连铸结晶器内瞬态流场的大涡模拟

Large Eddy Simulation of Transient Flow Field in Continuous Casting Mold

建立了基于同位网格的结晶器内流场与温度场耦合计算的数学模型,并采用大涡模拟的湍流模型对结晶器内的瞬态流动进行研究。该模型适用于形状不规则的六面体网格。使用滞后修正的QUICK格式改进了对流项的离散格式,提高了程序在高雷诺数和不规则网格计算条件下的稳定性。使用块结构化网格对计算区域进行了剖分,对结晶器内瞬态流场进行了模拟,结果表明流场具有不对称性和不稳定性,水口射流存在周期性的摆动,上回流区位置和自由表面波高周期性变化,并且这些非稳态现象之间存在相互关联。

A 3-D mathematical model based on collocated grid is built in order to investigate the transient flow in the continuous casting mold using large eddy simulation. The model can perform the spatial discretization for non-orthogonal hexahedral elements of mesh. QUICK scheme with deferred correction is adopted when discretizating the convection term in momentum equation in order to increase the stability of the code. Block-structured grid is adopted when meshing the computational domain. The transient flow field in the mold is investigated. The results indicate that the flow is unsteady and asymmetric. The nozzle jet swings periodically, and the upper recirculation zone center as well as the wave height change periodically. These transient phenomena are interrelated.