牛顿流体中表面活性剂对浮力驱动的单液滴动力学行为的影响研究

研究了不同粒径单液滴在去离子水中和加入表面活性剂的去离子水中的形变、上升速度和曳力系数等动力学参数，液滴当量直径范围290mm

Effects of surfactants on the dynamic behavior of single buoyancy driven drops in Newtonian fluids

The shape, rise velocity and drag coefficient of a single drop, with diameters varying from 2.90 mm to 11.11 mm, rising in distilled water and in water contaminated with surfactants are discussed, where the drops have Reynolds numbers from 120 to 800. The primary role of the surfactant in the deformation of a drop and its effect on the terminal velocity and drag coefficient are considered. Results for aspect ratio, terminal velocity and drag coefficient are compared with the previous correlations of both bubble and drop motions in pure and contaminated systems. The results show that drops deformed markedly in the contaminated system and the deformation ratio decreased with the increase of E?tv?s number (Eo). A semi-empirical approach developed by Tomiyam, which considers the deformation ratios, gives a good prediction of the average terminal velocity of the drops. The minimum value of the drag coefficient was found at Re=360 which can be associated with the transverse oscillation of drops. The effect of the surfactants on the oscillation of the drops was investigated by using Fourier analysis.