A study on the inclusion of forest canopy morphology data in numerical simulations for the purpose of wind resource assessment

• Use of architectural model trees, stereo-PIV and photographic analysis software has produced high quality canopy flow data for CFD validation.
• Including a representative description of the heterogeneous nature of canopy structures minimises the error observed in CFD simulations.
• Cheap and effective tools exist to effectively capture these required morphology data.
• SST turbulence closure model is best able to capture the detail of the presented canopy flow.

A series of numerical simulations of the flow over a forest stand have been conducted using two different turbulence closure models along with various levels of canopy morphology data. Simulations have been validated against Stereoscopic Particle Image Velocimetry measurements from a wind tunnel study using one hundred architectural model trees, the porosities of which have been assessed using a photographic technique.It has been found that an accurate assessment of the porosity of the canopy, and specifically the variability with height, improves simulation quality regardless of the turbulence closure model used or the level of canopy geometry included. The observed flow field and recovery of the wake is in line with characteristic canopy flows published in the literature and it was found that the shear stress transport turbulence model was best able to capture this detail numerically.