Effects of Duty Cycles of the Plasma Actuators on Improvement of Pressure Distribution Above a NLF0414 Airfoil

This paper investigates the effects of duty cycle on improvement of pressure distribution above a NLF0414 airfoil using the plasma actuators. Three dielectric barrier discharges as the plasma actuators are flush mounted on airfoil surface in different positions in order to improve pressure at post-stall angle of attacks. The experiments were performed at
$Re_{\rm C} = 7.5 \times 10^{5}$
and the post-stall angles of attacks. The main aim of the related experiments in this paper is to better understand how duty cycles must be applied in order to have the most effective conditions for different excitation frequencies and different angles of attack. Results show that the plasma actuators in unsteady excitations are more effective in lower duty cycles on low excitation frequencies, but the lower duty cycles loss their effectiveness on higher excitation frequencies.