CN114991993A

CN114991993A - Self-excitation detonation engine

Info

Publication number: CN114991993A
Application number: CN202210370146.XA
Authority: CN
Inventors: 陈玲; 陈科; 陈鸿; 陈道如
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-09-08
Filing date: 2022-04-08
Publication date: 2022-09-02
Anticipated expiration: 2042-04-08
Also published as: CN113803189A; CN114991993B

Abstract

A self-excited detonation engine mainly comprises an air inlet channel, a valve (with a valve or without a valve), a detonation chamber, an exploder, a spray pipe and systems for supplying, igniting, cooling, controlling and the like fuel; the detonator mainly comprises a plurality of single hyperbolic grooves and/or other convergence grooves, and each groove corresponds to a reflection area which is reflected, focused or converged by the grooves and is used for the pressure waves by the inner wall of the machine body; the single hyperbola refers to one of the hyperbolas; the inner wall of the engine body refers to the inner walls of the air inlet channel, the detonation chamber and the spray pipe; the pressure wave refers to an air inlet pressure wave, an atmospheric pressure wave returned from the rear end of the spray pipe or a high-temperature and high-pressure gas pressure wave. The technical scheme adopted by the invention is as follows: the detonation is achieved by reflective focusing or reflective convergence of the grooves of the detonator on the pressure wave.

Description

Self-excitation detonation engine

Technical Field

The invention relates to a self-excited detonation engine, which belongs to the category of pulse detonation engines and is a new concept engine based on detonation combustion.

Background

Since 1881 scientists discovered that knock phenomenon, knock theory, while gradually perfected, also produced the concept of a knock engine in application. The knocking engines currently under investigation are mainly: pulse detonation engines, oblique detonation wave engines, and rotary detonation wave engines.

The pulse detonation engine is a new concept engine which utilizes high-temperature and high-pressure fuel gas generated by pulse detonation waves to generate thrust. The detonation wave is a supersonic (about 2000 m/s) combustion wave with a compression function, the detonation combustion is close to constant volume combustion, and the thermal cycle efficiency (about 49%) is far higher than that of the constant pressure combustion (about 27%) of the traditional engine. The engine based on the detonation combustion has the advantages of high combustion and energy release speeds, high thermal cycle efficiency, low fuel consumption rate, simple structure, small volume, light weight, high thrust-weight ratio, large specific impulse and the like.

Although the detonation engine has a plurality of advantages, the detonation engine is still in an exploration and research stage due to the technical defects, and mainly the problems of high-frequency detonation, working stability and the like are not substantially developed. There are two current detonation schemes: direct initiation, which is achieved by high-voltage instantaneous discharge, and indirect initiation, which has a high initiation frequency but requires very high energy (about 10% ⁵ Joules/second), irreparable in application; the indirect detonation is converted to detonation (DDT) through detonation, but the DDT pipe is long in period from fuel filling to conversion from detonation to detonation, the detonation frequency is low (about 10 times/second), the detonation frequency far less than that of a detonation engine generating approximate continuous thrust (about 100 times/second), the two detonation schemes are not applicable, so that the real application cannot be realized, and the exploration of the applicable high-frequency detonation scheme is the key technology to be solved urgently at presentAnd (4) performing the operation.

Disclosure of Invention

A self-excited detonation engine mainly comprises an air inlet channel, a valve (with a valve or without a valve), a detonation chamber, an exploder, a spray pipe and systems for supplying, igniting, cooling, controlling and the like fuel; the detonator mainly comprises a plurality of single hyperbolic grooves and/or other convergence grooves, and each groove corresponds to a reflection area which is reflected, focused or converged by the grooves and is used for the pressure waves by the inner wall of the machine body; the single hyperbola refers to one of the hyperbolas; the inner wall of the engine body refers to the inner walls of the air inlet channel, the detonation chamber and the spray pipe; the pressure wave refers to an air inlet pressure wave, an atmospheric pressure wave returned from the rear end of the spray pipe or a high-temperature and high-pressure gas pressure wave.

The technical scheme adopted by the invention is as follows: the detonation is achieved by reflective focusing or reflective convergence of the grooves of the detonator on the pressure wave.

Drawings

Fig. 1 and fig. 2 are schematic transverse structural diagrams of a valve type self-excited detonation engine and a valveless self-excited detonation engine respectively.

Fig. 3 and 4 are schematic longitudinal structural diagrams of the valve type self-excited detonation engine and the valveless self-excited detonation engine respectively.

Fig. 5 is a schematic diagram of the axial structure of the output of the valveless rotary self-excited detonation engine (the engine is distributed along the circumference or spirally).

In the figure: 1, an air inlet pipe; 2-a nozzle; 3-rotary valve (fig. 1, fig. 3), guide cone (fig. 2, fig. 4, fig. 5); 4-rotary valve inlet (fig. 1, fig. 3), deflector ring (fig. 2, fig. 4, fig. 5); 5-thrust wall (planar thrust wall in fig. 1, 3, concave thrust wall in fig. 2, 4, 5); 6-thrust wall air inlet; 7-a spark plug; 8-exploder (fig. 3 and 4 are linear type, the tail end is turned into streamline type; fig. 5 is arc type or spiral type, which is respectively corresponding to the engine distributed along the circumference or spirally distributed); 9-initiator focus (fig. 1, 2), initiator focus along the line (dotted line in fig. 3, 4, 5); 10-a detonation tube; 11-a spray pipe; 12-a cooling pipe of the detonator (cooling liquid is circulated in and out of the pipe); 13-hyperbola (the inner focus of the left branch is located on the center of the circle of the inner wall section circle of the detonation tube 10, and the right branch is a curve where the edge of the section of the groove on the right side of the detonator 8 is located); 14-a radial pressure wave; 15-a web; 16-output shaft.

Connection process (fig. 1, fig. 3): the air inlet pipe 1 is connected with a detonation pipe 10; the detonation pipe 10 is connected with a spray pipe 11; the nozzle 2 is connected with an air inlet pipe 1; the rotary valve 3 is connected with a thrust wall 5; the thrust wall 5 is connected with a detonation tube 10; the spark plug 7 is connected with a detonation tube 10; the detonator 8 is connected with the thrust wall 5; the initiator cooling tube 12 is piped in with the cooling system through the thrust wall 5.

Connection process (fig. 2, 4, 5): the air inlet pipe 1 is connected with a detonation pipe 10; the detonation pipe 10 is connected with a spray pipe 11; the nozzle 2 is connected with an air inlet pipe 1; the diversion cone 3 is connected with the air inlet pipe 1; the guide ring 4 is connected with a detonation pipe 10; the spark plug 7 is connected with a detonation tube 10; the detonator 8 is connected with the thrust wall 5; the cooling pipe 12 of the detonator is connected with a cooling system through a built-in pipe of the diversion cone 3; the detonation tube 10 is connected with a web 15; the web 15 is coupled to an output shaft 16.

In the engine shown in fig. 1 and 2, the initiator with six and four single hyperbolic grooves is respectively illustrated, the outer focus of each single hyperbolic curve in the cross section of the groove is positioned on the center of the circular arc of the cross section of the inner wall of the detonation tube 10 corresponding to the single hyperbolic curve, so that the radial pressure wave 14 reflected by the corresponding circular arc is converged to the inner focus of the single hyperbolic curve after being reflected by the single hyperbolic curve. If the radius of the inner wall of the detonation tube 10 is r and the real axial length of the hyperbola 13 is 2a, the path length of the radial pressure wave 14 reflected to the inner focus through the single hyperbola is r-2 a.

The outer focuses of a plurality of single hyperbolas in the plane circle are all located at the circle center and are distributed and connected to form a curved edge shape along the circumference, and the curved edge shape is a linear single hyperbola-shaped groove initiator formed by translation along the direction vertical to the plane. The linear single-branch hyperbolic-shaped groove and radial pressure waves and convergent spherical waves reflected by the corresponding inner wall of the machine body have the properties of reflection and focusing; the radial pressure wave reflected by the arc-shaped or spiral single-branch hyperbolic-shaped groove and the corresponding inner wall of the machine body has the property of reflection and focusing.

Detailed Description

Fig. 3 shows that the working cycle of the engine comprises four basic processes of air intake, detonation, combustion (detonation wave propagation) and exhaust.

Firstly, air intake: firstly, the rotary valve is opened, compressed air is injected into the air inlet pipe, then the fuel is sprayed by the nozzle and mixed with the air in the air inlet pipe to enter the detonation chamber, and the rotary valve is closed when a proper amount of mixed gas enters.

II, detonating: when the rotary valve is closed, the spark plug ignites the mixed gas, part of the mixed gas is detonated to generate high-temperature and high-pressure gas, the radial centripetal pressure wave and the convergent spherical pressure wave of the high-temperature and high-pressure gas are reflected and focused by the groove of the initiator, and the radial centrifugal pressure wave and the divergent spherical pressure wave of the high-temperature and high-pressure gas are reflected to the groove of the initiator by the inner wall of the engine body and then are reflected and focused by the groove, so that the pressure and the temperature of the local mixed gas on the focal point edge line in the groove are rapidly increased, the mixed gas is excited to detonate and combust, and the detonation wave is generated.

Thirdly, combustion: the detonation wave generated by detonation propagates to the periphery at supersonic speed (about several kilometers per second), the mixed gas at the place where the detonation wave passes undergoes violent chemical reaction, and simultaneously, the high-speed energy release is accompanied, so that the pressure and the temperature of the detonation product after detonation are sharply increased (the pressure can reach 100 atmospheric pressures, and the temperature can reach 2000 ℃); and the expansion pressure of the detonation product in the detonation wave propagation process assists in pushing the detonation wave to continue to propagate to the periphery until all the mixed gas knocks, and the detonation wave is discharged out of the detonation chamber.

Fourthly, exhausting gas: after the detonation wave is discharged, detonation products (high-temperature and high-pressure fuel gas) are sprayed out from the spray pipe (hereinafter referred to as exhaust), and meanwhile, reaction thrust is generated, so that heat energy is converted into mechanical energy.

In the exhaust process, the detonation chamber is in a vacuum state in a short time due to the inertia effect of the gas flow, the rotary valve is opened at the moment, the mixed gas in the gas inlet pipe automatically enters the detonation chamber under the action of pressure difference, and the rotary valve is closed at proper time when a proper amount of mixed gas enters, and then the previous work cycle process of detonation, combustion and exhaust is carried out; in this way, the engine can work continuously.

The basic working cycle process of the engine of fig. 4 and 5 is the same as that of fig. 3, and the engine also needs auxiliary air intake and automatic air intake, detonation, combustion and exhaust by exhaust vacuumizing when starting to work, except that no mechanical valve is arranged, and the pressure fluctuation in the annular air inlet channel plays the role of an aerodynamic valve. Fig. 5 shows that the engine starts to operate by starting the engine to rotate for intake, and by exhausting for propulsion of the engine to rotate and for outward output of mechanical energy.

The engine realizes detonation by reflecting and focusing high-temperature and high-pressure gas pressure waves in the engine body through the groove of the detonator, and can realize detonation by reflecting and focusing other pressure waves in the engine body through the groove of the detonator.

Pressure-entering initiation: in the working process of the engine shown in the figures 3, 4 and 5, high-intensity turbulence is generated by high-speed air inlet, and the detonation can be realized by reflecting and focusing pressure waves generated by the pulsation of the high-intensity turbulence through the groove of the detonator, reflecting the pressure waves to the groove of the detonator through the inner wall of the engine body and reflecting and focusing the pressure waves through the groove.

Back pressure initiation: when the exhaust of the engines shown in fig. 3, 4 and 5 is finished, the jet pipe is in a vacuum state by the gas flow ejected by inertia, so that the atmospheric pressure wave at the rear end of the jet pipe returns to the detonation chamber, the reflected wave and the incident wave are synthesized into a pressure wave with a larger wave amplitude after being reflected by the thrust wall, and the detonation can be realized by the reflection focusing of the groove of the detonator, the reflection focusing of the groove to the groove of the detonator by the inner wall of the engine body and the reflection focusing of the groove.

Spontaneous combustion and detonation: in the engines shown in fig. 3, 4 and 5, a part of mixed gas is spontaneously combusted through the inner wall of the detonation chamber with high temperature to generate high-temperature and high-pressure gas, and the detonation can be realized through the reflection focusing of the pressure wave of the high-temperature and high-pressure gas by the groove of the detonator, the reflection focusing of the pressure wave of the high-temperature and high-pressure gas by the inner wall of the engine body to the groove of the detonator, and the reflection focusing by the groove.

The implementation process of the single-branch hyperbolic-groove initiator for realizing initiation by reflecting and focusing radial centripetal pressure waves and convergent spherical pressure waves is explained above. The single hyperbola-shaped groove initiator has many advantages: (1) the mixture gas is smoothly filled along the focal line; (2) the space in the detonator is large, a cooling device is convenient to arrange, the cooling effect is good, and the problem that the mixed gas is spontaneously combusted in advance when pressure waves arrive due to overhigh temperature of the bottom wall of the groove is fully solved; (3) the pressure and the temperature of the mixed gas on the focal point along the line are greatly increased through the reflection focusing of the groove; (4) the detonator with a plurality of grooves is convenient to arrange; therefore, the single-hyperbola-shaped groove exploder can greatly improve the success rate of explosion and has high practicability.

In addition, due to the disorder of turbulence, turbulence pulsation generates pressure waves of various wave systems, and the corresponding exploder with the convergence-shaped groove can reflect, focus or converge to realize explosion for the pressure waves of each wave system; for example, the detonators with parabolic grooves are used for pressure waves of parallel wave systems, and the detonators with smooth curved grooves such as elliptical arc grooves and sinusoidal grooves are used for pressure waves of different divergent wave systems.

The pulse jet engine forms a karman vortex street phenomenon in the air intake process, vortex in the vortex street is alternately released to enable a high-pressure area and a low-pressure area in the engine body to coexist simultaneously, and the pressure amplification of high-pressure waves and low-pressure waves reflected and focused by the inner wall of the engine body is small, so that the pulse jet engine cannot achieve the condition of high-pressure detonation, can only organize combustion based on a detonation mode, and has low detonation pressure (about 3 atmospheric pressures), high fuel consumption rate, low working frequency (about 50 times/second) and high vibratility.

In view of the problem that the pressure of a pulse jet engine for reflecting and focusing pressure waves cannot reach a high-pressure detonation condition, the invention adopts a scheme of subarea reflection and focusing to prevent low-pressure waves from reducing high-pressure waves, so that pressure waves centripetally transmitted by a high-pressure area are reflected and focused by a groove of a detonator, pressure waves centrifugally transmitted by the high-pressure area are reflected to the groove of the detonator by the inner wall of a machine body and are reflected and focused by the groove, and further, the pressure of local mixed gas on a focal point in the groove along a line is greatly increased to realize detonation.

The detonation pressure of the detonation engine is about 30 times of that of the pulse jet engine, so that the detonation engine is high in vacuum degree through exhaust vacuumizing, large in pressure difference between a detonation chamber and an air inlet channel and high in air inlet flow speed; the propagation speed of the detonation wave is about 100 times that of the detonation wave, so that the self-excitation detonation engine is presumed to have the working frequency of about thousands of times per second, and the continuity and stability of the generated thrust can exceed those of various current engines based on the detonation mode tissue combustion.

In conclusion, the self-excited detonation engine can perform automatic high-frequency detonation, is stable and reliable in work, has the advantages of high combustion and energy release speeds, high thermal cycle efficiency, low fuel consumption rate and the like, and has wide application prospects in various fields in the future.

Claims

1. A self-excited detonation engine mainly comprises an air inlet channel, a valve (with a valve or without a valve), a detonation chamber, an initiator, a spray pipe, and systems for supplying, igniting, cooling, controlling and the like, and is characterized in that: the detonator mainly comprises a plurality of single hyperbolic grooves and/or other convergence grooves, and each groove corresponds to a reflection area which is reflected, focused or converged by the grooves and is used for the pressure waves by the inner wall of the machine body; the single hyperbola refers to one of the hyperbolas; the inner wall of the engine body refers to the inner walls of the air inlet channel, the detonation chamber and the spray pipe; the pressure wave refers to an air inlet pressure wave, an atmospheric pressure wave returned from the rear end of the spray pipe or a high-temperature and high-pressure gas pressure wave; the detonation is achieved by reflective focusing or reflective convergence of the grooves of the detonator on the pressure wave.

2. A convergent recess according to claim 1, wherein: two sides of the smooth curved groove converge to the peak.

3. A convergent recess according to claim 1, wherein: two sides of the smooth curved groove are symmetrically converged towards the vertex.

4. The convergent channel as set forth in claim 1, wherein: two lateral vertexes are converged and the curvature is gradually changed.

5. A convergent recess according to claim 1, wherein: two sides of the smooth curved groove are symmetrically converged towards the vertex and have gradually changed curvature.