摘要
This study delves into the electrophysical processes and intricate fluid dynamics of an electrical-explosion-induced bubble in water. A fine copper wire is heated up and exploded to dense metallic aerosol (vapor-drop mixture) via a μs-timescale 10 kA current pulse, crossing a wide range of the density-temperature parametric space. High-speed photography along with discharge diagnostics reveals two modes for plasma development (restrike) inside explosion products: gas discharge and volume ionization. Experimental results indicate the metal-insulator transition of metal can easily throttle down circuit current at a moderate degree of vaporization, resulting in a free-expanding metallic aerosol in the presence of a quasi-direct current axial electric field of kV/cm level. After dozens of μs, an anode-directed, “ionization wave” is observed inside the aerosol bubble, propagating with a speed of 3-10 km/s. Remarkably, adjustments in the electric field permit the observation of cathode-directed discharge development. Increasing the charging voltage or wire diameter promotes the overheating degree, accompanied by partial ionized striation of electro-thermal instability. With sufficient high overheating of the wire (ξ > 1), the gas discharge disappears and restrike is dominated by volume ionization.
源语言 | 英语 |
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文章编号 | 047112 |
期刊 | Physics of Fluids |
卷 | 36 |
期 | 4 |
DOI | |
出版状态 | 已出版 - 1 4月 2024 |