静磁场对熔融液滴振荡变形影响的相场模拟

摘要

In order to study the characteristics of oscillatory process of a molten silicon droplet under static magnetic field,the phase field method was adopted to numerically simulate the interface oscillation and internal fluid convection of a molten silicon droplet. The influence of an axial static magnetic field on the internal convection and interface oscillation of a molten silicon droplet with an initial shape of the second-order Legendre function was analyzed. The numerical result exhibits that the shrink of the droplet under static magnetic field is faster than that without magnetic field. The static magnetic field suppresses the fluid convection inside the droplet. As the imposed magnetic field intensity increases from 0 to 0. 9 T,the maximum values of stream function reduce from 0. 57 to 0. 08,and the internal convection and interface oscillation are weakened gradually. Under magnetic field,the ratio of long-axis to short-axis of droplet quickly tends to 1. However,the magnetic field has almost no influence on oscillation frequency of droplet. The investigation indicates that the phase-field modeling can effectively simulate the interface oscillation and internal convection of the molten droplet even with high density.%为了解静磁场作用下熔融液滴振荡过程的特征，采用相场法数值模拟了硅熔体液滴的界面变形和内部对流过程，分析了轴向静磁场对初始形状为二阶Legendre函数硅熔体液滴界面振荡和内部对流的影响．研究表明：施加静磁场以后，液滴收缩较快，说明静磁场抑制了液滴内部流动；随着磁场强度从0增加至0．9 T，流函数最大值从0．57减小到0．08，液滴的界面振荡和内部对流逐渐减弱，液滴的长短轴比更快趋近于1，但磁场对液滴的振荡周期没有明显影响，显示相场法能够模拟密度较大的熔融液滴的界面振荡和内部对流过程．