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Intermittency in the not-so-smooth elastic turbulence.
- Source :
-
Nature communications [Nat Commun] 2024 May 27; Vol. 15 (1), pp. 4070. Date of Electronic Publication: 2024 May 27. - Publication Year :
- 2024
-
Abstract
- Elastic turbulence is the chaotic fluid motion resulting from elastic instabilities due to the addition of polymers in small concentrations at very small Reynolds ( Re ) numbers. Our direct numerical simulations show that elastic turbulence, though a low Re phenomenon, has more in common with classical, Newtonian turbulence than previously thought. In particular, we find power-law spectra for kinetic energy E(k) ~ k <superscript>-4</superscript> and polymeric energy E <subscript>p</subscript> (k) ~ k <superscript>-3/2</superscript> , independent of the Deborah (De) number. This is further supported by calculation of scale-by-scale energy budget which shows a balance between the viscous term and the polymeric term in the momentum equation. In real space, as expected, the velocity field is smooth, i.e., the velocity difference across a length scale r, δu ~ r but, crucially, with a non-trivial sub-leading contribution r <superscript>3/2</superscript> which we extract by using the second difference of velocity. The structure functions of second difference of velocity up to order 6 show clear evidence of intermittency/multifractality. We provide additional evidence in support of this intermittent nature by calculating moments of rate of dissipation of kinetic energy averaged over a ball of radius r, ε <subscript>r</subscript> , from which we compute the multifractal spectrum.<br /> (© 2024. The Author(s).)
Details
- Language :
- English
- ISSN :
- 2041-1723
- Volume :
- 15
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Nature communications
- Publication Type :
- Academic Journal
- Accession number :
- 38802336
- Full Text :
- https://doi.org/10.1038/s41467-024-48460-5