The Blowout of Turbulent Jet Flames in Co-Flowing Streams of Fuel-Air Mixtures

The blowout limit of a turbulent jet diffusion flame in co-flowing streams of lean fuel air mixtures is examined. The blowout limit of the flame, and thereby the maximum thermal output of a burner can be extended significantly, without any modification to the burner, through the presence of a small amount of fuel homogeneously mixed with the surrounding air. The extent of this extension is related to the observed limit of fuel concentration in the surrounding stream that brings about flame flashback conditions. The flame blowout limits involving different gaseous hydrocarbon fuels have been established at atmospheric pressure and the data were correlated in terms of the surrounding fuel concentrations relative to their corresponding flashback limits.