Aerodynamic effects of laminar separation bubble on wind turbine iced airfoil during accretion

Ice accretion on aerodynamic surfaces is associated with different profiles depending on the atmospheric and meteorological parameters. In this research, the aerodynamic effects of the laminar separation bubble region on the wind turbine cross section with DU93W210 airfoil have been studied. Four iced profiles under unsteady wind shear conditions at the nominal speed of the wind turbine have been introduced as an initial assumption. Computational fluid dynamics analyses have been performed using the finite volume discretization and turbulence calculations using the Reynolds-averaged Navier–Stokes equations, with solving the stress term using the shear stress transport of k–ω method. The results have been investigated by comparing the separation and reattachment points and the separation bubble length of the airfoil pressure side and suction side areas at different angles of attack. The separation bubble region remains shorter than 25% of the clean airfoil chord across various ice accretion time steps and flow angles of attack. Additionally, the rate of change in the pressure center location increases more significantly with rising angles of attack than with ice accretion duration. Iced airfoils significantly reduced aerodynamic efficiency, mainly due to lower lift and higher drag. At an angle of attack of 6°, efficiency dropped by 76.2% compared to a clean profile, showing how ice buildup severely impacts performance over time.