On the predictive capabilities of LES-actuator disk model in simulating turbulence past wind turbines and farms

In this paper, we validate an LES (large-eddy simulation)-actuator disk model by comparing the computed results with wind tunnel measurements for both stand-alone wind turbine case and wind farm case. In the actuator disk model, the forces are uniformly distributed. The effects of rotation and the effects of nacelle and tower are not taken into account. Dynamic subgrid scale model is employed in the LES. For the stand-alone wind turbine case, grid refinement studies with three different resolutions are performed. Discrepancies with the wind tunnel measurements are observed in the near wake locations (2D and 3D downstream). However, very good agreements with the wind tunnel measurements are obtained for further downstream locations. For the wind farm case, overall good agreements with the wind tunnel measurements are obtained for the streamwise variations of the streamwise mean velocity and the streamwise turbulence intensity at the bottom and top heights of wind turbines. Some discrepancies with the wind tunnel measurements are observed at the hub height of wind turbines.