Reza Farzad, Simon Schneiderbauer,
"CFD Simulation of the Droplet Size Distribution of Liquid-Liquid Emulsions in Stirred Tank Reactors"
: Proceedings of the 12th International Conference on Computational Fluid Dynamics in the Oil & Gas, Metallurgical and Process Industries (CFD 2017), 6-2017
Original Titel:
CFD Simulation of the Droplet Size Distribution of Liquid-Liquid Emulsions in Stirred Tank Reactors
Sprache des Titels:
Englisch
Original Buchtitel:
Proceedings of the 12th International Conference on Computational Fluid Dynamics in the Oil & Gas, Metallurgical and Process Industries (CFD 2017)
Original Kurzfassung:
Predicting the drop size distribution (DSD) is essential in
particulate flows such as emulsions as it affects mass transfer
and heat transfer. In the current work we developed a novel
numerical method to account for droplet breakup. The droplet
breakup relies on an in-house developed correlation which
depends on the local shear rate and some fluid properties.
Commonly, a population balance equation (PBE) is employed
to describe the breakup and coalescence of the droplets;
however, such an approach does commonly not distinguish
between different slip velocities of the smaller and larger
droplets. Therefore, we propose a hybrid modelling strategy,
which combines an Eulerian-Eulerian two-fluid model (TFM)
and a Lagrangian discrete particle model (DPM), which is
referred to as the Hybrid TFM-DPM model. This method
enables the efficient evaluation of the poly-disperse liquid liquid
drag force form the local distribution of the different
droplet diameters. The latter can be obtained by tracking
statistically representative droplet trajectories for each droplet
diameter class. Finally, we applied this novel approach to a
liquid-liquid emulsion in a stirred tank presented. The results
clearly show that the present method is able to predict the
droplet size distribution for different rotational speeds of the
stirrer.
Forschungs-