Application of computational fluid dynamics to multiphase flow in bubble columns

The application of Computational Fluid Dynamics (CFD) to the simulation of bubble columns devices is discussed. A comparison between different modeling approaches has been carried out in order to understand which is the present ability of CFD codes to predict the flow in a gas-liquid system. The effect of different options of simulation, such as 2D and 3D grids with different density of cells, order of discretization, turbulence closure, has been studied for systems characterized by different values of gas hold-up. The analysis is restricted to bubbly flow conditions. Eulerian-Eulerian two fluid models have been used to describe both the time-dependent motion of the bubble plume and the time-averaged flow pattern in the column. The systems considered are those experimentally characterized by the group of Eigenberger (Becker et al., 1994), by Mudde et al. (1997), by the group of Dudukovic (Sanyal et al., 1999) and by Ho Yu and Kim (1991).