An innovative approach for harnessing wind power by Darrieus turbines using a passive flow controller

Abstract The current study investigates the effect of passive flow control strategy to enhance the aerodynamic performance of vertical axis wind turbines (VAWTs), by positioning a passive flow separator (PFS) adjacent to the blade’s leading edge. Using a 2D computational fluid dynamics (CFD) analysis with the shear stress transport (SST) turbulence model to solve the unsteady Reynolds average Navier stokes (URANS) equations, the S1046 aerofoil is investigated under incompressible flow conditions. A range of PFS diameters is tested, with diameter-to-chord ratios (d/c) of 0.0428, 0.05, and 0.054. Results show that incorporating a PFS delays flow separation and significantly improves turbine performance compared to the baseline turbine. The highest power coefficient ( Cₚ ) is achieved at d/c = 0.05, with an enhancement of approximately 27.9%. Additional simulations using different aerofoils reveal that the NACA0012 profile, combined with a circular PFS, yields the highest Cₚ showing a performance gain of up to 45% over others PFS shapes. The impact of turbine solidity is also analyzed, with optimal improvements observed at a solidity of 0.2.