The energy cascade in grid-generated non-equilibrium decaying turbulence
The energy cascade in grid-generated non-equilibrium decaying turbulence
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DOI：
10.1063/1.4916628
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发表时间：
2013-07
影响因子：
4.6
通讯作者：
P. Valente;P. Valente;J. C. Vassilicos
中科院分区：
文献类型：
--
作者：
P. Valente;P. Valente;J. C. Vassilicos
通过测量方形网格背风面中逐尺度能量传递、耗散、平流、产生和输运的下游演化，研究了无量纲耗散系数Ce为Ce = ReMm/Reln且m = 1 n的非平衡湍流（ReM和Rel分别为全局/入口和局部雷诺数），并与Ce =常数的区域进行了比较。这些是冯卡门-豪沃思-莫宁方程的非均匀各向异性版本的主要条款。它示出在这里研究的网格生成的湍流，即使在不可忽略的湍流的产生和运输的存在下，生产和运输是大尺度的现象，并不有助于规模的规模小于约三分之一的积分长度尺度，l的尺度的尺度平衡，因此不影响能量转移到小尺度。在Ce = ReMm/Reln的非平衡区和Ce =常数的下游区，
We investigate non-equilibrium turbulence where the non-dimensionalised dissipation coefficient Ce scales as Ce∼ReMm/Reln with m ≈ 1 ≈ n (ReM and Rel are global/inlet and local Reynolds numbers, respectively) by measuring the downstream evolution of the scale-by-scale energy transfer, dissipation, advection, production, and transport in the lee of a square-mesh grid, and compare with a region where Ce ≈ constant. These are the main terms of the inhomogeneous, anisotropic version of the von Karman-Howarth-Monin equation. It is shown in the grid-generated turbulence studied here that, even in the presence of non-negligible turbulence production and transport, production and transport are large-scale phenomena that do not contribute to the scale-by-scale balance for scales smaller than about a third of the integral-length scale, l, and therefore do not affect the energy transfer to the small-scales. In both the non-equilibrium region where Ce∼ReMm/Reln and further downstream where Ce ≈ constant, the peak of ...