中文摘要：

为了分析气泡与铝熔体间的相互作用及汽液两相流动特性,提出准三维模型,即用多重参考系法模拟横向桨叶平面,用边界条件模型模拟纵向平面的搅拌过程,并将两种方法进行耦合;应用双流体模型模拟气液两相流场,标准k-ε湍流模型模拟液相流场的湍流效应。计算结果表明,最大周向速度在桨叶端部附近,桨叶上下方,各形成一个回流区,气体射流作用下,流场内旋涡较强;平均含气率随着气体流率及桨叶转速的增大而增大。

英文摘要：

Numerical simulations were carried out to understand the interaction between bubble and aluminum melt,as well as the behavior of gas-liquid two-phase flow.A quasi three-dimensional model was proposed,in which the flow field in the vessel horizontal section through the impeller was computed using Multiple Reference Frame（MRF） method and that in the vertical section through the axis of the vessel was calculated using Impeller Boundary Condition（IBC） method.Two-dimensional computations for the two flow fields were performed separately and coupled each other using the two-fluid approach to predict the gas-liquid flow in the stirred vessel.A standard k-εmodel was adopted to account for the turbulence effect of the liquid flow.Numerical simulation results showed that the tangential velocities close to the impeller tip were the highest.A large circulation zone was formed just above the impeller,while a smaller one was just below the impeller.There were strong vortexes under the action of gas injection.Gas content increased with the increase of impeller speed and gas flow rate.