基于FTM的不同初始形状同轴双气泡上升直接数值模拟

多气泡运动在各个工程领域广泛存在。为更好的研究不同形状的多气泡上升过程，采用界面追踪法（FTM, Front Tracking method）对四种具有不同初始形状的双气泡上升情形进行二维数值模拟。模拟结果表明，两竖直分布的气泡上升时，上部气泡的尾流会使下部气泡的速度更快；气泡的初始形状对气泡上升的速度和变形都有影响，圆形气泡相较于椭圆形气泡，上升速度更小；下部气泡为椭圆形时，上部气泡的变形更大。

Direct Numerical simulation of two coaxial bubbles rising with FTM

Multi bubbles motion exists widely in various engineering fields. Two-dimension simulation for four cases with different initial shape is carried out with FTM to make more deeply research about rising process of bubbles in different shapes. The results show that the wake by up bubble is the reason why the velocity of low bubble is bigger than up when two vertical bubbles rising; initial shape of bubble has effect on deformation and rising velocity; the more circular, the smaller of its velocity. The deformation of up bubble is lager when low is ellipse.