液滴冲击过程动态接触角模型研究  

Research on the Dynamic Contact AngleModel for the Droplet Impact Process

作　　者：王翔宇 柯鹏[1,2] 杜锋 WANG Xiangyu;KE Peng;DU Feng(School of Transportation Science and Engineering,Beihang University,Beijing 102206,P.R.China;Hangzhou International Innovation Institute,Beihang University,Hangzhou 311115,P.R.China)

机构地区：[1]北京航空航天大学交通科学与工程学院,北京102206 [2]杭州市北京航空航天大学国际创新研究院(北京航空航天大学国际创新学院),杭州311115

出　　处：《应用数学和力学》2024年第9期1133-1146,共14页Applied Mathematics and Mechanics

基　　金：国家自然科学基金(12372095)。

摘　　要：基于计算流体力学(CFD)模拟液滴冲击壁面,对于理解液滴在固体壁面铺展的动力学行为有重要的意义,可以为超疏水结构设计及防除冰涂层开发提供技术支撑,其中的难点在于如何在模型中准确刻画接触线及动态接触角的演化过程.总结了四种典型的动态接触角模型,从理论上分析了其应用范围,借助FLUENT中的UDF功能,将动态接触角模型应用于壁面边界条件.首先对液滴冲击光滑壁面的动力学过程进行了数值模拟研究,通过定量分析液滴形态的各项参数变化并与实验结果对比表明,Seebergh动态接触角模型更适用于模拟低毛细数下液滴的运动,Kistler模型与Jiang模型应用范围更广并且可以较准确地描述高毛细数下液滴的运动.随后基于Kistler动态接触角模型,对液滴在微结构表面的冲击与铺展过程进行了仿真研究,发现应用动态接触角模型会导致液滴内部流场在表面张力起主导作用的阶段内发生变化,并且在平衡状态下液滴接触角的模拟值与理论值相近.The simulation of droplet-wall impact process based on computational fluid dynamics(CFD)is of great significance for understanding the dynamic behavior of droplets spreading on the solid wall,and can pro-vide technical support for the design of superhydrophobic structures and the development of anti-icing coating.The difficulty lies in how to accurately describe the evolution process of the contact line and the dynamic con-tact angle in the model.Herein,4 typical dynamic contact angle models were summarized,and their application ranges were analyzed theoretically.With the UDF function in FLUENT the dynamic contact angle model was ap-plied to the wall boundary conditions,and the dynamic process of droplet impact on smooth wall was numeri-cally simulated.The quantitative analysis of the changes of droplet shape parameters and the comparison with the experimental results show that,the Seebergh dynamic contact angle model is more suitable for simulating the motion of droplets with lower capillary numbers.The Kistler model and the Jiang model are more widely used and can accurately describe the motions of droplets with higher capillary numbers.Then,based on the Kistler dynamic contact angle model,the impact and spreading processes of droplets on the microstructure sur-face were simulated.It is found that,the application of the dynamic contact angle model will lead to the change of the internal flow fields of droplets with the surface tension playing a dominant role,and the simulated drop-let contact angle value in equilibrium is close to the theoretical value.

关 键 词：液滴冲击 动态接触角 铺展系数 高度系数 微结构壁面 

分 类 号：O359.1[理学—流体力学]