CN101881238B - Air-breathing pulse detonation engine and detonation method thereof - Google Patents

Abstract

The invention discloses an air-breathing pulse detonation engine and its detonation method. An air inlet, a mixing evaporator, a detonation chamber and a tail nozzle are sequentially connected along the air intake direction. The gas direction is equipped with a reed valve, main fuel nozzle and air release chamber in sequence, and the fuel is injected radially through the main fuel nozzle; the air release chamber is connected to the outer wall of the air inlet through the through hole of the central body bracket and the air release pipe; the reed The valve is kept in the positive and normally open state; the detonator is installed in the detonation chamber through the mounting bracket, and the detonator is installed with a drainage tube, an igniter and a heat exchanger, and several jet holes are opened on the side wall or end surface of the tail; the igniter is located The front section of the tube and the drainage tube are respectively opened in the detonation chamber and near the igniter in the detonation tube. The invention can work reliably under harsh conditions, has simple structure, wide flight range, can realize small forward flow resistance, restrain and utilize reverse flow at the same time, and improve engine thrust.

Description

An air-breathing pulse detonation engine and its detonation method

technical field

The invention relates to the technical field of engines, in particular to an air-breathing pulse detonation engine and its detonation method.

Background technique

The pulse detonation engine is a new concept engine that uses intermittent or pulse detonation waves to generate thrust. Unlike the deflagration combustion in conventional engines (such as turbojet engines and piston engines, etc.), the combustion process in pulse detonation engines is detonation combustion. Compared with the deflagration cycle, the detonation cycle has higher thermal efficiency. The pulse detonation engine has low unit fuel consumption rate, wide operating range, simple structure, high thrust-to-weight ratio, can adapt to high-speed flight conditions, and the maximum flight Mach number can reach 5. It is recognized as the most promising aerospace power system at home and abroad.

The difference between detonation and deflagration is that it has a high supercharging capacity. The pressure ratio before and after the detonation wave can reach 20-40 times in the mixture of air as the oxidant, and the strong shock wave generated will be reversed back to the intake port. , so the detonation combustion chamber has high requirements on the intake port. To prevent detonation-induced flow oscillations from causing intake port failure, pulse detonation engines typically require an intake/detonation chamber isolation section to prevent detonation from passing from the detonation chamber into the intake air during specific periods of the cycle road. According to the realization method of this isolation section, the pulse detonation engine can be divided into two types: pulse detonation engine with valve and valveless pulse detonation engine. In a valved pulse detonation engine, the isolation section is a mechanical valve installed between the detonation chamber and the intake port. The valve is closed during detonation initiation, propagation and venting, and is open during filling. The large frontal area during valve closure and the stagnation of the incoming air flow can also result in a significant loss of performance. The isolation between the intake port and the detonation chamber of a valveless pulse detonation engine is achieved aerodynamically. This design is not only simple in structure, but also solves the adverse effects caused by stagnation of incoming flow.

The formation principle of the detonation wave requires the pneumatic valve to have the characteristics of small forward flow resistance and large reverse flow resistance. The forward air intake resistance is small to ensure the smooth intake of the pulse detonation engine; the reverse flow resistance is large, forming an approximate closed effect, which is conducive to the superposition of shock waves to form detonation waves, and at the same time prevents combustion products from flowing out of the engine in reverse, reducing and suppress negative thrust caused by regurgitation. At present, the pneumatic valves of pulse detonation engines have the problems of forward flow resistance and reverse flow control which cannot be well solved.

In addition, there are still many problems in the detonation of pulse detonation engines. At present, the detonation methods of multi-cycle pulse detonation waves are mainly divided into the following two types: the first one is single-stage detonation, which forms deflagration from weak sparks and then transforms into detonation. The use of high-frequency detonation can achieve higher frequency detonation initiation, but this method usually brings a huge loss of impulse, requires a longer distance and time for the transition from deflagration to detonation, and the engine exhaust time is longer, which is not conducive to detonation The frequency is further increased; the second is jet detonation, which generally allows the highly sensitive mixture to be ignited and expanded in the first small combustion chamber, and then discharged into the main combustion chamber through the connecting channel with the main combustion chamber, thereby igniting the main combustion chamber. Combustion chamber ignition generally requires an independent supply system that needs to carry a highly sensitive mixture, increasing the complexity and weight of the engine.

To sum up, the pulse detonation engine has a simple structure and a high thrust-to-weight ratio, but both the existing valved and valveless pulse detonation engines have disadvantages that cannot be ignored: the valve closure of the valved pulse detonation engine will bring great damage. The windward area produces a huge performance loss; while the pneumatic valve of the valveless pulse detonation engine has the problems of forward flow resistance and reverse flow control that cannot be well solved.

Contents of the invention

In order to overcome the contradiction between forward flow resistance and reverse flow control of pulse detonation engines in the prior art, the present invention provides an air-breathing pulse detonation engine, which can achieve smaller forward flow resistance while suppressing and utilizing reverse flow , to increase engine thrust.

The technical solution adopted by the present invention to solve its technical problems is: comprise the air intake duct 10, the detonation chamber 20 and the tail nozzle 40 connected successively along the air intake direction, the shell of the air intake duct and the central body 12 of the air intake duct form a An annular cavity, that is, the intake ring cavity, is installed with a reed valve 13, several main fuel nozzles 14 and air release chambers 15 in sequence along the intake direction in the intake ring cavity, and the main fuel nozzle 14 is arranged along the center of the intake channel The body is evenly distributed in the circumferential direction, and the fuel is injected radially through the main fuel nozzle to form an oil curtain in the intake ring cavity. There is a through hole in the central body support, and the venting cavity is communicated with the air release pipe 17 through the through hole of the central body support 16, and the air release pipe 17 is connected to the outer wall of the air inlet, and the opening direction is consistent with the direction of the tail nozzle 40. The reed valve 13 maintains a positive and normally open state, that is, the incoming flow can always flow into the engine in a positive direction. After the mixture in the detonation chamber is ignited and detonated, the reverse transmission shock wave will close the reed valve, and the reverse flow cannot flow out of the intake port. When the internal pressure drops below the incoming ram, the reed valve reopens. A mixing evaporator 21 is installed between the air inlet 10 and the detonation chamber 20, the igniter 22 is located at the front section of the detonation chamber 20, or at the front section of the detonator 30, and the detonator 30 is installed in the detonation chamber 20 through a mounting bracket 31 Inside. When the igniter 22 of the engine is located behind the mixing evaporator 21 in the front section of the detonation chamber 20, the weak spark ignition single-stage detonation is adopted, and the detonator 30, the detonator bracket 31, the drainage pipe 32 and the jet hole are not included in the invention. 34. At this time, the heat exchanger 33 will also be installed on the outer wall of the tail of the detonation chamber. However, this ignition method usually cannot achieve rapid detonation detonation, especially the low-sensitivity gas-liquid two-phase (such as kerosene/air) detonation wave that is most expected in practical applications. In order to speed up the formation process of the detonation wave, the present invention installs the igniter 22 on the front section of the detonator 30, and behind the drainage tube 32, one end of the drainage tube is opened in the detonation chamber 20, facing the inlet formed by the mixing evaporator. flow passage, and the other end opening is in the range of one diameter of the detonator near the igniter 22 in the detonator 30. The detonator is also an obstacle and a heat sink in the engine, which can promote the rapid transformation of the detonation wave in the detonation chamber 20, and can also absorb the circulating heat generated by the multi-cycle detonation to heat the fuel and air. The detonator 30 is installed in the detonation chamber 20 through a bracket 31 . A draft tube 32, an igniter 22 and a heat exchanger 33 are installed on the detonator 30, and a number of jet holes 34 are provided on the side wall or end surface of the tail, and the detonator is independently supplied with highly sensitive fuel/oxidizer through the starting fuel/oxidant inlet 35. The heat exchanger is a thin-walled cavity installed on the outer wall of the detonator tail. Its inner cavity is a spiral groove structure. The main fuel oil flows along the spiral groove and is preheated by circulating heat.

The central body of the air inlet and the shell of the air inlet can move back and forth relative to each other, thereby changing the actual effective flow area.

The central body 12 of the air inlet can be designed as a multi-segment combined structure similar to a pull antenna, and the axial distance between each segment can be adjusted. The reed valve 13 is installed in the middle section of the central body 12 of the air inlet.

The deflation chamber 15 is an inner groove at the tail end of the central body. The deflation chamber can be designed as a spherical, square or other arbitrary shape to absorb the forward shock wave and backflow. The deflation chamber connects the deflation tube through the central body support 16 17 communicates, and the opening direction of the deflation pipe 17 is consistent with the tail nozzle 50. After the backflow enters the deflation chamber 15, it flows into the deflation pipe 17 through the bracket 16 and is discharged from the engine, thereby utilizing the backflow to generate positive thrust.

The structure of the blending evaporator 21 is a Venturi tube, the first half is a converging tube, and the second half is an expansion tube. At the same time, the profile of the blending evaporator matches the deflation chamber 15, which ensures that the blending evaporator The profile extension line is in the air release cavity, guiding the backflow into the air release cavity, and inhibiting the backflow into the air inlet. After the air and fuel are mixed in the intake ring cavity formed by the intake port shell and the central body, they are further atomized, mixed and evaporated under the action of the mixing evaporator 21 . In addition, the blending evaporator can absorb the cycle heat formed by multi-cycle detonation, and heat the fresh air and fuel for the next cycle.

The inlet center body adopts a supersonic inlet center body or a subsonic center body, and the inlet casing adopts a supersonic inlet casing or a subsonic inlet casing, respectively forming a supersonic pulse detonation engine inlet Air duct and pneumatic valve system or subsonic pulse detonation engine intake duct and pneumatic valve system.

The air release chamber 15 is equipped with a valve 19 that moves forward and backward along the air intake direction. The valve cooperates with the air release chamber in a gap, and is controlled by an electric actuator, hydraulic pressure or a spring plus a detonation chamber pressure structure, so as to realize forward and backward movement. move. The valve 19 is in the original closed state at the end face of the vent chamber, and the fuel and air filled in the engine will not flow to the detonation chamber through the vent chamber; after the engine is ignited, the valve moves forward, and flows back through the vent chamber by The bleed pipe exits the engine.

When the diameter of the detonation chamber is greater than 15 cm, multiple detonation tubes arranged in parallel are used to accelerate detonation wave initiation.

The main fuel oil nozzles can also be evenly distributed on the air intake casing along the circumferential direction, the heat exchanger is installed at the rear end of the main detonation chamber, the main fuel oil circuit (including the main fuel nozzle oil circuit inlet 18, the main fuel oil inlet 36 and the Heater main fuel oil outlet 37 and connecting pipeline therebetween) are distributed outside the engine, simplifying the internal structure of the engine.

The detonation method of the detonator includes two working modes: one, when the engine is started or the working conditions are bad (including high-altitude flight or maneuvering flight), the detonator is independently supplied with a highly sensitive fuel/oxidant mixture through the starting fuel/oxidizer inlet 35 ("Highly sensitive" refers to fuel/oxidant mixtures that are easy to detonate, such as fuel/oxygen mixtures, gaseous fuel/air mixtures, etc.), the igniter ignites, the detonator detonates reliably, and the detonation jet passes through the jet hole at the side wall or tail 34 is sprayed into the detonation chamber 20, and the main detonation chamber is detonated fast. After working in this way for a period of time (the working time is 10-40s, the specific time is related to the detonation frequency of the detonator, the higher the frequency, the shorter the time), the temperature of the engine wall rises, especially the temperature of the detonator is very high (up to 500°C) , and a heat exchanger 33 is installed in the rear section of the detonator. The heated fuel can evaporate faster, and at the same time, the incoming air is also warmed by the heat of the engine wall, all of which increase the detonability of the main fuel/air. At this time, the supply of highly sensitive fuel oil/oxidant is stopped, and the detonator enters the second working mode. The preheated main fuel (such as aviation kerosene or aviation gasoline) flows into the main fuel nozzle 14 through the pipeline, is sprayed at the intake port and mixed with the incoming flow, and then the mixed evaporator 21 strengthens the mixing and evaporation, and a part of the mixture is drained The tube 32 flows into the detonation tube and is ignited by the igniter to realize pre-detonation. The detonation jet is sprayed into the detonation chamber 20 through the jet hole 34 on the side wall or the tail end to detonate the main detonation chamber. After the main detonation chamber is detonated, the heat exchanger 33 will be heated simultaneously by the detonation tube and the main detonation chamber, and the preheating effect of the main fuel oil is better.

The beneficial effects of the present invention are: the air inlet 10, the blending evaporator 21 and the detonator 30 adopted in the present invention are characterized in that they can all effectively suppress and utilize backflow. The principle is that the profile of the blending evaporator 21 can reflect a part of the shock wave transmitted from the detonation chamber 20 back to the detonation chamber, and at the same time introduce another part of the shock wave into the deflation chamber 15, which will be diffracted and attenuated, and enter the detonation chamber. The high-pressure gas in the deflation chamber 15 flows into the deflation pipe 17 through the bracket 16, and is discharged into the atmosphere in the same direction as the tail nozzle 40, thereby generating a forward thrust by backflow. After the attenuation of the mixing evaporator 21 and the air release chamber 15, the shock wave intensity decreases and enters the intake ring cavity, drives the reed, and closes the reed valve so that the backflow cannot flow out of the intake passage. At the same time, the use of the detonation tube can accelerate the formation of detonation in the main detonation chamber, shorten the detonation transition time and distance, so the length of the detonation chamber can be greatly shortened, so that the expansion wave formed by the exhaust of the detonation chamber is transmitted to the intake air The time of the passage is greatly reduced, and the forward shock wave can be caught up, so that the backflow flows to the tail nozzle 40 again.

In the multi-cycle process, the intake passage 10, the detonation chamber 20, the blending evaporator 21 and the detonator 30 are heated during the combustion process, and the liquid fuel is injected by the main fuel nozzle 14 after being preheated by the heat exchanger 33. After being mixed with the air heated by the intake port in the intake ring cavity, it is further preheated by the intake port and the blending evaporator, and enters the detonation chamber 20 and the detonation tube, and the fuel in the mixture formed by the partial or complete evaporation of the droplets Higher vapor pressure facilitates ignition and detonation. The ignition delay time required by the igniter 22 after discharging in this premixed combustible mixture is less, the inner diameter of the detonator 30 is much smaller than that of the main combustion chamber, and the pressure rise rate after ignition is significantly higher than the direct ignition pressure of the main detonation chamber The rising speed, so the flame propagation speed can reach the gas choking speed in a short distance and time, so that the shock wave can be formed quickly, and then the detonation wave can be initiated. Multiple high-temperature, high-pressure jets and the shock waves generated are injected into the main detonation chamber from the detonation tube, forming high-temperature, high-pressure hot spots and localized explosions in the main detonation chamber. At the same time, due to the highly developed turbulent flow in the main combustion chamber, the detonation is quickly formed. , and spread to both ends at a very fast speed. In addition to starting the engine, providing high-energy jet ignition, and preheating the fuel, the detonator 30 itself is also a detonation-promoting obstacle for the main detonation chamber, which can help the detonation chamber to form high-intensity turbulence, and complex shock wave reflections, collisions, etc. , to accelerate the main detonation chamber to form a detonation wave.

The invention obtains a high-speed pulse detonation propulsion device that can work reliably under severe conditions, has a simple structure, a wide flight range, and can realize small forward flow resistance, while suppressing and utilizing reverse flow to increase engine thrust, which can be used as Power devices for high-speed model aircraft, unmanned aerial vehicles, target drones, subsonic cruise missiles and small ships.

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Description of drawings

Fig. 1 is a structural sectional view of the present invention, and Fig. 1 (b) is a 90° sectional view rotated as shown in Fig. 1 (a).

Figure 2(a) and (b) are schematic diagrams of the detonation mixture filling and mixing process with and without valves in the deflation chamber, respectively.

Fig. 3 is a sequence diagram of the principle of suppressing and utilizing reverse flow of the air inlet pneumatic valve system.

Fig. 3(a) is a schematic diagram of the shock wave and flow in the intake duct and the front section of the detonation chamber when the detonation is formed.

Figure 3(b) is a schematic diagram of the shock wave and flow entering the intake port in reverse after the knock is formed.

Figure 3(c) is a schematic diagram of the shock wave and flow further propagating in the opposite direction and entering the deflation cavity.

Figure 3(d) is a schematic diagram of the back propagation of the expansion wave to the front section of the detonation chamber.

Fig. 3(e) is a schematic diagram of the further backpropagation of the expansion wave and its entry into the intake ring cavity.

Figure 3(f) is a schematic diagram of the expansion wave propagating back to the reed valve, and the backflow reflowing to the tail nozzle.

Fig. 4 is a schematic diagram of the timing sequence of the principle of the detonator detonating the detonation chamber.

Figure 4(a) is a schematic diagram of the ignition of the spark plug in the detonator to generate a detonation wave that is transmitted into the detonation chamber.

Figure 4(b) Schematic diagram of the detonation jet from the detonator detonating the flammable mixture in the detonation chamber.

In the figure, 10. Intake duct, 11. Intake duct shell, 12. Intake duct central body, 13. Reed valve, 14. Main fuel nozzle, 15. Vent cavity, 16. Center body bracket, 17. Air release pipe, 18. Main fuel nozzle oil passage inlet, 19. Air release chamber valve, 20. Detonation chamber, 21. Blending evaporator, 22. Igniter, 30. Detonation pipe, 31. Detonation pipe bracket, 32. Drain tube, 33. Heat exchanger, 34. Jet hole, 35. Starting fuel/oxidant inlet, 36. Main fuel inlet, 37. Main fuel outlet of heat exchanger, 40. Exhaust nozzle.

Detailed ways

The engine has two sets of mutually independent intake and oil inlet systems, an intake duct, a detonation chamber, a detonator and a tail nozzle. The intake duct 10 is located at the front end of the engine, with the opening forward, as shown in Figure 1(a), including Inlet casing 11, air inlet central body 12, reed valve 13, main fuel nozzle 14, air release chamber 15, air release pipe 17 and main fuel nozzle oil inlet 18, central body support 16 and main fuel nozzle 14 distribution At different circumferential positions, hence no centrosome support in Fig. 1. In another direction (rotated by 90°) in the sectional view 1(b), the air inlet housing 11 is connected to the air inlet central body 12 through a plurality of central body brackets 16 uniformly distributed around the circumference. The air intake casing 11 is fixed, and the size of the air intake ring cavity can be adjusted by adjusting the front and rear axial positions of the air intake central body 12, thereby adjusting the air flow. The central body 12 of the inlet port can be designed as a multi-segment combined structure, and the axial distance between each segment can be adjusted to meet complex working conditions. A plurality of main fuel nozzles 14 are evenly distributed on the central body 12 of the intake port, and the number of nozzles is determined according to the size and maximum operating frequency of the engine. The fuel flows into the oil passage inlet 18 of the main fuel nozzle through the outlet 37 of the heat exchanger 33, passes through the oil passage inside the central body 12 of the air intake channel, and then is ejected radially by the main fuel nozzle 14 at a certain angle and particle size. The deflation cavity 15 is located at the rear end of the central body 12 of the air inlet, and is communicated with the deflation pipe 17 through a hole in the central body bracket 16 . The number of air release pipes 17 can be distributed symmetrically according to the size of the engine and the amount of air release.

The reed valve 13 is in the normally open state, and the incoming flow flows through the reed valve into the annular cavity formed by the intake port casing 11 and the central body 12, and mixes with the fuel sprayed out by the main fuel nozzle 14, and further atomizes the fuel to form a preliminary fuel/air mixture. The mixture flows down and is further mixed under the action of the mixing evaporator 21. Under the multi-cycle working condition of the engine, the blending evaporator 21 absorbs part of the energy of the high-temperature gas of the previous cycle to heat up, and when the fuel/air mixture of the next cycle passes through it, the fuel droplets can absorb heat from the wall of the evaporator 21 and evaporate , which increases the explosiveness of the mixture.

In the embodiment using the deflation chamber valve 19, as shown in Figure 2 (a), when the mixture after further blending and evaporation flows into the detonation chamber 20, the main flow flows downstream of the detonation chamber, and part of the mixture flows into the detonator 30 through the drain pipe 32 , The number of drainage tubes is determined by the size of the detonator, the working frequency and the size of the drainage tube itself. Generally, there are more than 2 evenly distributed, and only one is drawn in this figure for illustration. The two ends of the draft tube 32 are open, one end is located in the flow channel of the blending evaporator and is facing the direction of the incoming flow, and the other end extends into the detonator 30 near the igniter 22 within one diameter of the detonator. Similar to the blending evaporator, the draft tube and detonator, especially the detonator will absorb part of the energy of the high-temperature gas in the previous cycle to heat up, further preheating the mixture in the detonator, which is beneficial to subsequent ignition and detonation. At the same time, the mixing evaporator, detonator and heat exchanger are also the enhanced detonation transformation structures in the main detonation chamber. When fuel/air is filled, a large number of vortex flow and detached vortex will be formed, which strengthens the detonation of fuel/air. the mixing process. By adjusting the axial position of the bleed chamber valve 19, the size of the flow path between the air inlet central body 12 and the blending evaporator 21 can also be changed to adjust the flow rate of the fuel/air mixture entering the detonation chamber, thereby adjusting the operating frequency of the engine. Adjust engine thrust.

In the embodiment without a valve in the deflation chamber, as shown in Figure 2 (b), when the mixture after further mixing and evaporation flows into the detonation chamber 20, the main flow flows downstream of the detonation chamber, and part of the mixture flows into the detonation pipe 30 through the drainage pipe 32, Also have a small amount of mixture to flow into the discharge pipe 17 through the discharge chamber 15, and discharge the engine.

When the engine starts and the working condition is bad, the starting fuel/oxidant inlet 35 supplies the highly sensitive fuel/oxidant to the detonator through the highly sensitive fuel/oxidant flow path in the detonator bracket 31, and simultaneously opens the igniter 22 to detonate the detonator quickly. . The igniter 22 and the corresponding ignition system can be selected from a conventional low-energy automobile spark ignition system, or other high-frequency ignition systems such as plasma ignition. The igniter 22 and its circuit system are arranged in the front bracket of the detonator, the front bracket is located behind the drain tube 32, and the discharge end of the igniter 22 is vertically screwed into the front section of the detonator, as shown in Figure 1(b). After the detonator works for a period of time, the heat exchanger 33 utilizes the circulating waste heat to preheat the main fuel oil in the heat exchanger. At the same time, the incoming air is also heated by the engine wall heat, which improves the detonability of the main fuel oil/air. Then, the priming fuel/oxidant inlet 35 is closed, the detonator is supplied with the detonating mixture, and the detonator turns into the normal working mode. The fuel oil heat exchanger 33 is welded outside the middle and rear section of the detonator 30, because both the detonation combustion in the detonation tube and the detonation combustion in the main detonation chamber will cause the wall temperature of the detonator to rise, so the wall surface of the detonator has the highest temperature and needs to be cooled , improve life, while providing the highest heat transfer capacity. The heat exchanger can have various forms. This example provides a shell with an inner spiral groove, and the front and rear ends are respectively connected with the main fuel inlet 36 and the main fuel nozzle oil passage inlet 18 . Fuel enters the heat exchanger from the main fuel inlet 36 through the main fuel flow path in the detonator bracket 31 , and the preheated fuel passes through the fuel outlet 37 of the heat exchanger to the oil inlet 18 of the main fuel nozzle.

The detonation process is shown in Figures 4(a) and 4(b). The detonation jet is injected into the detonation chamber through the jet hole 34 on the side wall or tail end of the detonation tube, ignites the detonable mixture in the main detonation chamber, and forms a high-temperature and high-pressure hot spot. And local explosion, so that the detonation is formed very quickly and spreads to both ends at an extremely fast speed. When the diameter of the main detonation chamber is large, multiple detonation tubes can be used to accelerate the detonation of the main detonation chamber with more detonation jets.

The detonation wave and gas flowing to the tail nozzle 40 are discharged from the engine to generate effective thrust, and the reverse propagating shock wave and gas are under the action of the mixing evaporator 21, part of the shock wave and gas are reflected back, and part of the shock wave and gas are discharged. The air cavity 15 enters the exhaust pipe 17 in the same direction as the tail nozzle opening, and is discharged from the engine to generate effective positive thrust. The remaining attenuated shock wave and gas enter the intake ring cavity, pushing the reed valve reed to close the flow path , unable to exit the intake duct. At the same time, due to the use of the detonator, the main detonation chamber detonates quickly, the length of the detonation chamber is short, and the expansion wave formed by the exhaust of the detonation chamber propagates forward continuously, and catches up with the forward shock wave in the intake duct, making the The air flow in the intake duct is redirected to the detonation chamber. Its principle is shown in Figure 3(a)-3(f). Thereby suppressing and utilizing the reverse flow, and improving the thrust of the engine.

The amount of engine oil is calculated according to the flight speed and operating frequency, and its control can be controlled by electronic injection technology or pressure control. When starting the engine, first open the starter fuel/oxidant inlet 35, supply highly sensitive/oxidant to the detonator 30, open the ignition system at the same time, detonate quickly, and inject air into the main detonation chamber 20, the amount of injection is related to the working frequency of the detonator related to size. After the detonator works for a period of time, the main fuel oil circuit is opened, then the starting fuel oil/oxidant inlet 35 is closed, and the ignition frequency of the detonator is adjusted according to the incoming flow, and the engine is detonated. The engine enters the pulse detonation working mode. With the gradual increase of the speed, the air intake flow increases, the fuel flow increases and the ignition frequency increases, the thrust increases, and the flight speed continues to increase until it reaches the design point. The thrust can also be controlled by the size of the intake ring cavity, and the fuel flow and ignition frequency can be adjusted accordingly. When the flow area of the intake ring cavity is increased, the incoming flow increases, correspondingly increasing the fuel flow, increasing the ignition frequency, and thus increasing the thrust, and vice versa.

Claims (9)

1. air-breathing pulse detonation engine, comprise the intake duct, detonation chamber and the jet pipe that connect successively along airintake direction, it is characterized in that: the shell of intake duct and air inlet passage center body have formed a toroidal cavity, it is the air inlet ring cavity, in the air inlet ring cavity, along airintake direction leaf valve, several main fuel nozzle and air discharge cavity are installed successively, the main fuel nozzle is circumferentially uniform along the air inlet passage center body, and fuel oil forms oil curtain by the radially spray of main fuel nozzle in the air inlet ring cavity; Have through hole in the central body bracket, air discharge cavity is communicated with exhaust tube by the through hole of central body bracket, and exhaust tube is communicated to outside the intake duct outer wall, and opening direction is consistent with the jet pipe direction; Leaf valve keeps the forward normally open; The blending vaporizer is installed between intake duct and detonation chamber, detonate tube is installed in the detonation chamber by mounting bracket, drainage tube, igniter and heat exchanger are installed on the detonate tube, afterbody sidewall or breech face have some jet holes, through starting fuel oil/oxidant inlet to the high responsive fuel oil/oxygenant of detonate tube independently supplying; Igniter is positioned at the detonate tube leading portion, and drainage tube one end opening comes circulation road over against what intake duct and blending vaporizer formed in detonation chamber, and the other end opening is in detonate tube near the igniter in one times of diameter range of detonate tube; Heat exchanger is the thin walled cavity that is installed in detonate tube afterbody outer wall, and its inner chamber is helical groove structure, and main fuel flows along spiral channel, and is recycled the heat release preheating.

2. a kind of air-breathing pulse detonation engine according to claim 1, it is characterized in that: the shell of described air inlet passage center body and intake duct can move forward and backward relatively.

3. a kind of air-breathing pulse detonation engine according to claim 1, it is characterized in that: described air inlet passage center body is the multistage composite structure, each intersegmental axial distance is adjustable; Leaf valve is installed in air inlet passage center body stage casing.

4. a kind of air-breathing pulse detonation engine according to claim 1, it is characterized in that: described blending evaporation structure is Venturi tube, and the first half section is the convergence pipe, and the second half section is expanding duct, and the profile of blending vaporizer is mated with air discharge cavity.

5. a kind of air-breathing pulse detonation engine according to claim 1, it is characterized in that: described air inlet passage center body adopts supersonic inlet centerbody or subsonics centerbody, air intake casing adopts supersonic inlet shell or subsonics air intake casing, forms respectively supersonic speed pulse-knocking engine intake duct and pneumatic valve system or subsonic speed pulse-knocking engine intake duct and pneumatic valve system.

6. a kind of air-breathing pulse detonation engine according to claim 1, it is characterized in that: be equipped with in the described air discharge cavity along the valve of airintake direction front and back start, valve and air discharge cavity Spielpassung, the structure that adds the detonation chamber internal pressure by electric actuator, hydraulic pressure or spring is controlled, start before and after realizing.

7. a kind of air-breathing pulse detonation engine according to claim 1 is characterized in that: described detonation chamber internal diameter uses the detonate tube of a plurality of parallel arranged during greater than 15cm.

8. a kind of air-breathing pulse detonation engine according to claim 1 is characterized in that: described main fuel nozzle is along circumferentially being distributed on the air intake casing, and heat exchanger is installed in main detonation chamber rear end, and the main fuel oil circuit is distributed in outside the motor.

9. the method for initiation of the described air-breathing pulse detonation engine of claim 1, when it is characterized in that comprising the steps: engine start, high-altitude flight or maneuvering flight, through starting fuel oil/oxidant inlet to detonate tube independently supplying fuel oil/oxygen mixture, the igniter igniting, the detonate tube reliable initiation, the pinking jet sprays into detonation chamber by the jet hole of sidewall or tail end, and main detonation chamber fast detonates; Like this behind work 10～40s, the high responsive fuel oil/oxygenant of stop supplies, main fuel after the preheating flows into the main fuel nozzle by the road, intake port injection and with the incoming flow blending, strengthen blending and evaporation through the blending vaporizer afterwards, a part of mixture flows into detonate tube through drainage tube, light a fire through igniter, realize quick-friedly in advance, the pinking jet sprays into detonation chamber by the jet hole of sidewall or tail end, and main detonation chamber detonates.

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