A numerical model for turbulent diffusion in gas-particle flows

A general two-dimensional numerical model for gas-particle flow is presented. The model accounted for two-way gas-particle coupling and the effect of the fluid turbulence on the particle motion. The turbulent interaction between the particles and the fluid was obtained by treating the effect of turbulent diffusion as an averaged body force on the particles. This resulted in the addition of a diffusion drift velocity to the particle velocity equation. The drift velocity was approximated from Fick's law of diffusion, and the difference between the fluid turbulent momentum diffusivity and the particle diffusivity was modeled by prescribing a turbulent Schmidt number. A comparison was made between numerical predictions and experimental data for particle flow in an electrostatic precipitator.