https://doi.org/10.1140/epje/i2016-16049-x
Regular Article
On the vortex dynamics in fractal Fourier turbulence
1
ISAC-CNR and INFN Sez. Lecce, 73100, Lecce, Italy
2
IIIT-Bangalore 26/C, Electronics City, Hosur Road, 560100, Bangalore, India
3
Dept. of Physics and INFN, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133, Roma, Italy
* e-mail: a.lanotte@isac.cnr.it
Received:
27
October
2015
Revised:
29
February
2016
Accepted:
15
March
2016
Published online:
29
April
2016
Incompressible, homogeneous and isotropic turbulence is studied by solving the Navier-Stokes equations on a reduced set of Fourier modes, belonging to a fractal set of dimension D . By tuning the fractal dimension parameter, we study the dynamical effects of Fourier decimation on the vortex stretching mechanism and on the statistics of the velocity and the velocity gradient tensor. In particular, we show that as we move from D = 3 to D ∼ 2.8 , the statistics gradually turns into a purely Gaussian one. This result suggests that even a mild fractal mode reduction strongly depletes the stretching properties of the non-linear term of the Navier-Stokes equations and suppresses anomalous fluctuations.
Key words: Topical Issue: Multi-scale phenomena in complex flows and flowing matter
© EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg, 2016
