环形浅液池内热毛细对流的热力学特性

为了了解径向温度梯度作用下环形浅液池内硅熔体热毛细对流的热力学特性,利用有限差分法进行了非稳态三维数值模拟。液池外半径r0=50 mm,内半径ri=15 mm,深度为d=3 mm。结果表明,当温度梯度较小时,流动为稳定轴对称流动,系统总熵产较小;随着温度梯度的增加,流动将失去其稳定性,首先转化为径向脉动波,此时系统总熵产呈周期性变化;温度梯度再增加时,流动转化为热流体波,系统总熵产较大,但不再随时间变化。

THERMODYNAMIC CHARACTERISTICS OF THERMOCAPILLARY CONVECTION IN A SHALLOW ANNULAR POOL

In order to understand the thermodynamic characteristics of thermocapillary convection of the silicon melt in a shallow annular pool with the radial temperature difference, a series of unsteady three-dimensional numerical simulations was conducted using the finite-difference method. The outer wall radius r0=50 mm, the inner cylinder radius ri = 15 mm and depth d=3 mm. The simulation results indicate that the thermocapillary convection is stable axisymmetric flow and the total entropy generation is small at the small temperature difference. Two flow transitions occur with increasing the radial temperature difference. At first, the steady two-dimensional flow becomes radial pulse waves. In this case, the total entropy generation varies periodically with time. Then, the hydrothermal waves appear and the total entropy generation increases, but it is independent of the time.