Numerical investigation of coalescence-induced self-propelled behavior of droplets on non-wetting surfaces
Numerical investigation of coalescence-induced self-propelled behavior of droplets on non-wetting surfaces
复制标题
DOI：
10.1063/1.5046056
复制
发表时间：
2018-11
影响因子：
4.6
通讯作者：
Yan Chen;Y. Lian
中科院分区：
文献类型：
--
作者：
Yan Chen;Y. Lian
我们用数值方法研究了液滴聚结过程中的自推进现象。数值方法是基于一个经过验证的多相流求解器，解决了三维Navier-Stokes方程。利用流体沿沿着方向的动量捕捉气液界面，并采用方向分裂法对气液界面进行平流。并采用近似投影法将速度和压力的计算解耦。通过与实验结果的比较，验证了该求解器的有效性。实验结果表明，该方法可以准确地捕捉到液滴的跳跃过程。模拟的液滴变形也与实验结果相吻合。为了研究跳跃机制，我们比较了两种情况下，没有接触基板的结果。垂直动量的历史表明，与接触基板，液滴有一个较长的加速周期。与基底接触的聚结液滴也具有较小的表面积，这表明更多的表面能使聚结液滴的表面积减小。
We numerically study the self-propelled droplet phenomenon upon droplet coalescence. The numerical method is based on a well-validated multiphase flow solver that solves the three-dimensional Navier-Stokes equations. The liquid-air interface is captured using the moment of fluid along with a direction splitting method applied to advect the interface. And an approximate projection method is used to decouple the calculation of velocity and pressure. The solver is validated by comparing with the experimental results. Our results show that the droplet jumping process can be accurately captured. The simulated droplet deformation also matches the experimental results. To investigate the jumping mechanism, we compare results between two cases with and without a contact substrate. The history of vertical momentum shows that with a contact substrate, the droplet has a longer period of acceleration. The coalesced droplet with a contact substrate also has a smaller surface area which indicates that more surface ener...