Statistics of vorticity alignment with local strain rates in turbulent premixed flames
Statistics of vorticity alignment with local strain rates in turbulent premixed flames
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DOI：
10.1016/j.euromechflu.2014.01.002
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发表时间：
2014-07-01
影响因子：
2.6
通讯作者：
Chakraborty, Nilanjan
中科院分区：
文献类型：
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作者：
Chakraborty, Nilanjan
针对具有不同放热参数值和跨越不同燃烧状态的全局路易斯数的统计平面湍流预混火焰，分析了涡量矢量与局部主应变率的瞬时对齐。研究表明，无论燃烧方式、放热参数和路易斯数如何，涡量矢量主要与湍流预混火焰中的中间主应变率一致。然而，涡度与最广泛和压缩主应变率的相对排列会根据潜在的燃烧条件而变化。为观察到的涡度与局部主应变率一致的行为提供了详细的物理解释。已经表明，燃烧引起的热释放显着影响涡度与局部主应变率的对齐。然而，无论涡度排列的性质如何，熵传递方程中涡旋拉伸项的平均贡献对于此处考虑的所有情况都保持为正。 (C) 2014 年 Elsevier Masson SAS。版权所有。
The instantaneous alignment of the vorticity vector with local principal strain rates is analysed for statistically planar turbulent premixed flames with different values of heat release parameter and global Lewis number spanning different regimes of combustion. It has been shown that the vorticity vector predominantly aligns with the intermediate principal strain rate in turbulent premixed flames, irrespective of the regime of combustion, heat release parameter and Lewis number. However, the relative alignment of vorticity with the most extensive and compressive principal strain rates changes based on the underlying combustion conditions. Detailed physical explanations are provided for the observed behaviours of vorticity alignment with local principal strain rates. It has been shown that heat release due to combustion significantly affects the alignment of vorticity with local principal strain rates. However, the mean contribution of the vortex-stretching term in the transport equation of enstrophy remains positive for all cases considered here, irrespective of the nature of the vorticity alignment. (C) 2014 Elsevier Masson SAS. All rights reserved.