| Description |
Wind ow through vegetative canopies plays an important role in many physical phenomena in the environment. Mean and turbulent characteristics within the canopy directly drive moisture and energy transport between the earth's surface and the atmosphere. Areas such as particle dispersion and deposition, airborne pathogen transport, and surface energy balance problems must properly account for turbulent mixing within the canopy layer. Sparse organized canopies, such as grape vineyards, are a special case of vegetative canopies that have received considerably less attention than horizontally homogeneous canopies. This work describes several experimental e orts to improve the understanding of ow through complex canopies and particle dispersion and deposition. First, a series of detailed wind tunnel experiments quantifying the role of turbulence on PM10 particle deposition onto realistic vegetative elements is presented. The resulting model shows substantial improvement compared to previous inertial deposition models. Next a full-scale turbulence and particle dispersion eld experiment was performed on a mature vegetative windbreak in southern Idaho. This unique experiment is the rst windbreak eld experiment to produce pro les of turbulence in a transect along with co-located particle plume concentration data. The results are used to validate the QUIC-URB and QUIC-Plume windbreak models and show very good performance of the model. Finally, a Particle Image Velocimetry (PIV) wind tunnel study focused on understanding the unique character of turbulence in a model vineyard canopy is presented. The results provide a detailed spatial understanding of the role of turbulent structures within sparse organized canopies and the e ect of row spacing on the ow eld. The rich spatial ow eld results were then used on a Large-Eddy Simulation (LES) a priori study to determine the performance of several common LES sub- lter scale (SFS) models when applied to heterogeneous canopies. |
