Scramjet Fuels Autoignition Study
Scramjet Fuels Autoignition Study
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DOI：
10.2514/2.5744
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发表时间：
2001-03
影响因子：
1.9
通讯作者：
M. Colket;L. Spadaccini
中科院分区：
文献类型：
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作者：
M. Colket;L. Spadaccini
进行了一系列激波管实验，以测量和比较用于超燃冲压发动机推进的几种候选燃料的点火延迟时间，并评估燃料裂解对吸热燃料/产品混合物自燃的重要性。在温度范围为 1100 ‐1500 K、压力为 3 ‐8 atm、当量比为 0.5 ‐1.5 的情况下，在反射冲击波后面的稀混合物中测量了乙烯、庚烷和 JP-10 的点火延迟。将实验数据与公布的庚烷和乙烯结果进行比较，并根据组合数据集确定新的点火延迟相关性。所得表达式也与之前对甲烷和氢气的研究进行了比较。此外，还模拟了典型的吸热燃料产品混合物（代表母体燃料的不同裂解程度），并测量了当量比为 0.5 和 1.0 时的点火延迟时间。发现不同燃料的相对点火延迟时间为甲烷>JP-10=»庚烷>重整吸热燃料>乙烯>氢气。结果支持燃料裂解增强点火的前提。然而，吸热反应产物混合物的自燃并不完全由具有最短点火延迟的成分（即乙烯或氢气）驱动。此外，单个组分浓度的微小变化不太可能使燃料的点火延迟时间发生显着变化。将经验数据与使用详细的化学动力学模型预测的点火延迟时间进行比较，它们支持已发表的甲烷和庚烷反应机制的有效性。
A series of shock-tube experiments was conducted to measure and compare the ignition-delay times of several fuel candidates for scramjet propulsion and to evaluate the importance of fuel cracking on the autoignition of endothermic-fuel/product mixtures. Ignition delays of ethylene, heptane, and JP-10 were measured in dilute mixtures behind ree ected shock waves for temperatures in the range 1100 ‐1500 K, pressures of 3 ‐8 atm, and equivalence ratios of 0.5 ‐1.5. The experimental data were compared to results published forheptane and ethylene, and new ignition-delay correlations were determined from the combined data sets. The resulting expressions were also compared to prior work on methane and hydrogen. In addition, typical endothermic-fuel product mixtures (representing different degrees of cracking of the parent fuel ) were simulated and their ignition-delay times measured for equivalence ratios 0.5 and 1.0. The relative ignition-delay times for the different fuels were found to be methane >JP-10 = » heptane >reformed endothermic fuel >ethylene >hydrogen. The results support the premise that fuel cracking enhances ignition. However, autoignition of the endothermic reaction product mixture is not driven entirely by the constituent with the shortest ignition delay (i.e., ethylene or hydrogen ). Furthermore, small changes in concentrations of the individual component species are not likely to make dramatic changes in the ignition-delay times of the fuel. The empirical data werecompared to ignition-delay times predicted using detailed chemicalkineticsmodelsandthey supportthevalidity ofpublishedreaction mechanismsformethaneand heptane.