Description of dispersed two-phase turbulent flow in the Lagrangian approach

Turbulent two-phase participate flows are considered. Emphasis is put on the modelling issue and, in particular, on the class of models based on the Langevin equation. New model for particle dispersion in the Lagrangian approach is introduced. Physical arguments behind this model are quite different from those previously proposed in the literature, for some averaged characteristics of the relative motion of solid-fluid particle pairs are considered rather than instantaneous relative velocities. The model takes both particle inertia and external force effects into account. Its performance is examined by comparison with existing experimental data on particle dispersion in grid turbulence and with the outcome of a numerical experiment (the Large-Eddy Simulation). The obtained results are found to be satisfactory.