Hydrodynamic behavior analysis of pulsed disc and doughnut column by
CFD-PBM with modified drag law
Abstract
With increasing pulsation intensity from zero, the dispersed-phase
holdup in pulsed disc and doughnut column (PDDC) decreases at first and
then increases, which forms a U-shape trend. In this study, the modified
drag law which is to account for the effect of turbulence is used for
predicting the dispersed holdup with Computational Fluid Dynamics (CFD)
simulations. The population balance model (PBM) kernel functions
obtained from literatures are coupled with the CFD method to investigate
the influence of drag law on the hydraulic performance of PDDC. The
results indicate that the U-shape trend of dispersed holdup is
successfully predicted with the modified drag law. The droplet size
distribution and Sauter mean diameter with modified drag law is
predicted better than that with Schiller-Nauman drag law. Local
hydraulic performance and drag force field are illustrated to depict the
typical flow behaviors in PDDC.