Development of Serrated Multi-Electrode Plasma Actuators for Enhanced Force Production

Abstract

The advantage in the thrust performance of the trielectode (TED) plasma actuator with serrated electrode edge was investigated. The trielectrode actuators have an additional exposed electrode, to which high DC voltage is applied, on the opposite edge of the buried electrode of the exposed AC electrode of SDBD plasma actuator. To prevent the uneven distributions of the discharge, the intentional dent that is evenly spaced on the exposed electrode was introduced. In this research, the induced body force of the TED plasma actuator was investigated on quiescent air by measuring thrust of the induced jet. A timeresolved PIV was used to acquire a velocity field in the quiescent air to measure the induced jet structure. To clarify the performance improvement mechanism, discharge plasma and flow field were numerically simulated. From the results of the thrust measurement, it is confirmed that the serrated TED plasma actuator enhances the thrust compared to the straight-edge TED plasma actuator especially at high DC voltage regimes. The absolute thrust attained 82.7mN/m, which was about 2.1 times larger than the straight-edge TED actuator and 17.5 times larger than the standard SDBD plasma actuator at the same conditions. The power efficiency became twice of the straight-edge TED plasma actuator and more than six times better than the SDBD plasma actuator at the same time. The PIV analysis clearly show that the serrated TED plasma actuator generate a uniform pattern of facing jet from both of the electrode for the positive DC voltage case, because of the uniform generation of the plasma from the sawtooth vertexes. For the negative DC voltage case, the uniformity of the induced flow was not improved.