关键词: 计算流体力学, 表观气速, 气含率, 液相速度

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