Discharge Stability Enhancement in Surface Corona Actuators

A surface corona actuator for flow control, already tested in wind tunnel experiments, is here characterized at the bench in still air. The anodic electrode is provided with periodic triangular tips and is operated with a pulsed waveform. The operating stability and voltage range turn out to be wider than for dc operation. The actuator is characterized by means of several measurements as a function of the frequency, including power absorption and ionic wind measurements in different locations. The ionic wind is measured first by a micropitot probe obtaining time-averaged values, then by a hot wire anemometer obtaining instantaneous velocities and turbulence spectra. The behavior of the actuator is interpreted accounting for the creation and removal of charges in the gap subject to a periodic excitation.