The Development of Sensitive Diagnostics for Formaldehyde ( CH2O) and Formyl (HCO) and their Use in Shock Tube Studies of Reaction Rate Coefficients

涉及甲醛（CH2O）和甲酰（HCO）自由基的反应是甲烷等物质的主要氧化途径，但涉及这些物质的关键反应的高温速率系数仍存在较大的不确定性。这种不确定性主要是由于测量CH2O和HCO的灵敏度不够。为了解决这种情况，开发了测量CH2O和HCO的敏感最佳诊断方法，并用于测量激波管研究中的重要速率系数。甲醛是用真空紫外灯（VUV）在174纳米吸收测量的。甲酰基测量使用调频（FM）激光吸收在614 nm。这些技术被应用于激波管研究中的几种基本反应以及热解和氧化实验的物种浓度时程数据库的研究。

Reaction involving formaldehyde (CH2O) and formyl (HCO) radical lie on the primary oxidation pathway for methane and other funds, but there are still large uncertainties in the high-temperature rate coefficients of key reactions involving these species. This uncertainty stems largely from instability to measure CH2O and HCO with sufficient sensitivity. To address this situation, sensitive optimal diagnostics to measure CH2O and HCO are developed and used to measure important rate coefficients from shock-tube studies. Formaldehyde is measured using vacuum ultraviolet (VUV) lamp absorption at 174 nm. Formyl is measured using frequency modulation (FM) laser absorption at 614 nm. These techniques are applied to the investigation of several elementary reactions in shock-tube studies and species concentration time-history databases from pyrolysis and oxidation experiments.