A cavitation implosion sound source based on rapid back-moving plate and its excitation method

Abstract

The present invention provides a cavitation implosion sound source based on the rapid back movement of plates and an excitation method thereof, belonging to the field of marine acoustic exploration. It comprises two symmetrical excitation units, each of which comprises a boss fixed at the center of the end cover, a hydraulic push device installed on the top of the boss and capable of lifting and lowering, a movable wall sleeved on the periphery of the boss and capable of sliding up and down, a magnetic suction device sealed at the end face of the movable wall, a return air chamber shell sleeved on the periphery of the movable wall, and a volume reduction device installed in the return air chamber shell; the present invention rapidly separates two nested and closed magnetic suction devices at high acceleration, forms cavitation bubbles of a certain scale on the separation path and even reaches a cavitation state, and then induces the water body to rush in and collide at a high acceleration rate through the high pressure difference between the flow field and the cavitation bubbles, triggering an implosion and releasing a sharp energy pulse. Compared with the traditional negative pressure air gun, the cavitation implosion sound source does not have an excitation cabin shell, so it can avoid the risk of implosion in the cabin.

Description

Technical Field

[0001] The invention belongs to the field of ocean acoustic exploration, and in particular relates to a cavitation-type implosion sound source based on rapid backward movement of a plate and an excitation method thereof. Background Art

[0002] Implosion is an important method for marine acoustic exploration. Its essence is to use low-pressure bubbles to collapse inward under hydrostatic confining pressure and release sharp pulse sub-waves. Low-pressure bubbles are the basic conditions for implosion excitation. It is difficult to obtain them under deep-water working conditions, so cavitation bubbles are gradually being used. Cavitation bubbles refer to gas cavities formed in fluids, which are caused by vaporization due to liquid pressure being lower than the saturated pressure or by the inability to fill in time due to the increase in fluid flow rate. This low-pressure bubble (cavitation area) provides good conditions for implosion excitation.

[0003] Based on the necessary connection between implosion and cavitation bubbles, some researchers have proposed a solution for negative pressure airgun sound sources (CN202310520514.9). The negative pressure airgun sound source creates a "negative pressure" environment by controlling the opening and closing of the excitation cabin shell to achieve the basic requirements of implosion. When the cabin door is opened during excitation, because the air pressure in the cabin is much lower than the surrounding water pressure, seawater will enter the cabin to squeeze the gas and form an implosion, generating sound source sub-waves. The negative pressure airgun sound source can break through the conventional water depth limit and achieve deep water environment excitation, so it can weaken and delay the interference of source ghost waves and effectively improve the imaging effect of seabed structures (especially shallow structures). Through simulation comparison, it is found that the residual bubble oscillation of the negative pressure airgun sound source is significantly weaker than that of the traditional high-pressure airgun. When the excitation cabin is an ideal vacuum environment, the residual bubble oscillation will completely disappear, so the sub-wave resolution ability is significantly improved. In addition, in order to address the vibration problem caused by uneven force on the gun body during excitation, the negative pressure air gun sound source optimized the symmetrical two-way opening mode and structure (CN202410448421.4), reducing the posture influence during sound source excitation and improving the energy release effect.

[0004] The research and development of the negative pressure air gun sound source has overcome the problem that traditional high-pressure air guns cannot operate in deep sea, but there are many challenges in the design and excitation process. First, before the excitation, the negative pressure air gun will use a hydraulic device to evacuate the excitation chamber, and open the shell of the excitation chamber to achieve implosion. With the increase of the operating water depth, the water pressure outside the chamber increases accordingly, and the potential risk of implosion in the chamber increases accordingly, which will have a great impact on the gun body structure and energy release efficiency. Secondly, the size of the excitation chamber is fixed during the design process. Since the optimal energy release capacity of the negative pressure air gun is related to the operating depth, this fixed size mode of the excitation chamber has a certain suppressive effect on the function realization of the negative pressure air gun. In addition, at this stage, due to the limitations of the excitation chamber shell structure, mechanical control (such as locking pins) is still used for excitation and resetting. The friction noise formed at the moment of opening the chamber has a certain interference with the source wavelet, reducing the signal-to-noise ratio of the source wavelet. Summary of the invention

[0005] In view of this, the present invention proposes a cavitation-type implosion sound source based on rapid backward movement of a plate and an excitation method thereof.

[0006] The technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides a cavitation implosion sound source based on rapid back movement of a plate, comprising a gun body structure formed by upper and lower end covers and a support rod connected between the upper and lower end covers, an upper excitation unit and a lower excitation unit located inside the gun body structure, wherein the two excitation units are symmetrically arranged up and down and can move up and down;

[0008] The upper excitation unit and the lower excitation unit each include a boss fixed at the center of the end cover, a hydraulic push device installed on the top of the boss and capable of being lifted up and down, a movable wall mounted on the periphery of the boss and capable of sliding up and down, a magnetic attraction device sealed at the end surface of the movable wall, a return air chamber shell mounted on the periphery of the movable wall, and a volume reduction device installed in the return air chamber shell;

[0009] The movable wall is composed of a movable side plate and a movable bottom plate. The movable bottom plate is sealed and slidably connected to the boss. There is a distance between the movable side plate and the boss. The outer wall of the movable side plate is sealed and slidably connected to the inner wall of the return air chamber shell. The hydraulic pushing device is slidably and sealedly connected to the inner wall of the movable side plate. The movable side plate, the movable bottom plate, the boss and the hydraulic pushing device surround and form a closed high-pressure air chamber. The movable side plate, the hydraulic pushing device and the magnetic suction device surround and form a closed movable air chamber. The bottom of the return air chamber shell is fixed on the inner side of the end cover. The return air chamber shell, the end cover, the boss and the movable bottom plate of the movable wall surround and form a closed return air chamber. The volume reduction device is located in the return air chamber. The bottom of the volume reduction device is fixed on the inner side of the end cover, and the top height is adjustable.

[0010] When the two excitation units are at the upper limit of the stroke, a pair of magnetic devices are completely fitted together, and there is no sealed chamber between the two; when the top height of the volume reduction device is the lowest and the excitation unit is at the lower limit of the stroke, the magnetic device and the hydraulic pushing device are completely fitted together, and the moving air chamber disappears.

[0011] According to a preferred embodiment of the present invention, the volume reduction device is an electric telescopic device, which can adjust the telescopic amount and change the height of the volume reduction device according to the instructions of the ship's control center.

[0012] According to a preferred solution of the present invention, the top of the magnetic attraction device is flush with the top end surface of the movable wall.

[0013] According to a preferred solution of the present invention, the sizes of the moving air chamber and the return air chamber vary with the movement of the hydraulic pushing device, and both are in vacuum environments.

[0014] According to a preferred solution of the present invention, when the excitation unit is at the upper limit position of the stroke, there is always a distance between the top of the capacity reduction device and the moving bottom plate of the moving wall.

[0015] According to a preferred embodiment of the present invention, a power supply circuit is provided inside the magnetic attraction device, and the magnetic attraction device is powered by the power supply circuit; the power supply circuit can be switched on and off according to instructions from the ship's control center.

[0016] In a second aspect, the present invention provides a method for exciting the above-mentioned cavitation implosion sound source, comprising:

[0017] 1) Inject high-pressure gas into the high-pressure gas chamber until the set pressure is reached;

[0018] 2) Before excitation, the cavitation implosion sound source is arranged at the desired excitation position underwater; the hydraulic push devices of the upper and lower excitation units are controlled to move closer to the middle, and when the top surface of the hydraulic push device is in contact with the bottom surface of the magnetic device, the hydraulic push device continues to move closer to the middle, thereby driving the magnetic device and the moving wall to move closer to the middle; when the magnetic devices of the upper and lower excitation units are completely in contact, the hydraulic push device stops working, the moving walls of the two excitation units are fully contacted and sealed, and the magnetic device is powered to maintain the contact state;

[0019] 3) During excitation, firstly, the control center on board synchronously sends a height adjustment command of the volume reduction device to the upper and lower excitation units, and the height to be adjusted is determined according to the depth of the cavitation implosion sound source; then, an excitation command is synchronously sent to the upper and lower excitation units, and after receiving the excitation command, the magnetic device is powered off, and under the action of the high-pressure gas pressure in the high-pressure gas chamber, the two magnetic devices and the moving wall are driven to move to both sides until the moving bottom surface of the moving wall contacts the top of the volume reduction device, and a certain scale of cavitation bubbles is formed on the separation path between the two magnetic devices, and even reaches a cavitation state, and then the high pressure difference between the flow field and the cavitation bubble induces the water body to rush in and collide at a high acceleration rate to trigger the implosion, forming a source sub-wave;

[0020] 4) After the excitation is completed, return to step 2) and wait for the next excitation.

[0021] The beneficial effects of the present invention are:

[0022] The cavitation implosion sound source proposed in the present invention quickly separates two nested closed magnetic devices at high acceleration, forming a certain scale of cavitation bubbles on the separation path and even reaching a cavitation state, and then induces the water body to rush in at a high acceleration rate through the high pressure difference between the flow field and the cavitation bubbles to cause implosion and release sharp energy pulses. Compared with the traditional negative pressure air gun, the cavitation implosion sound source does not have an excitation cabin shell, so it can avoid the risk of implosion in the cabin, and significantly improve the energy release efficiency. The fully fitted magnetic device plate increases the contact area, providing conditions for magnetic suction cabin opening, which will effectively reduce cabin opening noise and excitation real-time performance. In addition, a volume reduction device is designed in the return air chamber, and the moving distance of the magnetic device plate is changed by adjusting the height of the volume reduction device, thereby changing the cavitation capacity and realizing the optimization and adjustment of the implosion space at different excitation depths. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 It is a schematic diagram of the structure of a cavitation implosion sound source, wherein 1 is an end cover, 2 is a support rod, 3 is an upper movable side plate, 4 is a one-way drainage channel, 5 is a lower movable side plate, 6 is a hydraulic push device, 7 is a movable bottom plate, 8 is a high-pressure gas circuit, 9 is a one-way air inlet, 10 is a return air chamber, 11 is an upper magnetic device, 12 is a lower magnetic device, 13 is a movable air chamber, 14 is a high-pressure air chamber, 15 is a return air chamber shell, 16 is a volume reduction device, 17 is an initial slide, 18 is an increased volume reduction device, and 19 is a residual movable air chamber after excitation.

[0025] Figure 2 Schematic diagram of the excitation process of the implosion sound source after excitation.

[0026] Figure 3 This is a schematic diagram of the capacity reduction device at work.

[0027] Figure 4 The wavelet simulation results of cavitation implosion sound source based on fluid mechanics simulation; (a) wavelet model after excitation by H=50mm and 80mm sources; (b) wavelet model with H=200mm; (c) comparison of wavelets at different excitation heights under back velocity V=100m / s; (d) comparison of simulation results at different moving velocities under H=80mm, where the plate diameter is 120mm, and H and V represent the back movement distance and average moving velocity of the plate, respectively. DETAILED DESCRIPTION

[0028] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0029] like Figure 1 As shown, the present invention proposes a cavitation-type implosion sound source based on the rapid backward movement of a plate, comprising a gun body structure formed by upper and lower end covers 1 and a support rod 2 connected between the upper and lower end covers 1, an upper excitation unit and a lower excitation unit located inside the gun body structure, and the two excitation units are symmetrically arranged up and down and can move up and down;

[0030] The upper excitation unit and the lower excitation unit each include a boss fixed at the center of the end cover 1, a hydraulic pusher 6 installed on the top of the boss and capable of being lifted up and down, a movable wall mounted on the periphery of the boss and capable of sliding up and down, a magnetic attraction device sealed at the end surface of the movable wall, a return air chamber housing 15 mounted on the periphery of the movable wall, and a volume reduction device 16 installed in the return air chamber housing 15;

[0031] The movable wall is composed of a movable side plate and a movable bottom plate 7. The movable side plate in the upper excitation unit is called an upper movable side plate 3, and the movable side plate in the lower excitation unit is called a lower movable side plate 5. The movable bottom plate 7 is sealed and slidably connected to the boss. There is a distance between the movable side plate and the boss. The outer wall of the movable side plate is sealed and slidably connected to the inner wall of the return air chamber shell 15; the hydraulic pushing device 6 is slidably and sealedly connected to the inner wall of the movable side plate; the movable side plate, the movable bottom plate 7, the boss and the hydraulic pushing device 6 surround and form a closed high-pressure air chamber 14; the movable side plate, the hydraulic pushing device 6 and the magnetic attraction device surround and form a closed movable air chamber 13; the bottom of the return air chamber shell 15 is fixed on the inner side of the end cover 1, and the return air chamber shell 15, the end cover 1, the boss and the movable bottom plate 7 of the movable wall surround and form a closed return air chamber 10; the volume reduction device 16 is located in the return air chamber 10, the bottom of the volume reduction device 16 is fixed on the inner side of the end cover 1, and the top height is adjustable;

[0032] When the two excitation units are at the upper limit of the stroke, a pair of magnetic devices are completely fitted together, and there is no sealed chamber between the two; when the top height of the volume reduction device 16 is the lowest and the excitation unit is at the lower limit of the stroke, the magnetic device is completely fitted with the hydraulic pushing device 6, and the movable air chamber 13 disappears.

[0033] In a specific implementation of the present invention, the volume reduction device 16 is an electric telescopic device, the power source of which is arranged in the control cabin inside the boss, and the electric telescopic device drives the top cross bar or panel to move up and down through the vertical rod movement, and the magnetic device is pushed to move upward through the movement of the top cross bar or panel. The magnetic device is nested at the top end surface of the moving wall and the top of the magnetic device is flush with the top end surface of the moving wall. The moving wall is driven to move under the movement of the magnetic device.

[0034] The magnetic device is provided with a power supply circuit inside, and the magnetic device is powered by the power supply circuit. In this embodiment, the magnetic device is a metal plate with a built-in coil, and the two metal plates are attracted to each other when powered. The implementation principle of the magnetic device is common knowledge in the field and will not be repeated here.

[0035] In a specific implementation of the present invention, the top end surfaces of the upper and lower moving walls are provided with mutually matching annular stepped surfaces, and the vertical parts of the annular stepped surfaces of the two moving walls are closely attached to each other, and the vertical parts of the annular stepped surfaces constitute the initial slideways 17 of the moving walls of the two excitation units. The vertical part of the annular stepped surface has a set height, and a one-way drainage channel is provided at the annular stepped surface of at least one excitation unit. When the upper and lower excitation units are close to and connected to the initial slideway 17, the one-way drainage channel is used to discharge the water in the initial slideway 17.

[0036] The end cover 1 and the boss are provided with a high-pressure gas circuit 8 connected to the high-pressure gas chamber 14, and the gas inlet end of the high-pressure gas circuit 8 can be sealed. In this embodiment, one end of the high-pressure gas circuit 8 is connected to the high-pressure gas chamber 14, and the other end passes through the inside of the boss and the end cover 1. A sealing plug is installed at the one-way gas inlet 9 at the bottom of the end cover 1. After the high-pressure gas is injected into the high-pressure gas chamber 14, the high-pressure gas circuit 8 can be closed by the sealing plug.

[0037] A sealing ring is provided between the movable bottom plate 7 of the movable wall and the outer wall surface of the boss for achieving sealing during relative sliding; a sealing ring is provided between the outer wall of the movable side plate of the movable wall and the inner wall of the return chamber shell for achieving sealing during relative sliding.

[0038] In the cavitation implosion sound source provided by the present invention, the support rod 2 is fixed to the upper and lower end caps 1 to ensure the stability of the gun body structure during the excitation and resetting process; the upper moving wall 3 and the lower moving wall 5 are respectively connected to the upper magnetic device 11 and the lower magnetic device 12. When the magnetic devices are powered and fit each other, the upper and lower moving walls are also interlocked with each other, and the water at the interlocking position is discharged through the one-way drainage channel 4; when the sound source is to be excited, high-pressure gas is input into the high-pressure gas chamber 14 through the high-pressure gas circuit 8, and the size of the return gas chamber 10 and the moving gas chamber 13 changes with the movement of the hydraulic driving device 6, and both are vacuum environments. When the excitation unit is at the upper limit of the stroke, there is always a distance between the top of the volume reduction device 16 and the moving bottom plate 7 of the moving wall. After the volume reduction device 16 is reset, it is at the lowest height. At this time, the distance between the top of the volume reduction device 16 and the moving bottom plate 7 of the moving wall does not exceed the stroke size of the hydraulic driving device 6, so as to avoid the collision between the magnetic device and the hydraulic driving device 6 when the high-pressure gas drives the excitation unit to withdraw to both sides during excitation.

[0039] The excitation method of the above cavitation implosion sound source is as follows:

[0040] 1) Inject high-pressure gas into the high-pressure gas chamber 14 until a set pressure is reached; the set pressure affects the separation speed of the upper and lower excitation units during excitation.

[0041] 2) Before excitation, the cavitation implosion sound source is arranged at the desired excitation position underwater. There is an optimal relationship between the depth of the excitation position and the size of the cavitation capacity. The hydraulic pushing device 6 of the upper and lower excitation units is controlled to move closer to the middle. When the top surface of the hydraulic pushing device 6 fits with the bottom surface of the magnetic device, the hydraulic pushing device 6 continues to move closer to the middle, thereby driving the magnetic device and the moving wall to move closer to the middle. When the magnetic devices of the upper and lower excitation units are completely fitted, the hydraulic pushing device 6 stops working, the moving walls of the two excitation units are fully contacted and sealed, and the magnetic device is powered to maintain the fitting state. At this time, the implosion sound source is in Figure 1 The status shown;

[0042] 3) During excitation, firstly, a height adjustment instruction of the volume reduction device 16 is synchronously sent to the upper and lower excitation units through the ship's control center, and the height to be adjusted is determined according to the depth of the cavitation implosion sound source; then, an excitation instruction is synchronously sent to the upper and lower excitation units, and after receiving the excitation instruction, the magnetic device is powered off, and under the action of the high-pressure gas pressure in the high-pressure gas chamber 14, the two magnetic devices and the moving wall are driven to move to both sides until the moving bottom surface of the moving wall contacts the top of the volume reduction device 16, and a certain scale of cavitation bubbles is formed on the separation path between the two magnetic devices, and even reaches a cavitation state, and then the high pressure difference between the flow field and the cavitation bubble induces the water body to rush in and collide at a high acceleration rate to trigger the implosion, forming a source sub-wave;

[0043] If the volume reduction device 16 does not need to adjust the height, the upper and lower excitation units are at the lower limit of the stroke after excitation, the magnetic device and the hydraulic push device 6 are completely fitted, and the mobile air chamber 13 disappears. At this time, the implosion sound source is Figure 2 When the excitation command is issued, the magnetic device is powered off, and under the pressure of the high-pressure gas chamber 14, the magnetic device quickly moves to both sides, forming a cavitation area in the middle and forming an implosion.

[0044] If the volume reduction device 16 is adjusted to a certain height, thereby achieving the adjustment of the moving distance of the magnetic attraction device, there is a residual moving air chamber 13 after excitation, and the implosion sound source is at Figure 3 In the state shown, the increased volume reduction device 18 and the mobile air chamber 19 remaining after the excitation can be seen, which realizes the change of the cavitation area and the optimization of the implosion energy release.

[0045] 4) After the excitation is completed, return to step 2) and wait for the next excitation.

[0046] Figure 4 This is the sub-wave simulation result of the cavitation implosion sound source based on fluid mechanics simulation. Figure 4(a) is a set of pulse wavelet models obtained at the observation point of 1 m after the back-moving sound source is excited 500 m underwater. Its curve state is basically consistent with the implosion mode, from the negative pressure area before the implosion to the pulse-shaped high-pressure peak, and finally ends with some oscillation. The oscillation here comes from the reflection between the upper and lower walls of the sound source. Figure 4 (b) is the wavelet model after being excited by a sound source with a height of 200 mm. Compared with the sound source heights of 50 mm and 80 mm, the high-voltage spike pulse energy generated by the excitation is stronger, which can be controlled by the volume reduction device 16. Figure 4 (c) is a comparison of different back movement distances at the same speed, which can more intuitively show the effect of the back movement distance, that is, the excitation height, on the energy release. The energy release effect of 80mm is increased by 120.89% compared with 50mm. Figure 4 (d) is a comparison of the moving speeds of 100 m / s and 200 m / s under the same back-moving distance. It can be seen from the figure that at a depth of 500 m underwater and the same excitation height, the influence of high moving speeds above 100 m / s on the cavitation bubble sound source has been saturated.

[0047] Compared with the traditional negative pressure air gun, the cavitation implosion sound source does not have an excitation cabin shell, so it can avoid the risk of implosion in the cabin and significantly improve the energy release efficiency. The fully fitted magnetic suction device plate increases the contact area, providing conditions for the magnetic suction cabin opening, which will effectively reduce the cabin opening noise and the real-time excitation. In addition, a volume reduction device 16 is designed in the return air chamber 10. By adjusting the height of the volume reduction device 16, the moving distance of the magnetic suction device plate is changed, thereby changing the cavitation capacity and realizing the optimization adjustment of the implosion space under different excitation depths.

[0048] The above examples are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above examples, and many variations are possible. All variations that can be directly derived or associated with the contents disclosed by a person skilled in the art should be considered as the protection scope of the present invention.

Claims

1. A cavitation-type implosion sound source based on rapid back-moving of a plate, comprising a gun body structure formed by upper and lower end covers and a support rod (2) connected between the upper and lower end covers, an upper excitation unit and a lower excitation unit located inside the gun body structure, wherein the two excitation units are symmetrically arranged up and down and can move up and down; It is characterized in that The upper excitation unit and the lower excitation unit both include a boss fixed at the center of the end cover, a hydraulic pushing device (6) installed on the top of the boss and capable of being lifted up and down, a movable wall mounted on the periphery of the boss and capable of sliding up and down, a magnetic attraction device sealed at the end surface of the movable wall, a return air chamber shell (15) mounted on the periphery of the movable wall, and a volume reduction device (16) installed in the return air chamber shell (15); The movable wall is composed of a movable side plate and a movable bottom plate (7), the movable bottom plate (7) is sealed and slidably connected to the boss, there is a distance between the movable side plate and the boss, the outer wall of the movable side plate is sealed and slidably connected to the inner wall of the return air chamber shell (15); the hydraulic driving device (6) is slidably and sealedly connected to the inner wall of the movable side plate; the movable side plate, the movable bottom plate (7), the boss and the hydraulic driving device (6) surround and form a closed high-pressure air chamber (14); the movable side plate, the hydraulic driving device (6) and the magnetic attraction device surround and form a closed movable air chamber (13); the bottom of the return air chamber shell (15) is fixed on the inner side of the end cover, and the return air chamber shell (15), the end cover, the boss and the movable bottom plate (7) of the movable wall surround and form a closed return air chamber (10); the volume reduction device (16) is located in the return air chamber (10), the bottom of the volume reduction device (16) is fixed on the inner side of the end cover, and the top height is adjustable; When the two excitation units are at the upper limit of the stroke, the pair of magnetic devices are completely fitted together, and there is no sealed chamber between the two; when the top height of the volume reduction device (16) is the lowest and the excitation units are at the lower limit of the stroke, the magnetic devices are completely fitted together with the hydraulic pushing device (6), and the moving air chamber (13) disappears.

2. The cavitation implosion sound source based on the rapid backward movement of the plate according to claim 1, characterized in that: The volume reduction device (16) is an electric telescopic device.

3. The cavitation implosion sound source based on the rapid backward movement of the plate according to claim 1, characterized in that: The top of the magnetic attraction device is flush with the top end surface of the movable wall.

4. The cavitation implosion sound source based on the rapid backward movement of the plate according to claim 1, characterized in that: The top end surfaces of the upper and lower moving walls are provided with mutually matching annular step surfaces, and the vertical parts of the annular step surfaces of the two moving walls are closely attached to each other, and the vertical parts of the annular step surfaces constitute the initial slideways (17) of the moving walls of the two excitation units.

5. The cavitation implosion sound source based on the rapid backward movement of the plate according to claim 4, characterized in that: The vertical portion of the annular step surface has a set height, and a one-way drainage channel is provided at the annular step surface of at least one excitation unit, and the one-way drainage channel is used to discharge water in the initial slideway (17).

6. The cavitation implosion sound source based on the rapid backward movement of the plate according to claim 1, characterized in that: A high-pressure gas circuit (8) communicating with the high-pressure gas chamber (14) is arranged inside the end cover and the boss, and the gas inlet end of the high-pressure gas circuit (8) can be sealed.

7. The cavitation implosion sound source based on the rapid backward movement of the plate according to claim 1, characterized in that: The sizes of the moving air chamber (13) and the return air chamber (10) change as the hydraulic propulsion device (6) moves, and both are in a vacuum environment.

8. The cavitation implosion sound source based on the rapid backward movement of the plate according to claim 1, characterized in that: When the excitation unit is at the upper limit position of the stroke, there is always a distance between the top of the volume reduction device (16) and the moving bottom plate (7) of the moving wall.

9. The cavitation implosion sound source based on the rapid backward movement of the plate according to claim 1, characterized in that: A power supply circuit is provided inside the magnetic attraction device, and the magnetic attraction device is powered by the power supply circuit.

10. A method for exciting the cavitation implosion sound source according to claim 1, characterized in that: include: 1) Injecting high-pressure gas into the high-pressure gas chamber (14) until the set pressure is reached; 2) Before excitation, the cavitation implosion sound source is arranged at the desired excitation position underwater; the hydraulic pushing devices (6) of the upper and lower excitation units are controlled to move closer to the middle, and when the top surface of the hydraulic pushing device (6) is in contact with the bottom surface of the magnetic device, the hydraulic pushing device (6) continues to move closer to the middle, thereby driving the magnetic device and the moving wall to move closer to the middle; when the magnetic devices of the upper and lower excitation units are completely in contact, the hydraulic pushing device (6) stops working, the moving walls of the two excitation units are fully contacted and sealed, and the magnetic device is powered to maintain the contact state; 3) During the excitation, firstly, a height adjustment instruction of the volume reduction device (16) is synchronously sent to the upper and lower excitation units through the ship's control center, and the height to be adjusted is determined according to the depth of the cavitation implosion sound source; then, an excitation instruction is synchronously sent to the upper and lower excitation units, and after receiving the excitation instruction, the magnetic device is powered off, and under the action of the high-pressure gas pressure in the high-pressure gas chamber (14), the two magnetic devices and the moving wall are driven to move to both sides until the moving bottom surface of the moving wall contacts the top of the volume reduction device (16), forming a certain scale of cavitation bubbles on the separation path between the two magnetic devices, and even reaching a cavitation state, and then the high pressure difference between the flow field and the cavitation bubble induces the water body to rush in and collide at a high acceleration rate to trigger the implosion, thereby forming a source sub-wave; 4) After the excitation is completed, return to step 2) and wait for the next excitation.

Images