Computational Studies of Horizontal Axis Wind Turbines Using Advanced Turbulence Models

The work presented in this paper aims to study the aerodynamic characteristics and performance of the NREL phase II rotor that is a horizontal axis upwind wind turbine rotor using a commercial 3-D Navier-Stokes solver FLUENT®. This solver is third order accurate in space and second order accurate in time, and uses an implicit time marching scheme. In this study, four turbulence models including Spalart-Allmaras (S-A), Standard k-, RNG- k-  and SST k- models were used and evaluated. These models are considered to be the work horses of the turbulence modeling literature. The numerical results for considered wind turbine rotor were compared to  the available experimental data. An unstructured grid of approximately 2 million cells is generated using the GAMBIT software, was used in computations. The comparisons show that CFD results along with the turbulence models used can predict the span-wise loading of the wind turbine rotor with reasonable agreement.