Numerical Study on Unsteady Two-Dimensional Premixed Flame Using Elementary Reaction Mechanism (The Validity of Progress Variable and Its Gradient as Descriptor of Premixed Flame Structure)
Numerical Study on Unsteady Two-Dimensional Premixed Flame Using Elementary Reaction Mechanism (The Validity of Progress Variable and Its Gradient as Descriptor of Premixed Flame Structure)
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基于初等反应机理的非定常二维预混火焰数值研究（进度变量及其梯度作为预混火焰结构描述子的有效性）
DOI：
10.1299/kikaib.71.3038
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Kazuhiro Yamamoto
中科院分区：
文献类型：
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作者：
Toshihiro Katoh;N. Hayashi;H. Yamashita;Y. Nakamura;Kazuhiro Yamamoto
采用基本反应机理对非定常二维预混火焰的火焰结构进行了数值模拟。为了研究甲烷-空气预混料的非定常特性，在其入口速度上加入一个正弦波动：u0= um {1+ a·sin （2πky）·sin (2πft)}。平均速度um为1.25 ~ 2.00m/s，振幅A固定为1.0，频率f为100、250、500 Hz，波数k为0.1 ~ 0.4mm-1。采用斯姆克骨架机理作为基本反应机理。等效比率固定为0.75。利用氧化剂质量分数Cq及其火焰前梯度（dC/dn） q定义的进程变量，研究了预混火焰的非定常行为和火焰结构。结果表明：总放热率、温度梯度、最大物质浓度由Cq和（dC/dn） q决定，它们是预混火焰最重要的描述因子，支配着预混火焰的火焰结构。根据火焰曲率和火焰传播方向对非定常行为进行分类，分类区域与Cq和（dC/dn） q有关。
The flame structure of unsteady two-dimensional premixed flame is numerically simulated with elementary reaction mechanism. In order to investigate unsteady behavior, a sinusoidal fluctuation is added to the inlet velocity of methane-air premixed mixture as follows : u0= um {1+A·sin (2πky) · sin (2πft)}. The average velocity um is 1.25-2.00m/s, the amplitude A is fixed to 1.0, the frequency f is 100, 250, 500 Hz, and the wavenumber k is 0.1-0.4mm-1. The Smooke's skeletal mechanism is adopted as the elementary reaction mechanism. The equivalence ratio is fixed to 0.75. The unsteady behavior and flame structure of premixed flame are examined by using the progress variable defined with mass fraction of oxidizer Cq and its gradient (dC/dn) q at flame front. The obtained results are as follows : The total heat release rate, the temperature gradient, the maximum concentration of species are determined by Cq and (dC/dn) q. Consequently, they are the most important descriptors of premixed flame which dominate the flame structure of premixed flame. The unsteady behavior is classified by the flame curvature and the flame propagation direction, and the classified regions are related to Cq and (dC/dn) q.