Effects of hydrogen addition on the propagation of spherical methane/air flames: A computational study
Effects of hydrogen addition on the propagation of spherical methane/air flames: A computational study
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DOI：
10.1016/j.ijhydene.2009.06.001
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发表时间：
2009-08
影响因子：
7.2
通讯作者：
Zheng Chen
中科院分区：
文献类型：
--
作者：
Zheng Chen
通过数值模拟研究了不同条件下氢气对甲烷/空气球形火焰传播特性的影响。重点研究了甲烷/氢气双燃料的层流火焰速度和Markstein长度。结果表明，层流火焰速度随掺氢量的增加而单调增加，而Markstein长度随掺氢量的增加而非单调变化：先减小后增大。因此，氢气与甲烷/空气的混合以及甲烷与氢气/空气的混合都使火焰不稳定。此外，计算结果与文献中的测量数据进行了比较。计算和测量的层流火焰速度的比较显示出良好的一致性。然而，所测得的Markstein长度强烈依赖于用于数据处理的火焰半径范围，并具有非常大的不确定性。发现实验结果不能正确反映Markstein长度随掺氢量和掺氢压力变化的趋势，因而是不可靠的。因此，计算的Markstein长度，这是准确的，应使用在燃烧模型，包括火焰拉伸对火焰速度的影响。
A computational study is performed to investigate the effects of hydrogen addition on the fundamental characteristics of propagating spherical methane/air flames at different conditions. The emphasis is placed on the laminar flame speed and Markstein length of methane/hydrogen dual fuel. It is found that the laminar flame speed increases monotonically with hydrogen addition, while the Markstein length changes non-monotonically with hydrogen blending: it first decreases and then increases. Consequently, blending of hydrogen to methane/air and blending methane to hydrogen/air both destabilize the flame. Furthermore, the computed results are compared with measured data available in the literature. Comparison of the computed and measured laminar flame speeds shows good agreement. However, the measured Markstein length is shown to strongly depend on the flame radii range utilized for data processing and have very large uncertainty. It is found that the experimental results cannot correctly show the trend of Markstein length changing with the hydrogen blending level and pressure and hence are not reliable. Therefore, the computed Markstein length, which is accurate, should be used in combustion modeling to include the flame stretch effect on flame speed.