  Dielectric barrier discharge (DBD) plasma actuators are an attractive option
for separation control, lift enhancement, and drag reduction. Some plasma
actuators feature optimized electrode shapes, electrical waveforms to maximize
the aerodynamic forces at higher angles of attack. Here, we analyze the
performance of a direct current augmented DBD (DBD - DCA) actuator with a
sawtooth shape exposed electrode. The active electrode was positioned at 18%
chord and the electrode at 48% chord of NACA 0012 airfoil. Wind tunnel
experiments were conducted at wind speeds of 15 - 25 m/s, corresponding to
Reynolds number Re = 201k - 335k. Lift coefficient (C$_L$), drag coefficient
(C$_D$), and pitching moment coefficients (C$_M$), were measured with and
without plasma actuation for angles of attack $\alpha$ = 0$^o$ - 8$^o$ and the
DCA electrode potential ($\varphi_{DC}$) was varied from 0 kV to -15 kV. With
energized DCA electrode, the C$_L$ increases up to 0.03 and the C$_D$ decreases
by 50% at 15 m/s flow speeds and 0$^o$ angle of attack, the results are similar
throughout the range of $\alpha$. The effect of the actuator at higher Re
diminishes, suggesting that the maximum control authority could be achieved at
lower wind speeds.
