Figure 9. The proportion of binary breakage in different height and different diameter of mother droplets under mass transfer condition.

Daughter droplet size distribution

The DDSD is also an important parameter in the process of droplet breakup. It directly reflects the diameter of daughter droplets generated after droplet breakup and also reveals whether the droplet breaks equally or unevenly in the system. The multiple breakage is treated as a series of binary breakage with the method reported in our previous work 36. Figure 10 shows the experimental results of DDSD at different height. The results show that the DDSD is inverted U-shaped under mass transfer conditions. At the same time, the size distribution of daughter droplets produced by breaking mother droplets with different diameters is similar. The reason may be that under mass transfer conditions, the droplet diameter in the experimental system is relatively small and these droplets are more prone to tensile breakage. The small droplets produced in the process of tensile breakage tend to be equal in diameter. Therefore, the DDSD shows an inverted U-shaped distribution.