Computation of circulating fluidized-bed riser flow for the Fluidization VIII benchmark test

Conservation of mass and momentum equations for the solid and for the gas phases was used to compute the hydrodynamics of flow of fluidized catalytic cracking particles in a vertical pipe (riser) for the 1995 benchmark modeling contest. The computer code predicted a new phenomenon: an off-center maximum flux. The computed time-average radial fluxes and particle concentrations agree with PSRI experimental data. The computer code also predicted the observed core-annular flow regime. For the lowest gas velocity and highest solids flux, the code predicted low-frequency, snakelike density oscillations.