Effects of pulse polarity on nanosecond pulse driven dielectric barrier discharge plasma actuators

Nanosecond pulse driven dielectric barrier discharge plasma actuators are studied in quiescent air using a power supply capable of negative and positive polarity waveforms. The effects of pulse amplitude, actuator length and dielectric thickness are also investigated. Schlieren images are used to estimate the relative heating effects for each polarity. Electrical measurements are acquired simultaneously. Negative polarity pulses develop slightly more per unit length energy for thin actuators while positive polarity is slightly higher for thicker actuators. In most cases, the difference in per unit length energy produced by positive and negative pulses on equivalent actuators is not outside the measurement uncertainty. Negative polarity pulses are found to produce a stronger pressure wave across the majority of the test matrix. Results indicate that the negative polarity pulse more efficiently couples electrical energy to the near surface gas as heat. This suggests negative polarity pulses may be preferred for flow control applications.