Enhancing Power Output of Ducted Wind Turbines through Flow Control

Abstract

This study focuses on the performance enhancement of a ducted small-scale National Renewable Energy Laboratory (NREL) Phase VI wind turbine, utilizing a Wind Lens diffuser. The investigation is conducted at the critical cut-in wind speed of 5 m/s. The research evaluates the integration of passive flow control devices, including Vortex Generators, Microtab, and Slot, strategically positioned across the Wind Lens to augment the mass flow through the rotor. The results indicate significant amplifications in the turbine output of up to 127%, attributable to airflow manipulation across the diffuser, resulting in increased torque and power output. The study highlights the effectiveness of employed flow control devices in managing turbulence and/or flow separation, thereby enhancing aerodynamics, particularly under low wind conditions. A comprehensive analysis of various parameters such as pressure and flow fields, turbulence, and other relevant metrics is conducted to ascertain their collective influence on rotor aerodynamics. The results demonstrate the potential of these passive flow control devices in advancing small-scale wind turbine technology, especially in regions with low wind potential. Moreover, the design simplicity and cost-effectiveness of these passive flow control devices suggest wider applicability in the renewable energy sector, contributing to the reduction of carbon-intensive energy reliance.