Effect of vegetative canopy architecture on vertical transport of massless particles

摘要: Large-eddy simulations of approximately resolved heterogeneous vegetative canopies with repeating row structure were compared to ‘equivalent’ homogeneous explore how overall canopy density and horizontal heterogeneity influence the vertical transport non-depositing massless fluid parcels. A Lagrangian approach was used quantify particle dispersion. The subgrid component motion modeled a Langevin equation that integrated new semi-implicit scheme successfully minimized rogue trajectories. With trajectories controlled, model had negligible impact on average statistics. Analysis suggested above top, minor effect mean profiles concentration flux. However, increasing resulted in linear increase residence time, increased importance release height escape. time persistent motions did not follow this monotonic trend. For sufficiently dense canopies, scale decreasing agreement mixing-layer scaling. As wall shear became significant, transition observed which persistence decreased density. well correlated strength dispersive fluxes. Canopy for escape canopy, also reduced coherence motions.