Open AccessNon-equilibrium Scaling of the Turbulent-Nonturbulent Interface Speed in Planar Jets
Author(s) -
Gioacchino Cafiero,
J. C. Vassilicos
Publication year - 2020
Publication title -
physical review letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.688
H-Index - 673
eISSN - 1079-7114
pISSN - 0031-9007
DOI - 10.1103/physrevlett.125.174501
Subject(s) - turbulence , physics , taylor microscale , scaling , planar , kolmogorov microscales , length scale , nozzle , dissipation , lambda , jet (fluid) , cascade , mechanics , statistical physics , classical mechanics , turbulence kinetic energy , k omega turbulence model , geometry , thermodynamics , optics , mathematics , computer graphics (images) , computer science , chemistry , chromatography
The length scale which, combined with the fluid's kinematic viscosity ν, defines the local average speed of the turbulent-nonturbulent interface has been postulated to be the smallest (Kolmogorov) length scale η of the turbulence Corrsin and Kistler, [NACA Report No. 1244, 1955, p. 1033.]. This is indeed the case when the turbulence dissipation rate obeys the Kolmogorov equilibrium cascade scaling, but in the presence of the nonequilibrium turbulence dissipation scaling the average local turbulent-nonturbulent interface speed scales as ν/λ, instead of ν/η, where λ is the Taylor length. We derive this theoretically and confirm it experimentally in the range of distances between 20 and 50 nozzle widths of a turbulent planar jet.
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