Abstract The first implementation of a combined laser absorption diagnostic/gas chromatography (GC) sampling system for the measurement of combustion-relevant species in a conventional shock tube configuration is reported, with ethylene pyrolysis as an example application. A heated, endwall sampling system is used to extract a post-shock sample for GC analysis. Analysis of the gas sample yields a measurement of the ultimate mole fraction values of multiple species (currently ethylene, acetylene, hydrogen, and methane) at the end of the reflected shock test time. A 10.532-µm laser absorption diagnostic is simultaneously used to measure time-resolved ethylene. A method to accurately model sampled speciation results using published kinetic models is discussed. A method for extending laser measurements into the expansion fan region for direct comparison with sampled GC results has also been developed. The combined optical and sampled-gas measurement techniques were used to study ethylene pyrolysis (1.0% mole fraction ethylene/argon) at approximately 5 atm, over a range of temperatures (1200–2000 K). The ethylene mole fraction measurements obtained using both techniques show close agreement.

中文翻译：

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激波管中物种形成的组合激光吸收和气相色谱采样诊断

摘要 报告了第一次实施组合激光吸收诊断/气相色谱 (GC) 采样系统，用于测量传统激波管配置中的燃烧相关物质，以乙烯热解为例应用。加热的端壁取样系统用于提取冲击后样品以进行 GC 分析。在反射冲击测试时间结束时，对气体样品的分析产生了多种物质（目前是乙烯、乙炔、氢气和甲烷）的最终摩尔分数值的测量值。同时使用 10.532 µm 激光吸收诊断仪测量时间分辨乙烯。讨论了一种使用已发布的动力学模型对采样的物种形成结果进行准确建模的方法。还开发了一种将激光测量扩展到膨胀扇形区域以与采样的 GC 结果进行直接比较的方法。结合光学和采样气体测量技术用于研究在大约 5 个大气压下，在一定温度范围 (1200-2000 K) 内的乙烯热解（1.0% 摩尔分数乙烯/氩气）。使用这两种技术获得的乙烯摩尔分数测量值显示出非常一致的结果。