Verification of a low cost scale-adaptive CFD formulation for waked wind turbines

Large-eddy simulation (LES) models have been widely used for wind farm simulation and control research. However, LES is still computationally expensive when applied to large computational domains, multiple interacting wind turbines and extended simulation time intervals. To address this problem, the present work considers a turbulence model based on the von Kármán length scale, termed scale-adaptive simulation (SAS), and investigates its characteristics with respect to the LES model. The incompressible SAS formulation is reviewed first, and compared to the conventional k-ω shear stress transport (SST) model. Next, results from wind tunnel measurements of scaled wind turbines are used to investigate the performance of the SAS and LES formulations. The two methods are compared in terms of wind turbine wake characteristics, rotor integral quantities and computational effort. Results indicate that, for the cases considered here, SAS appears to be a valid moderate-accuracy low-cost alternative to LES.