Air bubble entrapment during drop impact on solid and liquid surfaces
Air bubble entrapment during drop impact on solid and liquid surfaces
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DOI：
10.1016/j.ijmultiphaseflow.2022.103974
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发表时间：
2022-01-20
影响因子：
3.8
通讯作者：
Mashayek, Farzad
中科院分区：
文献类型：
--
作者：
Halder, Subhayan;Granda, Rafael;Mashayek, Farzad
采用相场法模拟水滴撞击疏水介质薄膜表面的过程，研究了水滴在薄膜表面的滞留及其对沉积和回弹现象的影响。采用Cahn-Hilliard方程和Navier-Stokes方程相结合的方法，考虑了局部和全局的跌落冲击特性。水滴冲击的模拟结果直接与我们的实验测量的最大传播距离，和气泡的大小进行比较。模拟结果表明，空气可以被困在液滴下的初始冲击过程中，以及在收缩阶段在下降的中心，由于关闭的液体层上方的空腔。结果表明，液滴直径和撞击速度对空气卷吸现象有重要影响。在较低的撞击速度和较大的液滴尺寸下，气泡形成的概率较高。该模型还能够模拟水滴撞击水面的情况，并使用先前的文献数据验证了结果。此外，研究和讨论了相场变量和网格自适应方案对PFM的影响。因此，我们的研究结果提供了新的定性和定量的见解的影响，空气截留液滴沉积到疏水和液体表面。
The phase-field modeling (PFM) of water drop impact onto a dielectric hydrophobic parafilm surface is performed to explore air entrapment and its influence on deposition and rebound phenomena. Local and global characteristics of the drop impact are taken into account by using the combined Cahn-Hilliard and Navier-Stokes equations. The modeling results of water drop impact are directly compared with our experimental measurements in terms of maximum spreading distance, and air bubble size. The simulation results reveal that air can be trapped under the liquid drop during the initial impact as well as during the retraction phase at the center of the drop due to the closure of the liquid layer above a cavity. It is found that the drop diameter and the impact velocity play significant roles in the air entrapment phenomena. The probability of air bubble formation is higher at lower impact velocity and for larger drop size. The model is also capable of simulating the case of drop impact onto a water surface, and the results are validated using prior literature data. In addition, the influence of the phase-field variables and the mesh adaptation scheme on the PFM is studied and discussed. Thus, our findings provide new qualitative and quantitative insights into the influence of air entrapment on drop deposition onto hydrophobic and liquid surfaces.