Figure 2 Comparison of the
predicted results with experimental data in the
literature1,3,6,35
Combining the above parameters with the physical data provided in the
literature, we nondimensionalized the experimental data and plotted them
in Figure 2. It can be seen that the predicted results of the model are
in good agreement with the experimental data of Andersson and Maaß,
which further validates the accuracy and generalizability of the
theoretical model. However, Figure 2 shows that the predicted results of
the model are in relatively poor agreement with the experimental data of
Ashar et al., especially at the lower WeL , which
we analyze as a result of the higher drop viscosity of the experimental
system in Ashar et al. Moreover, the high spatial inhomogeneity of the
turbulent energy dissipation rate in their experimental device can also
cause deviations between the model predictions and experimental results.
4.2 Comparison of drop breakup frequency
models
As is discussed in Section 2, most breakup frequency models in the
literature are based on limited modeling frameworks.
Particularly,frameworks based on the eddy-particle collision and based
on the statistical description are mostly adopted by researchers.
Breakup frequency models proposed by Coulaloglou and
Tavlarides18 (CT model, as shown in Eq.) and proposed
by Luo and Svendsen15 (Luo model, as shown in Eq.) are
the most representative and well-known models under the above two
frameworks, respectively.
CT model:
Luo model:
In such a scenario, the two models are also analyzed in the present
work. To intuitively compare the experimental data of drop breakup
frequency obtained by different researchers, the method recommended by
Lehr et al. 36 to dimensionless the drop size and drop
breakup frequency is introduced, that is:
Where L * and T * have
length and time dimensions respectively:
In the original model of Coulaloglou and Tavlarides18,
the drop breakup frequency depends on the dispersed phase density, that
is, the density ρf in Eq. and Eq. takes the value
of the dispersed phase density ρd . Firstly, we
compared the predicted results of the CT model with the experimental
data, as shown in Figure 3a. It can be seen that by changing the
specific values of the adjustable parameters, the original CT model can
conform to the experimental data under different experimental
facilities, but the accurate prediction of the breakup frequency under
different facilities cannot be achieved by a fixed combination of the
parameters. From the original literature of Coulaloglou and Tavlarides,
it can be seen that the density term comes from the estimation of the
turbulent stress. According to the current cognition of most
researchers, the magnitude of the turbulent stress should be related to
the continuous phase density, which means that the dispersed phase
density in the CT model should be replaced by the continuous phase
density, and thus, the density ρf in Eq. and Eq.
is taken as the continuous phase density ρc in
the following analysis. And then, we compare the predicted results of
the density-corrected CT model with the experimental data, and the
result is shown in Figure 3b. It can be seen that by adjusting the
adjustable parameters combination, the modified CT model can better
match the experimental data of different researchers relative to the
original model. Also, we plot the predicted results of the Luo model in
Figure 3b, and it shows that the Luo model overestimates the actual
magnitude of the breakup frequency.