Simulation of a Swirling Gas-Particle Flow Using Different k-epsilon Models and Particle-Parcel Relationships

We performed several numerical simulations of a co-axial particle-laden swirling air flow in a vertical circular pipe. The air flow is modeled using the unsteady Favre-averaged Navier-Stokes equations. A Lagrangian model is used for the particle motion. The results of the simulations using three versions of the k — e turbulence model (standard, re-normalization group - RNG, and realizable) are compared with experimental mean velocity profiles. The standard model achieved the best overall performance. The realizable model was unable to satisfactorily predict the radial velocity; it is also the most computationally-expensive model. The simulations using the RNG model predicted extra recircula-tion zones. We also compared the particle and parcel approaches in solving the particle motion. In the latter, multiple similar particles are grouped in a single parcel, thereby reducing the amount of computation.