Two-dimensional simulation of the evolution of radial discharge columns in an atmospheric argon dielectric barrier discharge

Abstract

A two-dimensional model is employed to investigate the evolution of radial discharge columns (or filamentary channels) and the potential mechanism in an atmospheric argon dielectric barrier discharge (DBD). As the applied voltage amplitude increases, the number of discharge columns first increases and then deceases, and finally, the discharge evolves into the diffuse mode. With a lower voltage amplitude range, the more uniform distribution of surface charge density makes the original discharge column move outwards, providing a wider inner space to increase the filament number. A similar filamentation process is also observed in atmospheric helium. However, when the voltage amplitude is further increased, considering the lower ionization threshold of argon, even the relatively small amount of residual electrons diffusing from filaments to adjacent regions can serve as seed electrons to activate the former inhibition positions, which makes the filament number further increase. Moreover, influenced by the stronger radial electric field between the central column and its neighborhoods, more electrons located at the column near the middle position will drift toward the center. As a result, once charged particles move over the inhibition region with voltage amplitude rising further, the two discrete discharge columns will merge, causing the decrease in the filament number. Finally, it is revealed in our simulations that when the voltage amplitude exceeds one certain level, seed electrons of the preionization stage get harder to gather and all discharge columns vanish. These results may help to provide a new perspective on the evolution of radial filamentary channels in an atmospheric argon DBD.

Numerical modeling of gas‐phase reactions of tetraethoxysilane/O2/Ar atmospheric dielectric barrier discharge for deposition

“…Referring to the results of previous experiments and simulations, [37,44,45] the n e of Ar discharge is about 10 10 -10 12 cm −3 , the electron density in our model is within a reasonable range. The peak electron temperature T e is 3.90 V, and the peak reduced electric field E N is 38.3 Td.…”

“…In our previous studies on He discharge, [ 81–83 ] Penning ionization may lead to a reduction in ignition voltage and an improvement in uniformity. Considering the similarity of Ar and He discharges, [ 44 ] we believe that this phenomenon also exists in Ar discharge. Therefore, the decrease in ignition voltage and the evolution of uniformity are due to Penning ionization between TEOS and excited Ar.…”

“…Previous simulation and experimental studies have shown that the typical peak n e in (TMS/O 2 /) Ar DBD is between 10 10 and 10 cm 12 −3 . [37,44,45] For pulsed DBD and AC DBD, pulsed power input is another approximation that does not lead to an underestimation of n e . Although this approximation is not entirely consistent with our experiments on time scales, it satisfies the conservation of particle number and is selfconsistent in chemical kinetics.…”

Multiple current peaks and spatial characteristics of atmospheric helium dielectric barrier discharges with repetitive unipolar narrow pulse excitation

“…For the DBD driven by conventional sinusoidal voltage, it easily evolves into filamentary discharges [15][16][17][18][19]. However, in industrial applications, homogenous discharges are strongly demanded [20].…”

Pre-breakdown to stable phase and origin of multiple current pulses in argon dielectric barrier discharge

“…Many recent studies of MCPs in APHDBD have focused on light gases such as helium, nitrogen, oxygen and other air constituents, while attempts at modeling argon are less common (e.g. [19]). To our knowledge, a detailed study of the development of MCPs in argon APHDBD has not been published yet, although argon is commonly used in experiments [20,21], at room as well as at low pressure [22], and has demonstrated important applications in medicine [23], such as wound healing [24,25], cancer treatment [26][27][28], bio-decontamination and sterilization.…”