Dissipation, enstrophy and pressure statistics in turbulence simulations at high Reynolds number
Dissipation, enstrophy and pressure statistics in turbulence simulations at high Reynolds number
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DOI：
10.1017/jfm.2012.5
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发表时间：
2012-06-10
影响因子：
3.7
通讯作者：
Sreenivasan, K. R.
中科院分区：
文献类型：
--
作者：
Yeung, P. K.;Donzis, D. A.;Sreenivasan, K. R.
我们使用泰勒尺度雷诺数从140到1000的高分辨直接数值模拟的数据来研究能量耗散率和涡拟能密度（即局部涡度的平方）的统计。尽管这些变量中的每一个都有很大的变化，但它们的极端事件不仅以类似的方式缩放，而且随着雷诺数的增加，在空间上逐渐倾向于一起发生。虽然它们具有巨大振幅的非高斯尾，但某些特征性质的比值可以与各向同性高斯随机场的比值密切相关。我们目前的结果也统计的压力Laplacian和条件平均压力耗散和拟能。在低雷诺数下，强烈的负压波动优先与旋转为主的区域，但在高雷诺数下，高耗散和高涡度拟能具有类似的效果。
We use data from well-resolved direct numerical simulations at Taylor-scale Reynolds numbers from 140 to 1000 to study the statistics of energy dissipation rate and enstrophy density (i.e. the square of local vorticity). Despite substantial variability in each of these variables, their extreme events not only scale in a similar manner but also progressively tend to occur spatially together as the Reynolds number increases. Though they possess non-Gaussian tails of enormous amplitudes, ratios of some characteristic properties can be closely linked to those of isotropic Gaussian random fields. We present results also on statistics of the pressure Laplacian and conditional mean pressure given both dissipation and enstrophy. At low Reynolds number intense negative pressure fluctuations are preferentially associated with rotation-dominated regions but at high Reynolds number both high dissipation and high enstrophy have similar effects.