Water rocket, launching system and launching method

Abstract

This invention belongs to the field of educational demonstration products, specifically relating to a water rocket, a launch system, and a launch method. The water rocket includes a rocket body and a piston. The rocket body has a hollow cavity, and the piston is slidably and sealed within the cavity, dividing the cavity into a secondary cavity and a main cavity. The rocket body is equipped with an inflation nozzle I communicating with the secondary cavity and an inflation nozzle II communicating with the main cavity. A nozzle is also provided at the end of the rocket body away from the secondary cavity. During flight, as the pressure in the main cavity gradually decreases, the pressure in the secondary cavity becomes higher than that in the main cavity, pushing the piston towards the main cavity. This maintains the pressure balance in the main cavity, ensuring stable thrust during flight and partially compensating for the pressure loss in the main cavity, guaranteeing the thrust provided by the main cavity, and further improving the kinetic energy and speed of the water rocket.

Description

Technical Field

[0001] This invention belongs to the field of teaching demonstration products, specifically relating to a water rocket, a launch system, and a launch method. Background Technology

[0002] Water rockets are used as a teaching tool for scientific research. Because they are inexpensive, can stimulate students' creativity, are fun, and are relatively safe due to the availability of water and air, water rocket design competitions are frequently held in junior high schools, high schools, and some universities.

[0003] Currently, water rockets typically have low pressure, weak propulsion systems, and large weight, which limits their flight speed and distance. Furthermore, the conventional jetting method of water rockets causes a sharp drop in pressure inside the cavity at the start of flight, resulting in problems such as insufficient sustained power and unstable flight. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a water rocket, a launch system and a launch method that can ensure flight speed and improve flight stability while reducing weight.

[0005] This invention provides a water rocket, comprising a rocket body and a piston;

[0006] The rocket body has a hollow cavity inside, and the piston is slidably disposed in the cavity, dividing the cavity into a secondary cavity and a main cavity;

[0007] The arrow body is provided with an air inlet I that connects to the secondary cavity and an air inlet II that connects to the main cavity. A nozzle is also provided at the end of the arrow body away from the secondary cavity.

[0008] Furthermore, the present invention also includes an airbag disposed within the secondary cavity and communicating with the inflation nozzle I.

[0009] Furthermore, the nozzle is positioned on the central axis of the arrow body.

[0010] Furthermore, the nozzle includes a through hole I disposed on the arrow body and a plug disposed on the through hole I.

[0011] Furthermore, the present invention also includes a nozzle control mechanism for controlling the plug to block or open the through hole I.

[0012] Furthermore, the nozzle control mechanism includes an annular electromagnet and an electrical control box. The plug is made of iron material. The annular electromagnet is installed on the water rocket launch platform and located at the through hole I.

[0013] Furthermore, a sealing ring is provided on the side wall of the piston, and the sealing ring contacts the inner wall of the cavity.

[0014] The present invention also provides a launch system, including a water rocket and a launch platform, wherein the water rocket and the launch platform are connected by a guide rail slider.

[0015] A method for launching a water rocket, using a water rocket, includes the following steps:

[0016] A set volume of liquid is injected into the main chamber through the nozzle, and the nozzle is closed after the injection is complete.

[0017] The main chamber is pressurized to the set pressure through air inlet II, and the secondary chamber is pressurized to the set pressure through air inlet I;

[0018] Open the nozzle, and the water vapor ejected from the nozzle will generate a reaction force that propels the arrow forward.

[0019] The beneficial effects of this invention are that by sealing and sliding a piston within the cavity, the cavity is divided into a secondary cavity and a main cavity that are isolated from each other. Before flight, a set volume of liquid is first injected into the main cavity through a nozzle, and then the remaining space in the main cavity is pressurized through an inflation nozzle II. After pressurization is complete, the secondary cavity is pressurized through an inflation nozzle I. At this time, according to the pressure changes in the secondary cavity and the main cavity, the piston will move along the cavity axis and ensure the pressure balance between the secondary cavity and the main cavity. That is, by pressurizing the secondary cavity, the pressure regulation of the main cavity can be achieved. At the same time, the initial position of the piston can be controlled by controlling the pressure applied to the secondary cavity.

[0020] During flight, the liquid and high-pressure gas injected into the main chamber are ejected through the nozzle and generate thrust on the rocket body. As the pressure in the main chamber gradually decreases during flight, the pressure in the secondary chamber becomes higher than that in the main chamber, which pushes the piston towards the main chamber. This maintains the pressure balance in the main chamber, ensuring stable thrust during flight and partially compensating for the pressure loss in the main chamber. This guarantees the thrust provided by the main chamber and further enhances the kinetic energy and speed of the water rocket.

[0021] In addition, at the same flight distance and speed, the liquid volume in this invention can be less than that required by conventional water rockets, thereby reducing the water rocket's own weight and further increasing the flight distance and speed. Attached Figure Description

[0022] Appendix Figure 1 This is a schematic diagram of the water rocket in this invention;

[0023] Appendix Figure 2 This is a frontal sectional view of the water rocket in this invention;

[0024] Appendix Figure 3 for Figure 2 A magnified view of a section at point A in the middle;

[0025] Appendix Figure 4 for Figure 2 A magnified view of a section at point B in the middle;

[0026] Appendix Figure 5 This is a schematic diagram of the launch platform in this invention;

[0027] Appendix Figure 6 This is a front view of the launch platform in this invention;

[0028] Appendix Figure 7 This is a side sectional view of the launch platform in this invention;

[0029] Appendix Figure 8 This is a frontal sectional view of the water rocket in the present invention when it is installed on the launch platform;

[0030] Appendix Figure 9 for Figure 8 A close-up view of the mid-tail section;

[0031] Appendix Figure 10 This is a frontal cross-sectional view of the airbag in the water rocket after pressurization in this invention;

[0032] Appendix Figure 11 This is a frontal sectional view of the water rocket during takeoff in this invention;

[0033] Appendix Figure 12 for Figure 11 A close-up view of the mid-tail section;

[0034] Appendix Figure 13 This is a frontal sectional view of the water rocket separating from the launch platform in this invention;

[0035] Appendix Figure 14 for Figure 13 A close-up view of the mid-tail section;

[0036] Appendix Figure 15 This is a schematic diagram of the airborne water rocket in this invention.

[0037] In the diagram, 1-rocket body; 11-secondary cavity; 12-main cavity; 13-nose cone; 14-tail fin; 2-piston; 21-sealing ring; 3-inflation nozzle I; 4-inflation nozzle II; 5-nozzle; 51-through hole I; 52-plug; 6-bend; 61-liquid inlet; 62-bent connection; 63-liquid outlet; 7-launch platform; 71-guide rail plate; 72-mounting plate; 721-through hole II; 722-inflation through hole; 8-UAV; 9-nozzle control mechanism; 91-ring electromagnet; 92-electric control box; 10-liquid; 101-high pressure gas; 102-guide rail; 103-slider; 104-airbag. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0040] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0041] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0042] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0043] As attached Figure 1-15 As shown, the present invention provides a water rocket, including a rocket body 1 and a piston 2;

[0044] The arrow body 1 has a hollow cavity inside, and the piston 2 is sealed and slidably disposed in the cavity, dividing the cavity into a secondary cavity 11 and a main cavity 12. The piston 2 is sealed and slidably disposed in the cavity, and can move with the pressure changes of the secondary cavity 11 and the main cavity 12, thereby ensuring the pressure balance of the secondary cavity 11 and the main cavity 12, and can automatically adjust the volume of the secondary cavity 11 and the main cavity 12 by pressure.

[0045] The arrow body 1 is provided with an air inlet I3 communicating with the secondary cavity 11 and an air inlet II4 communicating with the main cavity 12. The arrow body 1 is also provided with a nozzle 5 at the end opposite to the secondary cavity 11. The air inlet I3 and the air inlet II4 are used to pressurize the secondary cavity 11 and the main cavity 12, respectively. A one-way air inlet valve is preferred. In some embodiments, the air inlet I3 and the air inlet II4 are respectively provided on the end faces of the secondary cavity 11 and the main cavity 12. The air inlet II4 can also be provided on the plug 52 of the nozzle 5 to simplify the structure of the arrow body 1.

[0046] This invention uses a piston 2, which is sealed and slidably installed within the cavity, to divide the cavity into a secondary cavity 11 and a main cavity 12 that are mutually isolated. Before flight, a predetermined volume of liquid 10 is first injected into the main cavity 12 through a nozzle 5. After injection, the nozzle 5 is closed, and then the remaining space in the main cavity 12 is pressurized through an inflation nozzle II 4. After pressurization is complete, the secondary cavity 11 is pressurized through an inflation nozzle I 3. At this time, according to the pressure changes in the secondary cavity 11 and the main cavity 12, the piston 2 will move along the cavity axis to ensure... The pressure in the secondary chamber 11 and the main chamber 12 is balanced. This means that by pressurizing the secondary chamber 11, the pressure in the main chamber 12 can be adjusted. At the same time, the initial position of the piston 2 can be controlled by controlling the pressure applied to the secondary chamber 11. Alternatively, the secondary chamber 11 can be pressurized first, and then the main chamber 12 can be pressurized to adjust the initial position of the piston 2. Specifically, the initial position of the piston 2 is usually located at 1 / 3 to 1 / 2 of the chamber length to avoid occupying too much of the volume of the main chamber 12 and to increase the water capacity.

[0047] During flight, the liquid 10 and high-pressure gas 101 injected into the main cavity 12 are ejected through the nozzle 5 and generate flight thrust on the rocket body 1. During flight, as the pressure in the main cavity 12 gradually decreases, the pressure in the secondary cavity 11 is higher than that in the main cavity 12, which pushes the piston 2 to move towards the main cavity 12. This can maintain the pressure balance in the main cavity 12, making the thrust during flight stable and partially compensating for the pressure loss in the main cavity 12, ensuring the thrust provided by the main cavity 12, and further improving the kinetic energy and speed of the water rocket.

[0048] In addition, at the same flight distance and speed, the liquid 10 volume in this invention can be less than that required by conventional water rockets, thereby reducing the water rocket's own weight and further increasing the flight distance and speed.

[0049] In one embodiment, the present invention further includes an airbag 104 disposed in the secondary cavity 11 and communicating with the inflation nozzle I3. In this embodiment, pressurizing the airbag 104 instead of pressurizing the secondary cavity 11 can reduce the sliding sealing requirements of the piston 2. Specifically, the airbag 104 is made of elastic plastic material and is inflated and pressurized through the inflation nozzle I3. After the airbag 104 expands, it fits against the cavity wall of the secondary cavity 11 and expands. When the piston 2 moves, the space of the secondary cavity 11 increases laterally, and the airbag 104 expands accordingly until the pressure inside the airbag 104 is equal to the pressure inside the main cavity 12.

[0050] In one embodiment, the nozzle 5 includes a through hole I 51 disposed on the arrow body 1 and a plug 52 disposed on the through hole I 51. The combination of the plug 52 and the through hole I 51 can ensure the simple structure of the nozzle 5, and at the same time facilitate the control of the blocking and opening of the through hole I 51. Specifically, before water is injected into the main cavity 12, the plug 52 is opened and water is injected into the main cavity 12 through the through hole I 51. After water is injected, the through hole I 51 is blocked by the plug 52 to ensure the sealing of the main cavity 12. Then, the secondary cavity 11 and the main cavity 12 are pressurized.

[0051] In one embodiment, the nozzle 5 is disposed on the central axis of the rocket body 1 to ensure that the spray center is located on the axis of the water rocket, thereby ensuring the flight stability of the water rocket and ensuring that the water rocket is driven to fly in a straight line in terms of thrust.

[0052] In one embodiment, the invention further includes a nozzle control mechanism 9 for controlling the plug 52 to block or open the through hole I 51, so as to control the water rocket to start flight. In a specific embodiment, the nozzle control mechanism 9 adopts a combination of annular electromagnet 91 and electrical control box 92. The electrical control box 92 is used to control the annular electromagnet 91 to be energized and de-energized. At this time, the plug 52 is made of iron material, such as iron. The annular electromagnet 91 is set on the water rocket launch platform 7 and located at the through hole I 51. After the plug 52 is inserted into the through hole I 51, the electrical control box 92 controls the annular electromagnet 91 to be energized and attract the plug 52 to fix the position of the plug 52 and keep the plug 52 blocking the through hole I 51. When it is necessary to control the water rocket to start flight, the electrical control box 92 controls the annular electromagnet 91 to be de-energized, and the plug 52 loses its restraining force. At this time, the liquid 10 is thrust by the high-pressure gas 101 and is ejected from the bend 6 to form thrust and realize the flight of the water rocket. In this embodiment, the plug 52 and the through hole I 51 can be sealed by a sealing ring. Thus, the opening of the nozzle 5 does not waste the thrust of the liquid 10, which can save a small amount of thrust and increase the flight distance of the water rocket. In addition, the combination of the nozzle 5 and the nozzle control mechanism 9 is also quite simple and convenient. It can be released simply and reliably with just one control command. The reusability and low cost of the water rocket are also retained.

[0053] In one embodiment, the cavity is a cylindrical cavity, which facilitates the sealing and sliding fit of the piston 2, and the arrow body 1 is also cylindrical in shape. The front part of the arrow body 1 is provided with a head cone 13, and the rear part of the arrow body 1 is provided with a tail fin 14 to improve the flight effect.

[0054] In one embodiment, a sealing ring 21 is provided on the side wall of the piston 2, and the sealing ring 21 contacts the inner wall of the cavity to improve the sealing effect of the piston 2.

[0055] In one embodiment, a bent pipe 6 is also included. The bent pipe 6 is disposed within the main cavity 12, with one end connected to the nozzle 5 and the other end bent to fit against the inner wall of the main cavity 12. Since the water in the main cavity 12 is connected to the nozzle 5 via the bent pipe 6, the water rocket can be launched and flown at a small angle or horizontally. During the flight of the water rocket, the volume of the main cavity 12 gradually decreases, preventing the water level of the remaining liquid 10 in the main cavity 12 from dropping too quickly or too low. Under certain conditions, the water level in the main cavity 12 can accumulate and rise during horizontal flight, ensuring that the water level is always higher than the liquid level entering through the bent pipe 6. Conventional rockets are launched vertically upwards from the ground. This results in a significant decrease in internal pressure and mass, and upward flight requires overcoming both air resistance and gravity, leading to high speeds and a sharp drop in velocity, resulting in short flight times and low speeds. This embodiment effectively overcomes these problems.

[0056] In one embodiment, a bend 6 is also included. The bend 6 is disposed within the main cavity 12, with one end connected to the nozzle 5 and the other end bent to fit against the inner wall of the main cavity 12. Since the water in the main cavity 12 is connected to the nozzle 5 via the bend 6, the water rocket can be launched and flown at a small angle or horizontally. During the flight of the water rocket, the volume of the main cavity 12 gradually decreases, preventing the water level of the remaining liquid 10 in the main cavity 12 from dropping too quickly or too low. This ensures that the water level is always higher than the diameter of the liquid inlet 61 of the bend 6, allowing water to be smoothly ejected from the bend 6 throughout the entire jetting process, maintaining the kinetic energy and speed of the water rocket.

[0057] In one embodiment, the bend 6 includes a liquid inlet 61, a bent connecting part 62, and a liquid outlet 63 connected in sequence. The liquid inlet 61 and the liquid outlet 63 are arranged in parallel, and the inlet direction of the liquid inlet 61 is parallel to the axis of the rocket body 1. At this time, the rocket body 1 is placed horizontally, the liquid 10 is located in the lower part of the main cavity 12, and the high-pressure gas 101 is located in the upper part of the main cavity 12. The high-pressure gas 101 will push the liquid 10 into the liquid inlet 61 and the bent connecting part 62 in sequence, and finally spray it out at the liquid outlet 63 to form the thrust of the water rocket. In this embodiment, the two parallel liquid inlet 61 and liquid outlet 63 are connected by the bent connecting part 62, which can avoid pressure loss along the way and reduce kinetic energy loss. At the same time, the inlet direction of the liquid inlet 61 being parallel to the axis of the rocket body 1 facilitates the inflow of liquid 10.

[0058] In one embodiment, the curved tube 6 is rotatably connected to the inner wall of the rocket body 1, or the curved connecting part 62 is rotatably connected to the liquid outlet part 63. In this way, when the rocket body 1 rotates along its own axis, the liquid 10 and the liquid inlet part 61 of the curved tube 6 are rotated to the lower part of the main cavity 12 by gravity, ensuring the stability of the liquid 10 ejection, thereby realizing the horizontal rotation flight of the water rocket.

[0059] The present invention also provides a launch system, including a water rocket and a launch platform 7, wherein the water rocket and the launch platform 7 are connected by a guide rail slider, and further includes a nozzle control mechanism 9 for controlling the opening and operation of the nozzle 5.

[0060] This launch system can provide a certain degree of guidance for the straight flight of the water rocket during takeoff, preventing the water rocket from deviating from its course. In addition, it provides installation space for the nozzle control mechanism 9. Specifically, the launch platform 7 includes a guide rail plate 71 and a mounting plate 72. The mounting plate 72 is perpendicular to the guide rail plate 71 and is located at one end of the guide rail plate 71. A guide rail 102 is provided on the side of the guide rail plate 71 near the mounting plate 72. A slider 103 is provided on the upper part of the rocket body 1, and the slider 103 is slidably engaged in the guide rail 102. The mounting plate 72 has a through hole II 721 at its center. A ring electromagnet 91 is located on the outside of the through hole II 721. The mounting plate 72 also has an inflation through hole 722. When the tail of the arrow body 1 slides to the mounting plate 72, the through hole I 51 and the through hole II 721 are aligned, and the inflation nozzle II 4 is aligned with the inflation through hole 722. After water is injected through the through hole I 51, the plug 52 is inserted from the through hole II 721 into the through hole I 51. The electrical control box 92 controls the ring electromagnet 91 to be energized to fix the position of the plug 52. In addition, when the plug 52 and the through hole 51 are simply sealed together, the radial fitting force of the plug 52 and the through hole 51 meets the sealing requirements, but the axial fitting force of the plug 52 and the through hole 51 is small. When the pressure inside the cavity is large, the rocket body 1 will be vibrated and fly forward while the plug 52 remains in place. Therefore, the plug 52 can be pressurized with the through hole 51, or a rocket body position fixing mechanism can be set on the guide rail and the slider to prevent the rocket body 1 from flying forward actively after the secondary cavity 11 and the main cavity 12 are pressurized. The rocket body positioning mechanism can be an electromagnet mounted on the guide rail plate 71. In this case, the slider 103 is made of iron. The electromagnet is controlled by the control box 92 to fix the position of the slider 103 at the set position of the guide rail 102. When the water rocket is installed on the launch platform 7, the control box 92 controls the electromagnet to attract the slider 103 and limit the position of the slider 103, and controls the annular electromagnet 91 to attract the plug 52 and limit the position of the plug 52. When the water rocket is started, the control box 92 controls the electromagnet and the annular electromagnet 91 to be de-energized at the same time. As the plug 51 is released, the slider 103 moves along the guide rail 102.

[0061] In one embodiment, the launch platform 7 is mounted on a drone 8, enabling airborne horizontal launch of the water rocket. The drone 8 can be a rotary-wing or fixed-wing drone. In this embodiment, the water rocket can utilize the power and potential energy of the drone 8 to achieve a longer flight distance and higher speed. Furthermore, because the water rocket can achieve horizontal launch and flight, it can be launched using the drone 8, thus achieving high-speed flight at low cost for related scientific research or entertainment purposes. Additionally, in this embodiment, the flight driving force of the water rocket does not exert a reverse thrust on the drone 8. The force exerted by the rocket body 1 on the drone 8 is the frictional force of the slider 103 on the guide rail 102, which is negligible. Therefore, the launch platform 7 can launch stably, and the launch moment will not generate a large force on the drone 8, ensuring the safety of the drone 8.

[0062] The present invention also provides a method for launching a water rocket, using a water rocket, comprising the following steps:

[0063] A set volume of liquid 10 is injected into the main chamber 12 through nozzle 5, and nozzle 5 is closed after the injection is completed.

[0064] The main chamber 12 is pressurized to the set pressure through the air inlet II4, and the secondary chamber 11 is pressurized to the set pressure through the air inlet I3;

[0065] Open nozzle 5, and the water vapor ejected from nozzle 5 will generate a reaction force that propels the arrow body 1 forward.

[0066] like Figures 11-14 As shown, during the flight of the water rocket, the volume of the secondary cavity 11 gradually increases, while the volume of the main cavity 12 gradually decreases, and the water level in the main cavity 12 remains basically unchanged, ensuring that the flight has continuous and reliable kinetic energy.

[0067] The specific working principle of a particular embodiment of the present invention is as follows:

[0068] First, the required amount of liquid 10 is injected into the main cavity 12 through the through hole I 51. Then, the rocket body 1 is mounted on the launch platform 7 of the UAV 8. After installation, the plug 52 is inserted into the through hole I 51 and fixed by the annular electromagnet 91, while sealing the main cavity 12 of the rocket body 1. Then, the control box 92 controls the position of the electromagnet fixing slider 103.

[0069] Then, the main cavity 12 is inflated and pressurized through the inflation nozzle II4 at the rear end. Figure 8 state);

[0070] After pressurization is achieved, the air bladder 104 is inflated and pressurized through the inflation nozzle I3 at the front end of the rocket body 1. At this time, the air bladder 104 expands and pushes the piston 2 to move. The piston 2 stops after moving to a certain position, usually at 1 / 3 to 1 / 2 of the length of the rocket body 1. Figure 10 state);

[0071] When the annular electromagnet 91 is de-energized by the control box 92, the slider 103 is released from its position lock, and the plug 52 will fly backward under the pressure of the main cavity 12. Figure 11 (State), therefore, the liquid 10 in the main cavity 12 will also be ejected from the through hole I 51 under pressure ( Figure 13 (In this state), a counter-thrust is generated, propelling the water rocket forward. The pressure in the main chamber 12 decreases, causing the secondary chamber 11 to push the piston 2 backward, maintaining the pressure and water level in the main chamber 12. Liquid 10 is introduced through the curved pipe 6 into the center of the rocket body 1 and ejected backward, maintaining flight thrust and speed.

[0072] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A water rocket, characterized in that, Includes the arrow body (1), piston (2) and curved tube (6); The arrow body (1) has a hollow cavity inside, and the piston (2) is sealed and slidably disposed in the cavity, dividing the cavity into a secondary cavity (11) and a main cavity (12). The arrow body (1) is provided with an air inlet I (3) that connects to the secondary cavity (11) and an air inlet II (4) that connects to the main cavity (12). The arrow body (1) is also provided with a nozzle (5) at the end away from the secondary cavity (11). The main cavity (12) is injected with a set volume of liquid (10), the air inlet II (4) is used to pressurize the remaining space in the main cavity 12, and the air inlet I (3) is used to pressurize the secondary cavity (11); The bent tube (6) is set inside the main cavity (12). One end of the bent tube (6) is connected to the nozzle (5), and the other end is bent and fitted to the inner side wall of the main cavity (12). The bent tube (6) includes a liquid inlet (61), a bent connection (62), and a liquid outlet (63) connected in sequence. The liquid inlet (61) and the liquid outlet (63) are arranged in parallel. The inlet direction of the liquid inlet (61) is parallel to the axis of the rocket body (1). The liquid (10) is located in the lower part of the main cavity (12), and the high-pressure gas (101) is located in the upper part of the main cavity (12). The high-pressure gas (101) will push the liquid (10) into the liquid inlet (61) and the bent connection (62) in sequence, and finally spray out at the liquid outlet (63) to form the thrust of the water rocket. The curved tube (6) is rotated to the inner wall of the rocket body (1), or the curved connecting part (62) is rotated to the liquid outlet part (63). In this way, when the rocket body (1) rotates along its own axis, the liquid (10) and the liquid inlet part (61) of the curved tube (6) are rotated to the lower part of the main cavity (12) by gravity, ensuring the stability of the liquid (10) ejection, and thus realizing the horizontal self-rotation flight of the water rocket.

2. The water rocket as described in claim 1, characterized in that, It also includes an airbag (104) disposed in the secondary cavity (11) and connected to the inflation nozzle I (3).

3. The water rocket as described in claim 1, characterized in that, The nozzle (5) is located on the central axis of the arrow body (1).

4. The water rocket as described in claim 1, characterized in that, The nozzle (5) includes a through hole I (51) disposed on the arrow body (1) and a plug (52) disposed on the through hole I (51).

5. The water rocket as described in claim 4, characterized in that, It also includes a nozzle control mechanism (9) for controlling the plug (52) to block or open the through hole I (51).

6. The water rocket as described in claim 5, characterized in that, The nozzle control mechanism (9) includes an annular electromagnet (91) and an electrical control box (92). The plug (52) is made of iron material. The annular electromagnet (91) is set on the water rocket launch platform (7) and located at the through hole I (51).

7. The water rocket as described in any one of claims 1-6, characterized in that, The piston (2) has a sealing ring (21) on its side wall, and the sealing ring (21) is in contact with the inner wall of the cavity.

8. A launching system, characterized in that, Includes the water rocket and launch platform (7) as described in any one of claims 1-7, wherein the water rocket and launch platform (7) are connected by a guide rail slider.

9. A method for launching a water rocket, using the water rocket as described in any one of claims 1-7, comprising the following steps: A set volume of liquid (10) is injected into the main chamber (12) through the nozzle (5), and the nozzle is closed after the injection is completed. The main cavity (12) is pressurized to the set pressure through the air inlet II (4), and the secondary cavity (11) is pressurized to the set pressure through the air inlet I (3); Open the nozzle (5), and the nozzle (5) sprays water vapor to form a reaction force that propels the arrow body (1) forward.

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