Statistics of Intense Turbulent Vorticity Events

Abstract

We investigate statistical properties of vorticity fluctuations in fully developed turbulence, which are known to exhibit a strong intermittent behavior. Taking as the starting point the Navier-Stokes equations with a random force term correlated at large scales, we obtain in the high Reynolds number regime a closed analytical expression for the probability distribution function of an arbitrary component of the vorticity field. The central idea underlying the analysis consists in the phase-space restriction to a particular sector where the rate of strain and the rotation tensors can be locally regarded as slow and fast degrees of freedom, respectively. This prescription is implemented along the Martin-Siggia-Rose functional framework, whereby instantons and perturbations around them are taken into account within a steepest-descent approach.

arXiv comment4 pages, RevTex4, 1 figure

References in corpus (6)

• Instantons in Burgers Equation
• Instantons and Intermittency
• Instanton for random advection
• Instanton for the Kraichnan Passive Scalar Problem
• Universality of Velocity Gradients in Forced Burgers Turbulence
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Cited by in corpus (7)

• The instanton method and its numerical implementation in fluid mechanics
• Large Scale Intermittency in the Atmospheric Boundary Layer
• Instantons and Fluctuations in a Lagrangian Model of Turbulence
• The Onset of Intermittency in Stochastic Burgers Hydrodynamics
• Gaussian Vortex Approximation to the Instanton Equations of two-dimensional Turbulence
• Two-Point Vorticity Statistics in the Inverse Turbulent Cascade
• Large Fluctuations in Stochastic Models of Turbulence