论文标题
旋转液滴正面碰撞中的非轴对称流动特性
Non-axisymmetric flow characteristics in Head-on Collision of Spinning Droplets
论文作者
论文摘要
使用流体量的方法研究了旋转运动对经历正面碰撞的旋转液滴和非旋转液滴之间的弹跳和聚结的影响。一个显着的发现是，旋转液滴可以诱导由相同液体组成的相等大小的液滴正面碰撞的显着非轴对称流动。具体而言，观察到非轴对称弹跳，这是由旋转角动量转化为轨道角动量引起的。由于液滴的旋转和径向流之间的相互作用，此过程伴随着旋转动能损失。还观察到临时聚结后的非轴对称内流和延迟的分离，它们是由增强的界面振荡和内流诱导的粘性耗散引起的。旋转运动还可以促进液滴的质量相互作用，因为局部不均匀的质量交换发生在早期碰撞阶段，并通过非轴对称流动，并在后来的碰撞阶段沿细丝进一步延伸。此外，发现非轴对称流量特征随着初始翻译运动的正交性和液滴的旋转运动而增加。
Effects of spinning motion on the bouncing and coalescence between a spinning droplet and a non-spinning droplet undergoing the head-on collision were numerically studied by using a Volume-of-Fluid method. A prominent discovery is that the spinning droplet can induce significant non-axisymmetric flow features for the head-on collision of equal-size droplets composed of the same liquid. Specifically, a non-axisymmetric bouncing was observed, and it is caused by the conversion of the spinning angular momentum into the orbital angular momentum. This process is accompanied by the rotational kinetic energy loss due to the interaction between the rotational and radial flows of the droplets. A non-axisymmetric internal flow and a delayed separation after temporary coalescence were also observed, and they are caused by the enhanced interface oscillation and internal-flow-induced viscous dissipation. The spinning motion can also promote the mass interminglement of droplets because the locally non-uniform mass exchange occurs at the early collision stage by non-axisymmetric flow and is further stretched along the filament at later collision stages. In addition, it is found that the non-axisymmetric flow features increase with increasing the orthogonality of the initial translational motion and the spinning motion of droplets.
