An experimental investigation of a premixed laminar flame using tunable diode laser and quantitative imaging of radiation intensity

Wang, Weichao. M.S.M.E., Purdue University, May 2015. An Experimental Investigation of a Premixed Laminar Flame Using Tunable Diode Laser and Quantitative Imaging of Radiation Intensity. Major Professor: Jay P. Gore, School of Mechanical Engineering. Simultaneous CO concentration and temperature measurements using Tunable Diode Laser Absorption Spectroscopy (TDLAS) are reported in this study. Ro-vibrational transitions of CO, R(27) and R(6) are used for probing absorbance profiles. Premixed ethylene-air flat flame on a McKenna burner is used for creating combustion gaseous products at equivalence ratio 0.83 to 1.82. Nitrogen shroud flow is used for preventing air mixing. Both Direction Absorption (DA) and Wavelength Modulation Spectroscopy (WMS) experiments are conducted. Experimental results are compared with literature and simulation using CHEMKIN and chemical equilibrium. Reasonable agreements are achieved between experiment and simulation. The CO detection limit is determined ~36 ppm-m for DA and ~11 ppm-m for WMS. To study the radiation profiles of the corresponding flat flame, a calibrated high speed infrared camera with three bands is used to capture CO2 and H2O radiation intensity. Quantitative images of radiation intensity for the flame at equivalence ratio 0.6 to 1.6 are documented and discussed.