Effects of Oxygen Content on the Behavior of the Dielectric Barrier Discharge Aerodynamic Plasma Actuator

Atmospheric pressure dielectric barrier discharge plasma actuators are experimentally investigated. The temporal force characteristics and dielectric surface charging are determined using interferometry and split electrode techniques. The experiments are conducted at atmospheric pressure in diminishing levels of oxygen content in order to investigate the effects of oxygen ions. The results show that the force production is dominated by oxygen ions down to a level of 2-5% oxygen content. Temporal force measurements show that the plasma accelerates the air twice during the bias cycle for all oxygen levels including pure nitrogen. Surface charging measurements show that, for oxygen content levels above 5%, a positive voltage region builds up on the dielectric downstream of the actuator. In the absence of oxygen, no such build up is observed. The temporal force production characteristics in the pure nitrogen discharge appear to be greatly affected by the dielectric surface charging. Finally, at a 20% oxygen content level, the majority of the force is produced by the actuator while the exposed electrode is negative. When all of the oxygen is removed, the majority of the force is produced while the exposed electrode is positive.