The effect of non-thermal plasma (NTP) on lean premixed flame in a model gas turbine combustor has been investigated experimentally by adopting a dielectric barrier discharge (DBD) technique. The plasma reactor had eight spikes electrodes with alternating current (AC) power supply to generate and keep a constant distribution of streamers. To identify the effect of flame on plasma generation, the streamer generation characteristics in lean premixed flame were first investigated. The results indicated that the existence of flame significantly enhances the plasma generation by the increase in the reduced electric field intensity due to high-temperature burnt gas and the abundance of positive and negative ions and electrons in the flame region. Flame liftoff heights and liftoff equivalence ratio were measured as functions of applied various voltages and frequencies.
The results showed that the streamers extended the stabilized the flames and lean flammable limit in terms of all conditions of equivalence ratio by high streamers.