Influence of the wake behind bubbles on the fluid mechanics and mass transfer in bubble columns

Phenomena arising from the wake behind solid and fluid particles moving in a continuous liquid are reviewed. The wake plays an important role in the fluid dynamics and has a pronounced influence on heat and mass transfer in two-phase dispersions. After reviewing the classical models for bubble columns, new and more sophisticated models are introduced, which take into consideration, qualitatively, recirculation caused by liquid transport by the wake behind a bubble moving upward, and radial transfer of fluid elements between the wake and the surrounding liquid. These models require further quantitative mathematical analysis before they can be used in practical applications.