Abstract

<jats:p>The interaction between a turbulent gas flow and particle motion was investigated by
numerical simulations of gas–particle turbulent downward flow in a vertical channel.
In particular the effect of inter-particle collision on the two-phase flow field was
investigated. The gas flow field was obtained by large-eddy simulation (LES). Particles
were treated by a Lagrangian method, with inter-particle collisions calculated by a
deterministic method. The spatial resolution for LES of gas–solid two-phase turbulent
flow was examined and relations between grid resolution and Stokes number are
presented. Profiles of particle mean velocity, particle wall-normal fluctuation velocity
and number density are flattened as a result of inter-particle collisions and these
results are in good agreement with experimental measurements. Calculated turbulence
attenuation by particles agrees well with experimental measurements for small Stokes
numbers, but not for large Stokes number particle. The shape and scale of particle
concentrations calculated considering inter-particle collision are in good agreement
with experimental observations.</jats:p>