Analysis of the laminar flamelet concept for nonpremixed laminar flames
Analysis of the laminar flamelet concept for nonpremixed laminar flames
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DOI：
10.1016/j.combustflame.2005.11.005
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发表时间：
2006-06
影响因子：
4.4
通讯作者：
K. Claramunt;R. Consul;D. Carbonell;C. Pérez-Segarra
中科院分区：
文献类型：
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作者：
K. Claramunt;R. Consul;D. Carbonell;C. Pérez-Segarra
本文的目的是研究层流小火焰的概念，非预混层流火焰的多维数值模拟的应用。分析了定常和非定常火焰的特性。揭示了火焰面建模的数学公式的推导过程，并对一些常用的简化方法进行了检验。不同的模型的标量耗散率依赖的混合物分数变量进行了分析。此外，不同的标准来评估拉格朗日型火焰寿命的非定常火焰。还研究了每种物质具有恒定刘易斯数的微分扩散和辐射传热等现象的包含情况。由McEnally和Pfefferle（Combust. Sci. Technol.116 -117（1996）183-209）和由班尼特、McEnally、Pfefferle和Smooke（Combust. Flame 123（2000）522-546）、Cnsul、Pérez-Segarra、Claramunt、Cadafalch和奥利瓦（Combust. Theory Modeling 7（3）（2003）525-544），以及Claramunt，Cnsul，Pérez-Segarra，and奥利瓦（Combust. Flame 137（2004）444-457）已被用作测试用例。使用小火焰的概念得到的结果进行了比较，从完整的传输方程使用原始变量的全分辨率获得的数据。在交错网格上的体积法被用来离散控制方程。一个并行多块算法的区域分解技术的基础上运行的松散耦合的计算机已被使用。为了评估本文提出的数值解的质量，验证过程的基础上广义Richardson外推技术和网格收敛指数（GCI）已被应用。
The goal of this paper is to investigate the application of the laminar flamelet concept to the multidimensional numerical simulation of nonpremixed laminar flames. The performance of steady and unsteady flamelets is analyzed. The deduction of the mathematical formulation of flamelet modeling is exposed and some commonly used simplifications are examined. Different models for the scalar dissipation rate dependence on the mixture fraction variable are analyzed. Moreover, different criteria to evaluate the Lagrangian-type flamelet lifetime for unsteady flamelets are investigated. Inclusion of phenomena such as differential diffusion with constant Lewis number for each species and radiation heat transfer are also studied. A confined co-flow axisymmetric nonpremixed methane/air laminar flame experimentally investigated by McEnally and Pfefferle (Combust. Sci. Technol. 116–117 (1996) 183–209) and numerically investigated by Bennett, McEnally, Pfefferle, and Smooke (Combust. Flame 123 (2000) 522–546), Cònsul, Pérez-Segarra, Claramunt, Cadafalch, and Oliva (Combust. Theory Modelling 7 (3) (2003) 525–544), and Claramunt, Cònsul, Pérez-Segarra, and Oliva (Combust. Flame 137 (2004) 444–457) has been used as a test case. Results obtained using the flamelet concept have been compared to data obtained from the full resolution of the complete transport equations using primitive variables. Finite-volume techniques over staggered grids are used to discretize the governing equations. A parallel multiblock algorithm based on domain decomposition techniques running with loosely coupled computers has been used. To assess the quality of the numerical solutions presented in this paper, a verification process based on the generalized Richardson extrapolation technique and on the grid convergence index (GCI) has been applied.