A method for controlling thrust mutation of wide-range ramjet engine

Abstract

A control device for a sudden thrust change of a wide-range ramjet engine is provided, comprising an upstream wall surface (1), a concave cavity (2), a downstream wall surface (3), a front wall surface (4), a rear wall surface (5), a left wall surface (6), a right wall surface (7), a lower wall surface (8), a left mounting hole (9) and a right mounting hole (10); the entire device is in an equal-width outward expansion configuration. A control method for a sudden thrust change of a wide-range ramjet engine is also provided. The present invention controls the sudden thrust change characteristics of a wide-range ramjet engine through a plasma-assisted jet, thereby achieving a smooth change in the thrust of a wide-range ramjet engine and improving the working stability of the engine. The use of left and right plasma-assisted ejectors for controlling the sudden thrust change of a wide-range ramjet engine can ensure sufficient fuel combustion, thereby improving the thrust performance of the engine.

Description

Technical Field

[0001] The invention belongs to the field of aerospace technology, and in particular relates to a method for regulating thrust mutation of a wide-range ramjet engine. Background Art

[0002] In order to achieve high-specific impulse flight of high-speed aircraft, ramjet engines came into being. According to the air flow speed at the engine inlet, ramjet engines can be divided into sub-combustion ramjet engines and scramjet engines. High-speed aircraft have different thrust requirements in stages such as accelerated climb and cruise flight. In order to meet the requirements of wide-speed range flight, ramjet engines are in sub-combustion working mode at low speeds and in scramjet working mode at high speeds. This type of engine is called a wide-range ramjet engine.

[0003] Wide-range ramjet engines are generally composed of components such as air inlets, isolation sections, combustion chambers and nozzles. Due to the large changes in flight altitude and flight Mach number, the airflow velocity, airflow pressure and airflow density at the inlet of wide-range ramjet engines change dramatically. After the airflow passes through the air inlet and isolation section, it couples with the working characteristics of the combustion chamber, resulting in drastic changes in the heat release of the engine and sudden thrust changes. The generation of thrust mutations poses a great challenge to the flight control of the aircraft. This problem is more prominent for fixed geometry ramjet engines.

[0004] At present, the research on thrust mutation of wide-range ramjet engines mainly focuses on the causes and related mechanisms of thrust mutation, and there is little research on the control of thrust mutation. In order to achieve stable thrust within the entire flight envelope of wide-range ramjet engines, it is urgent to carry out research on the control method of thrust mutation of wide-range ramjet engines. Summary of the invention

[0005] Aiming at the problem that a wide-range ramjet engine flies in a wide speed range and causes a sudden change in thrust, the present invention provides a control device for a sudden change in thrust of a wide-range ramjet engine, hereinafter referred to as the "control device", comprising an upstream wall 1, a concave cavity 2, a downstream wall 3, a front wall 4, a rear wall 5, a left wall 6, a right wall 7, a lower wall 8, a left mounting hole 9 and a right mounting hole 10; the entire device is in an equal-width outward expansion configuration; at the front wall 4 and the rear wall 5, the lateral spacing between the left wall 6 and the right wall 7 is equal, and the left wall 6 and the right wall 7 are parallel to each other; the spacing between the upstream wall 1 and the lower wall 8 at the front wall 4 is greater than the spacing between the downstream wall 3 and the lower wall 8 at the rear wall 5; the angle between the upstream wall 1 and the lower wall 8 is a smaller angle θ; the upstream wall 1 and the downstream wall 3 are on the same plane;

[0006] The upstream wall surface 1 is provided with two mounting holes for plasma-assisted ejectors along the span direction. The left mounting hole 9 and the right mounting hole 10 are through holes penetrating the regulating device from top to bottom, and are located upstream of the concave cavity. The two mounting holes are axially symmetrical about the flow direction mid-axis plane of the device of the present invention. The line connecting the centers of the left mounting hole 9 and the right mounting hole 10 is parallel to the front wall surface 4, and the shapes of the left mounting hole 9 and the right mounting hole 10 are designed to adapt to the plasma-assisted ejectors installed therein.

[0007] The concave cavity 2 is composed of a vertical wall surface 11, a bottom wall surface 12, and an inclined wall surface 13; the vertical wall surface 11 is perpendicular to the upstream wall surface 1, the bottom wall surface 12 is parallel to the upstream wall surface 1, and the inclined wall surface forms a certain angle with the plane where the upstream wall surface 1 is located; the first fuel inlet 21 and the second fuel inlet 22 are small holes arranged on the lower wall surface 8, and are located between the downstream of the left mounting hole 9 and the right mounting hole 10 and the vertical wall surface 11 of the concave cavity, and the line connecting the centers of the first fuel inlet 21 and the second fuel inlet 22 is parallel to the line connecting the centers of the left mounting hole 9 and the right mounting hole 10 on the lower wall surface 8; two fuel injection holes, a left injection hole 14 and a right injection hole 15, are arranged on the vertical wall surface 11, and the line connecting the centers of the two fuel injection holes is parallel to the bottom wall surface 12 of the concave cavity, the left injection hole 14 is connected with the first fuel inlet 21, and the right injection hole 15 is connected with the second fuel inlet 22;

[0008] The plasma assisted ejector is composed of a premixing chamber 16 and a jet generating chamber 17; the premixing chamber 16 is at the bottom, and is a cylindrical cavity, having a lower end face and an upper end face, and is made of insulating material as a whole; the jet generating chamber 17 is above the premixing chamber 16, and is composed of a cylindrical cavity and a central electrode located in the center of the cavity, having a lower end face and an upper end face, the upper end face and the side wall are made of conductive metal, and the lower end face is made of insulating material, and the diameter of the premixing chamber 16 is larger than the diameter of the jet generating chamber 17; wherein the upper end face of the premixing chamber 16 and the lower end face of the jet generating chamber 17 are combined into a common end face; the premixing chamber cavity and the jet generating chamber cavity are connected through a circular small hole arranged on the common end face between the two; an air inlet 18 and a fuel inlet 19 are arranged on the lower end face of the premixing chamber 16; a jet nozzle 20 is arranged on the upper end face of the jet generating chamber 17; the upper end face of the jet generating chamber 17 is flush with the upstream wall 1 of the regulating device;

[0009] A central electrode is arranged in the jet generating chamber 17, and the central electrode is led out to the premixing chamber 16 through a circular small hole on the common end surface via a wire, and then led out through a hole punched on the lower end surface of the premixing chamber 16 and connected to the high voltage end of the power supply; the upper end surface of the jet generating chamber 17 is a metal conductor, which is connected to the low voltage end of the power supply via a wire;

[0010] The central electrode of the plasma assisted ejector is connected to the high voltage end of the power supply, and the wall surface of the jet generation chamber 17 is connected to the low voltage end of the power supply.

[0011] In a specific embodiment of the present invention, θ is 2.5 degrees.

[0012] In another specific embodiment of the present invention, the height of the vertical wall 11 is 16 mm, the length of the bottom wall is 72 mm, and the angle between the inclined wall and the plane where the upstream wall is located is 50 degrees.

[0013] In another specific embodiment of the present invention, the channel between the left injection hole 14 and the first fuel inlet 21 is parallel to the left wall surface 6 , and the channel between the right injection hole 15 and the second fuel inlet 22 is parallel to the right wall surface 7 .

[0014] In another specific embodiment of the present invention, the diameters of the left injection hole 14 and the right injection hole 15 are both 0.3 mm.

[0015] In one embodiment of the present invention, the size and number of the circular holes provided on the common end surface between the premixing chamber cavity and the jet generating chamber cavity that are connected thereto are set according to the flow rate of the plasma-assisted ejector.

[0016] In another specific embodiment of the present invention, the fuel inlet 19 has a circular cross-section and a diameter of 2 mm, and is arranged at the center of the lower end surface of the premixing chamber 16; the air inlet also has a circular cross-section and a diameter of 5 mm, and is arranged between the center and the edge of the lower end surface of the premixing chamber 16.

[0017] In another specific embodiment of the present invention, the jet nozzle 20 has a circular cross section.

[0018] A method for controlling a sudden change in thrust of a wide-range ramjet engine is also provided, which specifically comprises the following steps:

[0019] Step 1: Install the wide-range ramjet engine thrust mutation control device as the bottom wall surface on the ramjet engine combustion chamber, and install the combustion chamber on the ramjet engine direct-connection test bench; the front end of the combustion chamber is connected to the isolation section of the direct-connection test bench, and the rear end of the combustion chamber is connected to the nozzle;

[0020] Step 2: Start the ramjet engine direct-connected test bench. After the supersonic airflow passes through the isolation section, it enters the wide-range ramjet engine thrust mutation control device and is then discharged to the atmosphere through the nozzle. Start the fuel injection so that the left injection hole 14 and the right injection hole 15 inject fuel into the cavity 2. After the fuel is atomized, evaporated, and mixed with the airflow, it is discharged to the atmosphere through the nozzle.

[0021] Step 3: Start the plasma-assisted ejector, air enters the premixing chamber 16 through the air inlet, and fuel enters the premixing chamber 16 through the fuel inlet; the air and fuel are mixed in the premixing chamber 16 to form a mixed gas, which enters the jet generation chamber 17; the mixed gas is heated by the plasma arc in the jet generation chamber 17, and then dissociates and burns to form a high-temperature combustion gas with a flame;

[0022] Step 4: The high-temperature fuel gas with flame is discharged to the combustion chamber through the jet nozzle of the plasma-assisted ejector and moves downstream; the high-temperature fuel gas with flame is further mixed with air in the combustion chamber for full combustion; at the same time, the high-temperature fuel gas with flame ignites the fuel ejected from the left injection hole 14 and the right injection hole 15 of the concave cavity, forming a jet wake flame stabilization mode to ensure full combustion of the fuel in the combustion chamber;

[0023] Step 5: In the process of gradually decreasing the engine flow velocity, by gradually reducing the fuel equivalence ratio and flow rate of the plasma-assisted ejector, the jet wake flame stabilization mode of the combustion chamber is gradually and slowly transitioned to the cavity flame stabilization mode, thereby achieving a smooth change in the engine thrust;

[0024] Step 6: As the engine flow velocity gradually increases, the fuel equivalence ratio and flow rate of the plasma-assisted ejector are gradually increased, so that the cavity flame stabilization mode of the combustion chamber is gradually and slowly transitioned to the jet wake flame stabilization mode, thereby achieving a smooth change in the engine thrust.

[0025] The present invention is used for smoothly regulating the thrust variation characteristics of a ramjet engine, reducing the difficulty of engine control and improving the working stability of the engine.

[0026] Compared with the prior art, the present invention has the following advantages and outstanding technical effects:

[0027] (1) The present invention uses plasma-assisted jet to regulate the sudden change characteristics of the thrust of a wide-range ramjet engine, thereby achieving a smooth change in the thrust of the wide-range ramjet engine and improving the working stability of the engine.

[0028] (2) The present invention uses two plasma-assisted ejectors, left and right, to regulate the thrust mutation of a wide-range ramjet engine, thereby ensuring sufficient fuel combustion and improving the engine thrust performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the control device for thrust mutation of a wide-range ramjet engine of the present invention, wherein Figure 1 (a) shows the internal structure of the device, Figure 1 (b) shows the bottom structure of the device (note that the two figures are adjusted by about 180 degrees);

[0030] Figure 2 Schematic diagram of the plasma assisted ejector of the present invention. DETAILED DESCRIPTION

[0031] The invention provides a control device for sudden thrust change of a wide-range ramjet engine.

[0032] A control device for sudden thrust changes of a wide-range ramjet engine (hereinafter referred to as the "control device") includes an upstream wall 1, a concave cavity 2, a downstream wall 3, a front wall 4, a rear wall 5, a left wall 6, a right wall 7, a lower wall 8, a left mounting hole 9 and a right mounting hole 10. The entire device is in an equal-width outward expansion configuration. At the front wall 4 and the rear wall 5, the lateral spacing between the left wall 6 and the right wall 7 is equal, and the left wall 6 and the right wall 7 are parallel to each other. The spacing between the upstream wall 1 and the lower wall 8 at the front wall 4 is greater than the spacing between the downstream wall 3 and the lower wall 8 at the rear wall 5. The angle between the upstream wall 1 and the lower wall 8 is a relatively small angle θ. In a specific embodiment of the present invention, θ is 2.5 degrees. The upstream wall 1 and the downstream wall 3 are in the same plane.

[0033] The upstream wall surface 1 is provided with two mounting holes for plasma-assisted ejectors along the span direction. The left mounting hole 9 and the right mounting hole 10 are through holes that penetrate the regulating device from top to bottom, and are located upstream of the concave cavity. The two mounting holes are axially symmetrical about the flow direction mid-axis plane of the device of the present invention. The line connecting the centers of the left mounting hole 9 and the right mounting hole 10 is parallel to the front wall surface 4, and the shapes of the left mounting hole 9 and the right mounting hole 10 are designed to adapt to the plasma-assisted ejectors installed therein (the specific introduction of the plasma-assisted ejectors is described later).

[0034] The concave cavity 2 is composed of a vertical wall surface 11, a bottom wall surface 12, and an inclined wall surface 13. The vertical wall surface 11 is perpendicular to the upstream wall surface 1, the bottom wall surface 12 is parallel to the upstream wall surface 1, and the inclined wall surface and the plane where the upstream wall surface 1 is located form a certain angle. The concave cavity 2 is a conventional technical means in this field, and its shape is a conventional shape. In a specific embodiment of the present invention, the height of the vertical wall surface 11 is 16 mm, the length of the bottom wall surface is 72 mm, and the angle between the inclined wall surface and the plane where the upstream wall surface is located is 50 degrees. The first fuel inlet 21 and the second fuel inlet 22 are small holes arranged on the lower wall surface 8, located between the downstream of the left mounting hole 9 and the right mounting hole 10 and the vertical wall surface 11 of the concave cavity, and the connecting line of the centers of the first fuel inlet 21 and the second fuel inlet 22 holes is parallel to the connecting line of the centers of the left mounting hole 9 and the right mounting hole 10 on the lower wall surface 8. Two fuel injection holes are arranged on the vertical wall 11, namely, the left injection hole 14 and the right injection hole 15. The line connecting the centers of the two fuel injection holes is parallel to the bottom wall 12 of the cavity. The left injection hole 14 is connected with the first fuel inlet 21, and the right injection hole 15 is connected with the second fuel inlet 22. The specific connection mode is generally determined by the convenience of processing. For the sake of simplicity, it can be designed as an "L"-shaped connection or a straight line connection. In one embodiment of the present invention, the channel between the left injection hole 14 and the first fuel inlet 21 is parallel to the left wall 6, and the channel between the right injection hole 15 and the second fuel inlet 22 is parallel to the right wall 7. In a specific embodiment of the present invention, the diameters of the two injection holes are both 0.3 mm. The line connecting the left injection hole 14 and the center of the mounting hole 9 is parallel to the left wall 6, and the line connecting the right injection hole 15 and the center of the mounting hole 10 is parallel to the right wall 7.

[0035] The plasma-assisted ejector is composed of a premixing chamber 16 and a jet generating chamber 17. The premixing chamber 16 is at the bottom and has a larger diameter. It is a cylindrical cavity with a lower end face and an upper end face, and is made of insulating material as a whole. The jet generating chamber 17 is above the premixing chamber 16, and is composed of a cylindrical cavity and a central electrode located in the center of the cavity. It has a lower end face and an upper end face. The upper end face and the side wall are made of conductive metal, and the lower end face is an insulating material. The upper end face of the premixing chamber 16 and the lower end face of the jet generating chamber 17 are combined into a common end face (insulating end face). The premixing chamber cavity and the jet generating chamber cavity are connected through circular holes set on the common end face between the two (the size and number of the holes are set according to the flow rate of the plasma-assisted ejector). An air inlet 18 and a fuel inlet 19 (both are through holes) are set on the lower end face of the premixing chamber 16. The fuel inlet 19 is usually a circular cross-section, and is usually set at the center of the lower end face of the premixing chamber 16, for example, with a diameter of 2 mm. The air inlet is usually also a circular cross-section, and is usually arranged between the center and the edge of the lower end face of the premixing chamber 16, for example, with a diameter of 5 mm. A jet nozzle 20 (a through hole) is arranged on the upper end face of the jet generation chamber 17, and the jet nozzle 20 is usually a circular cross-section, which is used to spray the plasma-assisted airflow into the combustion chamber. Therefore, as mentioned above, the shapes of the left mounting hole 9 and the right mounting hole 10 are just able to accommodate the plasma-assisted ejector therein and fit tightly therewith, so that the plasma-assisted ejector remains fixed in the left mounting hole 9 and the right mounting hole 10. The upper end face of the jet generation chamber 17 is flush with the upstream wall 1 of the regulating device; the lower end face of the premixing chamber 16 may be flush with the lower wall 8 of the regulating device, or may not be flush.

[0036] A central electrode is arranged in the jet generation chamber 17, and the central electrode is led out to the premixing chamber 16 through a circular small hole on the common end face via a wire, and then led out through a hole punched on the lower end face of the premixing chamber 16 (the hole is not shown in the figure, and the position is designed so as not to affect the air inlet 18 and the fuel inlet 19), and finally connected to the high voltage end of the power supply. The upper end face of the jet generation chamber 17 is a metal conductor, which is connected to the low voltage end of the power supply via a wire.

[0037] The central electrode of the plasma-assisted ejector is connected to the high-voltage end of the power supply, and the wall of the jet generation chamber 17 is connected to the low-voltage end of the power supply. When the power is turned on, the air between the central electrode and the wall of the jet generation chamber 17 is broken down by discharge to form plasma. Air and fuel enter the premixing chamber 16 from bottom to top through the air inlet and fuel inlet of the premixing chamber, respectively, and form a mixed gas in the premixing chamber 16. The mixed gas enters the jet generation chamber 17 through the circular small hole, and after plasma dissociation and ignition in the jet generation chamber, it is discharged to the combustion chamber through the jet nozzle 20 to form a plasma-assisted jet.

[0038] The present invention also provides a method for regulating sudden thrust changes of a wide-range ramjet engine.

[0039] Step 1: Install the wide-range ramjet thrust mutation control device as the bottom wall (that is, the control device is one of the four walls of the ramjet combustion chamber) on the ramjet combustion chamber, and install the combustion chamber on the ramjet direct-connected test bench. The front end of the combustion chamber is connected to the isolation section of the direct-connected test bench, and the rear end of the combustion chamber is connected to the nozzle.

[0040] Step 2: Start the ramjet engine direct-connected test bench. After the supersonic airflow passes through the isolation section, it enters the wide-range ramjet engine thrust mutation control device and is then discharged to the atmosphere through the nozzle. Start the fuel injection so that the left injection hole 14 and the right injection hole 15 inject fuel into the cavity 2. After the fuel is atomized, evaporated, and mixed with the airflow, it is discharged to the atmosphere through the nozzle.

[0041] Step 3: Start the plasma-assisted ejector, and air enters the premixing chamber 16 through the air inlet, and fuel enters the premixing chamber 16 through the fuel inlet. The air and fuel are mixed in the premixing chamber 16 to form a mixed gas, which enters the jet generation chamber 17. In the jet generation chamber 17, the mixed gas is heated by the plasma arc, dissociated and burned to form a high-temperature combustion gas with a flame.

[0042] Step 4: The high-temperature fuel gas with flame is discharged to the combustion chamber through the jet nozzle of the plasma-assisted ejector and moves downstream. The high-temperature fuel gas with flame is further mixed with air in the combustion chamber for full combustion. At the same time, the high-temperature fuel gas with flame ignites the fuel ejected from the left injection hole 14 and the right injection hole 15 of the concave cavity, forming a jet wake flame stabilization mode to ensure full combustion of the fuel in the combustion chamber.

[0043] Step 5: As the engine flow velocity gradually decreases, the fuel equivalence ratio and flow rate of the plasma-assisted ejector are gradually reduced, so that the jet wake flame stabilization mode of the combustion chamber is gradually and slowly transitioned to the cavity flame stabilization mode, thereby achieving a smooth change in the engine thrust.

[0044] Step 6: As the engine flow velocity gradually increases, the fuel equivalence ratio and flow rate of the plasma-assisted ejector are gradually increased, so that the cavity flame stabilization mode of the combustion chamber is gradually and slowly transitioned to the jet wake flame stabilization mode, thereby achieving a smooth change in the engine thrust.

Claims

1. A control device for sudden thrust change of a wide-range ramjet engine, hereinafter referred to as "control device", characterized in that: The device comprises an upstream wall surface (1), a concave cavity (2), a downstream wall surface (3), a front wall surface (4), a rear wall surface (5), a left wall surface (6), a right wall surface (7), a lower wall surface (8), a left mounting hole (9) and a right mounting hole (10); the entire device is in an equal width outward expansion configuration; at the front wall surface (4) and the rear wall surface (5), the lateral spacing between the left wall surface (6) and the right wall surface (7) is equal, and the left wall surface (6) and the right wall surface (7) are parallel to each other; the spacing between the upstream wall surface (1) and the lower wall surface (8) at the front wall surface (4) is greater than the spacing between the downstream wall surface (3) and the lower wall surface (8) at the rear wall surface (5); the angle between the upstream wall surface (1) and the lower wall surface (8) is a relatively small angle θ; the upstream wall surface (1) and the downstream wall surface (3) are on the same plane; The upstream wall surface (1) is provided with two mounting holes for plasma-assisted ejectors along the span direction, the left mounting hole (9) and the right mounting hole (10) being through holes penetrating the control device from top to bottom, being located upstream of the concave cavity, and the two mounting holes are axially symmetrical about the flow direction mid-axis plane of the device of the present invention; the line connecting the centers of the left mounting hole (9) and the right mounting hole (10) is parallel to the front wall surface (4), and the shapes of the left mounting hole (9) and the right mounting hole (10) are designed to adapt to the plasma-assisted ejectors installed therein; The concave cavity (2) is composed of a vertical wall surface (11), a bottom wall surface (12), and an inclined wall surface (13); the vertical wall surface (11) is perpendicular to the upstream wall surface (1), the bottom wall surface (12) is parallel to the upstream wall surface (1), and the inclined wall surface and the plane where the upstream wall surface (1) is located form a certain angle; the first fuel inlet (21) and the second fuel inlet (22) are small holes arranged on the lower wall surface (8), and are located between the downstream of the left mounting hole (9) and the right mounting hole (10) and the vertical wall surface (11) of the concave cavity, and ... the first fuel inlet (21) and the second fuel inlet (22) are small holes arranged on the lower wall surface (8), and are located between the downstream of the left mounting hole (9) and the right mounting hole (10) and the vertical wall surface (11) of the concave cavity, and the first fuel inlet (21) and the second fuel inlet (22) are small holes arranged on the lower wall surface ( The connecting line of the centers of the fuel inlet (21) and the second fuel inlet (22) is parallel to the connecting line of the centers of the left mounting hole (9) and the right mounting hole (10) on the lower wall (8); two fuel injection holes, a left injection hole (14) and a right injection hole (15), are arranged on the vertical wall (11); the connecting line of the centers of the two fuel injection holes is parallel to the bottom wall (12) of the cavity; the left injection hole (14) is connected to the first fuel inlet (21), and the right injection hole (15) is connected to the second fuel inlet (22); The plasma assisted ejector is composed of a premixing chamber (16) and a jet generating chamber (17); the premixing chamber (16) is at the bottom and is a cylindrical cavity, having a lower end face and an upper end face, and is made of insulating material as a whole; the jet generating chamber (17) is above the premixing chamber (16), and is composed of a cylindrical cavity and a central electrode located at the center of the cavity, having a lower end face and an upper end face, the upper end face and the side wall are made of conductive metal, and the lower end face is made of insulating material, the diameter of the premixing chamber (16) is larger than that of the jet generating chamber ( 17) diameter; wherein the upper end surface of the premixing chamber (16) and the lower end surface of the jet generating chamber (17) are combined into a common end surface; the cavity of the premixing chamber and the cavity of the jet generating chamber are connected through a circular small hole arranged on the common end surface between the two; an air inlet (18) and a fuel inlet (19) are arranged on the lower end surface of the premixing chamber (16); a jet nozzle (20) is arranged on the upper end surface of the jet generating chamber (17); and the upper end surface of the jet generating chamber (17) is flush with the upstream wall surface (1) of the regulating device; A central electrode is arranged in the jet generating chamber (17), and the central electrode is led out to the premixing chamber (16) through a circular small hole on the common end surface via a wire, and then led out through a hole punched on the lower end surface of the premixing chamber (16) and connected to the high voltage end of the power supply; the upper end surface of the jet generating chamber (17) is a metal conductor, which is connected to the low voltage end of the power supply via a wire; The central electrode of the plasma-assisted jet generator is connected to the high-voltage end of the power supply, and the wall surface of the jet generation chamber (17) is connected to the low-voltage end of the power supply.

2. The control device for sudden thrust change of a wide-range ramjet engine according to claim 1, characterized in that: θ is 2.5 degrees.

3. The control device for sudden thrust change of a wide-range ramjet engine according to claim 1, characterized in that: The height of the vertical wall surface (11) is 16 mm, the length of the bottom wall surface is 72 mm, and the angle between the inclined wall surface and the plane where the upstream wall surface is located is 50 degrees.

4. The control device for sudden thrust change of a wide-range ramjet engine according to claim 1, characterized in that: The hole between the left injection hole (14) and the first fuel inlet (21) is parallel to the left wall surface (6), and the hole between the right injection hole (15) and the second fuel inlet (22) is parallel to the right wall surface (7).

5. The control device for sudden thrust change of a wide-range ramjet engine according to claim 1, characterized in that: The diameters of the left injection hole (14) and the right injection hole (15) are both 0.3 mm.

6. The control device for sudden thrust change of a wide-range ramjet engine according to claim 1, characterized in that: The size and number of the circular holes arranged on the common end surface between the premixing chamber cavity and the jet generation chamber cavity that are connected are set according to the flow rate of the plasma-assisted ejector.

7. The control device for sudden thrust change of a wide-range ramjet engine according to claim 1, characterized in that: The fuel inlet (19) has a circular cross section and a diameter of 2 mm and is arranged at the center of the lower end surface of the premixing chamber (16); the air inlet also has a circular cross section and a diameter of 5 mm and is arranged between the center and the edge of the lower end surface of the premixing chamber (16).

8. The control device for sudden thrust change of a wide-range ramjet engine according to claim 1, characterized in that: The jet nozzle (20) has a circular cross section.

9. A method for controlling a sudden thrust change of a wide-range ramjet engine, based on the control device for a sudden thrust change of a wide-range ramjet engine according to any one of claims 1 to 8, characterized in that: The specific steps include: Step 1: Install the wide-range ramjet engine thrust mutation control device as the bottom wall surface on the ramjet engine combustion chamber, and install the combustion chamber on the ramjet engine direct-connection test bench; the front end of the combustion chamber is connected to the isolation section of the direct-connection test bench, and the rear end of the combustion chamber is connected to the nozzle; Step 2: Start the ramjet engine direct-connected test bench, and after the supersonic airflow passes through the isolation section, it enters the wide-range ramjet engine thrust mutation control device, and then is discharged to the atmosphere through the nozzle; start the fuel injection, so that the left injection hole (14) and the right injection hole (15) inject fuel into the concave cavity (2), and after the fuel is atomized, evaporated, and mixed with the airflow, it is discharged to the atmosphere through the nozzle; Step 3: starting the plasma-assisted ejector, air enters the premixing chamber (16) through the air inlet, and fuel enters the premixing chamber (16) through the fuel inlet; the air and fuel are mixed in the premixing chamber (16) to form a mixed gas, which enters the jet generation chamber (17); the mixed gas is heated by the plasma arc in the jet generation chamber (17), and then dissociates and burns to form a high-temperature combustion gas with a flame; Step 4: The high-temperature fuel gas with flame is discharged into the combustion chamber through the jet nozzle of the plasma-assisted ejector and moves downstream; the high-temperature fuel gas with flame is further mixed with air in the combustion chamber to be fully burned; at the same time, the high-temperature fuel gas with flame ignites the fuel ejected from the left injection hole (14) and the right injection hole (15) of the concave cavity, forming a jet wake flame stabilization mode to ensure that the fuel in the combustion chamber is fully burned; Step 5: In the process of gradually decreasing the engine flow velocity, by gradually reducing the fuel equivalence ratio and flow rate of the plasma-assisted ejector, the jet wake flame stabilization mode of the combustion chamber is gradually and slowly transitioned to the cavity flame stabilization mode, thereby achieving a smooth change in the engine thrust; Step 6: As the engine flow velocity gradually increases, the fuel equivalence ratio and flow rate of the plasma-assisted ejector are gradually increased, so that the cavity flame stabilization mode of the combustion chamber is gradually and slowly transitioned to the jet wake flame stabilization mode, thereby achieving a smooth change in the engine thrust.

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