Atmospheric-pressure pulsed plasma actuators for flow control: shock wave and vortex characteristics

Abstract

Pulsed plasma actuators are used for an active flow control application since the 2000s. In this paper, we discuss shock wave and vortex characteristics in pulsed plasma actuators after an introduction of research progress on atmospheric-pressure discharge plasma actuators. First, the shock wave characteristics in surface dielectric barrier discharge (SDBD) actuator operating in diffuse-like and multi-streamer modes are discussed. In the most general case, a shock wave in a diffuse-like SDBD actuator is stronger and faster than in a multi-streamer SDBD actuator. Improved plasma actuators, such as the three-electrode SDBD actuator and the plasma synthetic jet actuator have the enhanced shock wave characteristics. Second, in order to investigate the effects of pulse parameters on the shock wave characteristics in nanosecond-pulse SDBD actuator, a particle image velocimetry system is used to capture the formation of starting vortexes at different pulse rise times, pulse durations, and pulse repetition frequencies (PRFs). It is shown that the velocity of a starting vortex significantly increases when the pulse rise time decreases from 400 ns to 50 ns due to a more significant hydrodynamic effect generated during a shorter rise time. This phenomenon is confirmed by calculating a reduced electric field E/N at a short rise time, which turns out to be higher at a shorter rise time than that at a relatively longer rise time. It is also shown that the velocity of a starting vortex increases and its active area enlarges when the PRF increases.

Repetitively pulsed gas discharges: memory effect and discharge mode transition

“…The measurement of the associated electric field provides online monitoring and spatial–temporal information despite the indirect characterisation of surface charges. The electric field can be measured based on the electric‐field‐induced second harmonic generation [77], the four‐wave mixing method [74], optical emission spectroscopy [75], capacitive sensor [76], and electro‐optical sensor [58]. Winters et al [76] monitored the surface potential decay in the continuous repetitively pulsed surface discharge based on the capacitive sensor with different pulse polarities.…”

Dynamic Stall Control around Practical Airfoil Using Nanosecond-Pulse-Driven Dielectric Barrier Discharge Plasma Actuators

“…However, the ac-DBDPA is known to become less effective as the freestream velocity increases. A nanosecond-pulse-driven DBDPA (ns-DBDPA), which generates plasma by voltage pulses in the order of several hundreds of nanoseconds, has attracted a lot of interest as a device for high freestream velocity flow due to its effectiveness in suppressing flow separation [17][18][19][20][21][22]. An ns-DBDPA generates a pressure wave and two heated zones when the nanosecond voltage pulse is applied [23].…”

Mode transition and plasma characteristics of nanosecond pulse gas–liquid discharge: Effect of grounding configuration

“…Meanwhile, the energy of the pulse power is consumed for generating active species, instead of heating gas, and thermal instability of the gas–liquid discharge can be avoided . Furthermore, the short duration time is also beneficial for discharge stability because the plasma can extinguish before the instability occurs …”

“…[10,11] Furthermore, the short duration time is also beneficial for discharge stability because the plasma can extinguish before the instability occurs. [13] Inserting a dielectric in the discharge circuit may be another possible way to restrict the discharge instability. Indeed, dielectric layers improve the stability of dielectric barrier discharges in gas phase, and their role is reasonably well understood.…”