A two-scale second-order moment particle turbulence model and simulation of dense gas–particle flows in a riser

A two-scale second-order moment particle turbulence model is developed, based on the concept of particle large-scale fluctuation due to turbulence and particle small-scale fluctuation due to collision. It is then used to simulate dense gas–particle flows in a riser. The predicted results are in reasonable agreement with the experimental results and show the core-annulus flow structure observed in experiments. It is seen that the two-scale model is somewhat better than kf–εf–kp–εp–θ two-phase turbulence model and the single-scale second-order moment two-phase turbulence model (USM–θ model).