基于水平集法(Level set method),提出了一种处理三相流问题的计算方法.计算了钢-渣-气三相流条件下气泡在钢渣界面的行为,考察了不同大小的气泡穿过钢渣界面时的拓扑变化以及导致钢渣界面流场的变化,初步分析了大气泡上浮对卷渣的影响.计算结果表明,气泡直径从0.1~3mm,上浮过程中变形程度随直径的增大而愈发剧烈,钢渣界面处的流场差异也随之增大,可能成为卷渣的原因之一.
Liquid metal flow behavior in round strands continuous casting under intermittently reversing direction electromagnetic stirring was measured by ultrasonic Doppler velocity-meter in a physical simulation system in order to investigate the effects of time interval(t_i)of periodically reversed magnetic field on the spatial and temporal flow.The results show that under electromagnetic stirring with direction reserved magnetic field,there's a periodically change of the metal flow velocity and rotation direction with the periodically direction changing of the magnetic field.From both the experimental and mathematical model calculation results,it is found that when t_i is nearly equal to the time required for the metal flow speeding to the maximum velocity from still and decreases to zero again,there is a critical value of the rate of dynamic pressure,which means the wash effect of the liquid metal flow.On this point,rate of dynamic pressure was proposed to be a criterion for optimization the processing of electromagnetic stirring.
