A Reduced Set of Air Plasma Reactions for Nanosecond Pulsed Plasmas

Moon Soo Bak,Mark A Cappelli

doi:10.1109/tps.2015.2409300

Abstract

The reduction of a mechanism describing plasma chemistry for dry air has been carried out for conditions of nanosecond-pulsed discharge plasmas. The discharge conditions include both diffuse glow and filamentary spark modes. A reduced set for glow discharges is found to have inelastic electron-impact reactions of N 2 and O 2 , quenching of excited N 2 , electron attachment to O 2 - , ion conversion between N 2 + , N 4 + , O 4 + , O 2 + ·N 2 , and O 2 + , and ion-ion and electron-ion recombination. When the discharge is in a filamentary mode, additional reactions are required beyond those for the glow discharge as a result of the increased electron number density and high levels of molecular dissociation. Those additional reactions include electron-impact excitation of N and O, quenching of excited N 2 by N and O, and associative ionization by collisions between excited N 2 . A significant reduction in the number of species and reactions is obtained without compromising the predicted species' number densities and temperature. These results provide researchers with reduced kinetic mechanisms that high-fidelity simulations could rely on to save computational time.

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