Student: Tuholukov Andrii
Školitel: Dr. Vitalij Stelmashuk
Konzultant: RNDr. Karel Koláček, CSc. ÚFP AV ČR, Prof. RNDr. Jana Šafránková, DrSc.
Stav práce: přerušená
Abstrakt:
Electrical discharges in liquids are important for different technological applications, e.g. for underwater cutting and welding of metals, for biological applications for production of carbon nanotubes, extracorporeal shock wave lithotripsy. A theory of an underwater discharge and hydrodynamic waves, which are produced in the surrounding liquid, would be of value not only for understanding shock wave generation/propagation/focusing, but also for optimizing above mentioned practical applications.
An application of high voltage pulse with a fast rise time on two pin electrodes submerged in water leads to generation and rapid expansion of plasma channel. As a result of this expansion a cavitation bubble is formed and a shock wave is generated. The hydrodynamic characteristic of this process depends on the velocity of the energy deposition into the discharge and on the plasma parameters in the spark channel.
The main purpose of the proposed thesis is to design and create numerical model simulating hydrodynamic process initiated by electrical discharge in water and to compare it with experimental data. The pressure in a spherical shock wave propagating in water will be calculated using, for example, the method of Naugol’nykh and Roi. The results will be compared with experimentally recorded plasma channel expansion (by high speed camera) and with experimentally received pressure-field map in interesting regions (obtained by optical methods). In case of insufficient agreement between the numerical simulation and the experiment, the mathematical model will be refined using the further approaches.