The liquid-liquid interface evolution characteristic during droplets coalescence in the surrounding liquid is numerically studied taking no account of the influence of the gravity. The influences of viscosity ratio of internal and external fluids as well as the relative size and Oh number of the droplets on the coalescence process are analyzed. The results show that, three coalescence types are indicated in this numerical study. With the decrease of viscosity ratio and Oh, the droplet coalescence type transforms from coalescence with no pinch-off to coalescence with pinch-off. As the radius radio of the larger and smaller droplets decreases, the coalescence type transforms from “coalescence with single pinch-off” to “coalescence with double pinch-offs” or “coalescence with no pinch-off”. The liquid bridge radius increases slower under the less viscosity ratio and larger Oh due to the greater viscous resistance during coalescence process. The dimensionless pinch-off time of the neck decreases with the increase of the viscosity ratio and radius radio, and the decrease of Oh. And when viscosity ratio is greater than 10 and Oh is less than 0.01, the dimensionless pinch-off time changes little.

中文翻译：

---

液滴聚结过程中液-液界面演化的数值研究

在不考虑重力影响的情况下，对液滴在周围液体中聚结期间的液-液界面演化特性进行了数值研究。分析了内部和外部流体的粘度比以及液滴的相对大小和Oh数对聚结过程的影响。结果表明，该数值研究表明了三种合并类型。随着粘度比和降低喔，液滴的聚结类型从没有夹断的聚结转变为有夹断的聚结。随着较大液滴和较小液滴的半径射束的减小，聚结类型从“单捏聚结”变为“双捏聚结”或“无捏聚结”。由于在聚结过程中的更大的粘性阻力，在较小的粘度比和较大的Oh下，液桥半径的增加较慢。颈部的无量纲的夹断时间随着粘度比和半径半径的增加以及Oh的减小而减少。并且当粘度比大于10且Oh小于0.01时，无因次捏合时间几乎没有变化。