Direct numerical simulations of n-heptane spray autoignition in methane-air mixtures relevant to dual-fuel engines
Direct numerical simulations of n-heptane spray autoignition in methane-air mixtures relevant to dual-fuel engines
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DOI：
10.2514/6.2014-1020
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发表时间：
2014
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影响因子：
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通讯作者：
E. Demosthenous;G. Borghesi;E. Mastorakos;R. Cant
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文献类型：
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作者：
E. Demosthenous;G. Borghesi;E. Mastorakos;R. Cant
© 2015美国航空航天研究所有限公司。All rights reserved.采用直接数值模拟方法研究了正庚烷液滴在热空气中的着火行为。研究的配置是相关的双燃料发动机，其中甲烷-空气预混艾姆斯被点燃的液体燃料的先导喷射，并在一般的多燃料湍流燃烧。结果表明，甲烷的存在延缓了正庚烷的自燃。由于自燃发生在富混合物部分，氧气被消耗，留下未燃烧的甲烷，在实践中，可能产生不需要的排放物。当反应区从各个自燃点扩展开来时，甲烷-空气预混火焰最终被引发。
© 2015 American Institute of Aeronautics and Astronautics Inc. All rights reserved. The ignition behaviour of n-heptane droplets in hot air mixed with methane is studied by means of Direct Numerical Simulations with complex chemistry. The configuration studied is relevant to dual-fuel engines, where methane-air premixed ames are ignited by a pilot injection of liquid fuel, and to multi-fuel turbulent combustion in general. It was found that the presence of methane delayed the autoignition of n-heptane. Because autoignition happens at rich mixture fractions, oxygen is consumed leaving behind unburnt methane that, in practice, could produce unwanted emissions. The methane-air premixed ame is eventually initiated when the reaction zone spreads from the various autoignition sites.