Comparison of DBD plasma actuators flow control authority in different modes of actuation

The principal mechanisms by which DBD plasma actuators influence flow characteristics, and are thus able to control that flow, depend strongly on their modes of actuation. Here two different modes based on steady and unsteady actuation are compared and investigated. A simple sinusoidal voltage distribution and a duty cycled sinusoidal voltage were considered for these purposes. Leading edge separation around a stalled NACA 0012 airfoil at Re=3×106 is considered as test case. A simplified phenomenological model which uses the correct scale of the plasma body force is considered for the modeling of the plasma actuator effects. The steady actuation results show that flow control can be effectively achieved by this mode of operation with continuous injection of momentum in the boundary layer. Unsteady actuation with an imposed frequency equal to the calculated natural frequencies of the flow gives rise to a resonance actuation effect.