【摘要】 研究鼓泡塔内涡的结构及其演变规律,对揭示反应器内传热、传质性能具有重要意义．用大涡模拟(LES) 方法对中心进气式鼓泡塔内瞬态流动性能进行了模拟研究,结果表明,增大气速可使涡结构剧烈变化,增加液体黏度限制了涡尺度的发展,减少气泡尺寸加快了涡的变化速率．模拟结果与实验值吻合良好,大涡模拟方法能有效地揭示鼓泡塔内不同尺度的涡结构及其发展变化规律．更多还原

【Abstract】 Bubble column reactors are widely used in chemical industry, hydrometallurgy, biochemical engineering and wastewater treatment, etc. However, to characterize the detailed multiphase turbulent flow in these reactors is far beyond the present measuring techniques. In this paper, the gas-liquid two-phase turbulent flow in a centrally aerated bubble column reactor is studied by large eddy simulations (LES). Simulated results agree well with the experimental data for the bubble swarm motion and gas hold-up distribution. The formation process of gas-liquid turbulence transient structures and its evolvement are investigated by LES, which reflect the influences of different parameters on the vortex structures, e. g. , increasing the gas velocity can intensify the change of the vortex structures, increasing the liquid viscosity can inhibit the evolvement of the vortex scale, decreasing the bubble size can accelerate the variation of the vortexes.更多还原