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.
维普
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