A one-dimensional turbulence model; Enstrophy cascades and small-scale intermittency in decaying turbulence
作者:
P. Bartello,
T. Warn,
期刊:
Geophysical & Astrophysical Fluid Dynamics
(Taylor Available online 1988)
卷期:
Volume 40,
issue 3-4
页码: 239-259
ISSN:0309-1929
年代: 1988
DOI:10.1080/03091928808208827
出版商: Taylor & Francis Group
关键词: Turbulence;enstrophy cascades;intermittency
数据来源: Taylor
摘要:
Severe unidirectional Fourier truncation of the equations for 2-D incompressible flow leads to a system of three coupled PDEs in one space dimension with the same quadratic invariants as the original set (i.e. energy and enstrophy). Numerically generated equilibria for inviscid, truncated versions of the reduced system are well approximated by Kraichnan's energy-enstrophy equipartition spectra. Viscous calculations for decaying turbulence at moderate resolution (1024 degrees of freedom) also appear to be consistent with a direct,k−3, enstrophy cascading inertial range when the dissipation is small. Dissipation range intermittency in the form of spatially intermittent enstrophy dissipation with occasional strong bursts producing linear phase locking is also observed. In contrast to full 2-D simulations, no tendency towards the emergence of isolated, coherent vorticity structures is observed. The model consequently mimics some, but not all, of the properties of the full 2-D set.
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