勾形磁场对分离结晶法生长CdZnTe晶体过程中液层热毛细-浮力对流的影响

Effect of Cusp Magnetic Field on Thermocapillary-buoyancy Convection of Fluid Layer During the Growth Process of CdZeTe Crystal by Detached Solidification

借助数值模拟手段研究了常重力条件下分离结晶法生长Cd Zn Te晶体过程中液层热毛细-浮力对流,探讨了不同勾形磁场强度和狭缝宽度对流动的影响。计算选取液层的高径比A为1,狭缝宽度S分别为0.05、0.075以及0.1,磁场Hartmann数分别为45、90及135。结果表明:勾形磁场能够对液层内热毛细-浮力对流起到抑制的作用,且随着磁场强度的增加,流动失稳的临界Marangoni数增大;随着狭缝宽度S的增大,液层内部流动减弱。

Thermocapilary-buoyancy convection of fluid layer in detached solidification of Cd Zn Te under the condition of gravity was studied by numerical simulation. The effects of cusp magnetic field intensity and gap width on the flow were discussed. In the calculation,the height-radius ratio of melt A adopted 1;the gap width S adopted 0. 05,0. 075 and 0. 1; the Hartmann number was 45,90 and 135. The calculation results show that the cusp magnetic field has an inhibitory effect on the thermocapillarybuoyancy convection and the critical value of Marangoni number is increased with the Hartmann number increases; with the increase of gas gap,the velocity decreases due to the decrease of temperature gradient.