On the inverse kinetic energy cascade in premixed isotropic turbulent flames
On the inverse kinetic energy cascade in premixed isotropic turbulent flames
复制标题
预混各向同性湍流火焰中的逆动能级联
DOI：
10.1142/s0129183122500152
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发表时间：
2021-09
影响因子：
1.9
通讯作者：
Hong Yao
中科院分区：
文献类型：
--
作者：
Xiang Qian;Hao Lu;Chun Zou;Hong Yao
流体中能量传递的理解对于湍流反应流的精确建模是重要的。在这项研究中，我们调查尺度间的动能转移和亚网格尺度（SGS）的后向散射使用的数据从预混各向同性湍流火焰的直接数值模拟（DNSs）。结果表明，在所研究的预混火焰中，湍流动能输运方程中的压力传递项在大尺度上控制着非线性对流和耗散，并对逆动能级联有显著贡献。过滤后的DNS数据显示，SGS反向散射与正压膨胀功（即热膨胀）的出现相关。三个SGS应力模型的先验检验结果表明，Smagorinsky应力模型是无法捕捉SGS的后向散射，但两个非线性结构应力模型能够预测SGS的后向散射。
The understanding of energy transfer in fluids is important for the accurate modeling of turbulent reacting flows. In this study, we investigate interscale kinetic energy transfer and subgrid-scale (SGS) backscatter using data from direct numerical simulations (DNSs) of premixed isotropic turbulent flames. Results reveal that in the examined premixed flames, the pressure transfer term appearing in the transport equation of turbulent kinetic energy dominates the nonlinear advection and the dissipation at large scales, and noticeably contributes to the inverse kinetic energy cascade. Filtered DNS data show that SGS backscatter is correlated with the appearance of positive pressure-dilatation work, i.e. thermal expansion. A priori test results of three SGS stress models reveal that the Smagorinsky stress model is unable to capture SGS backscatter, but that two nonlinear structural stress models are able to predict SGS backscatter.