Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

Pool scrubbing is often used for removing harmful aerosol particles by injecting the gas mixture
into a liquid pool [1], where hydrodynamics affects the decontamination factor significantly. The poolscrubbing
bubble column is characterized by a large nozzle and high injection flow rates, which lead to
large gas structures in the injection zone. As they rise up, these globules break up and form a swarm of
small bubbles. The wide range of bubble size and shape poses a challenge for both two-fluid model
(TFM) and interface-tracking approaches [2].
In this work, we apply the hybrid multi-field two-fluid model MultiMorph [3] to simulate a
rectangular pool-scrubbing bubble column. The MultiMorph model considers the interaction between
the gas and liquid according to the scale of the interfaces, applying a VOF-like treatment at the largescale
interfaces and the conventional TFM to the small-scale ones. In this way, the description of the
topology changes and regime transition is realized with the same set of equations. In the simulation,
both the gas and liquid can be treated as either dispersed or continuous phases depending on the ratio
between the particle (droplet or bubble in this work) size and the local cell size. The capability of the
model is validated by comparing with experimental data from reference [4] as well as results obtained
with the VOF and TFM, respectively. The MultiMorph model turns out to show significantly improved
agreement with experimental data.