Study on the adhesion behaviour of oil droplets in water on solid surfaces with different wettability and inclination

Abstract Microscopic adhesion of oil droplets is a hot research topic within multiphase flow systems in the petrochemical field in recent years, and it is also the key to revealing the mechanism of oil droplet–wall interaction. In this paper, a high‐speed camera was used to capture the dynamic process of oil droplets impacting stainless steel, polyethylene, brass, and other materials in water, deeply analyze the influence mechanism of material wettability, droplet size, and inclination on adhesion behaviour in this process, and draw the Re~ θ eq phase diagram. The experimental results show that properly enhancing the lipophilicity of the material can prolong the drainage time and effectively inhibit adhesion. Too much lipophilicity can dramatically shorten the drainage time instead, which easily leads to the rapid adhesion of oil droplets. An increase in droplet size can also prolong the drainage time; at Re ≥46.31, the excessive initial kinetic energy is consumed in the form of oil droplet rebound, which is not conducive to adhesion, and the more lipophilic the material is, the more significant the rebound effect. In addition, although an increase in the inclination can inhibit oil droplet bounce off, it also decreases the wall restraint to oil droplets, resulting in lateral and normal displacements, which greatly increases the drainage time. The findings can facilitate the understanding of oil droplet–wall interaction and provide a scientific basis for the design and development of efficient separation equipment and the optimization of the low‐temperature gathering and transportation of high water‐bearing crude oil.