黏性流体中单气泡的运动特性

采用高速CCD成像技术实验测定了单个气泡在水及不同黏度甘油水溶液中的形变特性及上升终速度.结果表明,随着液相黏度的增加,小气泡均能呈良好球形,而大气泡则由类似椭球形的不规则形状逐渐向球帽形转变;气泡的周期性振荡趋于平缓,气泡上升终速度降低.提出了计算气泡上升终速度的关联方程,其预测结果与实验值吻合良好.

The Motion Characteristics of a Single Bubble in Stagnant Highly Viscous Liquids

The deformation characteristics and terminal velocity of a single air bubble rising freely in stagnant water and glycerol aqueous solutions with various viscosity were measured by a high speed charge coupled device (CCD) camera. The results show that, with the liquid viscosity increases, the small bubbles retain spherical shape well, while the large bubbles change gradually from the irregular ellipsoid to the form of spherical cap, the periodical oscillation and the bubble terminal velocity decreases. A correlation of the bubble terminal velocity was proposed and the predicted values are in good agreement with the experimental data.