Probability densities in strong turbulence

PHYSICA D-NONLINEAR PHENOMENA

卷:215

Article

Yakhot, V

关键词: turbulence;    statistical mechanics;   

DOI  :  10.1016/j.physd.2006.01.012

来源: Elsevier

【 摘 要 】

In this work we, using Mellin's transform combined with the Gaussian large-scale boundary condition, calculate probability densities (PDFs) of velocity increments P(delta(r)u, r), velocity derivatives P(u', r) and the PDF of the fluctuating dissipation scales Q(eta, Re), where Re is the large-scale Reynolds number. The resulting expressions strongly deviate from the Log-normal PDF P-L (delta(r)u, r) often quoted in the literature. It is shown that the probability density of the small-scale velocity fluctuations includes information about the large (integral) scale dynamics which is responsible for the deviation of P (delta(r)u, r) from P-L (delta(r)u, r). An expression for the function D (h) of the multifractal theory, free from spurious logarithms recently discussed in [U. Frisch, M. Martins Afonso, A. Mazzino, V. Yakhot, J. Fluid Mech. 542 (2005) 97] is also obtained. (c) 2006 Published by Elsevier B.V.

【 授权许可】

Free