Numerical analysis for turbulent gas-particle two-phase flows

Abstract

Numerical analyses have been made for gas-particle suspension flows in a vertical pipe as well as in a horizontal pipe using a "two-fluid equation" model. The bulk motion of particles is treated as a secondary fluid flow which exchanges mass and momentum with the primary conveying air stream. Governing transport equations were formulated, allowing two-way coupling between continuous fluid and solid phase. Closure of the equations is achieved by modelling eddy viscosity of the conveying fluid, virtual eddy viscosity and virtual laminar kinematic viscosity of the particulate phase. By incorporating Peskin``s crossing trajectory model, it was found that the present model can be applied in broader range of Stokes number up to about order one. Since the flow characteristics in a horizontal pipe is three dimensional, a numerical algorithm for three dimensional multiphase flow problem has been developed. The predicted mean flow properties of the two phases in both pipes are in good agreement with experimental data.