中文摘要：

等离子弧焊喷嘴孔径对熔池影响极大,合理的喷嘴孔径是获得良好焊接质量的前提。根据磁流体动力学理论建立压缩等离子弧焊电弧的数学模型,采用ANSYS软件对焊接电流100 A时不同约束喷嘴孔径的三维稳态等离子焊接电弧进行数值模拟,获得了其焊接电弧的温度分布、电弧轴线上等离子速度分布、阳极表面径向压力和热通量的分布形态。结果表明,约束喷嘴孔径与电弧温度、等离子速度、电弧压力和热通量成线性关系,为不同焊接工件和焊接要求下喷嘴结构设计提供了理论依据。

英文摘要：

Reasonable nozzle diameter is the premise of obtaining good welding quality, because nozzle diameter of the plasma arc welding has a great influence on weld pool. The mathematical model of plasma arc welding was established according to the theory of magnetic fluid dynamics. The distrbutions of arc temperature, plasma velocity on arc axis, radial pressure and heat flux on the anode surface were obtained by using ANSYS soft ware to simulate the 3D steady plasma welding arc of different constrained nozzle diameter at welding current 100 A. The results show that there is a linear relationship between the diameter of the constrained nozzle and the temperature, plasma velocity, pressure and heat flux of arc, which provide a theoretical basis for the design of nozzle structure to meet different work-piece and welding requirements.