Large-eddy simulation of turbulent gas-particle flow in a vertical channel: effect of considering inter-particle collisions

The interaction between a turbulent gas flow and particle motion was invest igated 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 met hod, with inter-particle collisions calculated by a deterministic method. T he spatial resolution for LES of gas-solid two-phase turbulent flow was exa mined and relations between grid resolution and Stokes number are presented . Profiles of particle mean velocity, particle wall-normal fluctuation velo city and number density are flattened as a result of inter-particle collisi ons and these results are in good agreement with experimental measurements. Calculated turbulence attenuation by particles agrees well with experiment al measurements for small Stokes numbers, but not for large Stokes number p article. The shape and scale of particle concentrations calculated consider ing inter-particle collision are in good agreement with experimental observ ations.