电弧作用下浸铜碳材料烧蚀过程的数值模拟

Numerical Simulation of Ablation Process of Copper-Impregnated Carbon Material under Arc Action

电弧侵蚀是影响浸铜碳材料使用寿命的关键因素之一。首先,将电弧等效为高斯分布的热源,基于热传导理论和流体理论,考虑材料相变,探讨了浸铜碳材料的温度变化过程、材料发生相变的熔化-凝固过程;接着,分析了液体表面张力是烧蚀熔池流动的主导因素,影响材料内部的温度分布;最后,考虑浸铜碳材料的蒸发升华,求解了材料表面的形貌及温度分布。仿真研究结果表明:电弧作用下,浸铜碳材料相变形成熔池域,电弧熄灭后,熔池域继续扩大一段时间才逐渐减小;熔池表面散热较内部散热快。液体表面张力导致熔池表面流动,进而加快材料表面散热。电弧持续作用下,浸铜碳材料表面逐渐形成烧蚀熔池和烧蚀凹坑。烧蚀熔池的半径和深度随着时间的变化近似线性增长,材料表面烧蚀凹坑处的温度最高,其值在碳的升华温度附近波动。

Arc erosion is one of the key factors that affect the service life of metal-impregnated carbon material.First,the arc was equivalent to a heat source of Gauss distribution.Based on the heat conduction theory,fluid dynamics,the temperature change of copper-impregnated carbon material and melting-solidification process of material phase transition were calculated.Then,the effects of liquid surface tension of molten pool on the temperature and velocity of copper-impregnated carbon material surface were analyzed.Finally,considering the evaporation and sublimation of copper-impregnated carbon material,the surface morphology and temperature distribution were solved.The simulation results show that the temperature of the copper-impregnated carbon material increases rapidly with arc,resulting in a pool domain formed by the phase transition.After the arc is extinguished,the pool area continues to expand for a period of time and then decreases gradually.The surface of molten pool dissipates heat faster than the interior.The surface tension of the liquid causes the flow of the melting pool surface,thereby accelerating the heat dissipation.Under the continuous action of arc,the surface of copper-impregnated carbon material gradually forms a molten pool and an ablation pit.The radius and depth of the molten pool increase linearly with time.The temperature of the ablation pit on the material surface is the highest,and its value fluctuates near the sublimation temperature of carbon.