamber; One end of the first tube and the second tube defines the annular air inlet, and the other end of the first tube and the second tube defines the annular air outlet; the swirl nozzle and the straight nozzle are both installed on the tube wall of the first tube.

2. The distributed fuel injection device for a rotating detonation combustion chamber according to claim 1, characterized in that: The first tube includes a first guide tube section, a first diffuser tube section and a first combustion tube section connected in sequence. The first guide tube section and the first combustion tube section are both equal-diameter sections, and the diameter of the first guide tube section is smaller than the diameter of the first combustion tube section; the diameter of the first diffuser tube section gradually increases from the first guide tube section to the first combustion tube section; a first inlet is provided on the tube wall of the first guide tube section, and the swirl nozzle is installed on the first guide tube section and is connected to the first inlet.

3. The distributed fuel injection device for a rotating detonation combustion chamber according to claim 2, characterized in that: The first tube also includes a first outer flange structure and a second outer flange structure. The first outer flange structure is connected to an end of the first guide tube section away from the first diffuser tube section, and the second outer flange structure is connected to an end of the first combustion tube section away from the first diffuser tube section.

4. The distributed fuel injection device for a rotating detonation combustion chamber according to claim 2, characterized in that: The second tube includes a second guide tube section, a second diffuser tube section, and a second combustion tube section connected in sequence. The second guide tube section and the second combustion tube section are both equal-diameter sections, and the diameter of the second guide tube section is larger than the diameter of the second combustion tube section. The diameter of the second diffuser tube section gradually decreases from the second guide tube section to the second combustion tube section. A second inlet is provided on the tube wall of the second guide tube section, and the straight-injection nozzle is mounted on the second diffuser tube section and communicates with the second inlet. The ends of the first guide tube section and the second guide tube section define an annular air inlet. The ends of the first combustion tube section and the second combustion tube section define an annular air outlet. The combustion chamber includes a flow guide section, a diffuser section and a combustion chamber that are connected in sequence. The flow cross-section of the flow guide section is smaller than the flow cross-section of the combustion chamber, and the flow cross-section of the diffuser section gradually increases in the direction from the flow guide section to the combustion chamber.

5. The distributed fuel injection device for a rotating detonation combustion chamber according to claim 4, characterized in that: The second tube also includes a first inner flange structure and a second inner flange structure. The first inner flange structure is connected to an end of the second guide tube segment away from the second diffuser tube segment, and the second inner flange structure is connected to an end of the second combustion tube segment away from the second diffuser tube segment.

6. The distributed fuel injection device for a rotating detonation combustion chamber according to claim 1, characterized in that: The swirl nozzle includes an outer shell and a swirl shell. The outer shell has a first open end and a first closed end opposite to each other. The first open end is used to input fuel. The swirl shell has a second open end and a second closed end opposite to each other. A plurality of swirl holes are provided on a peripheral wall of the swirl shell. The plurality of swirl holes are arranged at intervals in the circumferential direction of the swirl shell. The axis of each swirl hole is tangent to the peripheral wall of the swirl shell. Each swirl hole is connected to the second open end, and the second open end is connected to the combustion chamber. The swirl shell is installed in the outer shell, the second open end passes through the first closed end, and the swirl shell cooperates with the outer shell to define an annular oil channel connected to the swirl hole, and the annular oil channel is connected to the first open end.

7. The distributed fuel injection device for a rotating detonation combustion chamber according to claim 6, characterized in that: The swirl shell has an expanded diameter hole section, the diameter of which gradually decreases from the second open end to the second closed end, and the end of the expanded diameter hole section away from the second closed end is set as the second open end; the multiple swirl holes are all located between the second closed end and the expanded diameter hole section.

8. The distributed fuel injection device for a rotating detonation combustion chamber according to claim 1, characterized in that: The straight-injection nozzle is provided with a variable-diameter oil injection hole, wherein the end with a larger opening of the variable-diameter oil injection hole is used for inputting fuel, and the end with a smaller opening of the variable-diameter oil injection hole is communicated with the combustion chamber.

9. A distributed fuel injection method for a rotating detonation combustion chamber, characterized in that: The distributed fuel injection device for a rotating detonation combustion chamber according to any one of claims 1 to 8 comprises: When the engine is operating at a high altitude and at a low Mach number, the first fuel injection unit is activated, and the fuel enters the combustion chamber and is atomized under the action of the airflow to form a first atomization flow field uniformly distributed in the combustion chamber; When the engine is operating at high altitude and in a high Mach number state, the first fuel injection unit and the second fuel injection unit are started, and the fuel enters the combustion chamber. Under the action of the airflow, the fuel entering from the first fuel injection unit is atomized and forms a first atomization flow field distributed in the combustion chamber; the fuel entering from the second fuel injection unit is atomized and forms a second atomization flow field distributed in the combustion chamber; the first atomization flow field and the second atomization flow field are coordinated and evenly distributed in the combustion chamber.

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