Modeling of cathode spot crater formation and development in vacuum arc
Modeling of cathode spot crater formation and development in vacuum arc
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DOI：
10.1088/1361-6463/aa8db3
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发表时间：
2017-10
期刊：
影响因子：
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通讯作者：
X. Zhang;Lijun Wang;S. Jia;D. Shmelev
中科院分区：
文献类型：
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作者：
X. Zhang;Lijun Wang;S. Jia;D. Shmelev
建立了一个描述真空电弧阴极斑形成和发展的二维旋转轴对称模型。该模型包括流体动力学方程和传热方程，传热方程考虑了表面蒸发和焦耳加热。模型中的压力分布、能流密度分布、电流密度分布等参数均来自实验和其他研究者的工作。在此模型中，阴极斑点保持30 ns，在此期间，所有参数都是固定的。模拟结果表明，当能流密度为1.5 ~ 3 × 1012 W，放电电流为1-6 A，气压为1-3 × 108 Pa时，弹坑半径为1.4-4.1 μm，弹坑深度为1.4-2.1 μm，液态金属的速度为154-428 m·s-1，最高温度为2145-5342 K，位于半径为0.5-1.5 μm的区域。此外，在铬阴极上，最高温度较高，主要是因为较低的热导率。
A two-dimensional (2D) rotary axisymmetric model has been developed to describe the formation and development of cathode spot in vacuum arc. The model includes hydrodynamic equations and heat transfer equation which considers surface evaporation and Joule heating. Parameters used in this model, such as the distributions of pressure, energy flux density, and current density, come from experiments and other researchers’ work. In this model, cathode spot maintains 30 ns and during this time, all parameters are fixed. The simulation results show that when the energy flux density is 1.5–3 × 1012 W, discharge current is 1–6 A and the pressure is 1–3 × 108 Pa, the crater radius is 1.4–4.1 µm, the crater depth is 1.4–2.1 µm, the velocity of liquid metal is 154–428 m s−1 and the maximum temperature is 2145–5342 K which is located in the area with radius 0.5–1.5 µm. Besides, on the chromium cathode, the maximum temperature is higher mainly because of the lower thermal conductivity.