Numerical simulation of gas–liquid–solid fluidization systems using a combined CFD-VOF-DPM method: bubble wake behavior

Abstract

A new approach that can predict the characteristics of discrete phases of three-phase flows is provided in this study. In this model, the gas–liquid–solid flow in a fluidized bed is simulated by a combined method of the computational fluid dynamics (CFD) with the discrete particle method (DPM) and a volume-tracking represented by the volume-of-fluid (VOF) method. A bubble induced force model, a continuum surface force model and Newton's third law are, respectively, applied to account for the couplings of particle–bubble (gas), gas–liquid and particle–liquid interactions. A close-distance interaction model is included in the particle–particle collision model, which considers liquid interstitial effects among particles. Simulations of gas bubble rising in water in a small two-dimensional bed (height 0.1 m, width 0.06 m) with 1000 particles (glass beads, d p =0.8 mm, ρ p =2500 kg m −3) show that the model can capture the bubble wake behavior such as the wake structure and the shedding frequency. The simulation results are in good agreement with the experimental findings.