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The decay of homogeneous anisotropic turbulence

L. Biferale·G. Boffetta·A. Celani·A. Lanotte·F. Toschi·M. Vergassola
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Abstract

We present the results of a numerical investigation of three-dimensional decaying turbulence with statistically homogeneous and anisotropic initial conditions. We show that at large times, in the inertial range of scales: (i) isotropic velocity fluctuations decay self-similarly at an algebraic rate which can be obtained by dimensional arguments; (ii) the ratio of anisotropic to isotropic fluctuations of a given intensity falls off in time as a power law, with an exponent approximately independent of the strength of the fluctuation; (iii) the decay of anisotropic fluctuations is not self-similar, their statistics becoming more and more intermittent as time elapses. We also investigate the early stages of the decay. The different short-time behavior observed in two experiments differing by the phase organization of their initial conditions gives a new hunch on the degree of universality of small-scale turbulence statistics, i.e. its independence of the conditions at large scales.

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L. Biferale, G. Boffetta, A. Celani, A. Lanotte, F. Toschi, M. Vergassola. 2003-01-28. The decay of homogeneous anisotropic turbulence. https://doi.org/10.1063/1.1582859

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