Fluctuation velocity correlation closure model for dense gas-particle turbulent flow

Turbulence model of kg-ɛg-kp-ɛp-kpg-θ is proposed. In the model, the two-phase velocity correlation turbulent kinetic energy kpg is modeled by transport equation. To close this turbulence model, algebraic expressions of two-phase Reynolds stresses and two-phase velocity correlation variable are established by considering both gas-particle interaction and anisotropy. This turbulence model is used to simulate dense gas-particle flow in a riser and in a downer. The predicted results show the core-annulus flow structure observed in the riser and the skin effect of particle concentration in the downer. The present model gives simulation results in much better agreement with the experimental results than those obtained by kg-ɛg-kp-ɛp-θ model which is simply closed using a semi-empirical dimensional analysis.