Nonlinear transfer and spectral distribution of energy in α turbulence
Nonlinear transfer and spectral distribution of energy in α turbulence
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DOI：
10.1016/j.physd.2003.11.005
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发表时间：
2004-04-15
影响因子：
4
通讯作者：
Tran, CV
中科院分区：
文献类型：
--
作者：
Tran, CV
本文研究了无界区域和双周期区域中由α湍流方程控制的二维湍流，α湍流方程包括表面准地转方程（α = 1）、Navier-Stokes方程（α = 2）和均匀内加热驱动的旋转区域上的浅水流动控制方程（α = 3）。这个方程族保持了两个无粘不变量（Navier-Stokes情形中的能量和拟能），其动力学被认为经历了双重级联。它表明，逆级联可以存在于没有一个直接级联，后者是可能的，只有当逆级联量的逆传输速率接近自己的注射速率。在低于和高于注入范围的波数范围内的谱指数的约束。对于中等雷诺数的Navier-Stokes湍流，通过数值模拟证实了在完全没有直接涡拟能叶栅的情况下，逆能量叶栅的实现。(C)2003 Elsevier B. V.保留所有权利。
Two-dimensional turbulence governed by the so-called alpha turbulence equations, which include the surface quasi-geostrophic equation (alpha = 1), the Navier-Stokes system (alpha = 2), and the governing equation for a shallow flow on a rotating domain driven by a uniform internal heating (alpha = 3), is studied here in both the unbounded and doubly periodic domains. This family of equations conserves two inviscid invariants (energy and enstrophy in the Navier-Stokes case), the dynamics of which are believed to undergo a dual cascade. It is shown that an inverse cascade can exist in the absence of a direct cascade and that the latter is possible only when the inverse transfer rate of the inverse-cascading quantity approaches its own injection rate. Constraints on the spectral exponents in the wavenumber ranges lower and higher than the injection range are derived. For Navier-Stokes turbulence with moderate Reynolds numbers, the realization of an inverse energy cascade in the complete absence of a direct enstrophy cascade is confirmed by numerical simulations. (C) 2003 Elsevier B.V. All rights reserved.