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Simulation of pre-breakdown discharges in high-pressure air: II. Effect of surface protrusions
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Advisor(s)
Abstract(s)
Analysis of deviations from the similarity law, observed at high and very high pressures in
experiments on discharge ignition and breakdown in corona-like configurations, can serve as a
useful, albeit inevitably indirect, source of information about microprotrusions on the surface of
the electrodes. In this work, such analysis was performed by means of 2D numerical modelling.
Conical or cylindrical protrusions on the surface of the inner electrode were studied and the
kinetic scheme includes the electrons, one species of positive ions, and negative ions O−
2
, O−,
and O−
3
. It is shown that the deviations from the similarity law, observed in the experiment, may
indeed be attributed to enhanced ionization of air molecules in regions of amplified electric field
near the microprotrusions. A qualitative agreement with the experiment in all the cases is
achieved for protrusion heights of the order of 50 µm. Such values may appear rather high,
however there is no other explanation in sight at present. The enhancement of the field electron
emission from the surface of the negative electrode due to the amplification of the electric field
on the microprotrusion was estimated and found insignificant in the range of values of the
protrusion aspect ratio where the enhanced ionization in the gas phase is already appreciable.
Description
Keywords
Gas discharge modelling Surface protrusions Breakdown of high-pressure air . Faculdade de Ciências Exatas e da Engenharia
Citation
Ferreira, N. G. C., Naidis, G. V., & Benilov, M. S. (2021). Simulation of pre-breakdown discharges in high-pressure air: II. Effect of surface protrusions. Journal of Physics D: Applied Physics, 54(25), 255203.
Publisher
IOP Publishing