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[摘要]：Autoignition delay time measurements were performed for toluene/oxygen/argon mixtures at pressures of approximately 1.0 and 3.0 atm, temperatures of 1312-1713 K, oxygen mole fraction of 1.8-18.0%, and equivalence ratios of 0.5, 1.0, and 2.0 in a shock-tube facility. Ignition times were determined using electronically excited CH* and OH* emissions and reflected shock pressure monitored through the shock-tube sidewall. The dependence of the ignition delay times upon pressure, oxygen mole fraction, and equivalence ratio has been characterized. An empirical correlation for the ignition delay has been deduced by linear regression of the ignition data. Experimental results are compared to simulations of three recent chemical kinetic mechanisms for the oxidation of toluene. The overall trends are captured fairly well by the mechanisms. In addition, the important reaction pathways have been elucidated by both flux and sensitivity analyses. Ultraviolet and visible chemiluminescence of toluene combustion were measured using an intensified charge-coupled device camera coupled with a spectrometer. The transient spectra show remarkably high intensities of OH*, CH*, and C-2* electronic emission bands. Rotational and vibrational resolution spectra of OH*, CH*, and C-2* were clearly observed behind reflected shock waves. It was found that the peak intensity ratios of OH*/CH* and C-2*/CH* are strongly related to the equivalence ratio. |
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