Many-body dissipative particle dynamics simulation of droplet dynamic behavior on stripe-patterned surfaces

The motion of droplets on solid substrates represented a ubiquitous phenomenon in hydrocarbon exploitation. Effective regulation of droplet dynamics was of great scientific significance for enhancing fluid mobility. In this work, several different surfaces, including homogeneous surfaces and stripe-patterned surfaces, were constructed. Subsequently, droplet motion processes were simulated using the numerical method of many-body dissipative particle dynamics (MDPD). On homogeneous surfaces, the contact angle increased from ∼43° to ∼152° as the attractive parameter between the droplet and substrate increased within the range of −40 to −12.5. The droplet spontaneously migrated toward the hydrophilic region, and at the same attraction parameter, contact angles on different wetting surfaces deviated from those on homogeneous surfaces. However, the contact angle difference decreased with increasing attractive parameter. Findings revealed that the larger the attractive parameter between them, the more spherical the final morphology of the droplet became. The threshold force required to overcome adhesion and repulsion for droplet motion decreased from ∼0.05 to ∼0.0004 MDPD units as the attractive parameter increased from −40 to −15. On stripe-patterned surfaces, droplet motion in directions parallel and orthogonal to the stripes was investigated. As the magnitude of external force and simulation time increased, the displacements and velocities in both directions increased accordingly. The motion behavior and morphology of the droplet on solid surfaces were dependent on surface wettability, external forces, and stripe-patterned distribution. This work provided new and sound perspectives for the understanding of droplet motion and brought deep insight into enhancing flowability.