Dynamic characteristics and energy variation of droplet impacting on a quartz surface

Understanding the impact process of droplets on surfaces is a crucial prerequisite for enhancing the efficiency of wetting dust removal. The collision dynamics between water droplets and quartz surfaces were investigated using a high-speed camera, revealing four distinct stages in this process. During the first three stages, there was an increase in droplet width and three-phase contact line over time, while the droplet height and contact angle decreased. These observations can be attributed to the combined effects of impulsive force and surface tension. With increasing droplet velocity, the duration of the first three stages prolonged, accompanied by an increase in both the diameter of the three-phase contact line and droplet width during the final stage, whereas there was a decrease in droplet height and contact angle. This behavior primarily arises from energy transfer involving kinetic energy converted into contact surface energy, droplet surface energy, and dissipated energy during collision events. Contact surface energy and droplet surface energy exhibited an upward trend with rising droplet velocity. Simultaneously, collision-induced dissipated energy increased proportionally with respect to droplet velocity. Notably, both the rate and ratio of dissipated energy demonstrated positive correlations with the Weber number; specifically following a linear relationship characterized by a slope value of 2.81. These findings offer valuable insights for advancing technology development related to equipment used for wetting dust removal.