Revisiting the theory of positive glow corona with a comprehensive kinetic scheme

Abstract

The theory of positive glow corona is revisited by performing a detailed simulation based on the fluid model with a comprehensive kinetic scheme (CKS). The kinetic scheme includes 28 species, 127 chemical reactions for N2/O2 mixture. The simulation results are compared with that from an averaged kinetic scheme (AKS) which considers only five species and seven reactions. The two models give similar predictions in terms of discharge current. However, several differences in details of the results bring new physical insights to the theory of positive glow corona. It is shown that, the model with the AKS underestimates the detachment effect that plays an important role in positive glow corona discharge. Moreover, the wave-front of the current pulse calculated by the model with the CKS has a smaller steepness, a lower peak-to-peak value, and a longer rise time. These results are in better agreement with the experimental measurement reported in the literature. It is also found that the positive space charge of glow corona is dominated by O2 + in the ionization layer and by O4 + in the drift region far away from the anode. Negative ions are produced in the ionization layer close to the anode and the main species are O− and O3 −.

Adaptive strategies to fast multipole method in photoionisation calculations for streamer discharges

“…In such case, the magnitude of 15) is relatively small and therefore the summation from these I h ðỹ j Þ is neglectable to the photoionisation rate S ph xi ð Þ. As a result, we could pick those ỹj with high intensities and rewrite the summation (15) as…”

“…The fast multipole method evaluates (15) based on a hierarchical tree (octree in 3D) [35]. This hierarchical tree is constructed such that each leaf cube contains no more than a prescribed number of points.…”

“…It is worth mentioning that the introduced FMM is based on quadrature in (15), which is not limited to the model in (1) and could be applied to other integral models (e.g., [27,28]).…”

“…We remark here that our adaptive strategies could also be applied to FMM on adaptive grids, although we adopt a uniform mesh in the simulation of streamer discharge here. This is because the adaptive strategies in this paper is based on (15), which do not require the underlying computational grid is uniform or not. Nevertheless, the ratio of speed-up might be different from the results in this paper.…”

“…As a product of streamer discharges, the non-thermal atmospheric plasma paves the way to a large number of chemical reactions in applications such as the pollution control [10], solubilisation of carbon nano-material [11,12] and disinfection [13,14]. Therefore, streamer discharges draw continuous research interests during the last several decades [15][16][17][18].…”