Inevitable chemical effect of balance gas in low temperature plasma assisted combustion

Abstract

Electrical discharges (or plasmas) have attracted researchers’ attention to improve combustion characteristics. One of its key effects, which is not fully understood yet, is the in-situ production of chemically reactive species. Since most related low temperature kinetic studies to-date have been performed under highly diluted conditions (> 99%), here we present the inevitable and undesirable chemical effect of a balance gas (Ar, He, N2) on the plasma-chemical kinetics. We employ a zero dimensional plasma-chemical kinetics model in combination with a (detailed and reduced) H2/O2/Ar reaction mechanism. The presented results indicate that (dissociative) quenching of excited (metastable) states dominates the H2 and O2 dissociation processes under highly diluted conditions. Additionally, in the reduced field intensity (E/N) domain, the type and amount of the balance gas significantly alters the fraction of electron energy transferred to the other species in the mixture. Therefore, we propose essential steps for the design of future kinetic studies for plasma assisted combustion.