A Review of Computational Fluid Dynamics (CFD) Simulations of Mixing in the Pharmaceutical Industry

Due to the increasing computational power and availability of advanced commercial, as well as open-source computational fluid dynamics (CFD) software, performing CFD simulations is becoming more accessible and its use has expanded into many industrial sectors. For the pharmaceutical industry, the topic of mixing is especially of interest, since it is a common unit operation in pharmaceutical processes and empirical and semi-empirical correlations for predicting the hydrodynamic characteristics inside a batch mixing vessel do not consider the complete three-dimensional geometry of the vessel and impeller. This is important in processes such as crystallization, dissolution, compounding, and cellular production in bioreactors, and the obtained information can aid in the selection of the mixer geometry, the choice of mixing speed and for achieving comparable scale-up/down operation of laboratory and industrial mixing vessels.