Time-Dependent Simulation of a Swirling Two Phase Flow Using an Anisotropic Turbulent Dispersion Model

Time-dependent simulations of a particle-laden swirl flow in a pipe expansion based on the Euler-Lagrange approach are presented. Two equation and Reynolds Stress Models were used in the calculation of turbulent quantities in the continuous phase. Additional attention was payed to the influence of particle dispersion. The instantaneous fluid velocities seen by the particles was reconstructed by different dispersion models. To come to a time dependant solution for the Euler-Lagrange approach, a quasi-unsteady approach is taken. This results in a calculational scheme where one Eulerian time-step is divided in a number of Lagrangian steps. Particle source term are sampled which represent the influence of the disperse phase on the flow field. which call for additional coupling within one Eulerian time step. The effect of inter-particle collisions on the movement of the disperse phase is accounted for using a stochastic inter-particle collision model. Special interest of this study was the formation of dust ropes which are observed in such flows.