幂律流体中平行上升双气泡间相互作用研究

摘要

The interaction between double parallel rising bubbles in non-Newtouian power-law fluid was studied through volume of fluid (VOF) simulations. The results show that the contributions of the shear thinning effect and flow structure around bubbles to the interaction between bubbles decrease respectively with the increase of the distance between bubbles. The interaction between double parallel bubbles is mainly dominated by the vortices in the fluid between bubbles. Parallel coalescence between bubbles occurs when the initial distance is small, while the behavior of double bubbles becomes interacted parallel rising with the increase of the initial distance. Mter the initial distance is beyond a certain value, the behavior of double bubbles is much close to the single bubble rising process without interaction. For the parallel rising process without coalescence, the double bubbles have the same characteristics of deformation with the single bubble rising process, while the rising velocity of the former is less than that of the latter.%采用流体体积(VOF)法对非牛顿幂律流体中平行上升双气泡间相互作用进行了模拟研究.结果表明:剪切变稀效应及气泡周围流场结构对气泡间相互作用的贡献分别随着气泡间距增大而减小,气泡间相互作用主要受气泡间流体涡旋结构控制.当初始间距很小时,气泡平行聚并发生;随着初始间距增大,双气泡行为转变为相互影响的平行上升;当初始间距增大到一定程度后,双气泡更接近于彼此无影响的平行上升过程.对于无聚并平行上升过程,双气泡表现出与单气泡上升过程相似的形变特征,而上升速度小于单气泡上升过程.