Research On Dynamical Process Of Droplet Impacting On Inclined Surface

The free surface flow problems are commonly found out in the real life,it has inextricably linked with human survival and development. Droplets of liquid impact onto solid surfaces is a typical phenomenon of the free surface flow problem, The dynamic behaviors of droplet impact onto solid surface plays an important role in the study of nature phenomenon and the development of industrial technology.At first,this paper establishes the theoretical mode of the droplet deposition according fluid mechanical governing equation, VOF model in FLUENT of CFD software is applied to investigate the dynamic process of droplet impacting on inclined solid surface. In order to validated the model, simulated results are compared with experimental date. By altering concerned parameters, dynamics of droplet on solid surface are analyzed. Influence of parameters including feature of surface, impact velocity,impact angle and droplet properties on the deformation process is studied in detail. Next this article proposes three-dimensional VOF model based on 2D mathematical model, Then droplets impact onto horizontal and inclined surfaces were investigated by this model.The results has shown that despite of error in simulated results, by compared with experimental data, VOF method could capture the key feature of droplet dynamics when impacting the solid surface. In the case of normal impact.the flow is symmetric, but it is asymmetric for the oblique impact. During the process of droplets impact onto flat surfaces, The influence of surface wetting characteristics was investigated by using static contact angle (SCA) and dynamic contact angle (DCA) models. It was found that the DCA model is closer to the experiment observed value. During the process of droplets impact onto inclined surfaces, The flow state is seriously influenced by the wettability of surface, the high wettability surface sediment only shows spreading, the low wettability surface shows not only, spreading but also slip phenomenon; The impact velocity is bigger, the spreading diameter of droplet is bigger; In the same We,the impact angle is smaller, the spreading speed ids faster,and the last spreading relative diameter is bigger; The liquid characteristic such as viscosity has significant influence to the droplet impact dynamics. The smaller of the liquid viscosity, the bigger of the maximum relative diameter of the droplets can be obtained, and the spreading speed is slower.