Analysis of Airfoils Modifications on Horizontal Axis Wind Turbine Blades

Abstract

This project investigates the combination of upper surface dimples and trailing edge serrations of a 3D thin airfoil and their effect on aerodynamic performance. Dimples are known to reduce a golf ball’s drag while a serrated trailing edge is known to reduce noise. A flatback design is also studied to see if its properties apply to a thin airfoil. The airfoil in the present study is NREL S825, to be 3D-printed with six combinations of the proposed modifications and tested in a wind tunnel. This study has found that the combination of dimples, flatback, and serrations has increased the maximum lift coefficient by 9.85%; however the maximum lift-to-drag ratio has been reduced by 14.4%. Key Terms ⎯ Dimples, Flatback, NREL S825, Serrated Trailing Edge.