Large Eddy Simulation of Flow Over Streamwise Heterogeneous Canopies: Quadrant Analysis

Abstract

Large eddy simulations of flow over heterogeneous forest canopies are performed. Each simulated forest consists of equal-sized strip canopies which alternate in the streamwise direction between sparse and dense leaf area density. Quadrant analysis is then used to investigate the eddy fluxes near the top of the forest with an eye towards developing a parameterisation of particle motion through the forest. The quadrant analysis demonstrates that the sweep-ejection cycle is modified by the canopy heterogeneities. The greatest modifications occur with the largest difference in leaf area densities. Ejections appear to be enhanced over canopy heterogeneities of intermediate length. Forests with la..