Drop splashing after impact onto immiscible pools of different viscosities.
Drop splashing after impact onto immiscible pools of different viscosities.
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DOI：
10.1016/j.jcis.2023.03.040
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发表时间：
2023-03
影响因子：
9.9
通讯作者：
Ben D. Fudge;R. Cimpeanu;A. Antkowiak;J. Castrejón-Pita;A. A. Castrejón-Pita-A.
中科院分区：
文献类型：
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作者：
Ben D. Fudge;R. Cimpeanu;A. Antkowiak;J. Castrejón-Pita;A. A. Castrejón-Pita-A.
液滴撞击到液体池上是与许多自然现象和工业过程相关的典型场景。然而，尽管它们普遍存在，但具有由不同液体组成的液滴和池的多流体系统远未被很好地理解。我们的假设是，撞击后动力学在很大程度上取决于池液滴粘度比μ p/μ d，我们使用实验和理论方法（数学建模和直接数值模拟）相结合，在六个数量级的范围内探索。我们的研究结果表明，在这种情况下的飞溅阈值和喷出物片的组成控制的粘度比。当飞溅来自液滴时，增加液池粘度会降低高粘度液池的飞溅阈值（μ p/μ d ≤ 35）。相比之下，对于低粘度池，飞溅片来自池，并且增加池粘度增加飞溅阈值。令人惊讶的是，在我们实验室可达到的条件下，存在没有观察到飞溅的条件。此外，考虑到界面速度与渐近参数产生的喷出物，使我们能够理解有意义的变化，在影响过程中的压力和合理化所观察到的变化飞溅阈值。
Droplet impact onto liquid pools is a canonical scenario relevant to numerous natural phenomena and industrial processes. However, despite their ubiquity, multi-fluid systems with the drop and pool consisting of different liquids are far less well understood. Our hypothesis is that the post-impact dynamics greatly depends on the pool-to-droplet viscosity ratio μ p/μ d, which we explore over a range of six orders of magnitude using a combination of experiments and theoretical approaches (mathematical modelling and direct numerical simulation). Our findings indicate that in this scenario the splashing threshold and the composition of the ejecta sheet are controlled by the viscosity ratio. We uncover that increasing the pool viscosity decreases the splashing threshold for high viscosity pools (μ p/μ d≳ 35) when the splash comes from the droplet. By contrast, for low viscosity pools, the splash sheet comes from the pool and increasing the pool viscosity increases the splashing threshold. Surprisingly, there are conditions for which no splashing is observed under the conditions attainable in our laboratory. Furthermore, considering the interface velocity together with asymptotic arguments underlying the generation of the ejecta has allowed us to understand meaningful variations in the pressure during impact and rationalise the observed changes in the splashing threshold.