旋转和磁场耦合作用对振荡Marangoni-热毛细对流的影响

Coupling effect of pool rotation and axial magnetic field on Marangoni-thermocapillary convection

双向温度梯度下环形浅液池内的硅熔体中会形成Marangoni-热毛细对流,当其中一个温度梯度超过临界值时,流动会变成三维振荡流动,同时,自由表面上的辐射换热还会使流动变得更加复杂。为了寻找有效削弱三维振荡流动的方法,通过三维数值模拟分别研究了只有液池旋转、只有轴向磁场和两者耦合时环形浅液池内的Marangoni-热毛细对流。结果表明,液池旋转和轴向磁场都可以对Marangoni-热毛细对流产生一定的削弱作用,而两者的耦合会相互促进。考虑到磁场的负面效果,在尽量小的磁场强度下获得了维持轴对称稳态流动的最佳参数组合。

There is Marangoni-thermocapillary convection of silicon melt in annular shallow pool submitted to bidirectional temperature gradients.When either of them exceeds the critical value,the flow becomes a three-dimensional oscillatory convection,which becomes complicated by thermal radiation on the free surface.In order to find an effective method to suppress the three-dimensional oscillatory convection,a series of three-dimensional numerical simulations,considering only pool rotation or only axial magnetic field or their coupling,are carried out.It is found that both pool rotation and axial magnetic field can suppress Marangoni-thermocapillary convection to a certain extent,and their combination can promote the suppression further.To avoid the negative effect of the magnetic field,the optimal parameters to maintain axisymmetric steady flow is obtained under the minimum magnetic field intensity.