Blow-off mechanisms of turbulent premixed bluff-body stabilised flames operated with vapourised kerosene fuels

The lean blow-off (LBO) behaviour of unconfined premixed bluff-body stabilised flames with various fuels was investigated. Methane and vapourised ethanol, heptane, Jet-A, an alternative alcohol-derived kerosene (Gevo) were used. OH* chemiluminescence (5 kHz), OH- Fuel-PLIF CH 2 O-PLIF (10 Hz) deployed. For all fuels, as the flame approached LBO fragmentation observed downstream, two sides merged at axis, pockets OH O found in recirculation zone (RZ), eventually individual fragments extinguished. seemed to enter into RZ from downstream early process, reactants following suit times closer LBO. During LBO, integrated signal decreased slowly zero duration this transition ? 25 ( d / U BO ) methane ethanol 60 operated heptane kerosenes (where is diameter velocity). This large difference could be due re-ignitions partially-quenched fluid inside during event. Additionally, for same bulk velocity, higher equivalence ratios than single-component fuelled flames, which possibly Lewis number lower extinction strain rates these fuels. results suggest that mechanism qualitatively similar each fuels; however, complex chemistry associated heavy hydrocarbons appears result a prolonged