Effect of Upstream Deflector Utilization on H-Darrieus Wind Turbine Performance: An Optimization Study

Abstract

This paper aims to enhance the performance of H-Darrieus Vertical Axis Wind Turbine (VAWT) via introducing upstream deflectors. The impact of this addition has been investigated and discussed through different deflector configurations. The turbine performance before and after adding different wind rotor barriers was compared. A two dimensional, incompressible, transient, and turbulent flow model was built up in order to simulate the air flow around the turbine blades. Model verification and validation were performed through comparing the model solutions using different mesh sizes, time steps, turbulent models, and discretization schemes. Computational Fluid Dynamics (CFD) models were validated to provide novel insights on the effect of the deflectors on the aerodynamic characteristics of a VAWT blades. Results showed that the presence of a single deflector increases the highest value of the moment coefficient of the bare configuration by 24%, either increases the negative torque values, while two defectors increase the maximum value by 22% and the overall average value of the moment coefficient over the optimal range for the tip speed ratio.