A Comparison of Coarse-resolution Numerical Simulation with Experimental Measurements of Wind Turbine Aerodynamic Performance

Coarse-resolution computational fluid dynamics simulations using the unsteady Delayed-Detached-Eddy simulation (DDES) and the steady Reynolds-Averaged Navier-Stokes (RANS) methodologies were conducted to predict the aerodynamic performance of the Fortis Montana 5.8-kW horizontal-axis wind turbine (HAWT). The turbulence models used for the closure of the DDES and RANS methodologies were the one-equation Spalart-Allmaras model and the two-equation shear stress transport k − ω model, respectively. To assess and validate the predictive performance of these two simulation strategies conducted with coarse-resolution computational grids, experimental measurements of the Fortis Montana 5.8-kW HAWT were conducted at the 9 m × 9 m National Research Council Canada wind tunnel. Results of a detailed comparison between the wind tunnel experimental measurements and the model predictions are presented. It was found that predictions of the power curve using the DDES methodology yielded good conformance with the associated experimental measurements. Furthermore, it was found that the RANS method fails to capture the correct power output at moderate and high tip speed ratios. It is concluded that accuracy in a wind turbine power curve prediction using the relatively coarse mesh in this study is probably satisfactory for most real-world industrial and engineering applications.