大涡模拟搅拌槽中的液相流动

Large eddy simulation of turbulent flow in a stirred tank

采用大涡模拟湍流模型对有档板的Rushton桨搅拌槽进行了数值模拟研究。控制方程采用控制容积法进行离散,对流项用三阶QUICK格式,扩散项是二阶中心差分。压力-速度耦合方程在交错网格上采用SIMPLE算法进行求解。小尺度流动的模化采用动力学(dynamic)亚格子模型。搅拌桨与档板之间的相互作用采用改进的内外迭代法进行处理。计算结果和文献值吻合得很好。

The turbulent flow field generated in a baffled stirred tank with a Rushton turbine was computed by large eddy simulation （LES）. The dynamic subgrid model was used to model the unresolved scales. The spatial discretization of the governing equations was performed on a cylindrical staggered grid. The momentum and continuity equations were discretized by the finite difference method with a third order QUICK scheme for the convective terms. The interaction between rotating impeller and static baffles was accounted for through the improved inner-outer iterative algorithm. The phase-resolved predictions were compared with the experimental data of references and good agreement was observed both for mean resolved fields and turbulence quantities.