Numerical study on the dynamics of droplet impact on hydrophilic-hydrophobic striped cylindrical surfaces

The impact of droplets on solid surfaces is a common phenomenon, significantly affecting the efficiency of processes such as heat transfer and cooling. While the behavior of droplets on flat surfaces has been extensively studied, researches on complex surfaces, particularly on hydrophilic-hydrophobic striped cylindrical surfaces, still needs to be explored. In this study, numerical simulations are performed to elucidate the dynamic behavior of droplets on hydrophilic-hydrophobic striped cylindrical surfaces, focusing on analyzing droplet breakup characteristics under varying Weber numbers ( We ) and stripe widths. By simulating the spreading, retraction, and breakup processes of droplets in both axial and circumferential directions, the study reveals the influence of stripe width and We on droplet breakup patterns, satellite droplet formation, and the length of the three-phase contact line. The results demonstrate that higher We and appropriate stripe widths significantly promote droplet breakup in both axial and circumferential directions, leading to the formation of multiple satellite droplets and a substantial increase in the three-phase contact line length. Moreover, a breakup phase diagram is constructed to clarify the complex relationship between droplet initial diameter, We , and stripe width, providing a theoretical basis for optimizing surface design in industrial cooling and evaporation systems.