A Lattice Boltzmann model and Particle Image Velocimetry measurements of the flow within and above a modeled canopy

The flow through and above forest canopies which cover much of the Earth's surface is abundantly non-uniform and complex. Since it is an essential ingredient to multi-scale transport-modeling, such as material evaporation and dispersion, simplified flow models which can incorporate additional physics are advantageous. In this talk we present a two dimension lattice-Boltzmann study of the volume-Reynolds average Navier-Stokes (VRANS) equations which we derived for a finite canopy model. The approach  can be used to study the effect of leaf-area-density (LAD), turbulence intensity and boundary conditions on the flow through non-uniform canopies. We compare several solutions with detailed flow measurements obtained by a Particle Image Velocimetry at various regions along the finite canopy, and reveal the importance of the dispersive stress terms to the average momentum.