Impact process of a droplet on solid surfaces: Influence of surface wettability using lattice Boltzmann method

This research employed the pseudopotential multi-relaxation times lattice Boltzmann method to investigate the impact process of a droplet on solid surfaces, focusing on the influence of surface wettability for three different Reynolds numbers Re = 100, 200, and 500). Initially, the impact process is studied on both hydrophobic and hydrophilic surfaces, revealing distinct behaviors characterized by spreading and recoiling stages. Subsequently, the investigation extends to a mixed wettability wall, offering insights into the droplet's density behaviors. Through this study, we demonstrate that the wettability of the surface plays a crucial role in determining the contact dynamics with the impacting droplet. Notably, the average velocity of the droplet exhibits a monotonic increase with higher wettability. Furthermore, the droplet profile responds to variations in the Reynolds number, though droplet deformation remains relatively limited even when the interaction with the wetting surface intensifies. Our findings shed light on the complex interplay between wettability, droplet dynamics, and surface interactions during impact processes.