Characteristics of Secondary Droplets Produced During Impact Process of a Water Droplet on Water Film of Different Thicknesses

Abstract:

The splashing dynamics of a water droplet impacting a water film was experimentally investigated by a high-speed camera. The splashing limit， the size distribution of secondary droplets， and the velocity of secondary droplets were analyzed. The results show that within the range of the experimental parameters， the splashing occurs when the Weber number increases. The dimensionless parameter K （K=We·Oh^-0.4） could be used to describe the splashing limit. When K > 2 100， splashing phenomenon happens. In addition， with the increase of the K number， both the dimensionless secondary droplet diameter and the dimensionless velocity of secondary droplets increase. The effect of dimensionless film thickness on the diameter distribution of secondary droplets is not significant. However， the average dimensionless velocity of secondary droplets produced by crown splashing decreases with the increment of dimensionless film thickness.

Key words:water droplet impact;water film;splashing;secondary droplets