Simulation of rectangular fluidised bed with Geldart D particles.

In this study, simulations are carried out using the Euler-Euler granular model in STAR-CCM+ for a gas-solid flow in a rectangular bubbling fluidized bed. The problem studied was announced as Small Scale Challenge Problem (SSCP-I) in 2013. Experiments for this problem were conducted by The Department of Energy's (DOE) National Energy Technology Laboratory (NETL). The objective of this numerical study is to evaluate the reliability of the kinetic theory based granular model (KTGF) in predicting the hydrodynamics of gas-solid flows. The experimental measurements of the bubbling fluidized bed investigated in this numerical study are 3"x9"x48". The bed material for the experiment is Geldart group D particles of uniform size and high sphericity. Simulations were performed for all the three gas superficial velocities (U = 2.19, 3.28 and 4.38 m/s) for which experiments were conducted. Results from numerical simulations are validated for vertical component of particle velocity, horizontal component of particle velocity, granular temperature and the mean axial pressure gradient. The effect of the treatment at wall boundaries and coefficient of restitution (particle-particle interactions) is studied on the results