Flow separation critically limits airfoil performance, especially at high angles of attack relevant to unmanned aerial vehicles (UAVs) and short takeoff and landing (STOL) aircraft. This study investigates the aerodynamic and energetic impact of integrating a rotating cylinder at the leading edge of a NACA 2415 airfoil. Using unsteady two-dimensional simulations at low Reynolds number ( \(\text {Re} \approx 2 \times 10^5\) ), we assess the effects of cylinder radius and its tangential-to-freestream velocity ratio. This non-dimensional quantity governs the strength of momentum injection into the boundary layer. Results show that increasing both radius and velocity ratio enhances lift and delays separation, with the lift-to-drag ratio ( \(C_\text {L}/C_\text {D}\) ) peaking for large radii and high relative speeds due to stronger circulation. However, at low angles of attack—where the baseline flow is already attached—the rotating cylinder adds drag without improving lift, leading to reduced overall performance. Energy analysis further reveals diminishing returns beyond a certain input. These results highlight the potential of Magnus effect-based flow control for enhancing aerodynamic performance in challenging flight regimes. Future work should include three-dimensional simulations and experimental validation to capture spanwise structures and refine the assessment of practical limitations.
