Numerical Simulation of Non-Newtonian Droplets Impacting on Hydrophobic Surfaces

刘海龙1, 郑诺1, 吴洪雷1, 王军锋1
1Jiangsu University, Zhenjiang, Jiangsu Province, China
Published in 2020

Bouncing phenomenon of droplets impact on solid wall is of great importance to industrial applications. For example, spray cooling or inkjet printing require droplets to be deposited effectively, while anti-icing and self-cleaning demand droplets to bounce as much as possible to achieve good results. In this work, the effect of xanthan gum additive on droplet rebound phenomenon was investigated using experimental and numerical simulations. A numerical model based on the level-set method was developed by the finite element simulation software COMSOL Multiphysics. And the Carreau model is used to represent the dynamically changing viscosity of non-Newtonian fluid during droplet spreading stage. To obtain more realistic results, a dynamic contact angle model is introduced. The results demonstrate that, the apparent viscosity of droplets was gradually increased with higher concentrations of xanthan gum solution and exhibits shear-thinning characteristic. When we control Weber number to a certain scope, three kinds of behaviors appear in order after impact namely partial rebound, rebound and deposition.