AI 中文总结
本文通过数值模拟研究莱顿弗罗斯特液滴，发现环境湿度与液滴内部流动影响其形态和干燥动力学，指出轴对称模型模拟大液滴的偏差源于非现实约束，为完善相关模型提供了依据。
AI 中文摘要
将易挥发液滴轻柔放置于过热基底上时，液滴会悬浮在自身蒸气形成的薄膜上，避免与基底直接接触，该现象称为莱顿弗罗斯特效应。本文通过直接数值模拟，采用单一计算模型分析了半径跨越四个数量级的莱顿弗罗斯特水滴的特性，整合了前人关于大、小液滴的研究成果。利用该模型，我们发现环境湿度（莱顿弗罗斯特系统中被低估的因素）与液滴内部流动结合，对液滴几何形态及干燥动力学有显著影响。研究结果表明，常见的纯蒸气相和等温液滴假设存在不足。采用轴对称模型模拟大莱顿弗罗斯特液滴时，实验与计算结果存在较大偏差，经方位角稳定性分析，该偏差源于轴对称的非现实约束，此结论得到简化模型三维模拟的支持。最后，本文探讨了部分假设以解释与实验数据的剩余偏差。
英文摘要
A volatile droplet gently deposited on a superheated substrate can sit on a thin film of its own vapour, which prevents contact between the drop and surface. This phenomenon is called the Leidenfrost effect. In this paper, through direct numerical simulations, we analyse characteristics of Leidenfrost water droplets with a single computational model over four decades of droplet radius, stitching together previous works in the limit of large and small droplets. Using the model, we show that the ambient humidity, an underappreciated factor in the Leidenfrost system, in combination with the flow in the drop has a significant impact on the geometry and drying kinetics. Our results imply the inadequacies of commonly made assumptions of a pure vapour phase and an isothermal droplet. When modelling large Leidenfrost droplets with an axisymmetric model, large discrepancies between experiments and the computational results occur. Through azimuthal stability analysis, we show that this is due to the unrealistic constraint of axisymmetry. This finding is supported by 3D simulations of a simplified model. Finally, some hypotheses are explored to account for the remaining discrepancies with experimental data.
Comments29 pages, 15 figures, submitted to JFM
