Ignition and combustion of air/fuel mixture in a long tube induced by microwave subcritical streamer discharge

Abstract

There have been consistent efforts in developing more efficient combustion for propulsion systems. Ignition and combustion control using cold and non-thermal plasma in microwave discharges have become a major topic of interest. In this study, a microwave subcritical streamer discharge is used to initiate ignition and combustion of premixed air/fuel mixture in a long cylindrical tube. The streamer discharge is arising on the internal surface of the dielectric tube using a passive vibrator in a single pulse regime at atmospheric pressure and temperature. The propagation speed of the combustion front in the quartz cylindrical tube filled by the air/propane mixture is analyzed experimentally and numerically. The streamer discharge creating a multitude of ignition points provides practically instantaneous ignition of the mixture in the entire volume. The speed of streamer induced combustion front has been shown to be higher compared to that initiated by a spark. Increasing the length of streamer discharge leads to increasing the flame propagation speed. The combustion efficiency has also been shown to be higher when using the microwave streamer ignition.