CFD simulation of industrial bubble columns: Numerical challenges and model validation successes

Although bubble columns are widely used in many industrial situations, there are very few studies of such devices operating at high superficial velocities. Numerical simulations using an Euler-Euler methodology are reported here across a wide range of operating conditions, where we discuss model assumptions and model validation. Key to obtaining physically correct results is the choice of closure assumptions. Particular emphasis is placed on the various solution methods that can be employed. In particular, we show that massive speed-up is possible using the new Eulerian multiphase NITA solver in ANSYS Fluent 16. Comparison of results from ANSYS CFX and ANSYS Fluent show that both do a good job of capturing the main features of the flow, the mixing time and the oxygen transfer rate.