Effects of Turbulence Models on the Nacelle Anemometry of Horizontal Axis Wind Turbines

Turbulence Modeling constitutes the most critical part in wind turbine computations. The most popular turbulence models based on the approach of Reynolds Averaged Navier Stokes equations (RANS) are k-ε and k-ω, because of their low computation cost and acceptable accuracy. The present work investigates the effect of some turbulence models such as k-ε and k-ω Shear Stress Transport on the numerical predictions of nacelle anemometry measurements of the horizontal axis wind turbine NORDEX N80. Numerical simulations have been carried out for a steady state, two dimensional and axisymmetric flow conditions around the wind turbine nacelle. Relationships between the free stream wind speed upstream of the rotor and the nacelle wind speed measured by the anemometer downstream of the rotor in the near wake region have been established. Anemometer velocities were computed for different free stream wind speeds ranging from 5 to 25 m/s. Simulation results have been found to agree well with experimental measurements of the Energy research Center of the Netherlands ECN.