电渣重熔过程流场和温度场的数值模拟

Numerical Simulation of Flow and Temperature Fields in Electroslag Remelting Process

使用有限元分析软件ANSYS计算电渣重熔外部磁场,将外部磁场数据通过C语言编写的数据转换程序导入流体计算软件FLUENT中,应用MHD模型求解磁流体运动产生的附加磁场传输方程,并将电磁场产生的洛伦兹力和焦耳热作为源项分别加到动量方程和能量方程中,从而建立电渣重熔三维流动、传热数学模型。计算结果表明:由于磁流体运动引起的附加磁场很小,可以忽略不计;渣池内流动主要受洛伦兹力的影响,热浮升力只对近壁面处流动产生影响;电磁场产生的焦耳热在渣域远远大于金属域,渣池大量的焦耳热足以熔化自耗电极,形成稳定的金属熔滴不断滴落;非稳态计算在1 840 s之后在温度场接近稳定,金属熔池形成稳定的凝固边界。

Imposed magnetic field is obtained by finite element software ANSYS for electroslag remelting process. These magnetic data are changed to MHD data format by the program developed by using C language. The induced magnetic field due to fluid motion is solved by FLUENT and MHD model with the imported external magnetic field data. The Lorentz force and the Joule heating as MHD results are added into momentum equation and energy equation as additional source terms. 3 D flow and heat transfer models are established for electroslag remelting process. The calculated results show that the induced magnetic field is very small compared with external magnetic field,and may be neglected. Slag field vortices flow is mainly influenced by the Lorentz force and the buoyancy force only influences the flow near the wall. The Joule heating in slag field is much larger than that in metal field,and is enough for remelting electrode and droplets forming. The temperature field is stable and solidification interface is no more changed after 1 840 s.