Experimental device for generating cavitation bubbles based on electric spark

Abstract

The invention relates to an experimental device for generating cavitation bubbles on the basis of electric sparks and belongs to the field of basic subjects of water conservancy and hydropower projects. The experimental device comprises a transformer, a rectifying device, a capacitor, a high-speed camera and a computer system and also comprises a resistance bridge, air ball electrodes, a discharging water tank and tungsten-needle electrodes in the discharging water tank. For the transformer, a high-leakage-reactance testing transformer is adopted as a high-voltage generation device; a silicon-stack high-voltage rectifying device is adopted as the rectifying device; and the air ball electrodes, the discharging water tank and the tungsten-needle electrodes in the discharging water tank form a cavitation-bubble generation device. The experimental device has the advantages that the ball gaps among the air ball electrodes and the spacing among the tungsten-needle electrodes can be freely controlled, further the size of generated cavitation bubbles can be controlled and the testing needs can be better met; the whole experiment process is captured and recorded, and working operation with one-button type starting is realized; a circuit structure is optimized and is simple, and used materials are new; and the experimental device is small in size, low in cost and safe and convenient in operation.

Description

technical field [0001] The invention relates to a cavitation technology, in particular to an experimental device for generating cavitation bubbles based on electric sparks, and belongs to the field of basic disciplines of water conservancy and hydropower engineering. Background technique [0002] Cavitation refers to the process of formation, development and collapse of vapor or gas cavities (cavitation bubbles) inside the liquid or on the liquid-solid interface when the local pressure in the liquid decreases. In 1873, Reynolds predicted theoretically that the high-speed relative motion between the paddle and water would produce a vacuum cavity that would affect the performance of the paddle. In 1697, Barnaby and Parsons proposed the concept of "cavitation" after the "Courageous" torpedo boat and several steam engine ships successively experienced serious declines in propeller efficiency, and pointed out that there is high-speed relative motion between liquids and objects c...

AI Technical Summary

Problems solved by technology

Since the design instantaneous voltage for generating cavitation bubbles is above 100kV, this has high requirements for the insulation performance and high-voltage resistance performance of electrical equipment, so the components such as high-voltage silicon stacks, high-voltage capacitors and transformers are relatively large in size and relatively expensive. According to Safety regulations require that the entire set of equipment needs to be arranged in a dedicated laboratory with a large area;

[0007] (2) The size of cavitation bubbles generated by existing devices is difficult to control

Due to the inherent defects of the needle plate discharge device, it is difficult to accurately control the instantaneous voltage during each discharge, so that the size of the cavitation bubble is often randomly generated in a certain range;

[0009] (4) The safety of the device is low

Due to the high voltage generated during the test, the test device needs to keep a certain safe distance from the experimenter. The equipment works under high voltage conditions for a long time, and leakage will inevitably occur. If the experimenter is not familiar with the operation process or does not operate according to the specifications , there are potential safety hazards;

[0010] (5) Hazards during device operation

During operation, the instantaneous discharge generates a strong electromagnetic field, which causes great interference to various electronic equipment and data line connections in the laboratory. In severe cases, it even makes the computer unable to obtain test data; the instantaneous discharge will generate more than 100dB of noise. The health of the experimenters will also have a certain impact

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