Numerical Study of Plasma Actuator Placement for Flow Separation Control on a NACA ۶۴۱۲ Airfoil

We numerically assess how chordwise placement of a single dielectric barrier discharge (DBD) plasma actuator affects separation control on a cambered NACA ۶۴۱۲ airfoil at α = ۱۲° for U∞ = ۱ and ۱۰ m/s (Re ≈ ۶.۸۵×۱۰^۴ and ۶.۸۵×۱۰^۵, respectively). Steady RANS (SST k-ω) is coupled with a Shyy-type body-force model to represent the actuator. In the baseline, separation forms on the suction side with onset near x/c ≈ ۰.۶۰ at ۱ m/s and x/c ≈ ۰.۷۰ at ۱۰ m/s. Four plasma actuator locations are evaluated: x/c = ۰.۰۳ (LEL), ۰.۱۰ (LER), ۰.۴۰ (TEL), and ۰.۶۵ (TER). Simulation results indicated that placement strongly governs authority by determining where momentum is added to the boundary layer. A leading-edge actuator at x/c ≈ ۰.۰۳ consistently yields the best outcome, delaying or removing separation, strengthening the suction peak, and promoting smooth pressure recovery, especially at ۱۰ m/s. A downstream actuator near x/c ≈ ۰.۶۵ is the next most effective, targeting the vicinity of natural separation. LER (x/c ≈ ۰.۱۰) is the least effective, especially at ۱۰ m/s, where residual trailing-edge separation remains. For placements aft of the maximum thickness, very strong actuation (plasma jet ≫ free-stream) can induce a laminar separation bubble and increase drag despite lift gains. These findings offer practical guidance for selecting actuator position and strength on cambered airfoils at moderate incidence.

کلیدواژه ها:

Flow control ، DBD plasma Actuator ، Separation ، Control ، Momentum Injection ، NACA ۶۴۱۲