Eur. Phys. J. B 53, 219-224 (2006)
https://doi.org/10.1140/epjb/e2006-00354-y

Dynamics of spatial Fourier modes in turbulence

Sweeping effect, long-time correlations and temporal intermittency

¹ Commissariat à l'Énergie Atomique (CEA), 17 rue des Martyrs, 38054 Grenoble, France
² Laboratoire des Écoulements Géophysiques et Industriels (LEGI), 38041 Cedex 9, Grenoble, France

Corresponding authors: ^a cedric.poulain@cea.fr - ^b christophe.baudet@hmg.inpg.fr

Received: 13 April 2006
Revised: 28 June 2006
Published online: 27 September 2006

Abstract

We present the results of an experimental study of the spatial Fourier modes of the vorticity in a turbulent jet flow. By means of an acoustic scattering setup we have recorded the evolution in time of Fourier modes of the vorticity field, characterized by well defined wavevectors k. By computing the auto-correlation of the amplitude of the Fourier modes we evidence that, whatever the length scale (or equivalently k), the dynamic evolution of the vorticity field involves two well separated time scales. We have also performed the simultaneous acquisitions of pairs of Fourier modes with two wavevectors k and k'. Whatever the spectral gap k- k', any pair of Fourier modes exhibits a significant cross-correlation over long time delays, indicating a strong statistical dependence between scales.