Dispersion of passive tracers in a confined convective flow

A confined convective flow is experimentally studied at different Rayleigh numbers. Particle Tracking Velocimetry (PTV) technique is used both to reco nstruct Lagrangian trajectories and to evaluate Eulerian flow field. Disper sion properties of the flow are investigated by means of Lagrangian statist ics on particle displacements, For each run of the experiment, single parti cle statistics have been evaluated both on the whole set of trajectories an d by selecting trajectories starting in phase from different region of the flow domain. These regions are identified according to the local geometrica l characteristics of the velocity field. (C) 2001 Editions scientifiques et medicales Elsevier SAS.