CFD simulation of gas-liquid flow in bubble column

Numerical simulations of gas-liquid flow in a cylindrical bubble column with two-fluid approach were conducted at superficial gas velocities varying from 0.02 m·s^-1 to 0.30 m·s^-1. A single scalar transport equation which described bubble size changes characterized by bubble interfacial areas was also incorporated into the simulations. In the models, the effect of bubble coalescence and break-up was taken into consideration. A modified k-ε turbulence model was used to describe liquid phase turbulence in the simulations, by accounting for the pseudo turbulence due to bubbles, while the gas phase turbulence viscosity was estimated based on the Tchen's theory. The simulations only adopted the drag force for phase momentum exchange. The time averaged axial liquid velocities, gas hold up and gas phase interfacial areas obtained from the simulations were compared with the available experimental results. It was demonstrated from the simulations that the modeling in this work can reasonably predict the gas-liquid flow in the bubble column.