Computational investigation of NREL Phase-VI rotor: Validation of test sequence-S measurements

A CFD-based assessment and validation of the NREL Phase-VI Sequence-S rotor at seven wind speeds presented here. The ability of a three-dimensional, unstructured, unsteady RANS solver in successfully predicting the wind flow interactions with a rotating, twisted and tapered rotor is described. The uRANS equations were coupled with SST κ-ω turbulence model and a correlation-based Gamma-Theta transition model. The simulations were performed in ANSYS CFX using both Single Reference Frame (SRF) and Multiple Reference Frame (MRF) modelling approaches. A good agreement with measurements is observed at six of seven wind speeds when comparing the integral quantities, the spanwise and chordwise distributions. The only exception is the 10 m/s wind speed case, attributed to the onset of a massive leading edge stall around the mid-span region. It is successfully demonstrated here how uRANS-based CFD computations can be effectively employed in the study of wind turbine rotor aerodynamics.