1994/12/28 by L. Biferale, A. Crisanti, M. Vergassola +1 · 2 citations
Computer Science · Engineering · Physics and Astronomy · #Advanced Mathematical Modeling in Engineering #Compressibility #Diffusion #Eddy diffusion #Flow (mathematics) #Fluid Dynamics and Turbulent Flows #Lagrangian #Large eddy simulation #Quantum chaos and dynamical systems #Scalar (mathematics) #Thermal diffusivity #Turbulence #chao-dyn #comp-gas #cond-mat #nlin.CD #nlin.CG
paper · pdf · doi:10.1063/1.868651
21 Pages + 6 Figures Postscript (appended as .tar file), Latex submitted Phys of Fluids
arxiv created 1994/12/28 · openalex publication_date 1995/11/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Standard and anomalous transport in incompressible flow is investigated using multiscale techniques. Eddy diffusivities emerge from the multiscale analysis through the solution of an auxiliary equation. From the latter it is derived an upper bound to eddy diffusivities, valid for both static and time-dependent flow. The auxiliary problem is solved by a perturbative expansion in powers of the Péclet number resummed by Padé approximants and a conjugate gradient method. The results are compared to numerical simulations of tracers dispersion for three flows having different properties of Lagrangian chaos. It is shown on a concrete example how the presence of anomalous diffusion in deterministic flows can be revealed from the singular behavior of the eddy diffusivity at very small molecular diffusivities.