Characteristics of Gliding Arc and Its Application in Combustion Enhancement

A novel magnetically stabilized gliding arc reactor coupled with a counterflow burner was developed to study nonthermal plasma enhancement of ignition and extinction phenomena. The results showed that the new coupled plasma-flame system provides a well-defined platform for understanding of the basic mechanism of the plasma-flame interaction. It was shown that with a plasma discharge of the airstream, up to a 220% increase in the extinction strain rate was possible at low power inputs for air and methane diluted with nitrogen. Measurements of temperature profiles via planar Rayleigh scattering thermometry and OH number density profiles via planar laser-induced fluorescence (calibrated with absorption) were taken to quantify various effects. Detailed numerical simulations at elevated air temperatures and radical addition were performed for comparison with experimentally obtained results. Results of the extinction experiments initially suggested that the enhancement effect was predominantly thermal for our particular setup of experiments. However, in ignition experiments specifically for hydrogen, temperature measurements conducted for hydrogen-air mixtures suggested the contribution of active species to justify the extent of the enhancement effect. Further comparison with numerical simulations also provides an insight into the participation of species other than radicals in the enhancement effect.