Large-eddy-simulation closures of passive scalar turbulence: a systematic approach

• Type: Article in International Scientific Journal
• Date: 2003

Authors

Afonso, MM (Author) Other; Celani, A (Author) Other; Festa, R (Author) Other; Mazzino, A (Author) Other

Journal

Title: Journal of Fluid Mechanics

Vol. 496

Pages: 355-364

ISSN: 0022-1120

Publisher: Cambridge University Press

Indexing

ISI Web of Knowledge - 8 Citations

Scopus - 8 Citations

Other information

Authenticus ID: P-00N-NKX

DOI: 10.1017/s0022112003006505

Abstract (EN): The issue of the parameterization of small-scale ('subgrid') turbulence is addressed in the context of passive scalar transport. We focus on the Kraichnan advection model which lends itself to the analytical investigation of the closure problem. We derive systematically the dynamical equations which rule the evolution of the coarse-grained scalar field. At the lowest-order approximation in l/r, l being the characteristic scale of the filter defining the coarse-grained scalar field and r the inertial-range separation, we recover the classical eddy-diffusivity parameterization of small scales. At the next-leading order a dynamical closure is obtained. This outperforms the classical model and is therefore a natural candidate for subgrid modelling of scalar transport in generic turbulent flows.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10