Coarse-grained description of a passive scalar
- Others:
- Institut Non Linéaire de Nice Sophia-Antipolis (INLN) ; Université Nice Sophia Antipolis (1965 - 2019) (UNS) ; COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)
- Department of Physics of Complex Systems ; Weizmann Institute of Science [Rehovot, Israël]
- Department of Physics ; Università degli studi di Genova = University of Genoa (UniGe)
Description
The issue of the parameterization of small-scale dynamics is addressed in the context of passive-scalar turbulence. The basic idea of our strategy is to identify dynamical equations for the coarse-grained scalar dynamics starting from closed equations for two-point statistical indicators. With the aim of performing a fully-analytical study, the Kraichnan advection model is considered. The white-in-time character of the latter model indeed leads to closed equations for the equal-time scalar correlation functions. The classical closure problem however still arises if a standard filtering procedure is applied to those equations in the spirit of the large-eddy-simulation strategy. We show both how to perform exact closures and how to identify the corresponding coarse-grained scalar evolution.
Abstract
22 pages; submitted to Journal of Turbulence
Additional details
- URL
- https://hal.archives-ouvertes.fr/hal-00019855
- URN
- urn:oai:HAL:hal-00019855v1
- Origin repository
- UNICA