三维非轴对称直流电弧射流过程数值模拟

Numerical Simulation of 3D Non-axisymmetric DC Arc Jet Process

基于磁流体动力学(MHD)理论,建立了三维非轴对称电弧射流流动-传热-电磁耦合模型,对直流电弧的流动、传热、电磁之间存在着的耦合过程进行了分析,模型计算结果与已有的文献数据结果进行了比较,结果吻合较好.采用有限体积法对电弧射流的温度场、流场以及电磁场进行耦合数值求解,研究了电弧在时间和空间上演变过程炉内温度场、流场的分布.输入电流为2160 A时,电弧最高温度达到20000 K,最大射流速度达到1600 m/s.电弧从阴极到阳极的射流形态呈现螺旋偏转,电弧的温度场、流场分布在时间和空间上发生剧烈变化,这和文献报道的二维轴对称直流电弧模型得出的结果有明显区别.研究结果可进一步加深对直流电弧炉的起弧、偏弧以及冶炼过程的理解,对研究直流电弧形态的变化规律和电弧炉内传热过程有一定的实际指导意义.

Based on the theory of magnetohydrodynamics(MHD),a three-dimensional non-axisymmetric arc jet flow-heat transfer-electromagnetic coupling model was established and the coupling process between the flow,heat transfer and electromagnetic of the DC arc was analyzed.The results of the model calculation were compared with the existing literature data,and they are in good agreement.The temperature field,flow field and electromagnetic field of arc current were coupled numerically by finite volume method and the distribution of temperature field and flow field in furnace in the process of arc evolution in time and space was studied.With an input current of 2160A,the arc reached a maximum temperature of 20000K and a maximum flow speed of 1600m/s.The jet form of the arc from the cathode to the anode presented a spiral deflection phenomenon and the temperature field and flow field distribution of the arc change drastically in time and space.This is obviously different from the results obtained by the two-dimensional axisymmetric DC arc model reported in the literature.The research results provide an insight into the arc starting,partial arc and smelting process of the DC electric arc furnace and have practical guiding significance for the study of the change law of the DC arc shape and the heat transfer process in the electric arc furnace.