CN114320661B

CN114320661B - Backflow injection pressurization system based on detonation combustion excitation and pressurization method thereof

Info

Publication number: CN114320661B
Application number: CN202111573356.0A
Authority: CN
Inventors: 鲍文; 徐万千; 李松晶
Original assignee: Harbin Institute of Technology
Current assignee: Harbin Institute of Technology
Priority date: 2021-12-21
Filing date: 2021-12-21
Publication date: 2023-01-31
Anticipated expiration: 2041-12-21
Also published as: CN114320661A

Abstract

The invention provides a backflow injection pressurization system based on detonation combustion excitation and a pressurization method thereof, and belongs to the field of space equipment. The power requirement of the wide-speed-range aircraft is met, and the problems that the existing combined engine needs to be started by a turbine or a rocket at a low speed, the thrust-weight ratio is small due to the fact that the dead weight of the turbine combined engine is large, and the performance is difficult to meet due to the fact that the specific impulse of the rocket combined engine is low are solved. A fuel gas outlet of a pressurization source of the system is connected with an ejector, an air inlet of the pressurization source is connected with a backflow flow channel, the tail of the ejector, the head of the backflow flow channel and the head of an outlet spray pipe are respectively connected with a flow divider, one path of the flow divider enters the backflow flow channel, and the other path of the flow divider enters the outlet spray pipe. The invention utilizes the supercharging technology under the Ma0 speed, generates a high supercharging source through detonation combustion, and adopts the modes of backflow injection, pneumatic flow channel filtering and the like to ensure that the pressure is relatively stable and reaches a high pressure ratio working state, thereby realizing high-performance supercharging of high-speed incoming flow.

Description

Backflow injection pressurization system based on detonation combustion excitation and pressurization method thereof

Technical Field

The invention belongs to the technical field of space equipment, and particularly relates to a backflow injection pressurization system based on detonation combustion excitation and a pressurization method thereof.

Background

One of the key technologies of wide-speed-range combined power aircraft for the world round-trip transportation task is the starting problem at zero speed. The current single-cycle air-breathing engine has the optimal working Mach number and height range, and the requirements of specific impulse and thrust-weight ratio are difficult to meet at the same time, and the operation requirements of large airspace and wide speed range are difficult to meet. The existing combined engine needs to be started by a turbine or a rocket at a low speed, the dead weight of the turbine combined engine causes a small thrust-weight ratio, the specific impulse of the rocket combined engine is low, the performance is difficult to meet, a high specific impulse engine mode without turbine compression needs to be researched, the engine which can work at zero speed without turbine compression is obtained, and the engine has high specific impulse and thrust-weight ratio. The high-performance thrust system can be provided for supersonic aircrafts, hypersonic airplanes, world shuttle transportation systems and the like, and technical support and thinking are provided for realizing the research of high-performance, cheap and wide-speed-range engines.

A problem at the core of the engine is supercharging of the air flow. The supersonic incoming flow can be compressed by adopting a stamping shock wave, the subsonic velocity is mainly used for turbine blades, and the rocket can obtain high combustion pressure by adopting a turbine pump. The combined power organically integrates the performances of three basic engines, namely a turbine engine, a stamping engine and a rocket engine, and forms a novel power form for ultra-wide range work from ground zero speed to hypersonic speed work. The current combined power mainly comprises RBCC, TBCC, trijet, ATR and the like, and can be divided into two types of scramjet engines (TBCC, RBCC, three-combination) and high-speed turbines (precooling turbine, ATR), and supercharged combustion power represented by knocking can also work to a wide speed range.

The hypersonic speed TBCC engine is a combination of a gas turbine engine and a dual-mode ramjet engine in a serial or parallel mode, the working Mach number of the parallel TBCC can exceed 6, but an aircraft which solves the problem of full-size hypersonic speed TBCC modal conversion does not appear at present. Hypersonic TBCC engines have a high specific impulse, but the ground thrust is generally less than 4 and is bulky.

The Trijet three-combination cycle engine integrates a turbine engine, a rocket enhanced injection ramjet engine and a dual-mode hyper-combustion ramjet engine, can utilize a real-time turbine, and is a scheme which is possible to realize a hypersonic combined engine in the near future. The single component of the three-combination engine has high technical maturity, high specific impulse, large volume, large windward area and low thrust weight. A pre-cooling cycle engine is an engine that cools and cools the air stream entering the engine, compresses the air stream, and feeds the compressed air stream into a combustion chamber for combustion as an oxidant, typically a coordinated air breathing rocket engine (SABRE) in the uk. The SABRE theoretically has the capability of global operation from ground level to orbital space at speeds ranging from zero to on-track speed. The liquid hydrogen fuel is adopted as the fuel, so that the problems of extremely complicated system, lower and lower prediction performance, great technical difficulty and the like exist, and the specific application condition needs further demonstration.

The RBCC is a combined cycle power system combining a rocket engine with a dual-mode engine. During flight acceleration, the RBCC undergoes four modes: the system comprises an injection mode, a sub-combustion stamping mode, a super-combustion stamping mode and a pure rocket mode, and the full-airspace and full-speed-domain work is realized through mode switching. The RBCC thrust-weight ratio is large, but the injection mode specific impulse at low speed is generally not more than 450s, and the takeoff from zero speed is difficult.

The ATR has wide working height and speed application range, but has lower specific impact performance, the working speed is difficult to exceed Mach 5, and the ATR does not meet the wide-range working requirement of hypersonic speed by combining with other engines.

The combustion can achieve the purpose of supercharging, and a supercharged combustion mode is adopted, so that a new configuration with zero speed, high specific impulse and high thrust-weight ratio can be realized. Pulse combustion can be self-supercharged, but the specific impulse performance of the pulse combustion engine is lower; the detonation combustion is a typical high-efficiency supercharged combustion mode, and a detonation engine which utilizes the detonation combustion to generate thrust has higher thermodynamic cycle efficiency, a simple structure and large specific impulse in principle.

The detonation engine is divided into a Pulse Detonation Engine (PDE), a Continuous Detonation Engine (CDE) and an inclined detonation engine (ODE) according to different working modes. PDE requires higher knock frequency, and current engine performance at low speeds is some distance from the target and has not been explored to hypersonic speed. RDE is a hot spot of recent research and has achieved good engine performance at supersonic speeds, but there is no feasible solution for how it can be used at zero speed.

At the low speed of zero speed and subsonic speed, the most common air flow compression is turbine blade compression, and a high-speed turbine has great requirements on materials, rotor dynamics and the like, and is difficult to develop. The possible schemes of no turbocharging under low-speed incoming flow comprise modes of injection supercharging, detonation supercharging and the like, and the supercharging capacity of the modes is relatively limited; the compression without a turbine under supersonic incoming flow is relatively simple, and the compression capacity of more than 10 times can be achieved by adopting shock wave compression. It is therefore of interest to explore a turbocharging system without a turbine.

Disclosure of Invention

In view of the above, the problem that performance is difficult to meet due to small thrust-weight ratio and low specific impulse of the rocket combined engine caused by large dead weight of the turbine combined engine is solved in order to solve the power requirement of the wide-speed-range aircraft and solve the problem that the existing combined engine needs to start the turbine or the rocket at low speed. The invention provides a backflow injection pressurization system based on detonation combustion excitation and a pressurization method thereof, and in a novel pressurization technology at the speed of Ma0, a high pressurization source is generated through detonation combustion, and the pressure is relatively stable and reaches a high-pressure ratio working state by adopting modes of backflow injection, pneumatic flow channel filtering and the like, so that high-speed inflow high-performance pressurization is realized, and the backflow injection pressurization system is mainly applied to providing pressurization capacity at the speed of Ma 0.

In order to achieve the purpose, the invention adopts the following technical scheme: the utility model provides a backward flow draws pressure boost system that penetrates based on detonation combustion excitation, includes pressure boost source, ejector intake duct, ejector, shunt, backflow channel and export spray tube, the place ahead of ejector is provided with the ejector intake duct, the gas outlet and the ejector of pressure boost source are connected, the air inlet and the backflow channel of pressure boost source are connected, the afterbody of ejector, backflow channel's head and the head of export spray tube are connected with the shunt respectively, and the branch wherein gets into backflow channel all the way, another way gets into the export spray tube.

Furthermore, the pressurization source is a linear detonation chamber which adopts detonation combustion pressurization and generates pressure superposition gain through injection of backflow airflow.

A supercharging method of a backflow injection supercharging system based on detonation combustion excitation is characterized in that the backflow injection supercharging of the detonation combustion excitation is started, the pressure and the temperature of airflow entering an outlet nozzle are improved, the airflow repeatedly rotates in a flow channel to be supercharged, and external airflow is injected to enter the system, so that a sufficiently high supercharging ratio is achieved.

Furthermore, the supercharging method of the backflow injection supercharging system based on the detonation combustion excitation specifically comprises the following steps:

(1) The method comprises the following steps that airflow firstly enters a system from an air inlet channel of an ejector, after momentum and energy exchange is carried out between the airflow and high-energy fuel gas generated by a pressurization source in the ejector, the pressure and the temperature are increased, and the fuel gas enters a backflow flow channel through a flow divider after momentum and energy exchange is carried out;

(2) And then the high-energy gas is combusted in a pressurization source to do work, the high-energy gas is generated and enters the ejector for the second time, and enters the outlet spray pipe through the flow divider to be discharged out of the system to do work after momentum and energy exchange with the next external air, so that the primary working medium circulation is completed.

(3) Finally, through the backflow injection pressurization system based on detonation combustion excitation, enough external airflow can be injected into the detonation chamber, backflow can be enabled to provide gradually-iteratively-increased pressure, and finally a stable working state is established.

Furthermore, the supercharging method of the backflow injection supercharging system based on the detonation combustion excitation specifically comprises the following four stages:

first phase (a) ignition: pre-mixed gas is arranged in the pressurizing source and is ignited to generate high-temperature high-speed airflow;

the second stage is (b) injection: the main flow of the ejector is high-temperature fuel gas generated by a pressurization source, the secondary flow is external air entering from an air inlet channel of the ejector, and the high-temperature air flow generated by detonation combustion is used as the primary flow of the ejector and used for ejecting the external air flow to enter the ejector;

the third stage is (c) splitting: the airflow entering the ejector passes through the flow divider, one part of the airflow enters the backflow flow channel, the other part of the airflow enters the outlet spray pipe, and the energy of the airflow entering the outlet spray pipe is higher than that of the airflow entering the booster source under the condition of independent work; the airflow entering the backflow channel enters the next stage;

the fourth stage is (d) scavenging: residual gas in the pressurization source is blown away by the airflow entering the backflow channel in the last stage, meanwhile, a premixed environment is formed in the pressurization source by the mixed fuel, the backflow in the process also provides the pressurized incoming flow for the next circulation, and the pressure fluctuation of the backflow airflow can turn around along the flow channel for many times before the next detonation.

Compared with the prior art, the backflow injection supercharging system based on detonation combustion excitation and the supercharging method thereof have the beneficial effects that:

1. the invention can realize the pressurization effect of the downflow airflow at the speed of Ma0 by using a structure without a rotor, the airflow enters the ejector to inject the airflow into the system after being pressurized in the detonation cavity, and the pressurized external air is injected and pressurized to enter the detonation cavity as the filling condition of the next detonation.

2. By means of the characteristics of high pressure rise, high-frequency pulse and the like of detonation combustion, the pressure is relatively stable and the working state of high pressure ratio is achieved by adopting modes of backflow injection, pneumatic flow channel filtering and the like.

3. The invention can realize the supercharging effect under the condition of zero speed and can lead the aircraft to achieve the performance indexes of high thrust-weight ratio and high specific impulse.

4. The prior single-cycle air-breathing engine has the optimal working Mach number and height range, and the requirements of specific impulse and thrust-weight ratio are difficult to meet simultaneously, and the invention can provide two advantages compared with a turbine compressor system: firstly, the system can realize high-performance pressurization at the Ma0 speed, and secondly, the system is internally provided with no mechanical rotating part, so that the dead weight of the structure can be greatly reduced, and the thrust-weight ratio is improved.

5. The invention can provide the horizontal take-off and landing capability of starting from zero speed for a combined power aircraft and the like, is a high-performance thrust system, and can provide technical support and thinking for realizing the research of the high-performance, cheap and wide-speed-range engine.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic structural diagram of a backflow injection supercharging system based on detonation combustion excitation, wherein a blue area represents an injector, a pink area represents a supercharging source, a green area represents a backflow flow channel, and a gray area represents an outlet nozzle.

FIG. 2 is a schematic top view of a detonation combustion excitation-based backflow injection supercharging system.

Fig. 3 is a schematic diagram of an operation process of backflow pressurization in one cycle, and fig. 3 is divided into four operation processes, namely (a) ignition, (b) injection, (c) diversion and (d) scavenging processes, wherein red represents a high-temperature main flow generated by a detonation combustion chamber, and blue represents external air introduced into the system.

FIG. 4 shows exemplary thermodynamic and gas-dynamic calculations for a detonation combustor as an example of a pressure boosting source. (a) Is the result of thermodynamic calculations for one example of feasible work; the horizontal axis represents the calculated working medium cycle number, the definition of the working medium cycle number is explained in the embodiment, the vertical axis represents the pressure change in the detonation chamber, and the initial airflow pressure in the detonation chamber is increased from the environmental pressure of 0.1MPa to 0.3MPa through the reflux self-excitation; (b) Is the result of one-dimensional CFD simulation calculation of gas, where the black line is the combustion initiation pressure in the detonation chamber and the red line is the time-averaged value of that pressure, showing an example of a dynamic process of system startup; (c) The thermodynamic process diagram of 2 cycles before the starting process of the fluid working medium of the calculation example is shown, wherein black points and lines are thermodynamic processes of initial filling gas of the system, red lines are working medium thermodynamic process lines of second cycle injected into the system by the initial gas, and blue lines are external airflow thermodynamic process lines compressed by the injection of the third working medium cycle and not yet entering the flow divider; (d) The thermodynamic process diagram of the system from initial establishment to stabilization is calculated for 50 cycles in total, and the thermodynamic process of the working medium can be seen to gradually increase in an iterative manner from an initial state and finally reach a stable working state represented by a blue line.

In the figure: 1-a pressurization source, 2-an ejector air inlet channel, 3-an ejector, 4-a flow divider, 5-a backflow channel and 6-an outlet spray pipe.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely explained below with reference to the drawings in the embodiments of the present invention. It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict, and the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments.

Referring to fig. 1-4 to illustrate this embodiment, this embodiment's backward flow draws and penetrates turbocharging system based on detonation combustion excitation, including pressure boost source 1, ejector intake duct 2, ejector 3, shunt 4, backflow flow path 5 and export spray tube 6, the place ahead of ejector 3 is provided with ejector intake duct 2, the gas outlet and the ejector intake duct 2 of pressure boost source 1 are connected, the air inlet and the backflow flow path 5 of pressure boost source 1 are connected, the afterbody of ejector 3, the head of backflow flow path 5 and the head of export spray tube 6 are connected with shunt 4, and one of them way of reposition of redundant personnel gets into backflow flow path 5, and another way gets into export spray tube 6.

The application provides a detonation combustion excited reflux ejector supercharging system, through the air current in the supercharging source 1 after the pressure boost entering ejector 3 ejector air current entering system, the outside air after the pressure boost is ejected and is entered the supercharging source 1 after the pressure boost, as the filling condition of next detonation. When the airflow enters a stable working state after being repeatedly convoluted, enough airflow can be injected into the pressure boosting source 1, so that the pressure boosting source 1 continuously works; the tail gas combusted by the pressurization source 1 is subjected to energy and momentum exchange with the outside air through the ejector 3, enters the outlet spray pipe 6 and is discharged out of the system to do work, and thermodynamic closed loop of the fuel gas is realized.

The pressure increasing source 1 is a linear detonation chamber, adopts detonation combustion pressure increasing, is provided with an air inlet and a fuel gas outlet, generates pressure superposition gain through the injection action of backflow airflow, and is connected with the fuel gas outlet of the pressure increasing source 2 through an injection air inlet 2 and used for capturing external airflow.

The ejector 3 is used for exchanging energy and momentum between high-temperature fuel gas and external air flow and improving the pressure of the external air flow entering a system. The flow divider 4 serves to separate the ambient air flow from the main flow.

The function of the backflow channel 5 is to enable external air flow to enter the pressurization source 1 and enable the system to generate a self-excitation working state. The outlet nozzle 6 is used for improving the speed of the tail gas discharged from the system, so that the main flow which is not completely mixed expands to work and generates thrust.

The working process of the backflow injection supercharging system based on detonation combustion excitation is as follows:

in a working state, airflow firstly enters the system from the air inlet channel 2 of the ejector, and after momentum and energy exchange is carried out between the airflow and high-energy fuel gas generated by the pressurization source 1 in the ejector 3, the pressure and the temperature are increased, and the fuel gas enters the backflow flow channel 5 through the flow divider 4 after the momentum and energy exchange is carried out through the flow divider 4. Because the time scale of oxygen diffusion is far smaller than the time scale of air flow moving in the air inlet channel, the external air mainly concentrates on the upper part to enter the backflow channel 5 and is used as filling fuel of the pressurization source 1 after the fuel mixing process; and finally, burning in the pressurization source 1 to do work, generating high-energy gas, enabling the high-energy gas to enter the ejector 3 for the second time, exchanging momentum and energy with the next external air, enabling the high-energy gas to enter the outlet spray pipe 6 through the flow divider 4 to be discharged out of the system and do work, and completing primary working medium circulation. The designed backflow injection system can inject enough external airflow into the detonation chamber, can enable backflow to provide gradually-iteratively-increased pressure, and finally establishes a stable working state.

The method for supercharging the backflow injection supercharging system based on detonation combustion excitation comprises the following steps: the back flow induced injection supercharging excited by detonation combustion is started to improve the working capacity of the airflow entering the outlet nozzle 6, and the airflow repeatedly rotates in the flow channel to be supercharged and injects external airflow to enter a system to achieve a sufficiently high supercharging ratio.

Each cycle of airflow revolution comprises the following four stages, ignition, injection, diversion and scavenging (as shown in fig. 3):

firstly, the second stage (a) is ignited, premixed gas is arranged in the pressure increasing source 1, and high-temperature high-speed airflow is generated by ignition.

In the second stage (b), injection is carried out, the main flow of the ejector 3 is high-temperature fuel gas generated by the pressurization source 1, the secondary flow is external air entering from the air inlet passage 2 of the ejector, the high-temperature air flow of detonation combustion is used as the primary flow of the ejector 3, and external air flow is injected to enter the ejector 3.

In the third stage (c), the gas flow from the ejector 3 is split, and part of the gas flow passes through the splitter 4, enters the return flow channel 5, and part of the gas flow enters the outlet nozzle 6. The gas flow entering the outlet nozzle 6 expands and generates thrust in its nozzle; the gas flow entering the return flow channel 5 enters the next stage.

And (d) scavenging in a fourth stage, wherein residual gas in the pressurization source 1 is blown away by the airflow entering the backflow channel in the previous stage, meanwhile, the mixed fuel forms a premixed environment in the pressurization source 1, the backflow provides the pressurized inflow for the next circulation in the process, and the pressure fluctuation of the backflow airflow can rotate along the flow channel for multiple times before the next detonation.

Fig. 4 shows the expected operating process results, and fig. 4 (a) is the starting process of the system calculated based on thermodynamic theory, wherein the horizontal axis represents the calculated working medium circulation times, the vertical axis represents the pressure change in the detonation chamber, and the initial airflow pressure in the detonation chamber is increased from the ambient pressure of 0.1MPa to 0.3MPa through the backflow self-excitation.

Fig. 4 (b) is a start-up process of the system based on gas dynamics theory calculation, wherein the black line is the combustion initiation pressure in the detonation chamber and the red line is the time average of the pressure, and the figure shows an example of a dynamic process of system start-up.

Fig. 4 (c) is a thermodynamic process diagram of the previous 2 cycles of the fluid working medium in the system starting process, wherein black dots and lines are thermodynamic processes of the system initial filling gas, red lines are working medium thermodynamic process lines of the second cycle injected into the system by the initial gas, and blue lines are external air flow thermodynamic process lines of the third working medium cycle compressed by the injection action and not yet entering the flow divider.

Fig. 4 (d) is the thermodynamic process from the system start to the stable process, and 50 cycles are calculated in total, and it can be seen that the thermodynamic process of the working medium gradually and iteratively increases from the initial state, and finally reaches the stable working state indicated by the blue line. After the backflow supercharging working state is established, the system can provide supercharging performance which is not inferior to that of a turbine-compressor system, and further provides a power device with high specific impulse and thrust-weight ratio performance for an aircraft.

The detonation-excited backflow injection supercharging technology is a rotor-free supercharging combustion technology under the Ma0 condition, and means that airflow rotation is organized through a rotary flow channel, so that airflow which rotates last time provides a higher inlet condition for next supercharging. By means of a backflow injection pressurization system and by adopting a loop injection pressurization excited by detonation combustion, the inlet pressure ratio of the combustion chamber can reach more than 2. The incoming flow is injected and pressurized through a detonation-excited loop, so that zero-speed starting capability can be provided, and the performance of a detonation combustion chamber during low-speed incoming flow is improved.

Compared with a turbine compressor system, the detonation-excited reflux injection supercharging air-breathing engine based on the supercharging system can realize rotor-free high-performance supercharging of low-speed incoming flow. By means of the characteristics of high pressure rise, high-frequency pulse and the like of detonation combustion, a high-pressure ratio working state with relatively stable pressure is constructed through backflow injection, pneumatic flow channel filtering and the like.

The reflux injection supercharging system based on detonation combustion excitation is mainly characterized in that pulse primary flow generated by a detonation combustion chamber is used for exciting gas to form stable internal circulation in the ejector 3 and the reflux flow channel 5, so that high-speed reflux airflow continuously injects low-speed airflow, the total pressure and the temperature of the airflow entering the outlet nozzle are improved at low speed or even zero speed, and the performance higher than that of independent work of a supercharging source is obtained. The system realizes thermodynamic closed loop by ejection pressurization, and the ejection pressurization is a technology for ejecting and accelerating another low-speed fluid by utilizing the shearing and mixing effect of high-speed airflow and transferring the energy of the ejection flow to low-energy ejected flow. The mixed gas flows almost uniformly after passing through the mixing section. By redirecting the outlet of the ejector 3 to the low-speed airflow inlet, closed-loop feedback of airflow can be formed, and a rotating part is not introduced while the pressure rise is improved.

Based on the limitation of the power device which can be used for the space-ground round-trip transportation system at present, the invention provides a power scheme of a self-landing carrier platform, which can be used for bearing a horizontal landing aircraft capable of self-accelerating from zero speed. As a reusable transportation carrier, the power scheme of a wide-area adjacent space aircraft can be realized. The scheme is more extensive, the structure dead weight and the production cost can be effectively reduced, the problem that the existing combined power scheme needs a turbine or a rocket to start at a low speed is solved, and the problems that the thrust-weight ratio is small due to the fact that the dead weight of a turbine combined engine is large and the performance is difficult to meet due to the fact that the specific impulse of the rocket combined engine is low are solved.

The invention has no mechanical rotating part inside, can greatly improve the thrust-weight ratio of the wide-area aircraft, and can realize high-performance pressurization under the incoming flow condition of Ma0 speed.

The embodiments of the invention disclosed above are intended to be merely illustrative. The examples are not intended to be exhaustive or to limit the invention to the precise embodiments described. Many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention.

Claims

1. A supercharging method of a backflow injection supercharging system based on detonation combustion excitation is characterized in that: the method specifically comprises the following steps:

the method comprises the following steps that (1) airflow firstly enters a system from an ejector air inlet (2), after momentum and energy exchange is carried out between the airflow and high-energy fuel gas generated by a pressurization source (1) in an ejector (3), the pressure and the temperature are increased, and the fuel gas passes through a flow divider (4), is subjected to momentum and energy exchange and then enters a backflow flow channel (5) through the flow divider (4);

(2) Then the high-energy gas is combusted in the pressurization source (1) to do work, the high-energy gas is generated and enters the ejector (3) for the second time, and enters the outlet spray pipe (6) through the flow divider (4) to be discharged out of the system and do work after momentum and energy exchange with the next external air, and primary working medium circulation is completed;

(3) Finally, the backflow injection pressurization system based on detonation combustion excitation can inject enough external airflow into the pressurization source (1), can enable backflow to provide gradually iteratively increased pressure, and finally establishes a stable working state;

backflow injection supercharging system based on detonation combustion excitation comprises a supercharging source (1), an injector air inlet passage (2), an injector (3), a flow divider (4), a backflow flow passage (5) and an outlet spray pipe (6), wherein the front of the injector (3) is provided with the injector air inlet passage (2), a gas outlet of the supercharging source (1) is connected with the injector (3), an air inlet of the supercharging source (1) is connected with the backflow flow passage (5), the tail of the injector (3), the head of the backflow flow passage (5) and the head of the outlet spray pipe (6) are respectively connected with the flow divider (4), one path of the flow enters the backflow flow passage (5), and the other path enters the outlet spray pipe (6).

2. The supercharging method of the backflow injection supercharging system based on the detonation combustion excitation is characterized in that: each cycle of airflow revolution specifically comprises the following four phases:

first phase (a) firing: pre-mixed gas is arranged in the pressurizing source (1) and is ignited to generate high-temperature high-speed airflow;

injection in the second stage (b): the main flow of the ejector (3) is high-temperature fuel gas generated by the pressurization source (1), the secondary flow is external air entering from the ejector air inlet passage (2), and the high-temperature airflow of detonation combustion is used as the primary flow of the ejector (3) and used for ejecting external airflow to enter the ejector (3);

third stage (c) splitting: the airflow entering the ejector (3) passes through the flow divider (4), one part of the airflow enters the backflow flow channel (5), the other part of the airflow enters the outlet spray pipe (6), and the energy of the airflow entering the outlet spray pipe (6) is higher than that of the airflow entering the booster source under the condition of independent work; the airflow entering the backflow channel enters the next stage;

the fourth stage (d) scavenging: residual gas in the pressurization source (1) is blown away by the airflow entering the backflow channel in the last stage, meanwhile, the mixed fuel forms a premixed environment in the pressurization source (1), the backflow provides the pressurized incoming flow for the next circulation in the process, and the pressure fluctuation of the backflow airflow can rotate along the flow channel for many times before the next detonation.

3. The supercharging method of the backflow injection supercharging system based on the detonation combustion excitation is characterized in that: the pressurization source (1) is a linear detonation chamber, detonation combustion pressurization is adopted, and pressure superposition gain is generated through injection of backflow airflow.

4. A supercharging method of a detonation combustion excitation based backflow injection supercharging system according to any one of claims 1 to 3, characterized in that: the back flow injection pressurization of the detonation combustion excitation is started, the pressure and the temperature of airflow entering the outlet nozzle (6) are improved, the airflow repeatedly rotates in the flow channel for pressurization and injects external airflow to enter a system, and the sufficiently high pressurization ratio is achieved.