Turbulence-induced Reconfiguration of Fractal-Branched Trees in a Forest

The reconfiguration of trees and their ability to redistribute and damp aerodynamic forces are essential for their continual survival. In addition, the collective dynamics of trees and their interaction with the atmosphere flow could cause large-scale flow instability and the emergence of coherent wind gusts. In this work, we study the coupling of turbulent flow with rigid and flexible fractal trees in a forest to predict the role of tree flexibility in changing flow field and the creation of large coherent structures. A branched tree is modelled as a fractal multilink dynamic system and large eddy simulation is performed to investigate the interaction of many trees in a canopy with the atmospheric boundary layer. We will show the feedback mechanism between the formation of coherent vortex structures on top of the canopy, substantial dynamic opening in the canopy of reconfigured trees, and vertical drift of coherent flow structures due to more intense fluid-structure interactions. Finally, we discuss how the feedback response between the canopy and boundary layer is affected by branching pattern of trees and their deformability.