Dense Discrete Phase Modelling (DDPM) Approach for Hydrodynamics Study of the Gas – Solid Fluidized Bed

Abstract

This study focuses on the difficult task of forecasting the hydrodynamics of a bubbling fluidized bed that involves fine Geldart A particles. The existing literature has had limited success in simulating this phenomenon. This study utilized two homogeneous drag models, namely the Wen – Yu drag model and the Gidaspow drag model, coupled with the Dense Discrete Phase Model (DDPM) to predict the hydrodynamics of a bubbling fluidized bed. The DDPM methodology is an innovative discrete phase modeling method that can accurately trace the trajectories of dispersed phase and forecast their size distributions. The simulation findings indicate that both the Wen-Yu and Gidaspow models are inadequate in accurately predicting the solid volume fractions. This is due to the fact that these models do not take into account the cohesive interparticle forces and tend to overestimate the drag force. Nevertheless, the simulation outcomes of the Wen-Yu drag model exhibit superior performance when compared to the Gidaspow model. Thus, the Wen-Yu drag model was corrected by incorporating a scale factor C=0.35, resulting in a decrease in the anticipated drag force. This modification led to a notable enhancement in the accuracy of the predicted axial and radial solid concentrations.