曳力模型对模拟鼓泡塔气含率的影响

引言 鼓泡塔由于其良好的传热、传质特性而被广泛用于化工、生物制药、冶金等领域.近年来,计算流体力学(CFD)越来越多地被应用于研究鼓泡塔内部复杂的流体力学状态.然而,如何合理地描述气液相间作用及湍流模型是CFD模拟能够准确复现鼓泡塔内复杂流动状态的关键和难点.

Effect of drag models on simulation of gas hold-up in bubble columns

A transient two-phase and three-dimensional computational fluid dynamics (CFD) simulation within the Eulerian framework has been carried out to investigate the influence of drag models on the radial gas hold-up profile of a bubble column. The effect of the sparger modeling is investigated as well. It can be concluded that:(1)the approximate modeling method for the sparger in this work is capable of reasonably predicting the radial gas holdup profile; (2)the CFD simulation with the Tomiyama’s drag model differs little from the Ishii-Zuber drag model at the low superficial velocity, while at the high gas velocity, the former leads to an over-prediction of the gas hold-up profile; (3)the correction factor of drag coefficient has a larger influence on the radial gas holdup profiles for high superficial gas velocity than low velocity.