A Lagrangian model for the evolution of turbulent magnetic and passive scalar fields

Abstract

In this paper we present an extension of the \emph{Recent Fluid Deformation (RFD)} closure introduced by Chevillard and Meneveau (2006) which was developed for modeling the time evolution of Lagrangian fluctuations in incompressible Navier-Stokes turbulence. We apply the RFD closure to study the evolution of magnetic and passive scalar fluctuations. This comparison is especially interesting since the stretching term for the magnetic field and for the gradient of the passive scalar are similar but differ by a sign such that the effect of stretching and compression by the turbulent velocity field is reversed. Probability density functions (PDFs) of magnetic fluctuations and fluctuations of the gradient of the passive scalar obtained from the RFD closure are compared against PDFs obtained from direct numerical simulations.

References in corpus (2)

• Lagrangian dynamics and statistical geometric structure of turbulence
• Intermittency and universality in a Lagrangian model of velocity gradients in three-dimensional turbulence

Cited by in corpus (7)

• Orientation dynamics of small, triaxial-ellipsoidal particles in isotropic turbulence
• Instantons in a Lagrangian model of turbulence
• Magnetic fields from Multiplicative Chaos
• Structures and Lagrangian statistics of the Taylor-Green Dynamo
• Extreme events and instantons in Lagrangian passive scalar turbulence models
• Lagrangian model for passive scalar gradients in turbulence
• Analysis of scalar dissipation in terms of vorticity geometry in isotropic turbulence