Statistics of reaction progress variable and mixture fraction gradients of a pulverised coal jet flame using Direct Numerical Simulation data
Statistics of reaction progress variable and mixture fraction gradients of a pulverised coal jet flame using Direct Numerical Simulation data
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DOI：
10.1016/j.proci.2018.06.223
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发表时间：
2019
影响因子：
3.4
通讯作者：
U. Ahmed;C. T. d’Auzay;Masaya Muto;N. Chakraborty;R. Kurose
中科院分区：
文献类型：
--
作者：
U. Ahmed;C. T. d’Auzay;Masaya Muto;N. Chakraborty;R. Kurose
利用三维载波相位直接数值模拟（DNS）数据集分析了煤粉射流火焰中反应过程变量(c)的方差、协方差和梯度以及混合物分数（ξ）的统计行为。观察到candξ的有利-概率密度函数（PDFs）可以用标准β函数参数化。此外，还发现对数正态分布可以准确地表示|∇c|和|∇ξ|。还发现：∇c和∇ξ在整个火焰刷中保持对齐。最后将|∇c|和|∇ξ|的联合PDF与从载波相位DNS中提取的|∇c|的PDF与|∇ξ|的PDF的乘积进行比较，发现在所调查的情况下，|∇c|和|∇ξ|不是统计独立的。还考虑了有相关性和无相关性的二元对数正态分布，发现前者更符合载波相位DNS数据。
The statistical behaviour of the variances, covariance and gradients of the reaction progress variable (c), and the mixture fraction (ξ) have been analysed in a pulverised coal jet flame using a three-dimensional carrier phase direct numerical simulation (DNS) dataset. It has been observed that the Favre-probability density functions (PDFs) ofcandξcan be parametrised by the standardβfunction. Furthermore, the log-normal distribution has been found to accurately represent |∇c| and |∇ξ|. It is also found that ∇cand ∇ξremain aligned throughout the flame brush. Finally the joint PDF of |∇c| and |∇ξ| has been compared with the product of the PDF of |∇c| and PDF of |∇ξ| extracted from carrier phase DNS, and it has been found that |∇c| and |∇ξ| are not statistically independent in the case investigated.The bivariate log-normal distributions with and without correlation have also been considered, and the former is found to be in better agreement with the carrier phase DNS data.