Flame anchoring of a premixed jet flame in vitiated crossflow using nanosecond repetitively pulsed discharge

Abstract

This paper aims to investigate the effects of nanosecond repetitively pulsed discharge on the dynamics and on the anchoring of a premixed jet flame in hot vitiated cross flow. The lift-off height of the flame is studied for different mean plasma power, jet equivalence ratio and momentum ratio. It was found that the effect of plasma on the flame anchoring increases while decreasing jet equivalence ratio at fixed discharge mean power. Instantaneous and averaged OH-PLIF images showed the production of OH radicals on the windward side of the jet as well as their propagation along and around the windward jet shear layer over 2 to 5 jet diameters depending on the jet equivalence ratio and jet-to-cross-flow momentum ratio. It was shown that the presence of the NRPD on the windward side increases the overall OH density on both the windward and the leeward side of the jet. The chemical and thermal effects are discussed based on results of OH-PLIF images and emission spectroscopy. It is shown that rather low mean power (comparing to the flame power) discharge can serve as an efficient instrument for flame anchoring and stabilization.