Impingement and mixing between two shear-thinning droplets on the solid surface

Abstract

The impingement and the following mixing between non-Newtonian droplets on the solid surface are a common phenomenon in industry, where reasonably controlling the mixing is always of vital importance. In this work, Many Body Dissipative Particle Dynamics method is used to reveal the law of this process with two non-Newtonian droplets. Firstly, the variation of droplets morphology with the Weber number of the impinging droplet is studied. Then, by dividing this mixing process into convection-dominated and molecular diffusion-dominated stages, the relationship between duration of the former stage and Weber number is quantitatively determined. In the latter stage, it is found a special phenomenon in the mixing which results from the difference in particle diffusion coefficients. Finally, the mixing time for the two droplets and its variation with the Weber number is proposed, which can be helpful in the design of the related device when mixing is between non-Newtonian droplets.