The Lagrangian view of energy transfer in turbulent flow
INLN, 1361 route des Lucioles - F-06560,
2 Bell Labs, Lucent Technologies - 700 Mountain Ave, Murray Hill, NJ 07974, USA
3 CNLS and T-13, Theoretical Division, LANL - Los Alamos, NM 87545, USA
Accepted: 9 August 2001
Hydrodynamic turbulence in 3D is characterized by a non-linear transfer of energy from large to small scales. Here, we provide a geometrical view of energy transfer by relating it to the deformation of fluid volumes under Lagrangian dynamics. The energy flux is parametrized in terms of the coarse-grained velocity difference tensor together with the tensor describing the shape of the volume. Our construction provides an intepretation for the non-trivial time dependence of the energy of relative motion within a "cloud" of Lagrangian particles observed in the direct numerical simulation turbulence.
PACS: 47.27.-i – Turbulent flows, convection, and heat transfer / 47.27.Qb – Turbulent diffusion / 02.50.-r – Probability theory, stochastic processes, and statistics
© EDP Sciences, 2001