Computational investigations of atmospheric pressure discharges

摘要: This research work presents the numerical simulations of multispecies multi-dimensional fluid model of atmospheric pressure discharge. The semi-implicit sequential iterative scheme is used to solve the coupled system plasma model equations with a proper set boundary conditions. A one- dimensional self consistent drift-diffusion developed investigate characteristics of atmospheric discharge in pure helium and He-N2 gases. uniform pressure glow Townsend modes are examined under different operating intricate dynamic patterns evolved temporal evolution current densities at lower frequencies (≲7 kHz), which represent operation between atypical lower and higher ionization several consecutive cycles. To deduce aspects internal distributions discharge, two-dimensional advanced with symmetric conditions parallel plate reactor geometry. filamentary uniform behavior emerged by presence removal specific imposed APD. The periodic stationary pattern various parameters exhibited times during the prebreakdown, breakdown, formation cathode fall layer decay phases. Penning ionization process performs an outstanding role during phases complete cycle, which is explored averaged chemical reaction rates. analysis spatio- temporal species distribution demonstrates that they distinguished their distinctive properties in regimes APD. In bulk gas flow, symmetric distributions discharge species transformed into non-symmetric form. transport effects heavy species, such as He+, He2+, N2+, He* He2* considered for solution temperature equation the numerical magnitude glow mode decreases increase bulk gas flow speed. profiles density provide insight regimes, elucidated spatial structures the uniform, constricted APD. Finally, three-dimensional fluid model employed describe space time variations variables in the discharges. homogeneous slice electrons density compared frequencies, show trapping electrons positive column higher frequencies. non-uniform axial electric field illustrates the field strength part than smooth dielectric barrier surface. The shape configuration filaments exhibit directed from anode towards cathode barrier noticeable prominently observed 5 to 20 kHz frequencies because coalescence frequencies, leading exhibits that it represents composite behavior driving frequency 100 kHz. The simulation study reveals useful deliver satisfactory information the uniform discharges, describes origin non-uniformities.