Numerical investigation on the effect of specularity coefficient on hydrodynamics of gas-solid flow in spout fluidized bed with draft plates

Numerical simulation of dense gas-solid flow in a spout fluidized bed with draft plates was carried out using the Eulerian-Eulerian multi-fluid approach incorporating the kinetic theory of granular flow (KTGF). To save the computational time, simulation was performed in two-dimensional framework. Different values of specularity coefficient, which is important parameter of particle-wall boundary condition in, rang of 0.0001 to 0.1, were used. Numerical results show that by increasing the specularity coefficient, time-averaged particle flux increases in spout region and decreases in annulus region. The best agreement of solid axial velocity with experimental data was achieved for specularity coefficient equal to 0.03.