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arXiv · chao-dyn/9607014

Turbulence Fluctuations and New Universal Realizability Conditions in Modelling

Gregory L. Eyink·Francis J. Alexander
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Abstract

General turbulent mean statistics are shown to be characterized by a variational principle. The variational functionals, or ``effective actions'', have experimental consequences for turbulence fluctuations and are subject to realizability conditions of positivity and convexity. An efficient Rayleigh-Ritz algorithm is available to calculate approximate effective actions within PDF closures. Examples are given for Navier-Stokes and for a 3-mode system of Lorenz. The new realizability conditions succeed at detecting {\em a priori} the poor predictions of PDF closures even when the classical 2nd-order moment realizability conditions are satisfied.

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BibTeXRIS

Gregory L. Eyink, Francis J. Alexander. 1996-07-26. Turbulence Fluctuations and New Universal Realizability Conditions in Modelling. https://doi.org/10.1103/physrevlett.78.2563

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