A turbojet engine rotating detonation afterburner combustion chamber

Abstract

The present invention discloses a turbojet engine rotary detonation afterburner combustion chamber, which relates to the technical field of small turbojet engines. The chamber comprises an outer cylinder, an inner cylinder is sleeved in the outer cylinder, a gap is left between the outer cylinder and the inner cylinder to form an airflow channel, a flow channel selection valve capable of opening or closing the airflow channel is provided at the inlet of the airflow channel; a detonation ring cavity is provided at the outlet of the airflow channel, one end of the detonation ring cavity is fixed to the outer cylinder and the inner cylinder and communicated with the airflow channel, the other end of the detonation ring cavity is open, and a detonator is provided in the detonation ring cavity. The present invention opens and closes the afterburner combustion chamber through the flow channel selection valve, so that the afterburner combustion chamber does not need to work for a long time, and the purpose of being able to intermittently open the afterburner combustion chamber for continuous rotary detonation combustion is achieved under the premise of ensuring the safety of the afterburner combustion chamber.

Description

Technical Field

[0001] The invention relates to the technical field of small turbojet engines, in particular to a turbojet engine rotary detonation afterburner combustion chamber. Background Art

[0002] The afterburner is an important component of an aircraft engine. Although its mass only accounts for about 20% of the total mass of the engine, it can greatly increase the engine thrust. The turbojet engine uses an afterburner, and the thrust increase ratio can reach 40% to 50%; the turbofan engine uses an afterburner, and the thrust increase ratio can reach 60% to 70% or even higher. The use of an afterburner can greatly increase the unit head-on thrust and thrust-to-weight ratio of the engine, comprehensively improve the maneuverability of the aircraft, expand the flight envelope, and improve the air control capability of the fighter. Therefore, the afterburner occupies an important position in the development of military aircraft. The inlet speed of the conventional afterburner is as high as 200m / s or more. In order to achieve a stable combustion organization, it is necessary to first use a diffuser to slow down and diffuse the pressure, and then arrange a flame stabilizer in the decelerated airflow to construct a low-speed recirculation zone to achieve stable combustion. In addition, in order to ensure combustion efficiency, the combustion section of the afterburner is relatively long to meet a certain combustion reaction residence time. Due to the above reasons, the existing conventional afterburner combustion chamber is long in size and heavy in weight, which in turn limits the further improvement of the thrust-to-weight ratio performance of the afterburner turbine engine.

[0003] Continuous rotating detonation combustion has the advantages of combustion boost, fast combustion rate, and high combustion efficiency. After one detonation, the propellant can continue to detonate and burn. At subsonic to supersonic inflow speeds, the continuous rotating detonation combustion chamber can achieve stable operation. Therefore, the detonation afterburner constructed using detonation combustion technology no longer requires a diffuser to slow down and diffuse the pressure, nor does it require a flame stabilizer to construct a stable combustion reflow zone, and the combustion chamber structure length can be greatly shortened. This greatly reduces the structural size and weight of the afterburner, and can greatly improve the engine thrust-to-weight ratio. However, the detonation combustion temperature is very high, and the afterburner cannot work for a long time without thermal protection. In addition, the high pressure produced by the detonation wave is easily transmitted to the turbine, affecting the normal operation of the turbine. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art that a turbojet engine equipped with an afterburner chamber cannot work for a long time due to the afterburner chamber not being able to work for a long time, and to provide a turbojet engine with a rotating detonation afterburner chamber. The afterburner chamber is opened and closed by a flow channel selection valve, so that the afterburner chamber does not need to work for a long time. Under the premise of ensuring the safety of the afterburner chamber, the purpose of being able to intermittently open the afterburner chamber for continuous rotating detonation combustion is achieved.

[0005] The purpose of the present invention is mainly achieved through the following technical solutions:

[0006] A turbojet engine rotary detonation afterburner combustion chamber, comprising an outer cylinder, an inner cylinder is sleeved in the outer cylinder, a gap is left between the outer cylinder and the inner cylinder to form an airflow channel, and a flow channel selection valve capable of opening or closing the airflow channel is provided at the inlet of the airflow channel;

[0007] A detonation ring cavity is arranged in the air flow channel. The detonation ring cavity is sleeved in the air flow channel and close to the outlet end of the air flow channel. A detonator is arranged in the detonation ring cavity.

[0008] At present, when turbojet engines use afterburners for acceleration, they can usually only be used for a short time, because although the detonation combustion technology can be used to construct a detonation afterburner, there is no need for a diffuser to slow down and diffuse the pressure, and there is no need for a flame stabilizer to construct a stable combustion reflow zone, and the combustion chamber structure length can be greatly shortened. Thereby greatly reducing the structural size and weight of the afterburner, the engine thrust-to-weight ratio can be greatly improved. However, the detonation combustion temperature is very high, and the afterburner cannot work for a long time without thermal protection. And the high pressure produced by the detonation wave is easy to be transmitted to the turbine, affecting the normal operation of the turbine. The existing technology usually uses material updates to increase the working time of the afterburner, but it is affected by the development speed of materials science and cannot effectively and timely improve the utilization rate of the afterburner. Especially for small turbojet engines, due to the smaller space and poorer heat dissipation capacity, the utilization rate of the afterburner will also be lower, so how to increase the utilization rate of the afterburner and avoid the impact of the detonation wave on the turbine has become a problem to be solved in the field of small turbojet engine technology.

[0009] In the embodiment of the present application, the airflow channel is established through the outer cylinder and the inner cylinder, so that the turbine outlet gas can flow into the detonation ring cavity along the airflow channel, and the detonation combustion occurs in the detonation ring cavity through the detonator in the detonation ring cavity, thereby achieving the purpose of improving the thrust-to-weight ratio of the engine. The inlet of the airflow channel in the embodiment of the present application is provided with a flow channel selection valve that can open or close the airflow channel, so that the turbine outlet gas can flow into the detonation ring cavity through the airflow channel, and can also be blocked by the flow channel selection valve and flow through the inside of the inner cylinder. When the flow channel selection valve is opened, the detonation ring cavity can be supplied with turbine outlet gas, and the low-temperature and high-pressure air is introduced from the compressor to supplement oxygen for the oxygen-depleted gas at the inlet of the afterburner, so that the afterburner can work and the detonation ring cavity can perform detonation combustion; when the flow channel selection valve is closed, due to the lack of turbine outlet gas supply, the turbine core engine works and the rotary detonation afterburner does not work. At this time, the afterburner can get cooling and heat dissipation time to avoid damage under long-term operation, so that the detonation afterburner can continue to be used after a period of interval. Compared with the prior art, the embodiment of the present application adopts a method of setting a flow channel selection valve at the entrance of the air flow channel, so that the air flow channel and the detonation ring cavity can both obtain intermittent working time, and by selecting the direction of gas delivery at the turbine outlet, damage to the afterburner during long-term operation is avoided, and by setting the air flow channel before the detonation ring cavity and setting the detonator in the detonation ring cavity, a buffer space for the forward propagation of the detonation wave is obtained, thereby avoiding the influence of the detonation wave on the operation of the turbine. The present application effectively ensures the working safety of the afterburner and extends the service life of the afterburner. By intermittently opening the detonation afterburner, the disadvantage that the detonation afterburner cannot be used for a long time in the field of turbojet engines is effectively improved, and whether the afterburner is opened or not will not affect the normal basic use of the turbojet engine.

[0010] Furthermore, an oil spray rod is provided in the air flow channel, and the detonator is located at the entrance of the detonation ring cavity.

[0011] In an embodiment of the present application, the fuel injection rod can spray fuel and be carried into the detonation ring cavity by the airflow. The high-temperature combustion gas promotes the evaporation and mixing of the injected fuel, thereby improving the initiation and self-sustaining ability of the detonation combustion chamber. The detonator is arranged at the entrance of the detonation ring cavity, which can provide sufficient space for detonation combustion, thereby generating a stable driving force.

[0012] Furthermore, an isolation section capable of suppressing the forward propagation of the detonation wave is provided between the fuel spray rod and the detonator;

[0013] A throat is provided between the isolation section and the detonator, and the throat protrudes into the detonation ring cavity.

[0014] In the embodiment of the present application, an isolation section is provided between the injection rod and the detonator. The isolation section can effectively prevent the detonation wave from propagating forward, thereby avoiding the turbine from being affected. The throat accelerates the flow of air by narrowing, so that the detonation combustion can obtain sufficient high-pressure air support. The throat protrudes into the detonation ring cavity, so that the detonation wave can be blocked by the throat when propagating forward, thereby reducing the pressure of the isolation section.

[0015] Furthermore, the isolation section includes a plurality of bluff structures, and the bluff structures are parallel to each other and evenly distributed.

[0016] In an embodiment of the present application, the bluff body structure is arranged on the path of the forward propagation of the detonation wave, and a plurality of bluff body structures form an overall structure similar to a speed bump. The bluff body structure can effectively utilize the throat to jointly suppress the forward propagation of the high pressure generated by the detonation wave, thereby reducing the impact on the turbine.

[0017] Furthermore, the inner cylinder is provided with an inner oil screen on one side of the airflow channel, a gap is left between the inner oil screen and the inner cylinder, and the gap between the inner oil screen and the inner cylinder forms an inner heat insulation screen flow channel;

[0018] The outer cylinder is provided with an outer oil baffle on one side of the air flow channel, a gap is left between the outer oil baffle and the outer cylinder, and the gap between the outer oil baffle and the outer cylinder forms an outer heat insulation screen flow channel;

[0019] The inner heat insulation screen flow channel and the outer heat insulation screen flow channel both extend to the outlet end of the air flow channel.

[0020] In an embodiment of the present application, after the low-temperature high-pressure air flows into the airflow channel, it is mixed to form mixed combustion gas, and the heat is dissipated to the detonation ring cavity through the outer heat shield flow channel and the inner heat shield flow channel. The outer oil baffle and the inner oil baffle are used to block the fuel from entering the outer heat shield flow channel and the inner heat shield flow channel. In an embodiment of the present application, the inner heat shield flow channel and the outer heat shield flow channel can cover the gap between the detonation ring cavity and the airflow channel, so as to effectively achieve the purpose of dissipating the heat of the detonation ring cavity through the inner heat shield flow channel and the outer heat shield flow channel.

[0021] Furthermore, the outer heat shield flow channel is close to one side of the inlet of the air flow channel, so as to directly introduce low-temperature high-pressure air at the compressor outlet, thereby enhancing the cooling effect of the outer heat shield flow channel on the detonation ring cavity. The inner heat shield flow channel is close to one side of the outlet of the air flow channel, so as to introduce mixed and cooled combustion gas, thereby enhancing the cooling effect of the inner heat shield flow channel on the detonation ring cavity.

[0022] Furthermore, it also includes a gas collecting chamber, which is fixed on the outer surface of the outer cylinder and is close to the inlet of the air flow channel;

[0023] The gas collecting cavity is communicated with the air flow channel.

[0024] A gas collecting cavity is provided at the entrance of the air flow channel, through which low-temperature high-pressure air can be introduced, and then flow into the air flow channel after circumferential rectification, and be mixed with a small amount of fuel gas. The mixed low-temperature oxygen-rich mixed gas can increase the oxygen content of the high-temperature fuel gas and also play a role in cooling the detonation ring cavity.

[0025] Furthermore, the gas collecting chamber includes a side wall, the outer cylinder is provided with an outlet annular slit, and the side wall can completely surround the outlet annular slit;

[0026] An air bleed hole is provided on the side wall, and the air bleed hole is communicated with the compressor outlet.

[0027] In the embodiment of the present application, the outlet annular seam is used to connect the air collecting cavity and the air flow channel, and the side wall can completely surround the outlet annular seam to form an air collecting cavity, so that the low-temperature and high-pressure air introduced by the air inlet hole can be effectively circumferentially rectified in the air collecting cavity and mixed with a small amount of fuel gas in the air flow channel.

[0028] Furthermore, the guide plate is located in the air flow channel and faces the outlet annular gap, a gap is left between the guide plate and the outer cylinder, and the gap between the guide plate and the outer cylinder forms a guide plate channel.

[0029] In the embodiment of the present application, the high-temperature combustion gas flowing in from the inlet of the air flow channel can be introduced into the guide plate channel between the guide plate and the outer cylinder through the guide plate, thereby effectively completing the mixing of the low-temperature high-pressure air and the high-temperature combustion gas, thereby obtaining a low-temperature oxygen-rich mixture. The low-temperature oxygen-rich mixture is further mixed with the combustion gas to achieve the purpose of increasing the oxygen content of the detonation combustion, thereby making the detonation combustion process more complete, the obtained propulsion force is enhanced, and the thrust-to-weight ratio is further improved.

[0030] Furthermore, the detonation ring cavity comprises a detonation ring cavity inner ring and a detonation ring cavity outer ring, the detonation ring cavity inner ring is fixed to the inner cylinder, and the detonation ring cavity outer ring is fixed to the outer cylinder;

[0031] An aerodynamic plug nozzle is fixed to the outlet end of the inner ring of the detonation ring cavity.

[0032] The detonation ring cavity in the embodiment of the present application effectively forms a ring cavity body of the detonation ring cavity by setting an inner ring and an outer ring of the detonation ring cavity, providing space for detonation combustion. An aerodynamic plug nozzle is set at the outlet end of the inner ring of the detonation ring cavity, which can effectively play a role in further expansion of the high-temperature and high-pressure combustion gas after detonation combustion, thereby effectively forming a driving force.

[0033] In summary, the present invention has the following beneficial effects compared with the prior art:

[0034] The embodiment of the present application adopts the method of setting a flow channel selection valve at the entrance of the air flow channel, so that the air flow channel and the detonation ring cavity can both obtain intermittent working time, and the afterburner is prevented from being damaged during long-term operation by selecting the direction of gas delivery at the turbine outlet, and the air flow channel is set before the detonation ring cavity and the detonator is set in the detonation ring cavity, and a buffer space for the forward propagation of the detonation wave is obtained. The blunt body structure and throat set in the buffer space can avoid the influence of the detonation wave on the operation of the turbine. The present application effectively guarantees the working safety of the afterburner and prolongs the service life of the afterburner. By intermittently opening the detonation afterburner, the disadvantage that the detonation afterburner cannot be used for a long time in the field of turbojet engines is effectively improved, and whether the afterburner is opened or not, it will not affect the normal basic use of the turbojet engine. The blunt body structure is set on the path of the forward propagation of the detonation wave, and a plurality of blunt body structures are used to form an overall structure similar to a speed bump. The blunt body structure can effectively use the throat to jointly suppress the forward propagation of the high pressure generated by the detonation wave, thereby reducing the influence on the turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0036] Figure 1 This is a schematic diagram of the turbine working mode structure of the present invention;

[0037] Figure 2 This is a schematic diagram of the structure of the detonation boosting working mode of the present invention;

[0038] Figure 3 It is a partial enlarged view of the gas collecting cavity and the guide plate of the present invention;

[0039] Figure 4 This is a front view of the gas collecting chamber of the present invention;

[0040] Figure 5 This is a partial enlarged view of the inlet of the detonation combustion chamber of the present invention;

[0041] Figure 6 This is a partial enlarged view of the inlet of the detonation ring cavity of the present invention;

[0042] The reference numerals represent: 1-outer cylinder, 2-channel selection valve, 3-guide plate, 31-overflow annular gap, 4-outer oil baffle, 5-inner cylinder, 6-inner oil baffle, 7-gas collecting chamber, 71-air inlet hole, 72-outlet annular gap, 73-side wall, 8-injection rod, 9-isolation section, 91-blunt body structure, 10-detonating nozzle, 11-inner ring of detonation ring cavity, 111-throat protrusion, 112-throat, 12-outer ring of detonation ring cavity, 13-pneumatic plug nozzle, 14-inner cone, 15-air flow channel, 16-cavity, 17-guide plate flow channel, 18-outer heat insulation screen flow channel, 19-detonation ring cavity, 20-inner heat insulation screen flow channel. DETAILED DESCRIPTION

[0043] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0044] Example:

[0045] like Figure 1 to Figure 6 As shown, this embodiment relates to a turbojet engine rotary detonation afterburner combustion chamber, comprising an outer cylinder 1, wherein an inner cylinder 5 is sleeved inside the outer cylinder 1, a gap is left between the outer cylinder 1 and the inner cylinder 5 to form an air flow channel 15, and a flow channel selection valve 2 capable of opening or closing the air flow channel 15 is provided at the inlet of the air flow channel 15;

[0046] A detonation ring cavity is provided in the air flow channel 15 . The detonation ring cavity is sleeved in the air flow channel 15 and close to the outlet end of the air flow channel 15 . An initiator is provided in the detonation ring cavity.

[0047] A fuel injection rod 8 is provided in the air flow channel 15, and the detonator is located at the entrance of the detonation ring cavity.

[0048] The detonation ring cavity comprises a detonation ring cavity inner ring 11 and a detonation ring cavity outer ring 12, wherein the detonation ring cavity inner ring 11 is fixed to the inner cylinder 5, and the detonation ring cavity outer ring 12 is fixed to the outer cylinder 1;

[0049] An aerodynamic plug nozzle 13 is fixed to the outlet end of the inner ring 11 of the detonation ring cavity.

[0050] In this embodiment, the flow path of the detonation afterburner combustion chamber can be changed by actuating the flow path selection valve 2. When the flow path selection valve 2 is closed, the turbine is in the working mode. The turbine outlet gas flows through the core flow path composed of the inner cone 14 of the turbine, the flow path selection valve 2 and the inner cylinder 5, and the rotary detonation afterburner combustion chamber does not work.

[0051] The inner cone 14 in this embodiment is the internal structure of the turbojet engine and is presented here to facilitate the description of gas flow.

[0052] When the flow channel selection valve 2 is opened, it is in the rotational detonation boost mode. The high-temperature combustion gas at the turbine outlet flows through the outer ring flow channel composed of the flow channel selection valve 2, the inner cylinder 5, the outer cylinder 1 and the pneumatic plug nozzle 13, that is, the air flow channel and the detonation ring cavity. After the fuel injection rod 8 injects fuel into the combustion gas, a partially evaporated oil-gas mixture is formed. The detonator in this embodiment uses a detonating electric nozzle 10. After the detonating electric nozzle 10 is working, it detonates in the detonation ring cavity and forms a detonation wave. The high-temperature and high-speed combustion gas after the combustion reaction further expands and accelerates at the pneumatic plug nozzle 13, thereby generating thrust.

[0053] An isolation section 9 capable of suppressing the forward propagation of the detonation wave is provided between the spray rod 8 and the detonator;

[0054] A throat is provided between the isolation section 9 and the detonator, and the throat protrudes into the detonation ring cavity.

[0055] The isolation segment 9 includes a plurality of bluff structures 91 , and the bluff structures 91 are parallel to each other and evenly distributed.

[0056] After the detonator nozzle 10 is working, it detonates in the detonation ring cavity and forms a detonation wave, consuming the oil-gas mixture entering from the ring cavity body 19. The high-temperature and high-speed combustion gas after the combustion reaction further expands and accelerates at the pneumatic plug nozzle 13, thereby generating thrust. There is a throat convex block 111 at the front end of the detonation ring cavity inner ring 11, which forms a flow channel profile that first gradually shrinks and then suddenly expands with the detonation ring cavity outer ring 12, thereby forming a narrow throat 112 at the inlet of the detonation ring cavity. The isolation section 9 is composed of a plurality of blunt body structures 91. The detonation ring cavity inlet throat 112 and the isolation section 9 jointly suppress the forward propagation of the high pressure generated by the detonation wave, thereby reducing the impact on the turbine.

[0057] The inner cylinder 5 is provided with an inner oil screen 6 on one side of the air flow channel 15, and a gap is left between the inner oil screen 6 and the inner cylinder 5, and the gap between the inner oil screen 6 and the inner cylinder 5 forms an inner heat insulation screen flow channel 20;

[0058] The outer cylinder 1 is provided with an outer oil baffle 4 on one side in the air flow channel 15 , a gap is left between the outer oil baffle 4 and the outer cylinder 1 , and the gap between the outer oil baffle 4 and the outer cylinder 1 forms an outer heat insulation screen flow channel 18 .

[0059] With the spray rod 8 as the dividing position, the outer heat shield flow channel 18 is close to the inlet side of the air flow channel 15, and the inner heat shield flow channel 20 is close to the outlet side of the air flow channel 15;

[0060] The inner heat shield flow channel 20 and the outer heat shield flow channel 18 both extend to the outlet end of the air flow channel 15 .

[0061] In this embodiment, after the flow is diverted by the inner oil baffle 6, the mixed gas in the airflow channel 15 flows into the annular cavity 19 and the inner heat shield flow channel 20 respectively. The gas flowing into the inner heat shield flow channel 20 is used to cool the detonation annular cavity inner ring 11 and the pneumatic plug nozzle 13. The fuel injection rod 8 is evenly arranged along the axial direction, and the fuel is sprayed into the annular cavity 19. The direct nozzle sprays in a side spray direction. The high temperature of the fuel gas is used to promote the evaporation and mixing of the injected fuel to form a partially evaporated oil-gas mixture. The outer oil baffle 4 and the inner oil baffle 6 are used to prevent the fuel from entering the outer heat shield flow channel 18 and the inner heat shield flow channel 20.

[0062] It also includes a gas collecting chamber 7, which is fixed on the outer surface of the outer cylinder 1 and is close to the entrance of the air flow channel 15;

[0063] The gas collecting cavity 7 is communicated with the air flow channel 15 .

[0064] The gas collecting cavity 7 comprises a side wall 73, and an outlet annular slit 72 is formed on the outer cylinder 1, and the side wall 73 can completely surround the outlet annular slit 72;

[0065] The side wall 73 is provided with an air inlet hole 71, and the air inlet hole 71 is connected to the compressor outlet. In this embodiment, the compressor is a prior art in the structure of a turbojet engine.

[0066] It also includes a guide plate 3, which is located in the air flow channel 15 and faces the outlet annular gap 72. A gap is left between the guide plate 3 and the outer cylinder 1, and the gap between the guide plate 3 and the outer cylinder 1 forms a guide plate channel 17.

[0067] In this embodiment, the high-temperature combustion gas at the turbine outlet flows into the guide plate flow channel 17 and the detonation combustion chamber inlet flow channel 15 respectively. The high-pressure air introduced from the compressor passes through the air inlet hole 71 on the side wall 73 of the gas collecting cavity 7, enters the gas collecting cavity 16 for circumferential rectification, and then enters the guide plate flow channel 17 through the outlet annular gap 72 to mix with a small amount of combustion gas. A part of the mixed low-temperature oxygen-rich mixed gas flows into the detonation combustion chamber inlet flow channel 15 through the overflow annular gap 31 to mix with the high-temperature combustion gas to increase its oxygen content. The other part flows into the outer heat insulation screen flow channel 18 to cool the outer ring 12 of the detonation ring cavity.

[0068] The air inlet holes 71 opened on the side wall 73 of the gas collecting cavity 7 are of an oblong hole structure and are evenly arranged along the circumference. The oblong hole structure is more convenient for gas to flow in and is conducive to circumferential rectification in the gas collecting cavity 16.

[0069] In practical applications of this embodiment, the inlet air flow path of the detonation afterburner combustion chamber can be changed by actuating the flow channel selection valve 2. By selecting the turbine working mode and the rotary detonation afterburner mode, the purpose of intermittently using the detonation afterburner combustion chamber is achieved, so that the detonation afterburner combustion chamber will not be damaged during high-intensity work.

[0070] In this embodiment, low-temperature high-pressure air is introduced from the compressor to supplement oxygen to the oxygen-depleted combustion gas at the inlet of the afterburner, and low-temperature air is introduced into the outer heat shield flow channel 18 to cool the detonation ring cavity outer ring 12. This can not only make the detonation combustion more complete, but also cool the detonation ring cavity, thereby achieving the purpose of increasing the service life of the detonation ring cavity.

[0071] In this embodiment, the fuel injection rod 8 is arranged in front of the detonation ring cavity, and high-temperature combustion gas is used to promote the evaporation and mixing of the injected fuel, thereby improving the detonation and self-sustaining capabilities of the detonation combustion chamber.

[0072] This embodiment utilizes the throat 112 at the inlet of the detonation ring cavity and the isolation section 9 to jointly suppress the forward propagation of the high pressure generated by the detonation wave, thereby reducing the impact on the turbine.

[0073] In this embodiment, the throat protrusion 111 at the throat 112 protrudes toward the inside of the detonation ring cavity, so that a step is formed at the entrance of the detonation ring cavity. When detonation combustion occurs in the detonation ring cavity, the detonation wave is first weakened by the obstruction of the step, and then a speed bump is formed for the detonation wave through the blunt body structure 91 in the isolation section 9, thereby continuing to weaken the detonation wave. After the detonation wave passes through the blunt body structure 91, it is weakened to a smaller state, thereby avoiding the detonation wave from affecting the turbine.

[0074] In actual application of this embodiment, the flow channel selection valve is firstly opened or closed. When the closed state is selected, the rotary detonation afterburner combustion chamber does not work, thereby achieving the purpose of maintaining the detonation afterburner combustion chamber.

[0075] When the detonation afterburner is opened, the high-temperature gas at the turbine outlet flows into the air flow channel 15 through the flow channel selection valve 2, and part of the high-temperature gas enters the guide plate channel 17 through the guide plate 3. The low-temperature high-pressure air introduced by the air inlet 71 is circumferentially rectified in the gas collecting cavity 7 and mixed with the high-temperature gas to form a low-temperature oxygen-rich mixed gas. Part of the low-temperature oxygen-rich mixed gas flows into the detonation ring cavity, and part of the low-temperature oxygen-rich mixed gas passes through the outer heat insulation screen flow channel 18 to cool the outer ring 12 of the detonation ring cavity. At the same time, part of the gas will flow into the inner heat insulation screen channel 20 to achieve the purpose of cooling the inner ring 11 of the detonation ring cavity and the pneumatic plug nozzle 13. After the low-temperature oxygen-rich mixed gas is mixed with the high-temperature gas, it is detonated in the detonation ring cavity through the detonation nozzle 10, thereby providing a driving force.

[0076] When detonation combustion occurs in the detonation ring cavity, the forward high-pressure detonation wave is consumed by the throat protrusion 111 at the throat 112 and the isolation zone 9 in the air flow channel 15, thereby reducing the impact of the detonation wave on the turbine.

[0077] The flow channel selection valve 2 in this embodiment selects a model that can be configured in large quantities in the prior art to facilitate large-scale production of this embodiment. In addition to being able to perform on-off adjustment, the selected model should also be able to withstand high temperatures, thereby increasing the service life of this embodiment.

[0078] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A turbojet engine rotary detonation afterburner combustion chamber, comprising an outer cylinder (1), wherein an inner cylinder (5) is sleeved within the outer cylinder (1), characterized in that: A gap is left between the outer cylinder (1) and the inner cylinder (5) to form an air flow channel (15), and a flow channel selection valve (2) capable of opening or closing the air flow channel (15) is provided at the entrance of the air flow channel (15); A detonation ring cavity is provided in the air flow channel (15), and the detonation ring cavity is sleeved in the air flow channel (15) and close to the outlet end of the air flow channel (15); An oil spray rod (8) is provided in the air flow channel (15), and a detonator is located at the entrance of the detonation ring cavity; An isolation section (9) capable of suppressing the forward propagation of a detonation wave is provided between the oil spray rod (8) and the detonator; A throat is provided between the isolation section (9) and the detonator, and the throat protrudes into the detonation ring cavity; The inner cylinder (5) is provided with an inner oil screen (6) on one side inside the air flow channel (15), a gap is left between the inner oil screen (6) and the inner cylinder (5), and the gap between the inner oil screen (6) and the inner cylinder (5) forms an inner heat insulation screen flow channel (20); The outer cylinder (1) is provided with an outer oil baffle (4) on one side of the air flow channel (15), a gap is left between the outer oil baffle (4) and the outer cylinder (1), and the gap between the outer oil baffle (4) and the outer cylinder (1) forms an outer heat insulation screen flow channel (18); The inner heat insulation screen flow channel (20) and the outer heat insulation screen flow channel (18) both extend to the outlet end of the air flow channel (15).

2. A turbojet engine rotating detonation afterburner combustion chamber according to claim 1, characterized in that: The isolation section (9) comprises a plurality of bluff structures (91), wherein the bluff structures (91) are parallel to each other and evenly distributed.

3. A turbojet engine rotating detonation afterburner combustion chamber according to claim 1, characterized in that: The outer heat insulation screen flow channel (18) is located on a side close to an inlet of the air flow channel (15), and the inner heat insulation screen flow channel (20) is located on a side close to an outlet of the air flow channel (15).

4. A turbojet engine rotating detonation afterburner combustion chamber according to any one of claims 1 to 3, characterized in that: It also comprises a gas collecting chamber (7), wherein the gas collecting chamber (7) is fixed on the outer surface of the outer cylinder (1), and the gas collecting chamber (7) is close to the entrance of the air flow channel (15); The gas collecting cavity (7) is in communication with the air flow channel (15).

5. A turbojet engine rotating detonation afterburner combustion chamber according to claim 4, characterized in that: The gas collecting chamber (7) comprises a side wall (73), an outlet annular slit (72) is formed on the outer cylinder (1), and the side wall (73) is capable of completely surrounding the outlet annular slit (72); An air bleed hole (71) is provided on the side wall (73), and the air bleed hole (71) is in communication with an outlet of the compressor.

6. A turbojet engine rotating detonation afterburner combustion chamber according to claim 5, characterized in that: It also includes a guide plate (3), the guide plate (3) being located in the air flow channel (15) and facing the outlet annular gap (72), a gap being left between the guide plate (3) and the outer cylinder (1), and the gap between the guide plate (3) and the outer cylinder (1) forming a guide plate channel (17).

7. A turbojet engine rotating detonation afterburner combustion chamber according to any one of claims 1 to 3, characterized in that: The detonation ring cavity comprises a detonation ring cavity inner ring (11) and a detonation ring cavity outer ring (12), the detonation ring cavity inner ring (11) being fixed to the inner cylinder (5), and the detonation ring cavity outer ring (12) being fixed to the outer cylinder (1); An aerodynamic plug nozzle (13) is fixed to the outlet end of the inner ring (11) of the detonation ring cavity.

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