Experimental and Numerical Investigation of Tubercles and Winglets Horizontal Axis Wind Turbine Blade Design

This article presents wind tunnel experimentation and uses simulations to evaluate the performance of a 14 m-rotor diameter residential-scale wind turbine at different wind speeds. The blades of the rotor baseline design are built using GOE 447 airfoil. Five different tubercle designs were applied to the blade's leading edge. One of those designs produces more power than a baseline rotor, with an optimum power improvement of 5.5% achieved at 12.5 m/s wind speed. Furthermore, three winglet designs were added to the tip of the baseline design to investigate their influence on power production. The 90 deg, 60 deg, and 30 deg cant angles produce 5.0%, 7.9%, and 6.9% more power than the baseline design, respectively, at 12.5 m/s. Moreover, it is vital to investigate the effect of integrating leading-edge tubercles with winglets and then evaluate the influence of the combination on the aerodynamic performance and power output of the turbine model. It is found that when combining both techniques on the same blade, the improvement mechanism associated with each of them interferes with the other, leading to poor overall performance and less power in the majority of the run simulations.