论文标题
液体膜破裂以外的薄膜方程:多组分晶格鲍尔茨曼研究
Liquid film rupture beyond the thin-film equation: a multi-component lattice Boltzmann study
论文作者
论文摘要
在部分表面润湿性的条件下,稀薄的液体膜可能会因小小的扰动而破裂,并破裂成液滴。正如薄膜方程(TFE)成功预测的那样,破裂动力学由液体固定相互作用决定。该理论使用分离压力或等效地介绍了后者。由于存在不同的流体/表面相互作用能量,因此二级流体的引入可以导致更丰富的现象学,但尚未研究。在这项工作中,我们研究了使用多组分晶格Boltzmann(LB)方法浸入二次流体中的不同高度的液体膜的破裂。我们研究了广泛的表面相互作用能,平衡接触角和膜厚度。我们发现,对于相同的平衡接触角,但表面自由能不同,破裂时间可能会差异约一个数量级。有趣的是,TFE在质量上很好地描述了观察到的分手动力学,最多可达到130 $^\ circ $的平衡接触角。对于TFE的有效性,小膜厚度是一个更严格的要求,与LB结果的一致性仅适用于胶片高度$ h $的比率$ε= h/l $,以及横向系统大小$ l $,例如$ε\ listsim \ listssim \ times10^{ - 3} $。
Under the condition of partial surface wettability, thin liquid films can be destabilized by small perturbations and rupture into droplets. As successfully predicted by the thin film equation (TFE), the rupture dynamics are dictated by the liquid-solid interaction. The theory describes the latter using the disjoining pressure or, equivalently, the contact angle. The introduction of a secondary fluid can lead to a richer phenomenology thanks to the presence of different fluid/surface interaction energies but has so far not been investigated. In this work, we study the rupture of liquid films with different heights immersed in a secondary fluid using a multi-component lattice Boltzmann (LB) approach. We investigate a wide range of surface interaction energies, equilibrium contact angles, and film thicknesses. We found that the rupture time can differ by about one order of magnitude for identical equilibrium contact angles but different surface free energies. Interestingly, the TFE describes the observed breakup dynamics qualitatively well, up to equilibrium contact angles as large as 130$^\circ$. A small film thickness is a much stricter requirement for the validity of the TFE, and agreement with LB results is found only for ratios $ε=h/L$ of the film height $h$ and lateral system size $L$ such as $ε\lesssim\times10^{-3}$.