Direct numerical simulation of turbulence–radiation interactions in homogeneous nonpremixed combustion systems
Direct numerical simulation of turbulence–radiation interactions in homogeneous nonpremixed combustion systems
复制标题
均质非预混燃烧系统中湍流-辐射相互作用的直接数值模拟
DOI：
10.1016/j.proci.2006.07.139
复制
发表时间：
2007
影响因子：
3.7
通讯作者：
["K. Deshmukh
中科院分区：
文献类型：
--
作者：
["K. Deshmukh
化学反应湍流中的一个重要问题是湍流和辐射之间的相互作用（湍流-辐射相互作用-TRI）。TRI产生于温度和物种组成的波动与辐射强度波动之间的高度非线性耦合。本文采用直接数值模拟（DNS）方法研究了统计均质非预混体系中的TRI。采用光子蒙特卡罗方法求解辐射传输方程。辐射特性对应于一个非散射虚构的灰色气体与普朗克平均吸收系数，模仿典型的烃-空气燃烧产物。排放和吸收TRI的个人贡献已被隔离和量化。的温度自相关性，吸收系数普朗克函数相关性，和吸收系数强度相关性已被检查的光学厚度的中间到大的值，和所有三个相关性的贡献已被发现是显着的。还使用β PDF模型对排放TRI进行了分析估算。β PDF的计算结果与DNS的计算结果吻合较好。这表明，在非预混系统中的排放TRI相对简单的模型可能会开发的基础上，混合分数方差的模型方程。
An important issue in chemically reacting turbulent flows is the interaction between turbulence and radiation (turbulence–radiation interactions—TRI). TRI arises from highly nonlinear coupling between fluctuations in temperature and species composition with the fluctuations of radiative intensity. Here direct numerical simulation (DNS) has been employed to investigate TRI in a statistically homogeneous nonpremixed system. A photon Monte Carlo method has been used to solve the radiative transfer equation (RTE). Radiation properties correspond to a nonscattering fictitious gray gas with a Planck-mean absorption coefficient that mimics that of typical hydrocarbon-air combustion products. Individual contributions of emission and absorption TRI have been isolated and quantified. The temperature self-correlation, the absorption coefficient-Planck function correlation, and the absorption coefficient-intensity correlation have been examined for intermediate-to-large values of the optical thickness, and contributions from all three correlations have been found to be significant. Emission TRI has also been estimated analytically using a β PDF model. The β PDF results are in good agreement with DNS results. This suggests that relatively simple models for emission TRI in nonpremixed systems might be developed based on a modeled equation for mixture fraction variance.