Thermal effects on the performance of a nanosecond dielectric barrier discharge plasma actuator at low air pressure

Abstract

The thermal effects of a pulsed nanosecond dielectric barrier discharge plasma actuator with varying pulse voltages and pulse repetitive frequencies under different air pressures ranging from 0.1 to 1 bar are studied experimentally. The filamentary streamers extend along the radius direction, forming a thicker yet more stable and uniform plasma region due to the increasing ionized volume yielded by the decreasing air pressure to maintain the high values of the reduced electric field. The spatiotemporal temperature distribution on the surface is captured by an infrared camera, indicating that the heated surface can be divided into three typical regions with different features. Because gas heating is generated in the quenching process of excited molecules, the maximum temperature increase on the surface occurs in the plasma region and attenuates downstream. The surface temperature increase is primarily caused by heat convection from the residual heat in plasma and the heat generated by the dielectric losses. The results of heat flux on the surface suggest that the rising applied voltage may not increase the heat flux in a moderate air pressure ranging from 0.6 to 0.8 bar. Different discharge modes and discharge parameters exhibit markedly different thermal performances. The Schlieren technique and the pressure sensor are used to visualize the induced shock wave, estimate the thermal expansion region, and measure the overpressure strength. The results of the overpressure strength at different air pressures are similar to the thermal features, which highlights the strong influence of the discharge mode on the thermal effect of NSDBD.

Bandgap reduction and efficiency enhancement in Cs2AgBiBr6 double perovskite solar cells through gallium substitution

“…Also, it relies on the photo-generated current density. The V oc value for the undoped material is 0.92 V, and aer substitution, it increases to 0.94 V. 75,76 It might be possible that Ga substitution in Cs 2 AgBiBr 6 could increase the carrier concentration and induce an upward shi of the Fermi level of Cs 2 AgBiBr 6 , facilitating the injection and transfer of electrons to the conduction band of perovskite. Simultaneously, by increasing the carrier concentration, the electrons could effectively ll the interface traps, reducing interface trap density.…”

Characterization of heated volume generation by nanosecond pulsed plasma actuator with various pressure environments

“…The transition would also be affected by the repetition rate, electrode configuration, discharge waveform and other factors. In fact, it has been reported that the uniformity of discharge changes depending on the surrounding pressure [35], applied voltage [16], pulse frequency [24,36] and the rise time of the nanosecond pulse [37]. It has also been reported in AC-driven actuators that the concentration of discharge is caused by the sawtooth electrode [38].…”

A Numerical Investigation of Supersonic Combustion Flow Control by Nanosecond-Pulsed Actuations

“…Compared with DC or AC input [4], the nanosecond-pulsed discharge waveform is considered to be more efficient in controlling supersonic flow structure because it provides stronger pressure and temperature perturbations. Two types of nanosecond-pulsed actuators are commonly adopted in experimental research, namely, the nanosecond spark discharge actuator and the nanosecond-pulsed surface dielectric barrier discharge (NS-SDBD) actuator [5,6], which show similar effects for supersonic flow control. Studies have shown that nanosecond discharge is able to control detached shockwaves [7] and increase the instability of the cavity shear layer in supersonic flow [8], proving the feasibility of this actuation method.…”