Dynamics of weakly stretched flames: quantitative description and extraction of global flame parameters
Dynamics of weakly stretched flames: quantitative description and extraction of global flame parameters
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DOI：
10.1016/s0010-2180(98)00137-0
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发表时间：
1999-07
影响因子：
4.4
通讯作者：
C. Sun;C. Sung;L. He;C. Law
中科院分区：
文献类型：
--
作者：
C. Sun;C. Sung;L. He;C. Law
基于积分分析，导出了弱拉伸率变化下火焰响应的广义表达式。结合一维平面火焰计算结果确定的层流火焰速度、层流火焰厚度、一步总反应阶数和活化能，将拉伸火焰的这些表达式与球形向外传播、球形向内传播、逆流氢气/空气和丙烷/空气火焰的计算结果进行关联。这些相关性通过线性外推到零拉伸率，得到层流火焰速度，马克斯坦长度表示火焰响应对拉伸率的敏感性，以及火焰刘易斯数。在给定的等效比和系统压力下，从三种火焰构型中提取的Markstein长度和Lewis数基本相同，并且这些Lewis数与Joulin和Mitani的双反应物火焰理论预测的结果吻合得很好。提出了层流预混火焰拉伸效应先验定量测定的可行性。
Generalized expressions for the flame response to weak stretch rate variations were derived based on an integral analysis. Together with values of the laminar flame speed, laminar flame thickness, and the one-step overall reaction order and activation energy determined from the computational results of the one-dimensional planar flame, these expressions for the stretched flames were then used to correlate the computational results of the spherical outwardly propagating, spherical inwardly propagating, and counterflow hydrogen/air and propane/air flames. These correlations yielded the laminar flame speeds through linear extrapolation to zero stretch rate, the Markstein lengths representing the sensitivity of the flame response to stretch rate, and the flame Lewis number. Furthermore, it is shown that the extracted Markstein lengths and Lewis numbers from the three flame configurations are largely the same for given equivalence ratio and system pressure, and that these Lewis numbers also agree well with those predicted from the two-reactant flame theory of Joulin and Mitani. The feasibility of a priori quantitative determination of stretch effects on laminar premixed flames is suggested.