The objective of this study was to investigate a method to monitor the health of plasma actuators. Common actuator dielectric materials were used in this research, namely Kapton polyimide tape, and those manufactured from printed circuit boards (PCB) having a dielectric of FR-4 composite material. Actuators utilizing these dielectric materials are known to visually degrade during operation. However, a quantitative measure of the degradation of these actuators has not yet been examined. A parametric study was used to identify the role of operational parameters, actuator excitation voltage and frequency, on the rate of the degradation process over long durations. Measurements of the actuator power consumption and capacitance were used quantify the change in actuator health over time. It was shown that both the power consumed and effective capacitance of the plasma actuator may increase considerably during the degradation process, which was related to the thinning of the dielectric layer. Specifically, only the top exposed layer of Kapton was affected, whereas the underlying adhesive layer remained intact. The variation in actuator power consumption and capacitance could be mitigated by considering actuators with an increased number of Kapton tape layers. For actuators having a dielectric of the FR-4 composite material, the presence of the plasma affected the acrylic epoxy however, the woven fibreglass remained in tact. It was shown that over the duration of the experiments the power consumption and effective capacitance decreased for these actuators. Measurements of the wall-jet induced for each actuator type was used to monitor the momentum production over time. The momentum production decreased for the FR-4 actuators over time. For the Kapton polyimide tape actuators, momentum production could increase.
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