(438g) CFD Investigation of Gas-Liquid Mass Transfer in a Multiphase Taylor-Couette Reactor

Bubbly gas-liquid Taylor-Couette vortex flow has gathered increasing interest because of its potential applications to a variety of chemical and biochemical processing problems. In order to quantitatively describe the hydrodynamics and mass transport during two phase Taylor-Couette flow, a rigorous two-fluid CFD incorporating interphase mass transfer was developed for the simulation of bubbly Taylor-Couette flow and compared with data obtained from oxygen transport experiments using an air-water Taylor vortex flow system. Important parameters influencing the mass transfer coefficient were analyzed, including bubble Sauter mean diameter, slip velocity and turbulent dissipation rate. Several mass transfer models, such as the penetration model and eddy cell model, were compared tested against experimental data. Subsequently, an adaptive simulation method was developed that automatically selects the most appropriate mass transfer model based upon local flow conditions, leading to more accurate predictions for the global rate of mass transfer. Predictions of this adaptive method are in good agreement with experimental findings for a wide range of gas flow rates and azimuthal Reynolds numbers in gas-liquid Taylor-Couette flow.