方截面鼓泡床气液两相瞬态数值研究

在双流体模型中引入界面浓度输运方程,利用界面浓度和气泡平均Sauter直径模化各相间作用力。引入一附加 湍动能输运方程模化气泡诱导引起的液相湍流。利用该模型对方截面鼓泡床内气液两相流进行三维瞬态数值模拟。计算结 果表明该模型能较好得模拟方截面鼓泡床内气液两相流时均和瞬态流动特征。

MODELLING AND SIMULATION OF THE DYNAMIC FLOW BEHAVIOUR IN A RECTANGULAR BUBBLE COLUMN

Interfacial area transport equation has been combined to a classical hydrodynamic two-fluid model to investigate the operation of a rectangular bubble column. Interfacial forces are calculated based on interfacial area concentration and average Sauter diameter. Turbulence is modeled by an extra transport equation for bubble-induced turbulence, which allows for the inclusion of experimentally verified anisotropic. The numerical simulations successfully predict both the time-averaged and the dynamics flow behavior, which are dominated by the irregular movements of the bubble plume and the vortical structures in the liquid phase. The frequency of velocity fluctuations and Sauter diameter are investigated: frequency decreases with the superficial gas velocity. Averaged Sauter diameter increases with superficial gas velocity and an equilibrium Sauter diameter appears when the superficial gas velocity increases.