Kinetic Effects of Nanosecond Discharge on the Ignition Delay of Ethylene–Air Mixtures

This study develops a zero-dimensional kinetic model to investigate the effects of nanosecond pulsed discharge on the ignition characteristics of stoichiometric ethylene–air mixtures. The simulation framework combines ZDPlasKin for plasma kinetics and CHEMKIN for combustion chemistry. At an initial temperature of 1200 K, a pressure of 1.1 atm, and a fixed plasma energy input of 20 mJ/cm³, the results show that the nanosecond discharge significantly shortens the ignition delay time compared to autoignition. The ignition enhancement strongly depends on the reduced electric field $E/N$ , reaching a minimum delay at 200 Td. The primary radicals responsible for promoting ignition—O, H, C₂H, and C₂H₃—are mainly produced through quenching reactions of electronically excited nitrogen species, particularly N₂(A) and N₂( $\text{a}^{\prime }$ ). Path flux analysis reveals that electron collisions contribute significantly to O formation, while H and C₂H₃ are predominantly formed via N₂ quenching. The variation in radical production with $E/N$ explains the non monotonic trend of ignition delay time.