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.