Experimental Study of Microwave Streamer Discharge Ignition of Premixed Air/Fuel Mixtures

A subcritical microwave streamer discharge is used to initiate ignition of premixed air/fuel mixture. The streamer 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. Ignition of lean fuel mixtures by a streamer has been demonstrated at the atmospheric pressure. The performed studies showed that the streamer discharge, which creates a multitude of ignition points, provides practically instantaneous ignition of the mixture in the entire volume, where the streamers reach. Measurements have shown that the front velocity increases with an increasing discharge length. The speed of streamer-induced combustion has been shown to be higher compared with that initiated by a spark. The combustion efficiency has also been shown to be higher when using the microwave streamer ignition.