Discrete particle simulation of two-dimensional fluidized bed

Numerical simulation, in which the motion of individual particles was calculated, was performed of a two-dimensional gas-fluidized bed. Contact forces between particles are modeled by Cundall's Distinct Element Method (P.A. Cundall and O.D.L. Strack, Geotechnique, 29 (1979) 47), which expresses the forces with the use of a spring, dash-pot and friction slider. The gas was assumed to be inviscid and its flow was solved simultaneously with the motion of particles, taking into account the interaction between particles and gas. The simulation gives realistic pictures of particle motion. Formation of bubbles and slugs and the process of particle mixing were observed to occur in the same way as in experiments. The calculated pressure fluctuations compared well with measurements.