Figure 8. The relative appearance between binary, ternary, quaternary and quintuple breakage in different height (a) under mass transfer condition and (b) without mass transfer condition.
Figure 8(b) shows the proportion of droplet breakage at different heights without mass transfer. It can be seen from the figure that, unlike mass transfer conditions, at different heights, the proportion of binary, ternary and quaternary breakage of droplets is almost the same. In the height of 265 mm, a small amount of quintuple breakage occurs. However, no quintuple fragmentation is found at other heights. Under no mass transfer condition, the interfacial tension between the two phases does not change with the height, thus the ratio of fragmentation tends to be the same.
Figure 9 shows that the proportion of binary breakup is different under various mother droplet diameters. When the droplet diameter is small, the proportion of binary breakup at different heights is higher than 85%. With the increase of the diameter of mother droplets, the proportion of binary breakage decreases gradually. With the increase of the diameter of mother droplets, the instability of the interface will increase, which will increase the probability of multiple fragmentation. In addition, in the turbulent flow field, droplets with larger diameter are also vulnerable to more turbulent eddy collisions, thus obtaining more energy and undergoing multiple breakup.