Imidogen (NH) production in nanosecond repetitively pulsed glow discharges applied to an ammonia-hydrogen-air flame*

Nanosecond repetitively pulsed (NRP) glow discharges have shown promising results in enhancing hydrocarbon flames with minimal power input and negligible nitric oxide production. However, enhancing the stability of ammonia flames seems to require more electrical energy deposited in the discharges. This cannot be easily explained currently due to the large uncertainty in the plasma-assisted ammonia combustion mechanisms and cross-sections. In this work, spatially and temporally resolved laser induced fluorescence measurement of NH radicals are presented for NRP glow discharges applied to an ammonia-hydrogen-air flame. The results show that a significant amount of NH is produced in the discharge filament upstream of the flame. These results will help validate chemical mechanisms that will shed more light on plasma-assisted ammonia combustion.