A Computational Study of Plasma-assisted Ammonia/Hydrogen Combustion Using a Phenomenological Model

Nanosecond repetitively pulsed (NRP) discharges offer promising avenues for enhancing The combustion characteristics of ammonia (NH₃). However, the intricacies underlying this enhancement, particularly the optimization of plasma actuation strategies, are not fully understood. Existing zero-dimensional (0D) numerical studies, primarily concentrating on reaction kinetics, often lack experimental corroboration. This work highlights the significant uncertainties in plasma-assisted combustion (PAC) mechanisms and the cross-sectional data for NH₃. A phenomenological plasma model has been developed and refined to delineate the distribution of plasma energy among three primary channels: ultrafast heating, ultrafast dissociation of O₂ and NH₃, and slow gas heating from vibrational energy relaxation. This model has been integrated into a reacting flow solver for the analysis of a jet-wall burner, where a laminar lean NH₃/H₂ flame is subjected to NRP glow discharges. The findings illustrate that plasma-induced chemical effects cause a pronounced upstream shift in the flame stabilization and intensify the NO production in this specific case.