Abstract The air entrapment during droplet impingement is responsible for spontaneous droplet bouncing on an arbitrary solid surface at low Weber numbers. However, for the impact on liquid film surfaces, the outcome would significantly change, making it more favorable for the fabrication of non-wetting lubricant impregnated surfaces (LIS/SLIPS). In this paper, we describe a problem associated with the impact on a liquid surface using a three-phase flow model that captures the details of the gas layer thickness and dynamics of fluid motions. The numerical model was based on the finite volume solution coupled with the volume of fluid method to track the phases. The model was validated with the analytical solution. Consequently, the numerical tool was utilized to investigate the thickness of the entrapped air during the impact process while the behavior of droplet and the immiscible liquid film was quantitatively measured. The morphology of the interfacial gas layer was analyzed for key parameters including impact velocity and film thickness. It was observed that the presence of liquid film can reduce the probability of rupturing the gas layer. The results for the profile of liquid film during droplet impact illustrated that the effect of film thickness can considerably influence the bouncing behavior.

中文翻译：

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液滴撞击不混溶液膜期间空气滞留的数值分析

摘要 液滴撞击过程中的空气滞留是导致液滴以低韦伯数在任意固体表面上自发弹跳的原因。然而，对于液膜表面的影响，结果会发生显着变化，使其更适合制造非润湿润滑剂浸渍表面（LIS / SLIPS）。在本文中，我们使用三相流模型描述了与对液体表面的影响相关的问题，该模型捕获了气层厚度和流体运动动力学的细节。数值模型基于有限体积解法结合流体体积法来跟踪相。该模型通过解析解进行了验证。最后，利用数值工具研究撞击过程中夹带空气的厚度，同时定量测量液滴和不混溶液膜的行为。分析了界面气体层的形态的关键参数，包括冲击速度和薄膜厚度。据观察，液膜的存在可以降低气层破裂的可能性。液滴撞击过程中液膜轮廓的结果表明，膜厚度的影响可以显着影响弹跳行为。据观察，液膜的存在可以降低气层破裂的可能性。液滴撞击过程中液膜轮廓的结果表明，膜厚度的影响可以显着影响弹跳行为。据观察，液膜的存在可以降低气层破裂的可能性。液滴撞击过程中液膜轮廓的结果表明，膜厚度的影响可以显着影响弹跳行为。