Concentration measurements of atomic hydrogen in subatmospheric premixed C2H4/O2/Ar flat flames

Absolute number densities of atomic hydrogen have been measured in subatmospheric, premixed C2H4/O2/Ar flat flames via two-photon excited fluorescence. The fuel-equivalence ratios of the flames were 1.0 and 1.7. The fluorescence measurements are calibrated by partial equilibrium calculations and corrected for quenching effects by assuming a constant average cross-section and using kinetic theory. A sensitivity analysis of the calibration procedure reveals that slightly rich flames appear to be the best candidates for calibrating fluorescence measurements of atomic hydrogen by partial equilibrium. (Author)