A CFD-PBM coupled model under entire turbulent spectrum for simulating a
bubble column with highly viscous media
Abstract
To account for the effect of liquid viscosity, the bubble breakup model
considering turbulent eddy collision based on the inertial subrange
turbulent spectrum was extended to the entire turbulent spectrum that
included the energy-containing, inertial, and energy-dissipation
subranges. The computational fluid dynamics-population balance model
(CFD-PBM) coupled model was modified to include this extended bubble
breakup model for simulations of a bubble column. The effect of
turbulent energy spectrum on the bubble breakup and hydrodynamic
behaviors was studied in a bubble column under different liquid
viscosities. The results showed that when the liquid viscosity was
< 80 mPas, the bubble breakup and hydrodynamics were almost
independent on the turbulent spectrum. At liquid viscosity
> 80 mPas, the bubble breakup rate and gas holdup were
significantly under-predicted when the inertial turbulent spectrum was
used, and when using the entire turbulent spectrum the predictions were
more consistent with experimental data.