LES-Euler/Lagrange modelling of bubble columns considering mass transfer, chemical reactions and effects of bubble dynamics

Abstract

Based on a LES Euler/Lagrange approach, numerical computations of single bubble rise and bubble swarms in a column were conducted and validated including mass transfer and chemical reactions. Large Eddy Simulation (LES) was used for calculating the fluid flow and modelling turbulence in the carrier phase. Bubble motion was calculated considering all important interfacial forces. A bubble motion dynamic model based on stochastic generation of eccentricity and motion angle is considered, which of course goes beyond the classical point-mass approximation in Lagrangian approaches. Novel composite forces coefficients were applied considering the instantaneous bubble deformation. The effects of bubble dynamics on the mass transfer was modelled by a dynamic Sherwood number. The decay of the volume of CO2 single bubbles rising in water was compared with experimental data. A comparison with experiments for bubble swarms with chemical reaction was also realized and good agreement was found if bubble dynamics is modelled.