方坯连铸凝固传热的复合数值模拟

根据连铸机特点和铸流场特性，在拉坯方向上将整个铸流长度划分为上部计算域和下部计算域。对于铸坯温度场的数值模拟，上部计算域充分耦合钢液对流对传热的影响，采用了三维稳态流动传热耦合模型；下部计算域则将铸流场对传热的影响考虑为有效导热系数，并忽略拉坯方向上的传热效果，采用了二维非稳态有效导热系数模型。计算过程和结果表明，采用此复合模拟方法保证了数值模拟的准确性并降低了仿真程序的计算成本。

Hybrid Numerical Simulation for Heat Transfer and Solidification of Billet Continuous Casting

Based on characteristics of concaster and strand field, the total length of strand along casting direction is divided into two parts - upper and lower calculated part. To numerically simulate temperature field of billet strand, a 3\| dimensional steady fluid flow transfer coupled model in upper section is adopted to sufficiently couple up the effect of liquid steel convection on heat transfer; and a 2\| dimensional unsteady effective thermal conductivity model is used in lower section where the effect of fluid flow on heat transfer is considered as effective thermal conductivity and the heat transfer effect along casting direction is neglected. The calculation process and results show that to adopt the hybrid numerical simulation method ensures accuracy of numerical simulation and reduces calculated cost of emulator program.