Abstract New experimental and numerical results of a laminar ethylene-air co-flow non-premixed flame are compared, in terms of soot volume fraction and temperature, and of polycyclic aromatic hydrocarbons (PAH) distributions. Measurements involved UV-excited laser induced incandescence (properly calibrated), planar laser induced fluorescence (PLIF), and deconvoluted two-color pyrometry. In order to evidence soot and PAH, the comparison of prompt and delayed detection is carried out at four spectral detection wavelengths (340, 400, 450 and 550 nm). Numerical results are obtained using a detailed gas-phase chemical kinetics mechanism considering 94 species and 719 reactions, and a sectional soot model, together with a statistical narrow band correlated K (SNBCK) wide band model to account for radiation. Computed PAH, grouped by their number of rings, is found to exhibit a good correlation with experimental PLIF results at different spectral detection wavelengths. In particular, it is shown that 340 and 400 nm fluorescence signals indicate the presence of one up to four-ringed computed PAH, whereas the interpretation of measurements at larger wavelengths is found to be elusive, due to soot signal overlap. Furthermore, an interplay between temperature decrease, soot volume fraction increase and radiative heat transfer distribution with increasing fuel flow rate is also demonstrated.

中文翻译：

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共流乙烯/空气层流扩散火焰中 PAH 烟尘前体的测量和建模

摘要 在烟灰体积分数和温度以及多环芳烃 (PAH) 分布方面，比较了层流乙烯-空气共流非预混火焰的新实验和数值结果。测量涉及紫外线激发的激光诱导白炽光（正确校准）、平面激光诱导荧光 (PLIF) 和解卷积双色高温计。为了证明烟尘和PAH，在四种光谱检测波长（340、400、450和550 nm）下进行了即时检测和延迟检测的比较。使用考虑 94 种物质和 719 种反应的详细气相化学动力学机制、截面煤烟模型以及统计窄带相关 K (SNBCK) 宽带模型来计算辐射，获得了数值结果。计算出的 PAH，按它们的环数分组，发现在不同光谱检测波长下与实验 PLIF 结果具有良好的相关性。特别是，显示 340 和 400 nm 荧光信号表明存在一个最多四环的计算 PAH，而由于烟灰信号重叠，发现对较大波长测量的解释难以捉摸。此外，还证明了温度降低、烟灰体积分数增加和辐射传热分布与燃料流量增加之间的相互作用。而由于烟尘信号重叠，发现对较大波长的测量结果的解释是难以捉摸的。此外，还证明了温度降低、烟灰体积分数增加和辐射传热分布与燃料流量增加之间的相互作用。而由于烟尘信号重叠，发现对较大波长的测量结果的解释是难以捉摸的。此外，还证明了温度降低、烟灰体积分数增加和辐射传热分布与燃料流量增加之间的相互作用。