Quantifying acetylene mole fraction in rich flat laminar premixed C2H4/air flames using mid-infrared polarization spectroscopy

Abstract Mid-infrared laser polarization spectroscopy (IRPS) has been applied to measure the mole fraction of acetylene in rich premixed laminar C 2 H 4 /Air flat flames at equivalence ratios ( Φ ) 1.7, 2.1, and 2.3, under atmospheric pressure. The detection was conducted by probing ro-vibrational P(19) transition ~ 3.1 μm. total collisional broadening coefficient approximately 0.074 cm −1 atm varied within a range 0.5% different flame conditions, which made effect linewidth not obvious CH /air flame. calculated , using Chemkin model, = 1.3 1.5 used calibrate recorded IRPS signal intensities Height Above Burner (HAB). A single scaling factor then quantify measured highly sooting with Limit Detection (LoD) 35 ± 5 ppm. first observed appeared HAB 3 mm as 2003 ppm, 2217 2495 for respectively. increased reach maximum value 2296 2807 3478 respectively, up mm. It that reaches plateau region 8 production be subject critical gas temperature 1400 30 K. soot inception temperature, where incepted particles are observed, is same $${\chi }_{{{\mathrm{C}}_{2}\mathrm{H}}_{2}}^{\mathrm{max}}$$ χ C 2 H max detected, namely 1500 These measurements calibration procedure demonstrate plausible technique probe other better understand its correlation .