Experimental investigation on airfoil stall separation suppression by plasma actuation

Experimental investigation of plasma actuation based on NACA 0015 airfoil stall separation suppression is performed under low Reynolds number conditions. Research on how plasma actuation voltage, number of actuated electrode couples, actuation position and Reynolds number affect the flow separation suppression effect is done. Plasma actuator with asymmetric electrode distribution was laid on the airfoil suction surface. When the inflow velocity is 4.27 m/s and corresponding Reynolds number is 4.96 × 10⁴, obvious leading edge flow separation occurs on the airfoil suction surface since the angle of attack is 9° under no plasma actuation condition. Flow separation can reattach when the angle of attack is below 26° under plasma actuation. Experimental results indicated that, plasma actuation magnitude need to be higher when the flow separation becomes more serious, while the actuation voltage and actuated electrode couple number should be higher correspondingly. At a certain flow separation state, there are threshold values of plasma actuation voltage and couple number. The best position of plasma actuation is just the leading edge of flow separation origin line. When the Reynolds number becomes larger, flow separation becomes even harder to be suppressed.