Wind tunnel experiments of tracer dispersion downwind from a small-scale physical model of a landfill

Wind tunnel experiments have been carried out on a small-scale physical model of a municipal waste landfill (MWL) in the CRIACIV (Research Centre of Building Aerodynamics and Wind Engineering) “environmental” wind tunnel in Prato (Italy). The MWL model simulates a landfill whose surface is higher than the surrounding surface, applying a 1:200 scaling factor. Modelling an area source such as landfill is a difficult task for numerical models due to turbulence phenomena that modifies the flow near the source increasing ground level concentration (GLC). For the specific task a new set-up of the wind tunnel has been developed, with respect to previous studies carried out on line and point sources physical models. The tracer used in the experiments was ethylene, suitable for non-buoyant plume conditions, typical for MWL emissions. A detailed result data base has been obtained in terms of GLC and concentration profiles as well as flow turbulence and velocity field characterisation.