Streamer Discharge Modeling for Plasma-Assisted Combustion

Some of the popular and successful atmospheric pressure fuel/air plasma-assisted combustion use repetitive ns pulsed discharges and dielectric-barrier discharges. The transient phase in such discharges is dominated by transport under strong space charge from ionization fronts which is best characterized by the streamer model. The role of the non-thermal plasma in such discharges is to produce the radicals which accelerates the chemical conversion reaction leading to temperature rise and ignition. Therefore, the characterization of streamer and its energy partitioning is essential to develop a predictive model. We examine the important characteristics of streamers that influence combustion and develop some macroscopic parameters. Our results show that the radicals production efficiency at an applied field is nearly independent of time and the radical density generated depends only on the electrical energy density coupled to the plasma. We compare the results of the streamer model to the zero-dimensional uniform field Townsend like discharge, and our results show a significant difference. The results of the influence of energy density and repetition rate on ignition of hydrogen/air fuel mixture is presented.