Implementation Issues of the Conditional Moment Closure Model in Large Eddy Simulations
Implementation Issues of the Conditional Moment Closure Model in Large Eddy Simulations
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DOI：
10.1007/s10494-009-9226-y
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发表时间：
2010-04-01
影响因子：
2.4
通讯作者：
Mastorakos, Epaminondas
中科院分区：
文献类型：
--
作者：
Triantafyllidis, Antonios;Mastorakos, Epaminondas
不同的方式传输信息的混合物分数，其亚网格尺度方差和标量耗散率的大涡模拟（LES）/条件矩封闭（CMC）计算方面进行检查。在这样的模拟中，信息必须从细LES网格转移到通常较粗的CMC网格。通过过滤实验混合分数和标量耗散率数据在各种分辨率的CMC分辨率计算条件和无条件量的不同选项进行评估。结果发现，当使用CMC分辨率下的过滤密度函数的假定形状时，必须特别注意混合分数方差。研究还发现，振幅映射闭合模型可以用于条件标量耗散率。LES/CMC与详细的化学钝体稳定燃烧器进行了使用两种不同的方法计算湍流扩散率。火焰的结构是真实的，当使用两种扩散系数时，注意到的差别很小。
Different ways of transferring information regarding the mixture fraction, its sub-grid scale variance and the scalar dissipation rate are examined in terms of a Large Eddy Simulation (LES)/Conditional Moment Closure (CMC) calculation. In such a simulation, information must be transferred from a fine LES grid to a usually coarser CMC grid. Different options of calculating conditional and unconditional quantities in the CMC resolution are assessed by filtering experimental mixture fraction and scalar dissipation rate data at various resolutions. It was found that when a presumed shape for the Filtered Density Function at the CMC resolution is used, special care must be given to the mixture fraction variance. It was also found that the Amplitude Mapping Closure model can be used for the conditional scalar dissipation rate. LES/CMC with detailed chemistry of a bluff-body stabilised burner was performed using two different ways of calculating the turbulent diffusivity. The structure of the flame is realistic, with little difference noticed when using the two diffusivities.