Understanding the shear breakup in jet flows and the formation of droplets from ligaments is important to determine the final droplet size distribution (DSD). The initial droplet size, which affects the final DSD, is considered to be generated by the shear breakup. Large eddy simulation (LES) was performed to investigate the shear breakup in liquid-liquid jet flows. The explicit Volume of Fluid (VOF) model with the geometric reconstruction scheme was used to capture the oil-water interface. The estimated oil distribution including wave peaks, ligaments, droplets and water streaks were compared to the experiments with a good agreement. The estimated DSD matched with the measurements favorably well. In the simulation, the formation of droplets with a smooth and curved surface from ligaments or sheet-like structures was obtained. Different mechanisms were observed along with the shear layer including the formation of droplets from ligament through the capillary forces, breakage of a droplet into smaller ones and attachment of a droplet to a ligament. The destructive shear forces and resisting surface tension forces were quantified on stretching and retracting ligaments. The influence of internal viscous force was found to be negligible due to low oil viscosity. The critical capillary number was found to be larger than 5.0 for ligaments breaking with the shear breakup. The capillary number was below unity for retracting ligaments. The coalescence of two equal-sized droplets was obtained in the shear breakup region. The shear stress magnitude at the contact region increased more than two folds. The total surface area decreased nearly 20% after the coalescence.

了解射流中的剪切破裂以及由韧带形成的液滴的形成对于确定最终的液滴尺寸分布（DSD）很重要。影响最终DSD的初始液滴尺寸被认为是由剪切破裂产生的。进行了大涡模拟（LES）以研究液-液射流中的剪切破裂。具有几何重构方案的显式流体体积（VOF）模型用于捕获油水界面。将估计的油分布（包括波峰，韧带，水滴和水条纹）与实验进行了比较，吻合得很好。估计的DSD与测量值非常吻合。在模拟中，获得了由韧带或片状结构形成的具有光滑弯曲表面的液滴。观察到与剪切层一起的不同机制，包括通过毛细力从韧带形成液滴，将液滴破碎成较小的液滴以及将液滴附着至韧带。在拉伸和收缩韧带上定量破坏性剪切力和抵抗表面张力。由于低的油粘度，发现内部粘性力的影响可以忽略。对于随着剪切破裂而断裂的韧带，发现临界毛细管数大于5.0。对于缩回韧带，毛细管数低于1。在剪切破裂区域获得了两个相等大小的液滴的聚结。接触区域的剪应力大小增加了两倍以上。合并后，总表面积减少了近20％。