Underwater pulsed discharge is widely applied in medicine, machining, and material modification.The induced cavitation bubble and subsequent cavitation collapse are considered the major motivations behind these applic...Underwater pulsed discharge is widely applied in medicine, machining, and material modification.The induced cavitation bubble and subsequent cavitation collapse are considered the major motivations behind these applications. This paper presents an underwater pulsed discharge system.The experimental setup is established to induce and investigate the cavitation bubble assisted with a high-speed camera. Three aspects, including the characteristic of the discharge with different applied voltages and conductivities, the evolution of the cavitation bubble profile, and the energy efficiency of cavitation bubble inducing, are investigated, respectively. Especially, the mechanism of pre-discharge time delay in the low field intensity case is explained using the Joule heat effect.The results show the validity of the underwater pulsed discharger and experimental setup. The present underwater pulsed discharger is proved to be a simple, portable, and easy-to-implement device for the investigation of cavitation bubble dynamics.展开更多
The existence of space charge may be addressed as one of the reasons that could cause shielding failure of transmission lines. In order to study the effect of space charge on discharge propagation path, a new experime...The existence of space charge may be addressed as one of the reasons that could cause shielding failure of transmission lines. In order to study the effect of space charge on discharge propagation path, a new experimental system, including mainly DC high voltage generator, impulse voltage generator as well as rod-plane electrode, has been established. The space charge was generated around the rod by means of pre-applying DC high voltage, and the air gap dis- charge experiments were conducted with and without pre-applying DC high voltage, respectively. Meanwhile, high speed cameras worked simultaneously from the front and lateral side to record the discharge propagation path so as to obtain the curvature. After statistical analysis, it is shown that the curvature increases in the middle and lower portions of the propagation path when the effect of space charge is taken into account.展开更多
基金supported by National Natural Science Foundation of China (Grant Nos. 11874140, 11574072)National Key Research and Development Program of China (Grant No. 2016YFC0401600)+2 种基金Primary Research and Development Plan of Jiangsu Province, China (Grant No. BE2016056)Fundamental Research Funds for the Central Universities (Grant No. 2017B17814)Postgraduate Research & Practice Innovation Program of Jiangsu Province (Grant No. KYCX18_0552)
文摘Underwater pulsed discharge is widely applied in medicine, machining, and material modification.The induced cavitation bubble and subsequent cavitation collapse are considered the major motivations behind these applications. This paper presents an underwater pulsed discharge system.The experimental setup is established to induce and investigate the cavitation bubble assisted with a high-speed camera. Three aspects, including the characteristic of the discharge with different applied voltages and conductivities, the evolution of the cavitation bubble profile, and the energy efficiency of cavitation bubble inducing, are investigated, respectively. Especially, the mechanism of pre-discharge time delay in the low field intensity case is explained using the Joule heat effect.The results show the validity of the underwater pulsed discharger and experimental setup. The present underwater pulsed discharger is proved to be a simple, portable, and easy-to-implement device for the investigation of cavitation bubble dynamics.
文摘The existence of space charge may be addressed as one of the reasons that could cause shielding failure of transmission lines. In order to study the effect of space charge on discharge propagation path, a new experimental system, including mainly DC high voltage generator, impulse voltage generator as well as rod-plane electrode, has been established. The space charge was generated around the rod by means of pre-applying DC high voltage, and the air gap dis- charge experiments were conducted with and without pre-applying DC high voltage, respectively. Meanwhile, high speed cameras worked simultaneously from the front and lateral side to record the discharge propagation path so as to obtain the curvature. After statistical analysis, it is shown that the curvature increases in the middle and lower portions of the propagation path when the effect of space charge is taken into account.
