连铸结晶器中三维紊流场的层流等效模型

INITIAL DEVELOPMENT OF LAMINAR EQUIVALENT MODEL FOR 3 DIMENSIONAL TURBULENT FLOW IN THE CONTINUOUS CASTING MOLD

在揭示了板坯连铸结晶器中三维紊流流场和紊流粘性系数分布规律的基础上，提出了分区选定有效粘性系数的层流等效模型．计算表明，所建立的模型可获得定量和定性上与Ｋ－ε两方程紊流模型基本一致的流场，但大大简化了计算；在计算精度基本上不降低的条件下，可大幅度降低计算成本．文章采用流动与温度场非耦合方法，将凝固壳内的区域作为流场计算域，考虑了凝固壳厚度分布对流场的影响，使该方法更为合理地用于连铸结晶器中流动与凝固问题解析．同时。

The laminar equivalent model(LEM) with different effective viscosity in different subregions has been developed based on determination of turbulent viscosity distribution in the mold of continuous slab casting. It is shown that LEM can get the reasonable and agreeable results compared with the standard K ε turbulent model. However, the computation procedure can be simplified, and the computational cost reduces significantly without reduction of accuracy. The method of fluid flow which is uncoupled with heat transfer, has been employed, and the region surrounded by the solidified shell is regarded as computational zone.Thus,the influence of thickness distribution of the shell on the fluid flow is taken into account. The method developed in the present paper is efficient to get more realistic flow field and reasonable to take it into the consequent thermal analysis. In addition, the weakness existing in the original laminar equivalent model is pointed out.