Volume 127, Number 6, September 2019
|Number of page(s)||5|
|Section||Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics|
|Published online||14 October 2019|
The non-equilibrium part of the inertial range in decaying homogeneous turbulence
1 Université Grenoble Alpes, CNRS, Grenoble- INP, LEGI - F-38000, Grenoble, France
2 Department of Aeronautics, Imperial College London - London, UK
(a) Univ. Lille, CNRS, ONERA, Arts et Métiers ParisTech, Centrale Lille, FRE 2017 - LMFL - Laboratoire de Mécanique des fluides de Lille - Kampé de Feriet, F-59000 Lille, France; email@example.com
Received: 18 July 2019
Accepted: 29 September 2019
We use two related non-stationarity functions as measures of the degree of scale-by-scale non-equilibrium in homogeneous isotropic turbulence. The values of these functions indicate significant non-equilibrium at the upper end of the inertial range. Wind tunnel data confirm Lundgren's prediction that the two-point separation r where the second- and third-order structure functions are closest to their Kolmogorov scalings is proportional to the Taylor length-scale λ, and that both structure functions increasingly distance themselves from their Kolmogorov equilibrium form as r increases away from λ throughout the inertial range. With the upper end of the inertial range in non-equilibrium irrespective of Reynolds number, it is not possible to justify the Taylor-Kolmogorov turbulence dissipation scaling on the basis of Kolmogorov equilibrium.
PACS: 47.27.Ak – Fundamentals / 47.27.Gs – Isotropic turbulence; homogeneous turbulence / 47.27.Jv – High-Reynolds-number turbulence
© EPLA, 2019
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.