采用FLUENT6.3软件对搅拌器内的气液流动进行了数值模拟。自由液面的捕捉采用VOF（volume of fluid）方法，利用RNG k-ε紊流模型使气液两相流时均方程组封闭，速度与压力的耦合方程组利用半隐式SIMPLE（Semi-Implicit Method for Pressure-Linked Equations）算法结合多参考系法求解，对单层涡轮在不同安装高度时搅拌槽内的流场结构、含气率分布、混合时间及功率准数进行了研究。模拟结果表明: 在通气量和转速一定的情况下，转轮安装高度在中间位置时搅拌槽内含气率最高，混合时间最小，槽内液体的平均速度最大，更有利于搅拌槽内气液两相之间的混掺，随着安装高度的增加搅拌槽所消耗的功率准数减小。
英文摘要:
Based on the FLUENT6.3, the gas-liquid two-phase flow was simulated. The VOF (Volume of fluid) method was applied to track the flow surface. The gas-liquid two-phase time-averaged equations were closed with turbulence model. The coupling velocity and pressure equations were solved with the SIMPLE（Semi-Implicit Method for Pressure-Linked Equations）algorithm along with the multi-reference method. In a stirred vessel equipped with one impeller, the gas holdup distributions, liquid phase velocity flow fields, mixing times and power numbers at different installation height of the impeller are studied, which shows that with the same inlet ventilation volume and the same rotation speed of impeller under the installation of impeller at middle water height, the predicted total gas holdup value is maximum, the mixing time of liquid is minimum and the averaged velocity is maximum，which is good for the mixing of the gas and liquid in the mixing tank. With an increase of the installation height of impeller, the power rating used by the stirred tank decreases.