Investigation on aerodynamic characteristics of horizontal-axis wind turbine with boundary-layer suction based on γ -Re θ transition model

Abstract

Boundary layer suction (BLS) mitigates flow separation and stall on horizontal-axis wind turbine (HAWT) blades by sucking low-momentum fluid from the suction surface, thereby enhancing aerodynamic performance. Three-dimensional numerical simulations of the National Renewable Energy Laboratory Phase VI wind turbine are performed using the γ-Reθ transition shear stress transport (SST) k–ω turbulence model to investigate the aerodynamic effects of BLS. The numerical results for the clean blade have been validated against the NREL Phase VI wind tunnel experimental data, and this work focuses on the regulatory roles of the momentum coefficient, tip speed ratio (TSR), and spanwise suction slot layout in regulating power output and flow fields. It is demonstrated that BLS effectively enlarges the attached flow area, increases the blade pressure difference, delays separation, and improves flow stability. Significant power gains are obtained at TSRs ranging from 2.5 to 3.8. At the optimal momentum coefficient, the net power output evaluated after deducting the theoretical suction pump power and accounting for additional power losses reaches 193% of that of the clean blade; the gain is observed to increase with decreasing TSR but to drop at an extremely low TSR. Spanwise tip-only control and combined middle-tip control achieve the best aerodynamic performance via the maximum attached flow coverage and suppression of local separation vortices. Numerical results of this work support HAWT active flow control research, and preliminarily prove the γ-Reθ transition SST k–ω turbulence model fits BLS optimization studies.