2010 Volume 53 Issue 1 Pages 42-54
Immiscible liquid dispersions are widely used in chemical process, petroleum industries, polymerization, heterogeneous chemical synthesis, etc. In most of these chemical processes, the rate of inter-phase heat and mass transfer is known to strongly affect the overall performance and depends on the interfacial contact area between the phases. This study at CFD simulations of immiscible liquid dispersion has been performed on a vertical pipe. With specific reference to dispersed liquid-liquid flows, it was seen that the two-fluid approach (Eulerian-Eulerian approach) was extensively used for multiphase modeling, especially when detailed predictions are desirable over a range of holdups in exchange for a reasonable amount of computation power. The results of CFD predictions for water as a continuous and kerosene as a dispersed phase have been compared with the experiments of Farrar and Bruun and Al-Deen and Bruun. These simulations have also been done to understand the effect of various significant forces in turbulent liquid dispersions (drag, lift, turbulent dispersion and added mass). Several expressions for these forces were tested in order to choose the best combination. Further, the problem has been simulated using two different turbulence models. It has been found that lift force is more important than turbulent dispersion and added mass. Inter-phase closure guidelines for liquid-liquid bubbly flows were developed based on simulation results that yielded the best agreement with experimental data.
