Conclusions
The Euler–Euler two-fluid model coupled with the PBM was
employed to investigate the gas–liquid flow in a cylindrical
bubble column with 138mm in diameter. The work focused
on simulating the effects of various drag models as well as
a correction factor accounting for wake acceleration of large
bubbles. Main conclusions drawn from this work are as follow:
(1) Even though the deviation of simulated results reduce
after kb,large was implemented into drag models, the
numerical results show that only the modified PBMcustomized
drag model (i.e. model S-k) could produce
reasonable predictions with the experiment data in terms
of radial distribution of local gas holdup and overall gas
holdup. Both the Tomiyama and the DBS-based drag models
cannot accurately predict local gas hold-up profile and
total gas holdup where they either overestimate or underestimate
the experimentally reported data. Meanwhile, it
should be mentioned thatthe parabolic distribution of normalized
axial liquid velocity could be obtained by all three
modified drag model