Direct numerical simulation of lean premixed CH4/air and H-2/air flames at high Karlovitz numbers

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Bibtex

@article{c55c0f8905ff43198b0cec1132ed72d3,
title = "Direct numerical simulation of lean premixed CH4/air and H-2/air flames at high Karlovitz numbers",
abstract = "Three-dimensional direct numerical simulation with detailed chemical kinetics of lean premixed CH4/air and H-2/air flames at high Karlovitz numbers (Ka similar to 1800) is carried out. It is found that the high intensity turbulence along with differential diffusion result in a much more rapid transport of H radicals from the reaction zone to the low temperature unburned mixtures (similar to 500 K) than that in laminar flamelets. The enhanced concentration of H radicals in the low temperature zone drastically increases the reaction rates of exothermic chain terminating reactions (e.g., H + O-2+M = HO2 + M in lean H-2/air flames), which results in a significantly enhanced heat release rate at low temperatures. This effect is observed in both CH4/air and H-2/air flames and locally, the heat release rate in the low temperature zone can exceed the peak heat release rate of a laminar flamelet. The effects of chemical kinetics and transport properties on the H-2/air flame are investigated, from which it is concluded that the enhanced heat release rate in the low temperature zone is a convection-diffusion-reaction phenomenon, and to obtain it, detailed chemistry is essential and detailed transport is important. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.",
keywords = "Turbulent premixed combustion, Direct numerical simulation, High, Karlovitz number, Detailed chemistry, Differential diffusion",
author = "Henning Carlsson and Rixin Yu and Xue-Song Bai",
year = "2014",
doi = "10.1016/j.ijhydene.2014.09.173",
language = "English",
volume = "39",
pages = "20216--20232",
journal = "International Journal of Hydrogen Energy",
issn = "1879-3487",
publisher = "Elsevier",
number = "35",

}