A composite mechanical wave generator with surface electric explosion coupled to multiple physics field sources

Abstract

The application discloses a composite mechanical wave generating device coupled with a surface electric explosion and a multi-physical field source, and belongs to the technical field of pulse power. The application comprises a cavity, a surface electric explosion unit, a water discharge unit and a spark gap switch; the cavity is used for containing an insulating liquid, the surface electric explosion unit is used for generating a first shock wave, the water discharge unit is used for generating a second shock wave, and the spark gap switch is used for conducting the surface electric explosion unit and the water discharge unit; the application adopts a multi-electrode structure discharge mode, uses water surface discharge as a first shock wave source, and induces bubbles in water to provide a gas medium environment more favorable to discharge for the water discharge unit to generate a second shock wave, thereby effectively improving a shock wave peak value and energy utilization rate, and having a significant progress.

Description

Technical Field

[0001] This invention relates to the field of pulsed power technology, specifically to a composite mechanical wave generator that uses a surface electro-explosive coupled multi-physics field source. Background Technology

[0002] Due to the high density and low compressibility of water, the shock waves generated by pulsed discharge in water exhibit higher peak pressure and a slower decay rate. During rapid expansion of the discharge channel, a spherical shock wave is initially generated. Subsequently, as the bubble expands and contracts to its minimum volume, a secondary pressure pulsation wave is produced. This expansion and compression cycle can repeat several times, even more than ten times, resulting in multiple pressure pulsation waves. The shock wave effect in water has been widely applied in fields such as electrohydraulic molding, energy development, extracorporeal shock wave lithotripsy, and food processing.

[0003] Currently, safe and reliable physical methods are mostly used to generate shock waves in practical applications. These methods include water gap breakdown, underwater electrical wire explosion (UEWE), and laser-induced shock waves. Water gap breakdown, also known as the "electrohydraulic effect," refers to the optical, thermal, and shock wave effects triggered when a liquid medium is broken down by a high-voltage pulse. Underwater electrical wire explosion (UEWE) refers to the rapid melting, vaporization, breakdown / ionization of a metal wire under Joule heating driven by a pulsed current, accompanied by optical radiation and shock waves. Surface discharge in water has a similar discharge waveform to UEWE. It can be considered that surface discharge in water, due to the microscopic inhomogeneity of the current-carrying conductive coating, leads to uneven energy deposition, causing localized overheating and microscopic "electrical explosions," similar to an electrothermal instability mechanism. Laser-induced shock waves involve focusing a high-energy laser beam into water to generate shock wave effects.

[0004] The energy conversion efficiency of shock waves generated by a single discharge source is relatively low (up to 24%). Therefore, there is an urgent need for a device that can generate stronger and more controllable shock waves to increase the peak pressure of the shock waves, thereby providing a stronger and more controllable mechanical wave source for engineering and civil applications. Summary of the Invention

[0005] To address the technical problems existing in the prior art, this invention provides a composite mechanical wave generator based on surface electric explosion-induced bubbles in water. The surface electric explosion unit provides the first shock wave and induces the generation of bubbles. Then, the underwater discharge unit generates a second shock wave by discharging in the bubbles. This can achieve high discharge stability and controllability, and significantly improve the peak value and energy conversion efficiency of the shock wave.

[0006] A composite mechanical wave generator coupled with a multi-physics field source along a surface electric explosion includes a cavity, a surface electric explosion unit, an underwater discharge unit, and a gas spark gap switch.

[0007] The discharge section of the cavity is filled with insulating liquid;

[0008] The surface electro-explosion unit includes a pulse power supply, a conductive graphite body, and a first electrode; the first electrode is disposed in the cavity, with one side in contact with the surface of the insulating liquid; one end of the conductive graphite body is disposed in the gap of the first electrode; the pulse power supply is connected to the first electrode.

[0009] The underwater discharge unit includes a high-repetition-rate pulse power supply and a second electrode; the second electrode is disposed inside the discharge portion of the cavity, and the high-repetition-rate pulse power supply is disposed outside the cavity and connected to the second electrode;

[0010] The gas spark gap switch includes a first gas spark gap switch and a second gas spark gap switch, both of which are disposed outside the cavity; one end of the first gas spark gap switch is connected to the pulse power supply, and the other end is connected to the first electrode; one end of the second gas spark gap switch is connected to the repetition frequency pulse power supply, and the other end is connected to the second electrode.

[0011] Furthermore, the cavity is made of a transparent, rigid material.

[0012] Furthermore, a pulsed laser modulation unit is also provided outside the cavity. The pulsed laser modulation unit includes a convex lens and a pulsed laser, with the convex lens disposed on the pulsed laser.

[0013] Furthermore, the pulsed laser modulation unit also includes a timing control system.

[0014] Furthermore, the two plates of the first electrode have a protrusion at a relative position near one end of the electrode gap, and the protrusion is located on the side of the first electrode that is in contact with deionized water.

[0015] Furthermore, a spring is provided at the other end of the conductive graphite body.

[0016] Furthermore, the first electrode is fixed in the cavity by a first insulator; the second electrode is fixed in the cavity by a second insulator.

[0017] Furthermore, the second insulator is provided with multiple through holes.

[0018] Furthermore, the cavity is provided with an inlet and an outlet.

[0019] Furthermore, the distance between the first electrode and the second electrode is 10-50 mm; the gap between the first electrodes is 1-30 mm, and the gap between the second electrodes is 1-20 mm.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] This invention employs a multi-electrode discharge structure, using surface discharge as the initial shock wave source and inducing bubble generation in water to provide a more favorable gaseous medium environment for secondary shock waves generated by the underwater electrodes, effectively improving the peak value and energy utilization of the shock wave. Through a pulsed laser modulation unit, this invention can control the initial local explosion point position of the graphite surface discharge and induce breakdown of the underwater electrode gap, enhancing the controllability and intensity of the shock wave and further meeting the practical application requirements of underwater pulsed discharge. The surface electric explosion unit provided by this invention, with its concave electrode structure and spring structure, can automatically replenish the surface discharge medium, ensuring the continuity of the surface discharge. The multiple through holes on the insulator provided by this invention can adjust the distance between the surface electric explosion electrode and the water gap discharge electrode, improving the controllability of the composite shock wave. Based on the pulsed laser modulation unit, the surface electric explosion unit and the underwater discharge unit provided by this invention can achieve different discharge sequences for the third or more discharges of the two electrode structures, thereby obtaining different shock wave intensities. Simultaneously, laser-induced discharge can provide a certain amount of energy for the formation of the discharge channel, improving discharge efficiency. This device has a simple structure, low cost, and good stability. The shock wave can be further controlled by adjusting the electrode spacing in the water, the timing control system, and the pulse source frequency according to actual needs. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a preferred embodiment of the present invention; in the figure, to prevent the lines representing deionized water from being confused with other lines, the lines representing deionized water are omitted.

[0023] In the picture:

[0024] 1-Cavity; 201-First gas spark gap switch; 202-Second gas spark gap switch; 3-Spring; 4-Conductive graphite body; 5-First electrode; 601-First insulator; 602-Second insulator; 7-Second electrode; 8-Plasma water; 9-Inlet; 10-Outlet; 11-Convex lens; 12-Pulsed laser; 13-Pulsed power supply; 14-Repetition rate pulse power supply. Detailed Implementation

[0025] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0026] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0027] Furthermore, in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Additionally, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] The following is in conjunction with the appendix Figure 1 The specific embodiments of the present invention will be described in detail below.

[0029] This invention provides a multi-physics source composite mechanical wave control device, which uses a surface electric explosion unit to provide the first shock wave and induce the generation of bubbles, and then uses an underwater discharge unit to generate a second shock wave in the bubbles. This device can achieve high discharge stability and controllability, and significantly improve the peak value and energy conversion efficiency of the shock wave.

[0030] A composite mechanical wave control device based on surface electric explosion-induced bubbles in water includes a cavity, a surface electric explosion unit, an underwater discharge unit, and a spark gap switch.

[0031] The cavity 1 is used to hold deionized water 8 and fixed electrodes, including a discharge part and a containment part. The discharge part of the cavity 1 is filled with deionized water 8 or insulating liquid such as insulating oil, preferably deionized water 8.

[0032] The surface-mounted electric explosion unit is used to generate the initial shock wave and includes a pulse power supply 13, a conductive graphite body 4, and a first electrode 5; the pulse power supply 13 is a high-voltage DC power supply with a voltage range of 1. 15 kV; The first electrode 5 consists of a high-voltage electrode and a low-voltage electrode made of block electrodes, with a gap between them, and is set in the cavity 1. One side is in contact with the surface of the insulating liquid, and the other side is used to set the conductive graphite body 4; The front end of the conductive graphite body 4 is set in the gap of the first electrode 5; The first electrode 5 is composed of a block high-voltage electrode and a low-voltage electrode, and an electrode gap is formed between the two electrodes; The first electrode 5 is made of metal. Considering factors such as price, melting point, conductivity, and heat resistance, copper is the preferred material; To reduce consumption, the conductive graphite body 4 is designed as a layered structure, and only one layer of conductive graphite body 4 needs to be consumed each time an impact is generated;

[0033] The underwater discharge unit is used to generate a second shock wave, including a high-repetition-rate pulse power supply 14 and a second electrode 7; the second electrode 7 is disposed inside the cavity 1 and passes through deionized water 8 from the discharge section of the cavity 1; the high-repetition-rate pulse power supply 14 is an AC power supply with a voltage range of 1. 15 kV, with a frequency range of 1 Hz to 15 kHz, is located outside the cavity 1 and connected to the second electrode 7; the second electrode is preferably composed of a needle-shaped high-voltage electrode and a low-voltage electrode, with an electrode gap formed between the two tips, and is made of tungsten material.

[0034] There are two spark gap switches, which are set outside the cavity 1. One end of one of them is connected to the pulse power supply 13 and the other end is connected to the first electrode 5. The other end is connected to the repetition frequency pulse power supply 14 and the other end is connected to the second electrode 7. It is used to connect the pulse power supply 13 and the first electrode 5, and the repetition frequency pulse power supply 14 and the second electrode 7. The spark gap switch is an air gap. When the current of the pulse power supply 13 passes through the air gap, it can break down the air gap, turn on the spark gap switch, and then trigger subsequent discharge.

[0035] In use, the pulse power supply 13 is turned on to provide a pulse current with certain parameters to the surface electric explosion unit, and the spark gap switch located between the pulse power supply 13 and the first electrode 5 is turned on. When the spark gap switch is turned on, the current passes through the first electrode 5 and the conductive graphite body 4 to form a discharge circuit. By ablating the conductive graphite layer of the conductive graphite body 4, a surface local electric explosion is triggered to discharge, generating shock waves, plasma, bubbles, etc. in deionized water.

[0036] Then, the high-repetition-rate pulse power supply 14 is turned on to provide a pulse current with certain parameters to the discharge unit in the water. The spark gap switch located between the high-repetition-rate pulse power supply 14 and the second electrode 7 is turned on. The current path through the second electrode 7 forms a discharge circuit. In the deionized water 8, the second shock wave is generated by the discharge in the bubble produced by the first electric explosion. It forms a composite shock wave with the shock wave generated by the surface electric explosion unit, which effectively increases the peak value of the shock wave. Compared with the water gap, the electrode gap in the gas medium has a lower breakdown voltage and is easier to break down, which can effectively improve the energy utilization rate.

[0037] In a preferred embodiment, the cavity 1 is made of a transparent rigid material, preferably plexiglass. Plexiglass has a certain mechanical strength, can withstand the impact of shock waves generated by discharge, and its excellent light transmittance can be used for discharge spectral analysis.

[0038] In a preferred embodiment, a pulsed laser modulation unit is also provided outside the cavity 1. The pulsed laser modulation unit includes two convex lenses 11 and two pulsed lasers 12. The two convex lenses 11 are respectively disposed on the two pulsed lasers 12. The pulsed lasers 12 can generate pulsed lasers. The two convex lenses 11 are used to focus the parallel light emitted by the two pulsed lasers 12 to a point to form a laser spot. The pulsed laser modulation unit is used for laser focusing on surface electrical explosion. The material of the first electrode 5 in the surface electrical explosion unit is rough and uneven under microscopic conditions. The laser can provide energy for the electron emission of the surface material. Therefore, the laser hitting different positions of the surface material can make the corresponding positions more likely to generate the initial electrical explosion. The surface discharge is most intense at this position. Therefore, it can be used to control the initial local explosion point position and induce the breakdown of the gap of the first electrode 5. At the same time, the pulsed high intensity laser is used to generate subsequent discharge.

[0039] In a preferred embodiment, the pulsed laser modulation unit further includes a timing control system, which controls the sequence of surface electric explosion and breakdown of the second electrode 7, and is controlled by a digital delay generator (DG645). When the laser emitted by the pulsed laser modulation unit hits the gap of the first electrode 5 in the surface electric explosion unit, it can increase the energy of the electrons in the gap of the first electrode 5, thereby reducing the breakdown voltage threshold of the first electrode 5; when the laser hits the gap of the second electrode 7 in the underwater discharge unit, it can increase the energy of the electrons in the bubbles generated by the surface electric explosion, thereby reducing the breakdown voltage threshold of the second electrode 7; that is, when the voltage is slightly lower than the minimum discharge voltage, the electrode can be discharged by irradiating the laser, and the timing of the laser irradiation of the surface electric explosion unit or the underwater discharge unit can be controlled to cause the first electrode 5 or the second electrode 7 to break down and discharge.

[0040] The pulsed laser modulation unit described above can control the sequence and number of discharges, thereby regulating the intensity of the final composite shock wave and effectively increasing the peak value of the shock wave.

[0041] In a preferred embodiment, the two plates of the first electrode 5 are close to one end of the electrode gap, and protrusions are constructed at their relative positions. The protrusions are located on the side of the first electrode that contacts the deionized water. The two protrusions are used together to form a groove on the side of the electrode gap of the first electrode 5 where the conductive graphite body 4 is located. The conductive graphite body 4 is located in the groove at the electrode gap and can be used to fix the conductive graphite body 4.

[0042] In a preferred embodiment, a spring 3 is provided at the rear end of the conductive graphite body 4. The spring 3 is used to automatically replenish the consumed conductive graphite layer by moving the conductive graphite body 4 forward through its own elastic force after the conductive graphite layer at the front end of the conductive graphite body 4 is consumed.

[0043] In a preferred embodiment, the first electrode 5 is fixedly disposed in the cavity 1 by a first insulator 601; the second electrode 7 is fixedly disposed in the cavity 1 by a second insulator 602. The first insulator 601 and the second insulator 602 are used to separate the first electrode 5 and the second electrode 7 from the cavity 1 to prevent the first electrode 5 and the second electrode 7 from communicating with the cavity 1, or from experiencing phenomena such as breakdown or creepage.

[0044] In a preferred embodiment, the second insulator 602 is provided with a plurality of through holes, which are used to change the position of the second electrode 7 in the second insulator 602, thereby changing the distance between the second electrode 7 and the first electrode 5.

[0045] In a preferred embodiment, the cavity 1 is provided with an inlet 9 and an outlet 10. The inlet 9 and the outlet 10 are used for the intake and exhaust of deionized water 8, and can also be used for the directional discharge of discharge products for easy collection.

[0046] In a preferred embodiment, the distance between the first electrode 5 and the second electrode 7 is 10-50 mm; the gap size of the first electrode 5 is 1-30 mm, and the gap size of the second electrode 7 is 1-20 mm. The above-mentioned distance or distance range can ensure good energy deposition and stable triggering effect.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A composite mechanical wave generator device for coupling multi-physical field sources by surface electrical explosion, characterized in that, The device comprises a cavity, a surface discharge unit, a water discharge unit and a gas spark gap switch. The discharge part of the cavity is filled with an insulating liquid. The surface discharge unit comprises a pulse power source, a conductive graphite body and a first electrode. The first electrode is arranged in the cavity and contacts the insulating liquid on one side. The conductive graphite body is arranged in the gap of the first electrode. The pulse power source is connected to the first electrode.

2. The compound mechanical wave generator of claim 1, wherein The water discharge unit comprises a repetitive pulse power source and a second electrode.

3. The compound mechanical wave generator of claim 2, wherein The second electrode is arranged in the discharge part of the cavity.

4. The compound mechanical wave generator of claim 3, wherein The repetitive pulse power source is arranged outside the cavity and connected to the second electrode.

5. The compound mechanical wave generator of claim 1, wherein The gas spark gap switch comprises a first gas spark gap switch and a second gas spark gap switch, both of which are arranged outside the cavity.

6. The compound mechanical wave generator of claim 5, wherein One end of the first gas spark gap switch is connected to the pulse power source and the other end is connected to the first electrode.

7. The compound mechanical wave generator of claim 1, wherein One end of the second gas spark gap switch is connected to the repetitive pulse power source and the other end is connected to the second electrode.

8. The compound mechanical wave generator of claim 7, wherein The cavity is made of transparent rigid material.

9. The compound mechanical wave generator of claim 1, wherein The cavity is further provided with a pulse laser modulation unit.

10. The compound mechanical wave generator of any of claims 1-9, wherein, The pulse laser modulation unit comprises a convex lens and a pulse laser. The convex lens is arranged on the pulse laser. The pulse laser modulation unit further comprises a timing control system. The opposite position of the two electrode plates of the first electrode near one end of the first electrode gap has a protrusion. The other end of the conductive graphite body is provided with a spring. The first electrode is fixed in the cavity by a first insulator. The second electrode is fixed in the cavity by a second insulator. The second insulator is provided with a plurality of through holes. The cavity is provided with a water inlet and a water outlet. The distance between the first electrode and the second electrode is 10-50mm. The gap of the first electrode is 1-30mm and the gap of the second electrode is 1-20mm.

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