Optimizing wind energy generation by dimpled wind turbine blades

In this study the effect of dimpled surface blade on the performance of an horizontal axis wind turbine, HAWT, is numerically investigated. The goal is to compare the energy produced along the year with a dimpled surface on the suction side of the turbine and the smooth airfoil. The suction side of the wind turbine has been modified using spherical dimples. The governing continuity and momentum equations are solved using hybrid RANS-LES solution, DES turbulence model in particular, to evaluate the best dimple geometry, coupled with an Unsteady RANS model - Shear Stress Transport - γθ,Re,t - for the evaluation of power produced by the HAWT. Different kind of dimples have been tested, varying the diameter and location along the chord of the blade. The findings indicate that the optimal position occurs when the dimples are located at 30% of the chord length, spanning radially between 15% and 45%. The conducted simulations provide evidence that incorporating the dimpled design, in comparison to the nominal profile, results in a 4.36% increase in the energy generated. This translates to a rise from 2811 kWh/y to 2939 kWh/y, consequently elevating the capacity factor from 21.39% to 22.37%.