title: Direct measurements of anisotropic energy transfers in a rotating turbulence experiment.
abstract: We investigate experimentally the influence of a background rotation on the energy transfers in decaying grid turbulence. The anisotropic energy flux density F(r) = <δu(δu)²>, where δu is the vector velocity increment over separation r, is determined for the first time by using particle image velocimetry. We show that rotation induces an anisotropy of the energy flux ∇·F, which leads to an anisotropy growth of the energy distribution E(r) = <(δu)²>, in agreement with the von Kármán-Howarth-Monin equation. Surprisingly, our results prove that this anisotropy growth is essentially driven by a nearly radial, but orientation-dependent, energy flux density F(r).
authors.affiliation: Laboratoire FAST, CNRS, Univ Paris-Sud, UPMC Univ Paris 06, Bâtiment 502, Campus universitaire, 91405 Orsay, France.
authors.forename: Cyril
authors.initials: C
authors.lastname: Lamriben
authors.forename: Pierre-Philippe
authors.initials: PP
authors.lastname: Cortet
authors.forename: Frédéric
authors.initials: F
authors.lastname: Moisy