Newtonian and non-Newtonian Droplet Impact onto a Heated Hydrophobic Solid Surface

In recent years, numerous papers on droplet operations have been published due to its growing importance. The impact of droplets with solid surfaces is an interesting physical phenomenon that occurs in various engineering applications. In this present study, the behaviors of Newtonian and non-Newtonian droplets impinging on a hydrophobic surface have been investigated numerically using volume-of-fluid (VOF) technique to track the fluid-air interface. Some numerical results are given to validate the numerical method. The obtained results are compared with the available experimental data at the same condition. The results demonstrate that there is a good agreement with experimental trends concerning normalized diameter profile. Therefore, the focus of this study is on the impact of water droplet on a hydrophobic surface. Two different surface temperatures are applied to find the effects of heated and non-heated surface on droplet dynamics. In addition, the effects of changing Weber numbers are also studied. The results indicate that the dynamics behavior of droplet for Newtonian and non-Newtonian drops are different from eachother. Furthermore, the maximum spreading diameter for a Newtonian droplet was larger than that of a non-Newtonian one because of the difference in liquid viscosity.

کلیدواژه ها:

Droplet impact dynamics ، Newtonian and non-Newtonian drops ، Heated hydrophobic surface.