Wetting Dynamics Behavior of In Situ Generated Droplet on Micropore Surfaces

Abstract

The pinning dynamic of oil droplet on micropore surface has a significant impact on the stability of the oil film. Herein, the numerical model of the oil droplet generated in situ at the orifices is established. The influence of pore parameters and the inlet pressure on the movement of the three‐phase contact line are explored. The transformation mechanism between pinning and spreading of the droplet is revealed. The result shows that due to the competition between the surface tension and the driving force, the flow field parameters at the pinning point become unstable. Until the three‐phase contact line is unpinned, the droplet spreads on the micropore surface. With the reduce of the contact angle or the increase of the diameter of the pore, the pinning time of the droplet is shortened, and the droplets spread faster on the micropore surface. As the inlet pressure increases, the droplets grow faster at the orifice and spread from the orifice until the apparent contact angle reaches its maximum forward angle. The spread promotes the regeneration of the lubricating film, which is conducive to improving the stability of the oil film on micropore surface.