CFD modeling of flow over terrains with surface roughness discontinuities
Atmospheric Flow, Vegetation Surface Roughess, Large Eddy Simulation
Deforestation in Brazilian forests, especially in the Amazon and cerrado, affects biodiversity, climate and local populations, and alters the interaction between the forest and the wind. these interactions between the wind and the forest can be influenced by the surface roughness of the forest, which in turn affects the resistance to wind flow. Disturbances in the turbulent wind flow can lead to various effects, such as changes in the evaporation rate and the circulation of seeds and pollutants. Numerical modeling and simulation tools have been instrumental in studying this wind-forest interaction. Large Eddy Simulation (LES), in particular, has been useful to study turbulent wind flow through forests. However, most studies have focused on homogeneous forests in temperate climates, leaving a gap in knowledge about how this phenomenon manifests itself in tropical forests, such as those found in Brazil. In this study, we performed LES simulations of turbulent wind flow past a clearing to a forest, and from a forest to a clearing, in order to analyze vertical and horizontal profiles of turbulent wind flow by comparing them with experimental data from the literature. The simulations represented the turbulent velocity profiles well, although other profiles of turbulence intensity and momentum fluxes need a better fit, possibly with improved boundary conditions. Even so, the profiles follow trends observed in previous studies. The analysis of the momentum transport equation, through the horizontal profiles, shows the relevance of the advection terms and the pressure gradient near the forest edge. As a proposal for future work, a new simulation study will be carried out to study the interaction of wind with clearings in a tropical forest, using LES and realistic forest modeling. The research will use experimental data from Brazilian forests and the tools of Computational Fluid Mechanics to offer a deeper and more realistic analysis of the wind interaction with the forest.