Closure modeling for the conditional Reynolds stresses in turbulent premixed combustion
Closure modeling for the conditional Reynolds stresses in turbulent premixed combustion
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湍流预混燃烧中条件雷诺应力的闭合建模
DOI：
10.1016/j.proci.2020.07.046
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发表时间：
2021
影响因子：
3.4
通讯作者：
Mueller, Michael E.
中科院分区：
文献类型：
--
作者：
Lee, Jinyoung;Mueller, Michael E.
在低Karlovitz数预混火焰中，燃烧引起的膨胀对湍流有显著影响。基于传统无条件平均的传统湍流建模方法在准确捕获燃烧放热效应方面受到限制，因为它们必须捕获燃烧放热对湍流和火焰动力学的直接影响。求解相对于火焰结构变量（预混燃烧的进展变量）有条件地平均的动量输运方程可以为建模燃烧影响的湍流提供上级框架，因为火焰动力学被嵌入到火焰结构变量调节中。然而，条件动量方程包含许多在物理空间和相空间中演化的不封闭项。在许多未封闭项中，条件雷诺应力（雷诺应力的条件模拟）代表湍流输运对条件速度的影响。在这项工作中，一个新的模型，包括两个组件的条件雷诺应力湍流预混火焰捕捉热释放的湍流效应。第一个组成部分是Boussinesq模型的条件模拟，该模型表征了物理空间中的湍流剪切效应。第二个组成部分取决于条件速度梯度，而不是在物理空间，但在相空间和捕获的各向异性的条件雷诺应力驱动的热膨胀效应，火焰结构内的变化。该模型验证了先验使用DNS数据库的湍流预混射流火焰在低和高Karlovitz数。在低Karlovitz数下，相空间项使模型能够捕获所有条件雷诺应力分量上的直接热释放效应，特别是法向分量的正确各向异性和剪切分量的符号。在高Karlovitz数下，热释放对湍流的影响不显著，湍流剪切效应占主导地位，相空间项的影响几乎可以忽略不计。
Turbulence is significantly affected by combustion-induced dilatation in low Karlovitz number premixed flames. Conventional turbulence modeling approaches based on traditional unconditional averaging are limited in accurately capturing combustion heat release effects since they must capture both the direct influence of combustion heat release on turbulence and the flame dynamics. Solving momentum transport equations conditionally averaged with respect to a flame structure variable (progress variable for premixed combustion) could provide a superior framework for modeling combustion-affected turbulence since the flame dynamics are embedded into the flame structure variable conditioning. However, the conditional momentum equations contain numerous unclosed terms that evolve in both physical and phase spaces. Of the many unclosed terms, the conditional Reynolds stresses (conditional analog of the Reynolds stresses) represent the influence of turbulent transport on the conditional velocities. In this work, a new model consisting of two components for the conditional Reynolds stresses in turbulent premixed flames is developed to capture heat release effects on turbulence. The first component is the conditional analog of the Boussinesq model that characterizes turbulent shear effects in physical space. The second component depends on the conditional velocity gradient not in physical space but in phase space and captures the anisotropy in the conditional Reynolds stresses driven by thermal expansion effects that vary within the flame structure. The model is validated a priori using DNS databases of turbulent premixed jet flames at low and high Karlovitz numbers. At low Karlovitz number, the phase space term enables the model to capture direct heat release effects on all conditional Reynolds stress components, specifically the correct anisotropy of the normal components and the sign of the shear component. At high Karlovitz number where heat release effects on turbulence are insignificant, turbulent shear effects are dominant, and the phase space term has a nearly negligible effect.
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影响因子：
3.4
作者：
J. MacArt;T. Grenga;M. Mueller
通讯作者：
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影响因子：
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作者：
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DOI：
--
发表时间：
1983
期刊：
影响因子：
--
作者：
R. Cheng;N. T
通讯作者：
N. T
预混湍流火焰中湍流强度和雷诺应力的条件采样
DOI：
--
发表时间：
1984
期刊：
影响因子：
--
作者：
R. Cheng
通讯作者：
R. Cheng
影响因子：
4.4
作者：
Lee, Jinyoung;MacArt, Jonathan F.;Mueller, Michael E.
通讯作者：
Mueller, Michael E.