CFD prediction of liquid homogenisation in a gas-liquid stirred tank

In this work, simulations of liquid homogenisation were performed for a two-phase gas-liquid stirred tank using computational fluid dynamics (CFD). The predictions were compared with experimental results obtained in a baffled cylindrical vessel stirred by a pitched-blade impeller with constant impeller speed for various volumetric gas flow rates. The CFD simulations were performed in 3D using the FLUENT 6.3 numerical software. The influence of different techniques for simulation of impeller motion (the multiple reference frames and sliding mesh models) on predictions of gas-liquid flow field and tracer distribution was investigated. For the solution, a simplified numerical setup of mono-dispersed bubbles and the k-ɛ mixture turbulence model have been applied. Despite the assumed simplifications, the numerical predictions exhibit a good agreement with the experimental data.