Combustion Diagnostics with Femtosecond Laser Radiation

22nd International Conference on Spectral Line Shapes

Couris, S.^1,2 ; Kotzagianni, M.^1,2 ; Baskevicius, A.^3 ; Bartulevicius, T.^3 ; Sirutkaitis, V.^3

Department of Physics, University of Patras, Greece^1

Institute of Chemical Engineering Sciences (ICE-HT), Foundation for Research and Technology-Hellas (FORTH), Patras, Greece^2

Department of Quantum Electronics, Laser Research Center (VU LRC), University of Vilnius, Lithuania^3

关键词: Combustion diagnostics;    Excitation sources;    Fuel concentration;    Fuel mole fractions;    Fuel-air equivalence ratio;    Propane-air mixture;    Spectral characteristics;    Temporal variation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/548/1/012056/pdf
DOI  :  10.1088/1742-6596/548/1/012056

来源: IOP

【 摘 要 】

In the present work, the potential of Laser Induced Breakdown Spectroscopy employing femtosecond laser pulses (fs-LIBS) for fuel-air equivalence ratio measurements in premixed methane-air and propane-air flames is presented. A Ti-Sapphire laser system (100 fs, 10 Hz, 800 nm) was used as an excitation source for the plasma creation, while a spectrometer was employed to record the plasma emission spectra. The concentration of the investigated methane-air and propane-air mixtures were expressed by the fuel mole fraction Xfueland varied from only air - Xfuel=0(φ=0) to only fuel - Xfuel=1(φ=). The spectral characteristics of the fs-LIBS spectra are discussed, while the time and energy dependence of the main spectral features are presented. Moreover, from the analysis of fs-LIBS spectra collected at different fuel mole fractions Xfuel, it was found that the fuel variations could be very well correlated with the variation of the intensity of some spectral lines and/or their ratios. The prepared calibration curves of the fuel mole fraction Xfuelversus the atomic line total intensity ratios (Hα656.3 nm and O (I) 777 nm) and molecular lines total intensity ratios (C2516.5 nm and CN 388.3 nm) suggest the high potential of using fs-LIBS for the determination of the local fuel concentration and its temporal variations.