Large Eddy simulation of hydrogen-air premixed flames in a small scale combustion chamber
Large Eddy simulation of hydrogen-air premixed flames in a small scale combustion chamber
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DOI：
10.1016/j.ijhydene.2014.12.042
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发表时间：
2015-02-23
影响因子：
7.2
通讯作者：
Masri, A. R.
中科院分区：
文献类型：
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作者：
Abdel-Raheem, M. A.;Ibrahim, S. S.;Masri, A. R.
虽然氢作为清洁燃料是有吸引力的，但由于其高反应性，它构成了重大风险。本文采用大涡模拟方法对氢-空气混合物湍流预混火焰在小尺度燃烧室内的传播过程进行了研究。反应速率的亚网格尺度模型使用动态程序来计算火焰/流动相互作用。点火源和不同的流动配置的结果的灵敏度进行检查。使用从计算的相关参数，火焰位于燃烧的制度，并发现跨越薄和波纹小火焰制度，从而确认小火焰建模的有效性。的计算结果进行了比较，发表的实验数据为类似的配置。据发现，峰值超压和火焰位置的影响，由位于火焰的路径中的挡板的数量，这是与早期的研究结果为烃类燃料。此外，LES技术是能够再现相同的火焰形状的实验图像。对点火源敏感性的粗略研究表明，点火核的大小不影响火焰结构，但只影响峰值超压出现的时间，而将点火源从基板上移开会导致峰值超压的减小。版权所有（C）2014，氢能出版物有限责任公司。由爱思唯尔有限公司出版。保留所有权利。
While hydrogen is attractive as a clean fuel, it poses a significant risk due to its high-reactivity. This paper presents Large Eddy Simulations (LES) of turbulent premixed flames of hydrogen air mixtures propagating in a small scale combustion chamber. The sub-grid-scale model for reaction rate uses a dynamic procedure for calculating the flame/ flow interactions. Sensitivity of the results to the ignition source and to different flow configurations is examined. Using the relevant parameter from the calculations, the flames are located on the regimes of combustion and are found to span the thin and corrugated flamelet regimes, hence confirming the validity of flamelet modelling. The calculations are compared to published experimental data for a similar configuration. It is found that both the peak overpressure and flame position are affected by the number of baffles positioned in the path of the flame and this is consistent with earlier findings for hydrocarbon fuels. Also, the LES technique is able to reproduce the same flame shape as the experimental images. A coarse study of sensitivity to the ignition source shows that the size of the ignition kernel does not affect the flame structure but influences only the time where the peak overpressure appears while moving the ignition source away from the base plate leads to a decrease in the peak overpressure. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.