In the present work, a narrow span-wide rectangular channel (referred to as a slot) is introduced and drilled near the leading edge of a finite-span cambered airfoil to study its impact on the overall aerodynamic performance. These slots are proposed to have two legs, where the first leg starts from the vicinity of the leading edge, and the second leg exits from the pressure-side of the airfoil. NACA 4412 is used as the baseline airfoil profile, and the influence of several geometrical parameters of the slots at different angles of attack (AoAs) ranging from 0 to 16 degrees are investigated on the lift and drag coefficients. The influence of slot's length, width, and exit angles are studied, and it is demonstrated that longer and narrower slots that exit more aligned with the pressure-side streams are generally more suitable, and can result in better performance over the entire range of AoA. For the best case considered, a lift coefficient improvement as large as 15% is observed, while the drag penalty is insignificant. Furthermore, the inlet angle and the vertical position of slots are independently varied within reasonable ranges to characterize the slots further. Computational fluid dynamics (CFD) is used for modeling and analysis. Simulations are performed at the chord-based Reynolds number of 1.6E6. Results are validated against published data and the results from a set of wind-tunnel experiment.
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