No abstract

No abstract

Improving the performance of a dielectric barrier discharge plasma actuator (DBDPA) is required to further its practical use. In this study, the effects on DBDPA performance by the AC voltage waveform are experimentally investigated. For this purpose, we performed thrust measurements, consumption power measurements, and body force analysis using particle-image-velocimetry. Observations obtained using the basic symmetric waveforms yielded that changing the voltage gradient (dV/dt) like a sinusoidal waveform is effective to produce a strong body force with low consumption power. Therefore, we firstly propose the waveforms systematically composed of combinations of steep and gradual voltage slopes. In the investigation about proposed waveforms, we found that the negative steep-gradual voltage profile is effective for strong thrust induction, that is, the steep slope results in strong body force generation by a strong discharge, and the gradual slope maintains that body force. On the other hand, the effective positive-going voltage profile is different depending on the negative voltage profile. The positive steep-gradual profile works to induce body force with the same mechanism as the negative one, while the gradual-steep profile maintains the body force generated in the last negative-going voltage period and enhances the body force generated in the forthcoming negative-going voltage period. However, a positive-going voltage period itself generates only a weak body force independent from the voltage profiles. From the investigation, we found that a combination of the steep-gradual profile in both the negative- and positive-going voltage periods provides the strongest thrust generation. In addition, we further optimized the voltage waveform by changing the proportion of the negative-going voltage period in one AC cycle. We found that a waveform with a 70% negative-going voltage period achieves more than 40% stronger thrust and 20% higher efficiency than those of the sinusoidal waveform. Also, the waveform with an 80% negative-going voltage period yields over 35% stronger thrust with the highest efficiency, 25% higher than the sinusoidal waveform.

No abstract

No abstract