Modeling flowability of mushy zone with a hybrid model utilizing coherency solid fraction
Modeling flowability of mushy zone with a hybrid model utilizing coherency solid fraction
复制标题
利用相干固体分数的混合模型对糊状区域的流动性进行建模
DOI：
10.1016/s0921-5093(98)00481-x
复制
发表时间：
1998
期刊：
影响因子：
6.4
通讯作者：
M. D. Mat
中科院分区：
文献类型：
--
作者：
O. Ilegbusi;M. D. Mat
本文报道了在相变问题中发展糊状区混合模型的进展情况。糊状区在相干点以下被模拟为非牛顿半固体介质，之后被模拟为多孔介质。通过一种普通二元合金在二维矩形腔内的凝固实验，验证了该模型的有效性。预测包括流场和热场的时间演化以及粘性、速度分量和温度的空间分布。预测结果与传统的多孔介质模型具有可比性。预测的最大粘度等值线呈“岛”状，这表明该混合模型有可能代表枝晶间流动。相干点的选择对糊状区的速度、温度梯度和大小有很大的影响，特别是在腔的底部。
This paper reports on the progress made in the development of a hybrid model of the mushy region in phase change problems. The mushy region is modeled as a non-Newtonian semi-solid medium below the coherency point and a porous medium thereafter. The validity of the model is tested on the solidification of a generic binary alloy in a 2D rectangular cavity. The predictions include temporal evolution of the flow and thermal fields and spatial distribution of the viscosity, velocity components and temperature. The predicted results are comparable with those of the conventional porous medium model. The predicted maximum viscosity isopleths appear as ‘islands’ suggesting that the hybrid model has potential to represent interdendritic flow. The choice of the coherency point has a profound effect on the velocity, thermal gradient and size of the mushy region, especially at the bottom of the cavity.