Ignition and blow-off process assisted by the rotating gliding arc plasma in a swirl combustor

Abstract

A rotating gliding arc (RGA) in three different discharge powers (from 35 W to 250 W) was designed to enhance ignition and combustion in a swirl model combustor with a flow speed from 15 m/s to 60 m/s. The flame development process was recorded using the 10 kHz high-speed CH⁎ imaging. It was concluded that the repeatable ignition in the presence of the RGA can be observed in the combustor. The RGA method is capable of gaining a greater probability to inject energy into the appropriate local equivalence ratio and instantaneous air velocity. The ignition process by the RGA can be divided into three stages: sliding stage; flame spread stage and flame fluctuation stage. The RGA method can also increase the probability of re-ignition in a lean blow-off process than the auto re-ignition. The uniformity of the lean blowout performance was improved after the RGA-assisted combustion. The lean blowout limit can be extended by 62.2% in the presence of the RGA in the swirl combustor. The lower frequency and higher averaged power of the RGA is more capable of igniting the fuel and maintaining the swirl flame in the lean equivalence ratios.