Discrete particle simulations of a segregating system are performed using various drag relations and boundary conditions, and compared to experiments. The boundary conditions on the walls are found to have a large influence on the segregation behaviour of the fluidised bed, where no-slip conditions result in unrealistic flow patterns. A polydispersity factor, which was recently derived on the basis of lattice-Boltzmann (LBM) simulations, is found to have a major effect on the segregation velocity and the final degree of segregation. The best agreement with experimental results is obtained with drag relations that were recently proposed based on LBM-simulations in combination with the aforementioned polydispersity factor.
Beetstra, R., van der Hoef, M. A., & Kuipers, J. A. M. (2007). Numerical study of segregation using a new drag force correlation for polydisperse systems derived from lattice-Boltzmann simulations. Chemical engineering science, 62(1-2), 246-255. https://doi.org/10.1016/j.ces.2006.08.054