Validation and Simulation of Cellular Automaton Model for Dendritic Growth during the Solidification of Fe–C Binary Alloy with Fluid Flow
Validation and Simulation of Cellular Automaton Model for Dendritic Growth during the Solidification of Fe–C Binary Alloy with Fluid Flow
复制标题
DOI：
10.2355/isijinternational.isijint-2015-573
复制
发表时间：
2016-04
影响因子：
1.8
通讯作者：
S. Luo;Wei‐ling Wang;Miao‐yong Zhu
中科院分区：
文献类型：
--
作者：
S. Luo;Wei‐ling Wang;Miao‐yong Zhu
在我们以前建立的二维CA-FVM模型的基础上，全面考虑了流体流动的凝固过程中溶质驱动的枝晶生长的传输现象和动力学条件，在此基础上进行了广泛的模型验证和进一步的模型应用。首先，对盖子驱动空腔的流型进行了很好的预测，并与经典的基准解进行了定量的比较，Re在100~3200之间。其次，对Fe-0.82wt%C合金在静态过冷熔体和对流过冷熔体中自由枝晶生长的数值模拟分别在较小的过冷度范围内与LGK预测和OseenIvantsov解符合得很好。经过详细的模型验证，对Fe-0.82wt%C合金等轴/柱状枝晶生长过程进行了数值模拟，结果表明，流体流动对枝晶形态和溶质分布有显著影响，并且随着流动Péclt数的增加，枝晶形态和溶质分布的不对称性越来越严重。在有流体流动的过冷熔体中，由于等轴枝晶的生长，溶质被从上游冲刷到下游，加速了上游尖端和垂直尖端的枝晶生长，抑制了下游尖端的枝晶生长。对于盖子驱动腔内柱状枝晶的生长，环流有利于枝晶主干边缘面向来流的侧枝，促进枝晶形态和溶质分布的不对称。
Based on our previous developed 2D CA-FVM model, where the transport phenomna and kinetics conditions of solute-driven dendritic growth occurred in the solidification process with fluid flow were totally taken into consideration, an extensive model validation and furhter model application are demonstrated here. Firstly, the flow pattern of the lid-driven cavity is well predicted and quantitatively coincides with the classic benchmark solutions, as Re is in the range of 100 to 3 200. Secondly, the numerical simulations of the free dendritic growth of Fe-0.82 wt%C alloy in the static undercooled melt and the convectional undercooled melt agree well with the LGK predictions in a relatively low undercooling range and the OseenIvantsov solutions, respectively. After the detailed model validation, numerical simulations of the equiaxed/ columnar dendritic growth of Fe-0.82 wt%C alloy with fluid flow have been carried out and the results show that the dendrite morphologies and solute profiles are significantly affected by the fluid flow and the asymmetries of the dendrite morphologies and solute profiles become more and more serious with the increase of the flow Péclet number. For the equiaxed dendritic growth in the undercooled melt with fluid flow, the solute is washed away from the upstream to the downstream region, resulting in accelerating the dendritic growth of the upstream tip and perpendicular tip and inhibiting the dendritic growth of the downstream tip. For the columnar dendritic growth in the lid-driven cavity, the circulation flow facilitates the side branch of the dendrite trunk edge, which faces to the incoming flow, and promotes the asymmetrical dendrite morphology and solute profile.