CFD simulation of immiscible liquid dispersions

Immiscible liquid dispersions are extensively encountered in the chemical, process and petroleum industries. Some common examples are solvent extraction, emulsification, polymerization, caustic treatment, heterogeneous chemical synthesis, etc. In most of these chemical processes, the rate of interphase heat/mass transfer is known to strongly affect the overall performance and depends on the interfacial contact area between the two phases. Experiments can yield significant insight into the factors affecting the interfacial area. However, problems such as the limited range of applicability of the empirical correlations so developed, difficulty in extrapolating the inferences to other geometries or even scaled-up versions of the same equipment, overall cost and time frame limitations etc. have led to more attention being focused on numerical approaches such as Computational Fluid Dynamics (CFD). This is particularly true for multi-fluid flow in complex/intricate geometries. The proven success of CFD to accurately predict the hydrodynamics in most single-phase flows cannot however, be readily translated to the case of multiphase dispersions. The presence of the dispersed phase invariably introduces additional complexities. Nevertheless, if fundamental multiphase characteristics such as the dispersed phase holdup could be accurately predicted, it would be easier to estimate the contact area provided the dynamics of the dispersed phase (size distributions, breakup, coalescence, etc.) are properly accounted for. This can eventually be accomplished, provided CFD analysis is carried out meticulously by slowly increasing the problem complexity. (Abstract shortened by UMI.)...