铸钢件凝固过程中自然对流引起的宏观偏析模拟

使用ＳＩＭＰＬＥＲ算法，基于体积平均的描述对铸件凝固宏观传输过程的温度场、溶质场、流场耦合模型进行了求解。应用此模型对铸钢件凝固过程进行了模拟，考察了自然对流对传热、传质的影响。结果表明，自然对流显著改变了糊状区等温经的形状与溶质浓度的分布，此模型定量地预测了铸件的宏观偏析，采用Ｓｕｚｕｋｉ判据，计算出了Ａ型偏析可能出现的位置。

QUANTITATIVE PREDICTION OF MACROSEGREGA-.TION FORMATION CAUSED BY NATURAL CONVECTION DURING SOLIDIFICATION OF STEEL CASTING

The modeling of full coupling of the temperature, concentration and velocity fields during solidification of castings is solved using the SIMPLER algorithm. The model is applied into the large steel casting to examine the effect of thermosolutal convection on the heat and solute transfer mations and further to predict the macrosegregation quantitatively. The natural convection dramatically alters the shape of the isotherms in muddy zone and the distribution of the solute. Suzuki criterion is applied to predict the presence of A-segregates.