The present work provides an experimental investigation of a novel MEMS SDBD plasma actuator based on quartz substrate as dielectric barrier material (AF32@Schott 0.3 mm-thick) and two titanium-tungsten electrodes owning a thickness of 210 nm, undergoing sinusoidal plasma actuation. Experiments are conducted in a vacuum chamber over a wide pressure range, from 20 kPa to values of reduced pressure of 0.01 Pa. iCCD visualizations and electrical signals (current/voltage/power) define the diagnostic toolbox. Results highlight that at 20 kPa the plasma discharge is driven by formation of micro sparks on the inner edge of the exposed electrode, which propagate downstream in larger current structures. At 1 kPa, the plasma discharge becomes more glow type with negative current regimes longer than the positive ones, while the voltage signals preserve their sinusoidal shape. In such a plasma regime, the discharge extends over the entire region cover by the electrodes, suggesting the use of larger grounded electrodes to further enlarge the actuation region. Furthermore, the momentum action of the plasma discharge is not anymore unidirectional as it acts on the whole SDBD plane. At pressure between 50 Pa and 2.5 Pa, the plasma discharge is unstable exhibiting a fast modification of the plasma discharge. Below 2.5 Pa, it becomes volumetric full glow type, extending its action mainly upstream with a higher plasma density on the exposed electrode. The establishment of the new plasma regime at pressure below 2.5 Pa is also retrieved in negative electrical dissipated powers and asymmetric shapes of both voltage and current signals.
Experimental assessment of a MEMS surface DBD plasma actuator for active flow control in air-breathing space vehicles
Fontanarosa D.;Toscano A. M.;Signore M. A.;Pescini E.;De Giorgi M. G.;Ficarella A.;
2022-01-01
Abstract
The present work provides an experimental investigation of a novel MEMS SDBD plasma actuator based on quartz substrate as dielectric barrier material (AF32@Schott 0.3 mm-thick) and two titanium-tungsten electrodes owning a thickness of 210 nm, undergoing sinusoidal plasma actuation. Experiments are conducted in a vacuum chamber over a wide pressure range, from 20 kPa to values of reduced pressure of 0.01 Pa. iCCD visualizations and electrical signals (current/voltage/power) define the diagnostic toolbox. Results highlight that at 20 kPa the plasma discharge is driven by formation of micro sparks on the inner edge of the exposed electrode, which propagate downstream in larger current structures. At 1 kPa, the plasma discharge becomes more glow type with negative current regimes longer than the positive ones, while the voltage signals preserve their sinusoidal shape. In such a plasma regime, the discharge extends over the entire region cover by the electrodes, suggesting the use of larger grounded electrodes to further enlarge the actuation region. Furthermore, the momentum action of the plasma discharge is not anymore unidirectional as it acts on the whole SDBD plane. At pressure between 50 Pa and 2.5 Pa, the plasma discharge is unstable exhibiting a fast modification of the plasma discharge. Below 2.5 Pa, it becomes volumetric full glow type, extending its action mainly upstream with a higher plasma density on the exposed electrode. The establishment of the new plasma regime at pressure below 2.5 Pa is also retrieved in negative electrical dissipated powers and asymmetric shapes of both voltage and current signals.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
