An Adaptive Micro/Macro Integrated Solidification Model and Experiments for Melt Flow, Microstructure Formation and Non-Equilibrium Kinetics

摘要-张 本文的工作是建立一个模拟柱状晶凝固的模型。 该模型将结合宏观传输现象和微观发展的数学描述。 由质量、动量和能量方程组成的输运方程将在适当的动力学约束下在宏观和微观两个层次上求解。 一个微观细胞模型，它考虑到熔体过冷和非平衡动力学将被开发来预测的形状，尺寸和间距的细胞。 采用网格聚类和迁移的数值方法将用于跟踪凝固前沿。 Bridgman凝固和单液滴凝固的实验将在瞬态和稳态条件下进行。 微观结构特性的测量将与预测结果进行比较。

Abstract - Zhang The proposed work is to develop a model to simulate columnar solidification. The model will incorporate mathematical descriptions of macroscopic transport phenomena and microscopic development. The transport equations composed of the mass, momentum, and energy equations will be solved at both the macroscopic and microscopic levels subject to appropriate kinetic constrains. A microscopic cellular model, which takes into account melt undercooliing and non-equilibrium kinetics will be developed to predict the shape, size, and spacing of cells. A numerical method that employs grid clustering and migration will be used to track the solidification front. Experiments for Bridgman solidification and single droplet solidification will be conducted under both transient and steady-state conditions. Measurements of the micro-structural characteristics will be compared with predicted results.