Pressure Dependence of Dielectric Barrier Discharge Plasma Flow Actuators

Single dielectric barrier discharge plasma actuators were investigated for a range of static pressures from 0.17 to 9.0 bar. The actuator minimum ionization voltage and static thrust were measured and similar data in the literature. The minimum ionization voltage decreased with decreasing pressure; however, at a given pressure, the ionization voltage scaled with the actuator capacitance per unit area. The static thrust was found to have a minimum at a pressure of approximately 2 bar. A narrow local maximum was found near 0.9 bar, below which the thrust decreased. A second broad local maximum occurred near 6 bar. The location of the two local maxima, respectively, moved to lower and higher pressures as the actuator voltage increased. At any pressure, thrust scaled with voltage to a power. The power-law exponent increased linearly with increasing pressure from the lowest pressure tested to approximately 5 bar. Above 5 bar, the power-law exponent asymptotes to approximately 7.3, which was approximately twice that at atmospheric pressure. The experimental results were evaluated using a space-time lumped-element model for single dielectric barrier discharge plasma actuators. The overall trends were found to be best modeled through a pressure dependence of the minimum ionization voltage and the electron density.