The impact and freezing processes of a water droplet on different inclined cold surfaces

The present study experimentally investigated the impact and freezing processes of a water droplet on different inclined cold surfaces. The surface temperature was changed from room temperature 24.0 °C to −15.0 °C. The materials of the surfaces included red copper, quartz glass, carbon fiber reinforced composite (CFRC), and glass fiber reinforced composite (GFRC). During the impact process of the water droplet, the surfaces were found to have a minor influence on the spreading time and gliding time but an apparent effect on the equilibrium time. Besides, these surfaces significantly affected the spreading maximum diameter, gliding maximum diameter, and maximum displacement of foremost point of the water droplet. In addition, once the equilibrium state of water droplet was reached, the contact diameter of the water droplet depended heavily on the type of the surfaces. As for the freezing process, the cold surfaces affected not only the freezing time of the water droplets, but the shape of the ice beads as well.