Performance enhancement of small-scale wind turbine featuring morphing blades

Abstract

The demand for renewable energy is driven by the depletion and adverse environmental impacts of fossil fuels. There is a growing global consensus for research and development of renewable energy, including wind. In the current study, National Renewable Energy Laboratory (NREL) Phase VI wind turbine blade is integrated with morphing trailing-edge, installed on the aft-30% blade chord, across outboard 75% blade span. The morphing trailing-edge generates unique topology for each wind speed such that the glide ratio is maximized along the blade span. Three-dimensional transient computational fluid dynamics (CFD) analyses are conducted over low to medium wind speeds to investigate the blade aerodynamics. The analyses exhibit significant increments in the low-speed shaft torque and power of the morphed blades compared to the baseline. The integration of morphing trailing-edge high-lift flow control mechanism on the NREL Phase VI blade enhanced energy harvesting and reduced the wind turbine cut-in wind speed. Comparative investigations are also conducted to assess the improvements in thrust, bending moment, and aerodynamic load distribution, as well as alterations in the pressure, flow field, turbulence, surface flow, and wake. The aeroacoustics directivity of the wind turbines exhibits marginal far-field noise increment in case of morphing trailing-edge integrated blades.