Dynamics of low-temperature filamentary plasma-assisted ignition-stabilized combustion

We present dynamics of ignition-stabilized combustion performed in two reactor configurations. The first configuration is a quartz flow channel incorporating a dielectric barrier discharge. The discharge is produced using 10 ns duration and 23 kV amplitude repetitive pulses. We observe filamentary plasma in air with gas temperatures below the methane auto-ignition temperature. Repetitive ignition is observed when a methane-air mixture flows through the discharge. From high-speed chemiluminescence imaging, we found that the repetitive ignition frequency depends on ignition-induced dynamics. High-speed images are processed to explore ignition dynamics. Flame front locations and absolute flame speed have been evaluated for various flow speeds and equivalence ratio conditions. The second reactor configuration has two co-axial channels. Four discharge configurations similar to the first setup are located in the outer channel, just below the interaction with the flow from the inner channel. A stable lean combustion is achieved at flow speeds above lean blowout limit.