铸铁水平连铸中圆坯凝固过程的数值模拟

将铸铁水平连铸中圆坯凝固过程的整个传热系统作为模拟对象，采用自由热收缩模型计算铸坯与结晶器的界面传热系数，从非稳态传热的角度并按照柱坐标系中二维传热的方式进行铸坯凝固过程的数值模拟，在数值计算中，采用静、动坐标系相结合的方法，使铸坯传热的控制方程得以简化且便于耦合处理结晶器与铸坯的温度场计算，由此确立的模拟方法可用于模拟不同尺寸的圆坯在各种工艺条件下的凝固过程。

NUMERICAL SIMULATION ON SOLIDIFICATION PROCESS OF HORIZONTALLY CONTINUOUSLY CAST ROUND IRON BARS

An universal method of numerical simulation on solidification process of horizontally continuously cast round iron bars is developed, in which transient heat transfer equations are used and longitudinal heat conduction is taken into account. The interfacial heat-transfer coefficient between iron bar and graphite sleeve, which is determined by using a free thermal contraction method, is used as a boundary condition, and the whole system including iron bar, graphite sleeve and water cooled jacket is considered in heat transfer calculation. In the calculation, a stationary coordinate system and a moving one are used for graphite sleeve and iron bar respectively, in order to make the heat transfer equation applied in iron bar be simplified and the coupled calculation of temperature fields in both iron bar and graphite sleeve convenient. The developed method can be used to simulate solidification process of the iron bars with different diameters under different technological conditions.