CN108915893B - A multi-tube helical pulse detonation engine - Google Patents

Abstract

The invention provides a multi-tube helical pulse detonation engine, which includes an air intake and distribution device and an engine main body; a plurality of the helical detonation tubes are uniformly distributed and fixed between the engine outlet cover and the engine closing cover according to the center of the air chamber. The gas inlet and distribution device includes a gas oxidant inlet pipe, a fuel gas inlet branch pipe, a gas oxidant gas inlet branch pipe and a gas oxidant chamber cover plate; the gas chamber is divided into a fuel gas chamber and a gas oxidant chamber by a partition plate, so The fuel gas chamber and several of the helical detonation tubes are communicated through a plurality of the fuel gas inlet branch pipes, a gas oxidant chamber cover plate is arranged between the gas oxidant chamber and the fuel gas inlet branch pipes, and the gaseous oxidant gas inlet The branch pipe communicates with the gas oxidant chamber and the helical detonation pipe. The invention can greatly shorten the horizontal length of the engine, can greatly improve the working frequency of the engine, and is beneficial to the engine to output power continuously and stably.

Description

A multi-tube helical pulse detonation engine

technical field

The invention relates to the technical field of aviation propulsion, in particular to a multi-tube helical pulse detonation engine.

Background technique

As a type of combustion wave, the detonation wave is composed of a strong shock wave followed by a violent exothermic region. The shock compresses the reactants, like a piston between the reactants and products, because there is not enough time to equilibrate the pressure, so that the detonation wave approximates isovolumic combustion, and engines based on isovolumic combustion have more Higher thermal efficiency. The potential advantage of high thermal cycle efficiency drives research into detonation-based powerplants.

Pulse detonation engine is a new concept engine that uses pulsed detonation waves to generate thrust. Compared with traditional engines, pulse detonation engines have the advantages of high thermal cycle efficiency, simple structure, large thrust-to-weight ratio, and wide working range. Continuous output of strong thrust requires the engine to have a high operating frequency, and at the same time, it is also necessary to generate a stable detonation wave in the shortest possible distance to reduce the structural size of the engine. At present, the straight-tube type is mostly used for pulse detonation engines, and because the detonation wave is difficult to trigger directly, it is usually necessary to gradually complete the transition from slow combustion to detonation through processes such as flame acceleration and hot spot explosion, thereby forming a powerful The detonation wave of the thrust is generally longer, so the length of the straight-tube detonation engine is generally longer. For the same combustible mixture, under the same initial conditions and the same diameter and wall conditions in the pipeline, the distance to form a stable detonation wave is the same, and the horizontal length of the spiral pipeline with the same axial expansion length is significantly smaller than that of the straight pipe. At the same time, since the wall surface of the spiral pipeline is not perpendicular to the end surface of the pipeline, the reflection of the shock wave in the pipeline will accelerate the formation of the detonation wave. Therefore, compared with the straight tube, the helical tube can shorten the detonation distance, thereby shortening the horizontal length of the engine. This conclusion is also confirmed by the research results of the document "Experimental Research on Helical Pulse Detonation Engine". Subsequent patents with publication number CN 103899436A and patents with publication number CN 106704036A all involve helical pulse detonation engines, and both adopt the form of arranging a plurality of channels (detonation chambers) in an annular casing, However, the adjacent detonation chambers in the two patents are closely connected, and there is no gap, which is not conducive to the heat dissipation of the engine. And there are moving parts and seals, etc., so the structure is relatively complex.

SUMMARY OF THE INVENTION

In view of the deficiencies in the prior art, the present invention provides a multi-tube helical pulse detonation engine, which has a simple structure, high operating frequency, heat dissipation capability and can accelerate detonation waves.

The present invention achieves the above technical purpose through the following technical means.

A multi-tube helical pulse detonation engine includes an air intake and distribution device and an engine main body; the engine main body includes an engine outlet cover plate, a spiral detonation tube, an engine closing cover plate and an air chamber; the air chamber is fixed on the Between the engine outlet cover and the engine closing cover, a plurality of the spiral detonation tubes are screwed and fixed between the engine outlet cover and the engine closing cover according to the center of the air chamber; spark plugs are arranged on the spiral detonation tubes. ;

The gas inlet and distribution device includes a gas oxidant inlet pipe, a fuel gas inlet branch pipe, a gas oxidant gas inlet branch pipe and a gas oxidant chamber cover plate; the gas chamber is divided into a fuel gas chamber and a gas oxidant chamber by a partition plate, and the gas The oxidant inlet pipe is inserted into the fuel gas chamber and enters the gas oxidant chamber through the partition plate; the fuel gas chamber is communicated with a plurality of the helical detonation pipes through a plurality of the fuel gas intake branch pipes, and the fuel gas chamber is provided with a fuel gas inlet pipe; a gas oxidant chamber cover plate is arranged between the gas oxidant chamber and the fuel gas inlet branch pipe, the gas oxidant chamber cover plate is installed with a gas oxidant inlet branch pipe, and the gas oxidant inlet branch pipe is connected to the gas oxidant chamber with helical detonation tube.

Further, a guide block is provided at the bottom of the gas oxidant chamber near the engine outlet cover plate.

Further, the guide block is a W-shaped guide block, and the center of the W-shaped guide block is coaxial with the gas oxidant inlet pipe.

Further, one end of the gas oxidant inlet pipe inserted into the gas oxidant chamber is wedge-shaped; the gas oxidant inlet pipe, the gas oxidant chamber and the W-shaped guide block form a W channel.

Further, the fuel gas intake branch pipe is perpendicular to the fuel gas chamber.

Further, the gas oxidant inlet branch pipe is a tapered pipe, and the gas oxidant chamber is connected to the helical detonation pipe through the gas oxidant inlet branch pipe.

Further, the gas oxidant inlet branch pipe forms an acute angle with the gas flow direction of the gas oxidant inlet pipe.

Further, a second solenoid valve is installed on the fuel gas intake branch pipe; a first electromagnetic valve is installed on the gas oxidant intake branch pipe.

The beneficial effects of the present invention are:

1. The multi-tube helical pulse detonation engine of the present invention, the helical detonation tubes are spirally uniformly fixed between the engine outlet cover plate and the engine closing cover plate, and the gas oxidant can absorb the gas oxidant when flowing through the gas oxidant chamber. The waste heat generated by the spiral detonation tube increases the intake air temperature, thereby accelerating the reaction rate and accelerating the formation of detonation waves.

2. The multi-tube helical pulse detonation engine of the present invention forms a W channel through the gas oxidant inlet pipe, the gas oxidant chamber and the W-shaped guide block, which can reduce the flow resistance of the gas oxidant at the turning point.

3. The multi-tube spiral pulse detonation engine of the present invention forms an acute angle with the airflow direction of the gas oxidant inlet branch pipe and the gas oxidant inlet pipe to promote the mixing of the fuel gas and the gas oxidant and avoid ignition due to insufficient oxidant. fail.

4. In the multi-tube helical pulse detonation engine of the present invention, the gas oxidant inlet branch pipe is a tapered tube, and due to the sudden change in cross-section, the flow resistance is relatively large, in order to reduce the gas oxidant entering the spiral explosion from the gas oxidant chamber. pressure during blasting.

5. The multi-tube helical pulse detonation engine of the present invention does not have any moving parts, the structure is simple, and there is a gap between adjacent detonation tubes, so it has a certain heat dissipation capacity. The use of a spiral detonation tube can greatly shorten the horizontal length of the engine, and the use of multiple pipes can greatly increase the operating frequency of the engine, which is conducive to the continuous and stable output of the engine. The tube is surrounded, which can absorb part of the engine waste heat, increase the intake air temperature, and speed up the reaction speed, which is conducive to promoting the formation of detonation waves.

Description of drawings

FIG. 1 is a perspective view of the multi-tube helical pulse detonation engine according to the present invention.

FIG. 2 is a cross-sectional view of the multi-tube helical pulse detonation engine according to the present invention.

FIG. 3 is a cloud diagram of the W channel X forward velocity distribution according to the present invention.

FIG. 4 is a cloud diagram of the forward velocity distribution of the square channel X in the prior art.

In the picture:

1- Engine outlet cover; 2- Spiral detonation tube; 3- Engine closed cover; 4- Gas oxidant inlet pipe; 5- Fuel gas inlet pipe; 6- Spark plug; 7- Fuel gas chamber; 8- Fuel gas inlet Gas branch pipe; 9-Gas oxidant inlet branch pipe; 10-Gas oxidant chamber; 11-Guide block; 12-Gas oxidant chamber cover plate; 13-First solenoid valve; 14-Second solenoid valve.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

As shown in Figures 1 and 2, the multi-tube helical pulse detonation engine of the present invention includes an air intake and distribution device and an engine main body; the engine main body includes an engine outlet cover 1, a helical detonation tube 2, an engine Closed cover 3 and air chamber; the air chamber is fixed between the engine outlet cover 1 and the engine closed cover 3, as shown in FIG. 2, one end of the air chamber passes through the engine closed cover 3, the The other end of the air chamber is flush with the engine outlet cover plate 1 . Several described helical detonation tubes 2 are spirally uniformly distributed between the engine outlet cover plate 1 and the engine closing cover plate 3 according to the center of the air chamber; each of the spiral detonation tubes 2 is provided with a spark plug 6; as shown in Figure 2 As shown, one end of each spiral detonation tube 2 is welded and fixed to the engine closing cover plate 3, and the other end of each spiral detonation tube 2 passes through the engine outlet cover plate 1 for outputting detonation waves.

The gas inlet and distribution device includes a gas oxidant inlet pipe 4, a fuel gas inlet branch pipe 8, a gas oxidant gas inlet branch pipe 9 and a gas oxidant chamber cover plate 12; the gas chamber is divided into a fuel gas chamber 7 and a gas oxidant chamber by a partition plate. chamber 10, the gas oxidant inlet pipe 4 is inserted into the fuel gas chamber 7, and enters the gas oxidant chamber 10 through the partition plate; the fuel gas chamber 7 and several of the helical detonation tubes 2 are fed through several of the fuel gas The branch pipe 8 is connected, and the fuel gas chamber 7 is provided with a fuel gas inlet pipe 5; a gas oxidant chamber cover plate 12 is provided between the gas oxidant chamber 10 and the fuel gas inlet branch pipe 8, and the gas oxidant chamber cover plate The gas oxidant inlet branch pipe 9 is installed on the 12 , and the gas oxidant inlet branch pipe 9 communicates with the gas oxidant chamber 10 and the helical detonation pipe 2 . In the multi-tube helical pulse detonation engine of the present invention, when the gas oxidant flows through the gas oxidant inlet pipe 4 and the gas oxidant chamber 10, the gas oxidant can absorb part of the engine waste heat, increase the intake air temperature, and then accelerate the chemical reaction rate, Promote the formation of detonation waves and shorten the formation distance of detonation waves. As shown in the figure, the number of the spiral detonation tubes 2 is 6.

As shown in FIG. 2 , a guide block 11 is provided at the bottom of the gas oxidant chamber 10 near the engine outlet cover plate 1 . The guide block 11 is a W-shaped guide block, and the center of the W-shaped guide block is coaxial with the gas oxidant inlet pipe 4 . One end of the gas oxidant inlet pipe 4 inserted into the gas oxidant chamber 10 is wedge-shaped; the gas oxidant inlet pipe 4, the gas oxidant chamber 10 and the W-shaped guide block form a W channel. Using CFD software to simulate the gas flow in the W-shaped channel and the square channel involved in the present invention under the same boundary conditions, the X-direction velocity nephogram of the gas flow in the channel as shown in Figures 3 and 4 can be obtained. The part where the X-direction velocity is positive. For the gas in the gaseous oxidant inlet 4, a positive value of the X-direction component velocity indicates that the fluid propagates forward along the positive X-axis. Since the gas in the gas oxidant chamber 10 needs to flow to the gas oxidant inlet branch pipe 9 and finally enter the helical detonation tube 2, the gas in the gas oxidant chamber 10 mainly flows in the negative direction of the X-axis. If the X-direction component velocity of the gas flow is a positive value, it means that the flow direction of this part of the fluid is opposite to the flow direction of the main flow part, that is, backflow occurs. Since the flow direction of the fluid in the recirculation zone is opposite to the flow direction of the main flow, it constitutes a certain obstacle to the flow of the main flow of the fluid. It can be seen from Figures 3 and 4 that the backflow area formed in the square channel is significantly larger than the W-shaped channel involved in this paper, that is, the fluid flow resistance in the square channel is greater than the fluid flow resistance in the W-shaped channel. At the same time, it is noted that a recirculation area also appears at the right angle on the right side of the square channel, and no other recirculation area is formed in the W-shaped channel except for the recirculation area formed near the wedge-shaped wall at one end of the gas oxidant chamber 10 . Based on the above analysis, the W-shaped guide block 11 installed at the bottom of the gas oxidant chamber 10 facing the gas oxidant inlet 4 can reduce the flow resistance of the gas oxidant when the gas oxidant turns in the pipeline.

The gaseous oxidant inlet branch pipe 9 is a tapered pipe, and the gaseous oxidant chamber 10 is connected to the helical detonation tube 2 through the gaseous oxidant inlet branch pipe 9 being tapered. The fuel gas chamber 7 is located upstream of the gaseous oxidant chamber 10, and the fuel gas intake branch pipe 8 is perpendicular to the circumferential axis of the helical detonation pipe 2, while the gaseous oxidant intake branch pipe 9 and the fuel gas intake branch pipe 8 are arranged at an acute angle, and the gas The outlet of the oxidant inlet branch pipe 9 faces the side of the fuel gas inlet branch pipe 8, so that the gaseous oxidant entering the helical detonation pipe 2 has a speed of flowing upstream, which can accelerate the mixing of the fuel gas and the oxidant and effectively avoid the failure due to insufficient oxidant. Ignition failure.

After the gas oxidant and fuel gas enter the spiral detonation tube 2, they can be ignited and burned by the spark plug 6, and the combustion flame will eventually form a detonation wave in the spiral detonation tube 2 through flame acceleration and other processes to generate thrust.

A second solenoid valve 14 and a first solenoid valve 13 are respectively installed on the fuel gas intake branch pipe 8 and the gas oxidant gas intake branch pipe 9, and the electronic controller is used to control the first solenoid valve 13, the second solenoid valve 14 and the spark plug 6. On/off can make the spiral detonation tube 2 realize the working process of charging, igniting and burning, and forming detonation according to specific rules, so as to continuously output thrust to the outside.

The invention uses the helical detonation tube, which can greatly shorten the horizontal length of the engine. Due to the use of multiple pipes, the operating frequency of the engine can be greatly increased, which is conducive to the continuous and stable output of power by the engine, and there is a certain gap between the adjacent pipes, so that the The engine has a certain cooling capacity. At the same time, because the gas oxidant chamber is surrounded by the spiral detonation tubes arranged along the circumference, it can absorb part of the engine waste heat, increase the intake air temperature, speed up the reaction rate, and facilitate the formation of detonation waves.

The embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above-mentioned embodiments, and any obvious improvement, replacement or Modifications all belong to the protection scope of the present invention.

Claims (5)

1. A multi-tube spiral pulse detonation engine is characterized by comprising a gas inlet and distribution device and an engine main body;

the engine main body comprises an engine outlet cover plate (1), a spiral detonation tube (2), an engine closed cover plate (3) and an air chamber; the air chamber is fixed between the engine outlet cover plate (1) and the engine closed cover plate (3), and the plurality of spiral detonation tubes (2) are spirally and uniformly distributed and fixed between the engine outlet cover plate (1) and the engine closed cover plate (3) according to the center of the air chamber; a spark plug (6) is arranged on the spiral detonation tube (2);

the gas inlet and distribution device comprises a gas oxidant inlet pipe (4), a fuel gas inlet branch pipe (8), a gas oxidant inlet branch pipe (9) and a gas oxidant chamber cover plate (12); the gas chamber is divided into a fuel gas chamber (7) and a gas oxidant chamber (10) by a partition plate, and the gas oxidant inlet pipe (4) is inserted into the fuel gas chamber (7) and penetrates through the partition plate to enter the gas oxidant chamber (10); the fuel gas chamber (7) is communicated with the plurality of spiral detonation tubes (2) through a plurality of fuel gas inlet branch tubes (8), and a fuel gas inlet tube (5) is arranged on the fuel gas chamber (7); a gas oxidant chamber cover plate (12) is arranged between the gas oxidant chamber (10) and the fuel gas inlet branch pipe (8), a gas oxidant inlet branch pipe (9) is arranged on the gas oxidant chamber cover plate (12), and the gas oxidant inlet branch pipe (9) is communicated with the gas oxidant chamber (10) and the spiral detonation pipe (2); a flow guide block (11) is arranged at the bottom of the gas oxidant chamber (10) close to the engine outlet cover plate (1); the flow guide block (11) is a W-shaped flow guide block (11), and the center of the W-shaped flow guide block (11) is coaxial with the gas oxidant inlet pipe (4); -one end of the gaseous oxidant inlet pipe (4) inserted into the gaseous oxidant chamber (10) is wedge-shaped; the gas oxidant inlet pipe (4), the gas oxidant chamber (10) and the W-shaped flow deflector block (11) form a W-channel.

2. A multi-tube helical pulse detonation engine according to claim 1, characterised in that the fuel gas inlet manifold (8) is perpendicular to the fuel gas chamber (7).

3. A multi-tube helical pulse detonation engine according to claim 1, characterised in that the gaseous oxidant inlet branch (9) is a reducer, the gaseous oxidant chamber (10) being in tapered communication with the helical detonation tube (2) through the gaseous oxidant inlet branch (9).

4. A multi-tube helical pulse detonation engine according to claim 1 characterised in that the gaseous oxidant inlet branch (9) is at an acute angle to the direction of gas flow of the gaseous oxidant inlet tube (4).

5. A multi-tube spiral pulse detonation engine according to claim 1, characterised in that a second solenoid valve (14) is mounted on the fuel gas intake manifold (8); and a first electromagnetic valve (13) is arranged on the gas oxidant inlet branch pipe (9).

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