Experiment on lift-off characteristics of butane jet flame in vitiated co-flow

Butane has the potentiality to be a new-era energy source. MILD combustion can be realised by jet flame in vitiated co-flow. Lift-off height is an important parameter of jet flame in vitiated co-flow. This study aimed at understanding the effects of co-flow condition on lift-off characteristics of the butane jet flame. Vitiated co-flow conditions are created with O-2-methane pre-combustion, co-flow equivalence ratios of methane/air mixtures changed from 0.5 to 0.7. On the basis of the results, O-2 concentration shows main effects on the lift-off height changing tendency versus Re-j. The increase of O-2 concentration results in a decreasing tendency, while a further increment of O-2 concentration stabilises the value of lift-off height. Under the turbulent butane central jet fuel, co-flow rate doesn't show an obvious and monotonous effect on the lift-off height of butane jet flame in vitiated-flow.