Numerical Simulation of Wind Turbine Scale Effects By Using CFD

Numerical analysis of wind turbine scale effect was performed by using computational fluid dynamics. For the numerical analysis of wind turbine, three dimensional Navier-Stokes solver with realizable k-e turbulence model was used. To validate the present method, performance of NREL (National Renewable Energy Laboratory) Phase VI wind turbine model was analyzed and compared with experiment and blind test data. Using the present method, numerical simulations for various sizes of wind turbine models were carried out and scale effects were observed in detail. For the correction of scale effect, a new method based on two dimensional airfoil analysis was introduced and it was applied to NREL Phase VI wind turbines. Finally, KARI (Korea Aerospace Research Institute) performed wind tunnel test of 12% NREL Phase VI wind turbine and the result was corrected by the present method. Granting that the new correction method is valid only above Reynolds No. 100,000, it showed reasonable agreement between scaled model and full scale wind turbines in the linear torque region. Nomenclature