Wide- and narrow-band saturated fluorescence measurements of hydroxyl concentration in premixed flames from 1 bar to 10 bar

摘要: We have studied the use of wide-band detection in conjunction with saturation a rovibronic transition OH within itsA2σ+−X2∏(0,0) band. For detection, which fluorescence is detected from entire excited rotational manifold, yield sensitive to collisions two ways. First, it ratio rate coefficients describing energy transfer and electronic quenching; this determines number neighboring levels that are populated during laser pulse. Second, can vary total collisional coefficient; only after sufficient collisions, corresponding ≈ 2.5 ns an atmospheric flame, does manifold reach steady state. also compare measurements employing (detecting theR1 andR2 branches) narrow-band single transition) saturated OH. Over wide range conditions — obtained by varying equivalence ratio, temperature, N2 dilution, pressure wide- techniques well. Given good agreement, could be especially useful for analyzing flames XeCl-excimer lasers; one potentially obtain 2—D images high signal-to-noise reduced sensitivity irradiance quenching.