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Extensive strain along gradient trajectories in the turbulent kinetic energy field

Gampert, Markus ; Goebbert, Jens Henrik ; Schaefer, Philip ; Gauding, Michael ; Peters, Norbert ; Aldudak, Fettah ; Oberlack, Martin (2024)
Extensive strain along gradient trajectories in the turbulent kinetic energy field.
In: New Journal of Physics, 2011, 13 (4)
doi: 10.26083/tuprints-00020563
Article, Secondary publication, Publisher's Version

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Item Type: Article
Type of entry: Secondary publication
Title: Extensive strain along gradient trajectories in the turbulent kinetic energy field
Language: English
Date: 5 March 2024
Place of Publication: Darmstadt
Year of primary publication: April 2011
Place of primary publication: London
Publisher: IOP Publishing
Journal or Publication Title: New Journal of Physics
Volume of the journal: 13
Issue Number: 4
Collation: 16 Seiten
DOI: 10.26083/tuprints-00020563
Corresponding Links:
Origin: Secondary publication DeepGreen
Abstract:

Based on direct numerical simulations of forced turbulence, shear turbulence, decaying turbulence, a turbulent channel flow as well as a Kolmogorov flow with Taylor-based Reynolds numbers Reλ between 69 and 295, the normalized probability density function of the length distribution of dissipation elements, the conditional mean scalar difference ⟨Δk∣l⟩ at the extreme points as well as the scaling of the two-point velocity difference along gradient trajectories ⟨Δun⟩ are studied. Using the field of the instantaneous turbulent kinetic energy k as a scalar, we find good agreement between the model equation for as proposed by Wang and Peters (2008 J. Fluid Mech. 608 113–38) and the results obtained in the different direct numerical simulation cases. This confirms the independence of the model solution from both the Reynolds number and the type of turbulent flow, so that it can be considered universally valid. In addition, we show a 2/3 scaling for the mean conditional scalar difference. In the second part of the paper, we examine the scaling of the conditional two-point velocity difference along gradient trajectories. In particular, we compare the linear s/τ scaling, where τ denotes an integral time scale and s the separation arclength along a gradient trajectory in the inertial range as derived by Wang (2009 Phys. Rev. E 79 046325) with the s·a∞ scaling, where a∞ denotes the asymptotic value of the conditional mean strain rate of large dissipation elements.

Identification Number: Artikel-ID: 043012
Status: Publisher's Version
URN: urn:nbn:de:tuda-tuprints-205637
Classification DDC: 500 Science and mathematics > 530 Physics
600 Technology, medicine, applied sciences > 620 Engineering and machine engineering
Divisions: 16 Department of Mechanical Engineering > Fluid Dynamics (fdy)
Date Deposited: 05 Mar 2024 10:11
Last Modified: 27 May 2024 07:18
SWORD Depositor: Deep Green
URI: https://tuprints.ulb.tu-darmstadt.de/id/eprint/20563
PPN: 518577805
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