复合磁场作用下板坯结晶器内流场与温度场的数值模拟

Numerical simulation of fluid flow and temperature field of slab under composite magnetic field

提出了一种用于板坯流动控制的复合磁场,在弯月面附近施加电磁搅拌,在浸入式水口附近施加电磁制动,以形成对流场及温度场的复合控制.使用Fluent软件建立了结晶器内复合磁场作用下的钢液流场与温度场三维计算模型.通过与无磁场作用的钢液流动及传热行为进行对比,揭示了复合磁场对结晶器钢液流场和温度场的作用规律.结果表明:复合磁场在一定电磁参数条件下可以减弱水口出流主流股对窄面的冲击,冲击位置处的最大湍动能值降低62%,减少下返流侵入深度;弯月面附近得到了充分的搅拌,结晶器壁面附近的钢液流速增强30%,有利于凝固前沿的冲刷;同时结晶器壁面附近温度提高了1~2 K,均匀了结晶器内温度分布.结晶器电磁搅拌与电磁制动的流场控制优势得以同时发挥.

In this paper,a type of composite magnetic field for flow control in slab mold is proposed.Electromagnetic stirring(EMS)is imposed near the meniscus,and electromagnetic braking(EMBr)is carried out near the outlet of the submerged entry nozzle(SEN),simultaneously to form a composite control of the flow field in the mold.A three-dimensional model of mold is established,the software Fluent is used to solve the flow field and temperature field.The results in composite magnetic field are compared with those in without magnetic field and the principles of the flow field and temperature field distribution under the composite magnetic field are summarized.It shows that composite magnetic field under certain electromagnetic parameters can obtain both merits of EMS and EMBr,the impact of the main stream on the narrow surface is weakened,the maximum turbulent kinetic energy value at the impact location is decreased by 62%,downward flow strength is reduced,the velocity of molten steel near the mold wall is increased by 30%,the meniscus is well stirred,solidification front is effectively scoured and the temperature is raised by 1~2 K.