Determination of burning velocities from spherically expanding H-2/air   flames

doi:10.1016/j.proci.2014.05.137

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	Determination of burning velocities from spherically expanding H-2/air flames
	Varea, Emilien ; Beeckmann, Joachim ; Pitsch, Heinz ; Chen, Zheng ; Renou, Bruno
刊名	proceedings of the combustion institute
	2015
关键词	Laminar burning velocity Spherically expanding flames Stretch effects Flame speed Consumption speed FLAMMABILITY LIMIT THERMAL-EXPANSION PREMIXED FLAMES HIGH-PRESSURE LEWIS NUMBER MIXTURES PROPAGATION SPEEDS COMBUSTION RADIATION
DOI	10.1016/j.proci.2014.05.137
英文摘要	Laminar burning velocities of hydrogen/air mixtures can show discrepancies up to 30%, making chemical mechanism validation and improvement difficult. The source of uncertainties may come from different factors influencing at each processing and post-processing steps the final value. Considering a spherically expanding flame configuration, reflection on the accuracy of the formulations, used to derive the desired quantity, is proposed. Starting from the exact definition of the laminar burning velocity, two formulations - direct and indirect flame speeds formulations - are derived for spherical flames. Each single source of uncertainty involved in the formulations is pointed out. The emphasis is focused on a specific mixture at an equivalence ratio of 0.50, atmospheric pressure, and an initial temperature of 300 K. This point represents the best tradeoff between low ratio of flame velocity and recording sampling rate and the occurrence of cellular flames (Le < 1). An extensive experimental and numerical study (1D spherically expanding flames) of this mixture is carried out. As a result, the experimental laminar burning velocities determined by using the direct flame speed or the indirect flame speed formulae depict different values. However, when numerically determined, both formulae yield the same value. This paves the way to understand and identify the experimental error sources. Stretch and Lewis numbers effects (super-adiabatic temperatures) as well as radiation processes (burned gas motion) are studied. Nonetheless, they do not show to be the main source of uncertainty. The extrapolation procedure (linear or non-linear) according to the limited number of experimental points (rapid apparition of cellular structure) appears as the main factor influencing the discrepancy in laminar burning velocities. (C) 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.; Thermodynamics; Energy & Fuels; Engineering, Chemical; Engineering, Mechanical; SCI(E); 0; ARTICLE; emilien.varea@itv.rwth-aachen.de; 711-719; 35
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/206590]
专题	工学院
推荐引用方式 GB/T 7714	Varea, Emilien,Beeckmann, Joachim,Pitsch, Heinz,et al. Determination of burning velocities from spherically expanding H-2/air flames[J]. proceedings of the combustion institute,2015.
APA	Varea, Emilien,Beeckmann, Joachim,Pitsch, Heinz,Chen, Zheng,&Renou, Bruno.(2015).Determination of burning velocities from spherically expanding H-2/air flames.proceedings of the combustion institute.
MLA	Varea, Emilien,et al."Determination of burning velocities from spherically expanding H-2/air flames".proceedings of the combustion institute (2015).