Castrejón-Pita J R, Castrejón-Pita A A, Hinch E J, Lister J R, Hutchings I M
Department of Engineering, University of Cambridge, Cambridge CB3 0FS, United Kingdom.
Phys Rev E Stat Nonlin Soft Matter Phys. 2012 Jul;86(1 Pt 2):015301. doi: 10.1103/PhysRevE.86.015301. Epub 2012 Jul 5.
The final stages of pinchoff and breakup of dripping droplets of near-inviscid Newtonian fluids are studied experimentally for pure water and ethanol. High-speed imaging and image analysis are used to determine the angle and the minimum neck size of the cone-shaped extrema of the ligaments attached to dripping droplets in the final microseconds before pinchoff. The angle is shown to steadily approach the value of 18.0 ± 0.4°, independently of the initial flow conditions or the type of breakup. The filament thins and necks following a τ(2/3) law in terms of the time remaining until pinchoff, regardless of the initial conditions. The observed behavior confirms theoretical predictions.
针对纯水和乙醇，对近无粘性牛顿流体滴状液滴的夹断和破裂的最后阶段进行了实验研究。利用高速成像和图像分析来确定夹断前最后几微秒内附着在滴状液滴上的韧带的锥形极值的角度和最小颈部尺寸。结果表明，该角度稳定地趋近于18.0±0.4°的值，与初始流动条件或破裂类型无关。无论初始条件如何，细丝在夹断前剩余时间方面遵循τ(2/3)定律变细并形成颈部。观察到的行为证实了理论预测。
