About coherent structures in random shell models for passive scalar advection

Abstract

A study of anomalous scaling in models of passive scalar advection in terms of singular coherent structures is proposed. The stochastic dynamical system considered is a shell model reformulation of Kraichnan model. We extend the method introduced in \cite{DDG99} to the calculation of self-similar instantons and we show how such objects, being the most singular events, are appropriate to capture asymptotic scaling properties of the scalar field. Preliminary results concerning the statistical weight of fluctuations around these optimal configurations are also presented.

4 pages, 2 postscript figures, submitted to PRE

References in corpus (3)

• Instanton for the Kraichnan Passive Scalar Problem
• Multi-time, multi-scale correlation functions in turbulence and in turbulent models
• Analytic calculation of anomalous scaling in random shell models for a passive scalar

Cited by in corpus (6)

• The instanton method and its numerical implementation in fluid mechanics
• Instantons and the path to intermittency in turbulent flows
• Instanton Calculus in Shell Models of Turbulence
• A Hybrid Monte Carlo algorithm for sampling rare events in space-time histories of stochastic fields
• Chaotic and regular instantons in helical shell models of turbulence
• Bose-like condensation of Lagrangian particles and higher-order statistics in passive scalar turbulent advection