Hypersonic Combined Cyclic Power System with Water-Jet Ejector and Its Control Method

Abstract

This invention discloses a hypersonic combined cycle propulsion system and its control method using water-jet ejection, belonging to the field of cross-domain combined propulsion technology. The invention includes a scramjet engine body, a telescopic water inlet pipe, and a water-jet engine. The scramjet engine body includes a variable-altitude air intake, an isolation section connected to the air intake, a fuel nozzle at the end of the isolation section, a combustion chamber, and an adjustable-angle nozzle. The water-jet engine includes a gas generator, a combustion chamber connected to the gas generator, and a tail nozzle at the rear end of the combustion chamber. A telescopic water inlet pipe and a streamlined water inlet are used. This invention addresses the high Mach number flight characteristics of scramjet engines and the water-jet engine's use of water as an oxidizer by combining high-altitude scramjet ejection with near-water-surface water-jet ejection, meeting the requirements for continuous high-speed flight of the vehicle in both high-altitude and near-water operating environments, improving the strike capability and flight flexibility of attack weapons.

Description

Technical Field

[0001] This invention relates to a hypersonic combined cycle power system and its control method using water jet ejection, belonging to the field of cross-domain combined power technology. Background Technology

[0002] In the 21st century, with the development of radar technology, traditional strategic strike weapons, such as tactical and strategic missiles, are easily detected by enemy radar in high-altitude flight, making them difficult to adapt to the battlefield environment.

[0003] Addressing the vulnerability of strategic strike weapons to detection at high altitudes, this paper proposes a combined air-sea propulsion engine. This engine operates near sea level when approaching targets, significantly enhancing stealth. A rocket-based combined cycle engine, combining rocket propulsion and ramjet propulsion, enables sustainable flight across all airspaces, but it cannot achieve sea-skimming flight. Currently, most high-speed underwater vehicles utilize water-ramjet engines. These engines use seawater as an oxidizer and carry their own metal-based propellant, achieving high specific impulse and long operating times. However, they suffer from significant underwater drag. Therefore, a sea-skimming approach is proposed, combining the operating modes of water-ramjet and scramjet engines to achieve effective strikes of strategic weapons in both high and low altitudes. Summary of the Invention

[0004] To address the vulnerability of strategic strike weapons to detection at high altitudes, the main objective of this invention is to provide a water-rammed air-launched hypersonic combined cycle propulsion system and its control method. This system enables hypersonic flight at high altitudes and sea-skimming flight when approaching targets, thereby enhancing the strike capability and flight flexibility of the weapon.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] This invention discloses a hypersonic combined cycle propulsion system using water-jet ejection, comprising a scramjet engine body, a telescopic water inlet pipe, and a water-jet engine. The scramjet engine body includes a variable-height air intake, an isolation section connected to the air intake, a fuel nozzle at the end of the isolation section, a combustion chamber, and an adjustable-angle nozzle. The water-jet engine includes a gas generator, a combustion chamber connected to the gas generator, and a tail nozzle at the rear end of the combustion chamber. The gas generator contains a metal-based solid propellant charge, and the tail nozzle outlet is the scramjet engine combustion chamber. The water-jet engine gas generator includes a front end cap, a cylinder, and a gas generator nozzle; the combustion chamber includes a front cover connected to the gas generator nozzle and a combustion chamber cylinder; the tail nozzle includes a converging section and a diverging section. The front end of the converging section is connected to the combustion chamber cylinder via a flange, and the rear end is threadedly connected to the diverging section at the nozzle throat. The telescopic water inlet pipe supplies water to the combustion chamber of the water-jet engine. The telescopic water inlet pipeline includes a streamlined water inlet, a main water inlet pipe, a water inlet pipe buffer chamber connected to the main water inlet pipe, an end water inlet pipe and a middle water inlet pipe connected to the water inlet pipe buffer chamber, and a portion of the end water inlet pipe and the middle water inlet pipe are respectively connected to the combustion chamber, and a ball control valve for the water inlet pipe is provided at the connection point.

[0007] To facilitate the transition from high-altitude mode to deceleration mode and near-water mode, preferably, the variable-height air intake in the scramjet engine body consists of two movable ramps connected by a shaft and driven and controlled by the aircraft body to adjust the throat height of the air intake; simultaneously, the adjustable-angle nozzle changes its expansion ratio by adjusting the lower base plate of the nozzle, thereby enabling the transition of the scramjet engine body to the working mode of a water ramjet engine.

[0008] To ensure the propellant can react with water in near-water mode, the gas generator in the water ramjet engine preferably uses a high-energy solid propellant containing a metal that readily reacts with water to generate greater thrust. This water-reactive metal includes, but is not limited to, magnesium and aluminum.

[0009] As a further preferred option, a novel high-energy solid propellant containing metals, PBAN / Al / Mg / AP, is adopted, with a formulation of 2.5%-15% PBCN, 60%-70% aluminum, 7.5%-10% magnesium, and 15%-20% ammonium perchlorate; the scramjet engine uses hydrocarbon fuel and air for combustion, which is convenient to store and easy to ignite.

[0010] To ensure uniform combustion in the afterburner chamber of the water-jet engine, it is preferable that the afterburner chamber is connected to multiple water inlet pipes, which are divided into end water inlet pipes and middle water inlet pipes, with multiple pipes arranged alternately. The end water inlet pipes are located at the ends of the afterburner chamber, and the middle water inlet pipes are located in the middle of the afterburner chamber.

[0011] To reduce the resistance generated by air or water encountered during the flight of the aircraft, a streamlined water inlet is preferably selected at the water inlet. The inlet is open at both ends, with water entering at one end and the other end connected to the main water inlet pipe to form a telescopic pipe. This pipe is fixed to the bottom of the aircraft. When in high-altitude mode and deceleration mode, the water inlet pipe retracts and fits against the lower wall of the aircraft. When the aircraft switches to near-water mode, the water inlet pipe extends and opens to allow water to enter.

[0012] This invention also discloses a control method for a water-jet-assisted hypersonic combined cycle propulsion system, used to control the water-jet-assisted hypersonic combined cycle propulsion system. The control method for the water-jet-assisted hypersonic combined cycle propulsion system includes high-altitude mode, deceleration mode, and near-water mode, and comprises the following steps:

[0013] (1) High-altitude mode: The streamlined water inlet and main water inlet pipe are retracted. The telescopic water inlet pipe consisting of the water inlet pipe buffer chamber, the end water inlet pipe, and the middle water inlet pipe is not working. The gas generator and the water ramjet engine combustion chamber are not working. The variable height air inlet is opened to the maximum height. The air ramjet passes through the variable height air inlet and the isolation section. The fuel stored in the scramjet engine fuel tank is ejected through the scramjet engine fuel nozzle and reacts fully with the air in the scramjet engine combustion chamber. The generated gas is ejected through the variable angle nozzle to generate thrust.

[0014] (2) Deceleration mode: The streamlined water inlet and main water inlet pipe retract, the telescopic water inlet pipe consisting of the water inlet pipe buffer chamber, end water inlet pipe, and middle water inlet pipe does not work, the gas generator in the water ramjet engine and the water ramjet engine combustion chamber do not work, the opening height of the variable altitude air inlet decreases with the flight altitude, the airflow through the variable altitude air inlet and the isolation section is controlled, the fuel ejected from the scramjet engine fuel nozzle is reduced, and the angle of the variable angle nozzle is adjusted to generate a gradually decreasing thrust, and the variable altitude air inlet is gradually lowered, the scramjet engine stops working, and deceleration is achieved.

[0015] (3) Near-water mode: The streamlined water inlet and main water inlet pipe extend to below the sea level. The opening height of the variable height air inlet is reduced again. Gas passes through the isolation section of the scramjet engine. No fuel is ejected from the fuel nozzle of the combustion chamber. Seawater flows through the streamlined water inlet into the main water inlet pipe. After passing through the water inlet buffer chamber, the control valves of the end water inlet pipe and the middle water inlet pipe are opened. Seawater flows into the afterburning chamber of the water ramjet engine through the pipeline. The propellant in the gas generator is burned to produce primary gas with a large amount of magnesium and aluminum particles under continuous high temperature and high pressure. The gas flows into the afterburning chamber of the water ramjet engine and reacts with the seawater. The gas after combustion flows out through the nozzle of the water ramjet engine and flows through the combustion chamber of the scramjet engine. The air is ejected through the variable height air inlet and isolation section. The air is heated by the high temperature and high pressure gas. The variable angle nozzle returns to its working angle. The gas and air flow out together to generate thrust.

[0016] Beneficial effects:

[0017] 1. The hypersonic combined cycle propulsion system and its control method disclosed in this invention, which takes into account the high Mach number flight characteristics of scramjet engines and the characteristic of water ramjet engines using water as an oxidizer, combines high-altitude scramjet with near-water surface water ramjet ejection to meet the requirements of continuous high-speed flight of the vehicle in both high-altitude and near-water operating environments, thereby improving the strike capability and flight flexibility of the weapon.

[0018] 2. The hypersonic combined cycle propulsion system and its control method disclosed in this invention, which uses a telescopic water inlet pipe to address the resistance generated by the water inlet at high altitudes, allows the water inlet pipe to contract and avoid generating additional resistance when the high-altitude water ramming engine is not working. At the same time, in near-water environments, the water inlet adopts a streamlined water inlet, which greatly reduces the resistance caused by the water inlet pipe of the vehicle when it moves underwater.

[0019] 3. The hypersonic combined cycle propulsion system and its control method disclosed in this invention, with water ramjet ejection, allows the engine to enter scramjet mode during the high-altitude phase, where hydrocarbon fuel is injected to react with air, achieving efficient combustion, reducing the weight of the vehicle, simplifying the vehicle structure, and making it easier to achieve high maneuverability at high Mach numbers during the high-altitude phase.

[0020] 4. The hypersonic combined cycle propulsion system and its control method disclosed in this invention, during the deceleration phase, as the vehicle moves from high altitude to near sea level, continuously adjusts the intake air volume by adjusting the variable altitude air intake, reducing fuel injection, and accordingly adjusts the variable angle nozzle to complete the deceleration from high altitude to sea level. During the air-to-water mode transition phase, to avoid flameout caused by the injection of a large amount of water, the propellant in the gas generator of the water ramjet engine undergoes self-sustaining combustion, reacting with the air injected through the air intake to achieve a smooth transition until the water ramjet engine achieves stable combustion, the air intake is closed, the scramjet engine stops working, and the vehicle enters the near-water phase.

[0021] 5. The hypersonic combined cycle propulsion system and its control method disclosed in this invention, in the near-water mode, the water entering through the inlet reacts in the gas generator of the water ramjet engine to generate thrust. This invention uses a novel high-energy solid propellant containing metals, PBAN / Al / Mg / AP, which has the characteristics of high specific impulse. It can achieve high thrust propulsion of the vehicle in near-sea surface environment, bringing high kinetic energy and enabling the strike weapon to produce greater destructive power. Attached Figure Description

[0022] Figure 1 is a schematic diagram of a hypersonic combined cycle power system and control process for water-jet ejection according to the present invention, wherein... Figure 1a It is a high-altitude mode. Figure 1b For deceleration mode, Figure 1c It is a near-water mode.

[0023] Figure 2 This is a perspective view of a water-ramming engine in a hypersonic combined cycle power system for water-ramming ejection according to the present invention.

[0024] Figure 3 This is a cross-sectional view of a water-ramming engine in a hypersonic combined cycle power system for water-ramming ejection according to the present invention.

[0025] Figure 4 This invention relates to a streamlined water inlet for a hypersonic combined circulating power system using water jet ejection.

[0026] Among them, 1-variable height air intake, 2-isolation section, 3-combustion chamber fuel nozzle, 4-scramjet engine combustion chamber, 5-variable angle nozzle, 6-telescopic water inlet pipe, 7-gas generator, 8-scramjet engine casing, 9-water ramjet engine afterburner chamber, 10-water ramjet engine nozzle, 11-scramjet engine fuel tank, 6.1-streamlined water inlet, 6.2-main water inlet pipe, 6.3-water inlet buffer chamber, 6.4-end water inlet Pipeline, 6.5-End water inlet pipe control valve, 6.6-Middle water inlet pipe, 6.7-Middle water inlet pipe control valve, 7.1-Gas generator charging elastic pad, 7.2-Gas generator charging, 7.3-Gas generator front end cap, 7.4-Gas generator housing, 7.5-Gas generator rear end cap, 9.1-Afterburning chamber front housing, 9.2-Afterburning chamber housing, 10.1-Water slammed engine nozzle converging section, 10.2-Water slammed engine nozzle expanding section. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0028] See Figure 1 and Figure 2 , Figure 3 This embodiment discloses a hypersonic combined cycle power system with water-jet ejection, including a telescopic water inlet pipe, a scramjet engine body, and a water-jet engine. The telescopic water inlet pipe 6 includes a streamlined water inlet 6.1, a main water inlet pipe 6.2, a water inlet buffer chamber 6.3, an end water inlet pipe 6.4, an end water inlet pipe control valve 6.5, a middle water inlet pipe 6.6, and a middle water inlet pipe control valve 6.7.

[0029] The main body of the scramjet engine includes a variable height air intake 1, an isolation section 2, a combustion chamber fuel nozzle 3, a scramjet engine combustion chamber 4, a variable angle nozzle 5, a scramjet engine housing 8, and a scramjet engine fuel tank 11.

[0030] The water-jet engine includes a gas generator 7, a water-jet engine combustion chamber 9, and a water-jet engine nozzle 10; the gas generator 7 includes a gas generator front end cap 7.3, a gas generator propellant elastic pad 7.1, a gas generator propellant 7.2, a gas generator housing 7.4, and a gas generator rear end cap 7.5; the water-jet engine combustion chamber 9 includes a combustion chamber front housing 9.1 and a combustion chamber housing 9.2; the water-jet engine nozzle 10 includes a water-jet engine nozzle converging section 10.1 and a water-jet engine nozzle converging section 10.2, which are connected by threads.

[0031] During the high-altitude and deceleration phases of the aircraft, the streamlined water inlet 6.1 and the main water inlet pipe 6.2 retract to the vicinity of the hull to reduce air resistance; during the near-water phase of the aircraft, the streamlined water inlet 6.1 and the main water inlet pipe 6.2 extend to allow water to flow through the pipes into the combustion chamber of the water ramjet engine.

[0032] One end of the main water inlet pipe 6.2 is connected to the streamlined water inlet 6.1 by a thread, and the other end is connected to the water inlet buffer chamber 6.3. An end water inlet pipe 6.4 and a middle water inlet pipe 6.6 extend from the water inlet buffer chamber 6.3 and are respectively connected to the water-jet engine combustion chamber 9 by a thread through an end water inlet pipe control valve 6.5 and a middle water inlet pipe control valve 6.7. The end water inlet pipe control valve 6.5 is located at the end of the water-jet engine combustion chamber 9, and the middle water inlet pipe control valve 6.7 is located in the middle of the water-jet engine combustion chamber 9, which enhances the mixing effect of oxidizer and fuel gas.

[0033] The variable height intake duct 1 consists of two movable plates connected by a through rod, and is connected to the isolation section 2 by a movable rod. By changing the movable rod connected to the isolation section 2, the through rod in the variable height intake duct 1 is moved to realize the opening and closing of the intake duct during different working processes; the variable angle nozzle 5 is connected to the scramjet engine housing 8 by a movable rod.

[0034] The telescopic water inlet pipe 6 is located inside the scramjet engine housing 8, and the combustion chamber fuel nozzle is located at the tail of the isolation section 2, at a certain angle to the housing, and connected to the scramjet engine fuel tank 11.

[0035] The gas generator housing 7.4 is connected to the gas generator front end cap 7.3 and the gas generator rear end cap 7.5 via flanges. The gas generator rear end cap 7.5 is connected to the combustion chamber front housing 9.1 via threads, wherein the gas generator rear end cap 7.5 is converging. The gas generator charge 7.2 is located inside the gas generator 7 and is in contact with the gas generator front end cap 7.3 via a gas generator charge elastic pad 7.1, which supports and fixes the gas generator charge 7.2.

[0036] The water-jet engine combustion chamber 9 is composed of a combustion chamber front shell 9.1, a combustion chamber shell 9.2, and a water-jet engine nozzle 10 connected in sequence by flanges.

[0037] refer to Figure 4 The streamlined water inlet 6.1 has a square opening on its inner side facing the direction of the ship's movement for water intake. The upper end of the water inlet is connected to the main water inlet pipe 6.2 by a thread. It is a transition section from the streamlined type to the circular pipe. The middle section of the water inlet is a columnar body with a streamlined bottom surface. The bottom is a semi-rotating body obtained by rotating the streamlined type by 180 degrees.

[0038] This embodiment also discloses a control method for a water-jet-guided hypersonic combined cycle propulsion system, used to control the water-jet-guided hypersonic combined cycle propulsion system. The control method for the water-jet-guided hypersonic combined cycle propulsion system includes high-altitude mode, deceleration mode, and near-water mode, and the specific implementation steps are as follows:

[0039] 1. High-altitude mode: The streamlined water inlet 6.1 and main water inlet pipe 6.2 retract; the telescopic water inlet pipeline 6, consisting of the water inlet buffer chamber 6.3, end water inlet pipe 6.4, and middle water inlet pipe 6.6, is not in operation; the gas generator 7 and the afterburner chamber 9 of the water jet engine are not in operation; the variable height air inlet 1 is as follows. Figure 1a As shown, with the maximum opening height, the air ramjet passes through the variable height intake duct 1 and the isolation section 2. The fuel stored in the scramjet engine fuel tank 11 is ejected through the scramjet engine fuel nozzle 3 and reacts fully with the air in the scramjet engine combustion chamber 4. The resulting gas is ejected through the variable angle nozzle 5 to generate thrust.

[0040] 2. Deceleration Mode: The streamlined water inlet 6.1 and main water inlet pipe 6.2 retract; the telescopic water inlet pipeline 6, consisting of the water inlet buffer chamber 6.3, end water inlet pipe 6.4, and middle water inlet pipe 6.6, is not in operation; the gas generator 7 and the afterburner chamber 9 of the water jet engine are not in operation; the variable height air intake duct 1 is as follows... Figure 1b As shown, as the flight altitude decreases, the airflow through the variable altitude intake 1 and the isolation section 2 is controlled to reduce the fuel ejected from the scramjet engine fuel nozzle 3, and the angle of the variable angle nozzle 5 is adjusted to generate a gradually decreasing thrust. The variable altitude intake 1 is gradually lowered, and the scramjet engine stops working, thus achieving deceleration.

[0041] 3. Near-water mode: Streamlined inlet 6.1 extension, with the end extending below sea level, variable height air intake 1 as shown Figure 1c As shown, the altitude decreases again. Gas passes through the scramjet engine isolation section 2, and fuel is not ejected from the combustion chamber fuel nozzle 3. Seawater flows through the streamlined inlet 6.1 into the main inlet pipe 6.2, through the inlet buffer chamber 6.3, and opens the end inlet pipe control valve 6.5 and the middle inlet pipe control valve 6.7. Seawater flows through the pipeline into the water ramjet engine afterburner chamber 9. The propellant in the gas generator 7 is burned, producing a continuous high-temperature and high-pressure primary gas carrying a large number of magnesium and aluminum particles. This primary gas flows into the water ramjet engine afterburner chamber 9 and reacts with the seawater. The combusted gas flows out through the water ramjet engine nozzle 10 and through the scramjet engine combustion chamber 4. Air is ejected through the variable-height intake duct 1 and isolation section 2. The air is heated by the high-temperature and high-pressure gas. The variable-angle nozzle 5 returns to its working angle, and the gas and air flow out together to generate thrust.

[0042] In summary, this embodiment of a hypersonic combined cycle propulsion system and control method using water ramjet ejection employs a combination of scramjet and water ramjet engines, combined with hydrocarbon fuels and metal-based solid propellants, to design a combined propulsion system that meets the flight requirements of the vehicle under different operating conditions at high altitudes and near-sea levels. The design of the telescopic water inlet pipe and streamlined water inlet effectively reduces the air resistance of the vehicle at high altitudes and high Mach numbers. Flight near sea level can effectively reduce the probability of strategic strike weapons being detected by radar when approaching the target, thereby improving the success rate of the strike.

[0043] The above detailed description further illustrates the purpose, technical solution, and beneficial effects of the invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A hypersonic combined cycle propulsion system for water-jet ejection, characterized in that: The system includes a scramjet engine body, a telescopic water inlet pipe, and a water-jet engine. The scramjet engine body includes a variable-height air intake, an isolation section connected to the air intake, a fuel nozzle at the end of the isolation section, a combustion chamber, and an adjustable-angle nozzle. The water-jet engine includes a gas generator, a combustion chamber connected to the gas generator, and a tailpipe at the end of the combustion chamber. The gas generator contains a metal-based solid propellant charge, and the tailpipe outlet is the scramjet engine combustion chamber. The water-jet engine gas generator includes a front end cap, a cylinder, and a gas generator nozzle. The combustion chamber includes components connected to the gas generator nozzle. The system includes a front cover and a combustion chamber cylinder; the tail nozzle includes a converging section and a diverging section, the front end of which is connected to the combustion chamber cylinder via a flange, and the rear end of which is connected to the diverging section at the nozzle throat via a threaded connection; the telescopic water inlet pipe is used to supply water to the combustion chamber of the water-jet engine; the telescopic water inlet pipe includes a streamlined water inlet, a main water inlet pipe, a water inlet pipe buffer chamber connected to the main water inlet pipe, an end water inlet pipe and a middle water inlet pipe connected to the water inlet pipe buffer chamber, a portion of the end water inlet pipe and the middle water inlet pipe are respectively connected to the combustion chamber, and a ball valve for the water inlet pipe is provided at the connection point.

2. The hypersonic combined cycle propulsion system for water jet ejection as described in claim 1, characterized in that: The variable-height air intake in the main body of the scramjet engine consists of two movable ramps connected by a shaft and driven and controlled by the air hull to adjust the throat height of the air intake. At the same time, the adjustable-angle nozzle changes its expansion ratio by adjusting the lower base plate of the nozzle, thereby realizing the conversion of the scramjet engine main body into the working mode of a water ramjet engine.

3. The hypersonic combined cycle propulsion system for water jet ejection as described in claim 2, characterized in that: The gas generator in the water-ramming engine uses a high-energy solid propellant containing a metal that readily reacts with water to generate greater thrust.

4. The hypersonic combined cycle propulsion system for water jet ejection as described in claim 3, characterized in that: The metals mentioned include, but are not limited to, magnesium and aluminum, which are readily reactive with water.

5. The hypersonic combined cycle propulsion system for water jet ejection as described in claim 4, characterized in that: The new high-energy solid propellant PBAN / Al / Mg / AP with metals is adopted, and its formula is 2.5%-15% PBCN, 60%-70% aluminum, 7.5%-10% magnesium and 15%-20% ammonium perchlorate; the scramjet engine uses hydrocarbon fuel to burn with air.

6. The hypersonic combined cycle propulsion system for water jet ejection as described in claim 1, characterized in that: The combustion chamber is connected to multiple water inlet pipes, which are divided into end water inlet pipes and middle water inlet pipes, and multiple pipes are alternately arranged. The end water inlet pipes are located at the end of the combustion chamber, and the middle water inlet pipes are located in the middle of the combustion chamber.

7. The hypersonic combined cycle propulsion system for water jet ejection as described in claim 1, characterized in that: A streamlined water inlet is selected at the water inlet, with openings at both ends. Water enters at one end of the streamlined design, and the other end connects to the main water inlet pipe to form a telescopic pipe, which is fixed under the aircraft. When in high-altitude mode and deceleration mode, the water inlet pipe contracts to fit against the lower wall of the aircraft. When the aircraft switches to near-water mode, the water inlet pipe extends and opens to allow water to enter.

8. A hypersonic combined cycle propulsion system for controlling a water-jet ejector as described in claims 1, 2, 3, 4, 6, or 7, characterized in that: Includes the following steps, (1) High-altitude mode: The streamlined water inlet and main water inlet pipe are retracted, the telescopic water inlet pipe consisting of the water inlet pipe buffer chamber, end water inlet pipe, and middle water inlet pipe is not working, the gas generator and water ramjet engine combustion chamber in the water ramjet engine are not working, the variable height air inlet is at its maximum opening height, the air ramjet passes through the variable height air inlet and the isolation section, the fuel stored in the scramjet engine fuel tank is ejected through the scramjet engine fuel nozzle, and reacts fully with the air in the scramjet engine combustion chamber. The generated gas is ejected through the variable angle nozzle to generate thrust; (2) Deceleration mode: The streamlined water inlet and main water inlet pipe retract, the telescopic water inlet pipe consisting of the water inlet pipe buffer chamber, end water inlet pipe, and middle water inlet pipe does not work, the gas generator and water ramjet engine combustion chamber in the water ramjet engine do not work, the opening height of the variable altitude air inlet decreases with the flight altitude, the airflow through the variable altitude air inlet and the isolation section is controlled, the fuel ejected from the scramjet engine fuel nozzle is reduced, and the angle of the variable angle nozzle is adjusted to generate a gradually decreasing thrust, and the variable altitude air inlet is gradually lowered to stop the scramjet engine from working, thus achieving deceleration; (3) Near-water mode: The streamlined water inlet and main water inlet pipe extend to below the sea level. The opening height of the variable height air inlet is reduced again. Gas passes through the isolation section of the scramjet engine. No fuel is ejected from the fuel nozzle of the combustion chamber. Seawater flows through the streamlined water inlet into the main water inlet pipe. After passing through the water inlet buffer chamber, the control valves of the end water inlet pipe and the middle water inlet pipe are opened. Seawater flows into the afterburning chamber of the water ramjet engine through the pipeline. The propellant in the gas generator is burned to produce primary gas with a large amount of magnesium and aluminum particles under continuous high temperature and high pressure. The gas flows into the afterburning chamber of the water ramjet engine and reacts with the seawater. The gas after combustion flows out through the nozzle of the water ramjet engine and flows through the combustion chamber of the scramjet engine. The air is ejected through the variable height air inlet and isolation section. The air is heated by the high temperature and high pressure gas. The variable angle nozzle returns to its working angle. The gas and air flow out together to generate thrust.

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