Abstract: Computational fluid dynamics (CFD) was used to simulate the fluid mechanics behavior with four superficial gas velocities in the inner flow field of bubble columns. The internal distribution of overall gas hold-up and the change of liquid phase velocity in the shaft cross-section with time were analyzed. At different superficial gas velocities，local gas hold-up and liquid phase velocity radical distribution at different heights were compared. Overall gas hold-up increased quickly with time first and then stabilized. At the same height，local gas hold-up increased with increasing superficial gas velocity. When H/D<3，liquid phase showed single-phase circulation flow；when H/D=3，it showed dual-phase circulation flow，which was more complex.

Key words: computational fluid dynamic, superficial gas velocity, gas holdup, liquid phase velocity

摘要： 采用计算流体力学CFD软件对鼓泡塔内部4种表观气速下内部流场的流体力学行为进行模拟。分析了鼓泡塔内部整体气含率及轴截面处（X=0）液相速度随时间的变化情况；并且对比了在不同表观气速下局部气含率和液相速度在不同高度处的径向分布情况。模拟结果表明，随着时间的增大，整体气含率增大速度比较快，到达稳定时间，整体气含率不再增大。在同一高度处局部气含率随着表观气速的增大而增大。H/D<3时，液相循环流动表现为单相循环流；当H/D=3时，表现为双循环流，流型较单相复杂。

关键词: 计算流体力学, 表观气速, 气含率, 液相速度