HYDRODYNAMICAL TURBULENCE BY FRACTAL FOURIER DECIMATION
Alessandra Sabina Lanotte, Luca Biferale, Shiva Kumar Malapaka, Federico Toschi
Session: Intermittency and scaling 1
Session starts: Tuesday 25 August, 10:30
Presentation starts: 12:15
Room: Room H
Alessandra Sabina Lanotte (CNR ISAC, Lecce, Italy)
Luca Biferale (Univ. Tor Vergata, Rome, Italy)
Shiva Kumar Malapaka (Univ. Tor Vergata, Rome, Italy)
Federico Toschi (Technical Univ. Eindhoven, The Netherlands)
We present a systematic numerical investigation of high-resolution 3D isotropic and homogeneous turbulence resolved on
a decimated set of Fourier modes. Fractal decimation acts to decrease the effective dimensionality of the flow by allowing triadic
interactions only in a set of Fourier modes N(k) proportional to k^DF for large k. While keeping the symmetries of the original 3D
Navier-Stokes equations unchanged, a dramatic change in small-scale statistics is detected at decreasing the fractal dimension DF .
Already at fractal dimension DF = 2.8, a global self-similar behaviour is observed in the inertial range of scales, the consequence of
such transition are the restoration of the scaling symmetry and vorticity distribution that becomes close to Gaussian.
We relate the results to the different roles of local vs non-local interactions in the energy transfer range.