Evaluation of Drag Force Effect on Hold-Up in a Gas–Liquid Stirred Tank Reactor

Abstract

A comprehensive computational method based on the Eulerian–Eulerian approach is presented for gas–liquid flows in a mechanically stirred vessel. Separate submodels were developed to investigate the influence of the drag coefficient on bubbles due to the interaction between bubbles and turbulence. A new model is used for the definition of drag coefficient and a detailed simulation method is used to estimate the interphase drag force. A standard k−ε turbulent model is used and the impeller rotation is modelled by the multiple reference frame approach. Simulation results are compared with previous drag models and the experimental measurements. The results indicate that the new model is able to predict the influence of turbulent intensity on drag coefficient and the distribution of gas holdup. The computational model and the proposed correlation for drag in turbulent flow will be useful for simulation gas holdup distribution and flow regimes in stirred vessels.